|Table of Contents|
Letter of transmittal
Table of Contents
List of Illustrations
Review of plants
The nursery and the revolving fund
Care of trees and plants in public areas
Landscape planting and the supervision of plants in public areas
Seed and plant accessions and visitors to the gardens
Future of the gardens
Annual report of the Canal Zone experiment gardens for the fiscal year 1934
For the Fiscal Years
1933 and 1934
THE PANAMA CANAL PRESS
MOUNT HOPE. C. Z.
For additional copies of this publication address The Panama Canal, Washington, D. C., or
Balboa Heights, Canal Zone.
LET-TER OF TRANSMITTAL
CANAL ZONE EXPERIMENT GARDENS,
Summit, C. Z.) YIulY 17. 1933.
SIR: I have the honor to transmit herewith a Report of the Canal
Zone Experiment Gardens for the year ending June 30, 1933. Publi-
cation is recommended when funds become available. *
J. EDGAR HIGGINS,
Mr. Roy R. W~ATSON,
Chief Quarterm aster,
Balboa Heights, Canal Zone.
Through M\r. J. H. K. HUMPHREY,
Assistant Chief Quartermaster.
*Publication authorized February 19, 1938.
............. .......... .....
General Statement--------------------------------------------------- 7
Review of Plants---------------------------------------------------- 8
Mangosteen (Garcinia mangostana)---------------------------------------8
Solo Papaya ----------------------------------------------------I
Cashew (Anacardium occidentale)--------------------------------------- II
Trees Yielding Anti-Lepric Oils. .. ..-------------------------------------- 12
Plant Sources of Insecticides---------------------------------------13
Teak (Tectona grandis)----------------------------------------------15
Notes on Marijuana (Cannibis sativa)-------------------------------- 16
Other Noteworthy Plants of the Year---------------------------------20
The Nursery and the Revolving Fund------------------------------------22
Care of Trees and Plants in Public Areas..---------------------------------- 23
Landscape Planting and the Supervision of Plants in Public Areas-------------- 24
Seed and Plant Accessions-------------------.--------------------------- 26
Visitors to the Gardens. .....----------------------------------------------- 26
Future of the Gardens -----------------------------------------------27
Traveller's Tree, Ravenala madagascariensis.
Cashew Fruit, Aancardium occidentale, of a variety introduced from Trinidad.
Tectona grandis, Teak Trees, nine years old.
Monodora grandiflora in flower.
Guadua angustifolia, a giant bamboo.
Antidesma bunius, Bignay, a fruit tree introduced from the Philippines.
Lagerstroemiaflos-reginae. Queen Crapemyrtle.
An Orchid-clad Tree, at the Experiment Gardens showing Epidendrum
stamfordianum in full flower.
Landscape Effects, attained in two years growth.
Digitized by the Internet Archive
Ravenala madagascariensis.-Traveler's Tree
p, 6 ....
CANAL ZONE EXPERIMENT GARDENS FOR 1933
J. EDGAR HIGGINS, Director
During the fiscal year 1933, the Canal Zone Experiment Gardens
have been operating under great difficulties because of shortage of funds,
as has been the case not alone with other branches of the Canal organi-
zation but with nearly all public and private institutions. It was
necessary to cut the budget from $24,000 to about $14,70., This
necessitated the reduction of expense for labor by nearly fifty percent,
after allowing for certain fixed overhead and after cutting all other items
to a minimum. As it was impossible for the laborers with one exception,
to secure employment elsewhere, because of the general depression,
it was considered best to place the men on half-time administrative
furlough instead of discharging half of them. This resulted in some
additional inconvenience but the laborers and their families were at least
able to buy food. One man who had been trained at the Gardens in
plant propagation secured private employment because trained men in
this line of work are extremely few in Panama. As further plans in the
economy program, the eight-acre plantation of Chaulmugra oil trees
(Taraktogenos kurzii) at Flat Rock on the Chagres river had to be
neglected; practically all annual cultures were eliminated except such
as were necessary to retain propagating material; no travel was per-
formed in the interests of plant introduction and new accessions were
confined almost entirely to exchanges. It has not been possible to
publish any annual report since that for I93o. No expansion in the
planted area has been attempted and only a few minor and much needed
improvements have been made. A small dam has been put in, making
a new pond for the care of aquatic plants, the old pond being fully
occupied. The big ditch in front of the building which formerly was
occupied as an office, was washing away with landslides and has been
filled, after laying a large pipe to carry off storm water. The labor on
both of these jobs was performed by the prison labor gang.
To meet the conditions requiring strictest economy and to do so with
the least possible sacrifice of the Gardens, some trees of species that have
been represented by a considerable number of specimens have been cut
down to make place for the planting of other kinds of trees that are new
in this country. In all cases, however, the best specimens have been
left. In this way recent introductions can be given a place. It is hoped
that with the restoration of normal conditions in Government operations,
funds may be appropriated to carry on the work of the Gardens with
the expansion that is necessary to success.
REVIEW OF PLANTS
Each year some plants present new features or new developments in
their maturity. A brief statement will be made concerning some of the
plants which have called for special attention during the year just closed.
THE MANGOSTEEN (Garcinia mangostana)
Of* all the new varieties and species of tropical fruits that have been
introduced at the Gardens, none appears to be more contented with the
conditions on the Isthmus than the mangosteen, that famous fruit of the
Oriental tropics which Fairchild, the great explorer for plants, considers
as perhaps the most delicious of all the varied fruits of warm countries.
Young trees of mangosteen, probably the first ever introduced into
this country, were brought to the Canal Zone by Fairchild after first
establishing them in hot houses in the Department of Agriculture in
Washington, D. C., whither they had been brought as very perishable
seeds from the East Indies. A tree of the original introduction has
been fruiting at Frijoles, but the first planting of any considerable size
was made at these Gardens less than ten years ago from plants received
from the United States Department of Agriculture. These which now
constitute an orchard of fifty to sixty trees and some minor scattered
plantings, are among the most thrifty growths to be seen in the Gardens.
Two years ago a few trees began producing a little fruit but this year
at the time of this writing the first real crop is maturing which will
afford an apportunity for some eager plant enthusiasts to experience a
long deferred satisfaction in the tasting of this new and exotic product.
In the matter of cultural requirements, it has frequently been stated
that the mangosteen tree requires shade and it is probably correct that
in its early stages of development shade is beneficial and perhaps
important. Based upon this accepted belief the trees at Summit were
provided with artificial shade during the first few years in the orchard
PLATE I I
Cashew fruit.-Anacardium occidentale of a variety introduced from Trinidad
but for four or five years past they appear to have outgrown the need
of shade. Few fruit trees are able to adapt themselves to so wide a
range of moisture conditions as are the mangosteens. While retarding
of growth has been observed in spots where stagnant water accumulates,
practically all of the plantings at the Gardens are on soils that remain,
during the entire rainy season, too wet for most cultivated fruit trees.
Although the mangosteen for successful fruit production appears to
require irrigation during the dry season, the tree appears to have the
power to resist considerable drought by going into a period of rest during
which no new growth is made but the foliage retains its form and color.
Every cultivated plant has its natural enemies but up to the present
time about the only pest that has attacked the mangosteen in the Canal
Zone is the stingless black bee, Trigona sp., the same insect which cuts
the young foliage of citrus and some other trees. In the case of the
mangosteen the bee does not trouble the foliage but causes real damage
to the fruits in all the early stages of development. This disfigurement
is so great as to spoil the fruit for market purposes if the insect is not
controlled. Fortunately it has been found possible at the Gardens to
reduce this injury to very minor proportions by the systematic destruc-
tion of the nest's of the bees in the Gardens and the surrounding fields.
In the early years after introduction, the propagation of the mango-
steen at Summit met with considerable difficulties. The first difficulty
was the lack of seed because mangosteen seed is extremely perishable
and only by the working out of most careful methods of packing was it
found possible to get a reasonable percentage of viable seed after the
long journey from the countries where this species has long been in estab-
lished cultivations. It is a soft seed which quickly dries out and dies
if exposed to the air, as is true of the litchi and many other tropical
tree seeds. On the other hand, in the presence of excess moisture it
either decays or quickly germinates and perishes in the package. It
has been found necessary to carefully adjust the moisture to the needs so
as to prevent drying out and also to avoid germination in transit. Some
shipments of seed were received at the Gardens from the Orient via
Europe and gave a fair percentage of germination after planting(.
By the methods for shipping soft seeds that have been w orked out by
tropical horticulturists in various parts of the w orldl, this difficulty "Of
introducing seed has been ov%,ercomie to a large degree. In the meantime,
however, as indicated above, our own trees have nowN come into bearing
so that the need of importingnwsemilpoal not again arise
T'he second great difficuLtV in the early attempts at propagation w as
found in the fact that carefully nursed seedlings inl pots and Canls in thle
propagation houses seemed to iose Nvigor anid made most uinsatisfactory,
growth. Apparently they suffered from too much nursing and the con-
finement of their root systems. By placing them out in the open nursery
row, in deeply trenched and well-manured soil, and providing slight
shade, a vigorous growth has been produced which is in every way
satisfactory. The trees are taken up with a good ball of soil and may
be transplanted without difficulty while young.
Much interest has been manifested by tropical horticulturists and
plantsmen in the problems of the asexual propagation of the mangosteen
and some work has been done in budding and grafting, notably by the
late Peter J. Wester of the Philippine Bureau of Agriculture. This
interest has been based in part upon the desire to propagate rapidly and
accurately any specially good seedlings that may be found, for it will be
remembered that up to the present time practically all market fruits of
mangosteen are the product of seedling trees. Without doubt, trees
will be found excelling in productivity or in quality of fruit. Also
because seedling trees of all kinds are more tardy in coming into bearing
than are those that have been grafted, a second reason for this interest
in asexual propagation is easily understood. But because most seedling
mangosteens are of excellent quality, it is probably that the greatest
urge was to find rootstocks that could be more easily grown than
mangosteen seedlings and that might lend a wider range of adaptability
to soil and climatic conditions. Hence several different species of
Garcinia, the genus to which the mangosteen belongs, have been tried as
possible rootstocks. While it is possible to establish unions between the
mangosteen and some of these relatives, it is probably correct to affirm
that no great success has yet been attained in the production of mango-
steens on other rootstocks. Since the mangosteen root system itself
appears to be well adapted to a considerable range of soil conditions and
since methods have now been achieved for the successful production of
strong seedlings, it would appear that the next important step in progress
must lie in the application of budding and grafting methods to the
propagation of the mangosteen upon mangosteen rootstocks.
It is probable that there are few if any of the recently introduced
fruits plants which give larger promise of establishing for themselves an
important place in tropical American horticulture for the great American
markets than the mangosteen. It is not only delicious in flavor and
texture but is a fruit of attractive appearance, protected by a thick
tough shell, and endures well the effects of shipping long distances.
The way now seems to be opening for the establishing of commercial
THE SOLO PAPAYA
Several references have been made to this variety of papaya in earlier
reports. It is most unfortunate that this exquisitely flavored papaya
has been found to hybridize so freely in this country by natural means
with less desirable sorts that it has lost its most desirable characters and
practically disappeared, although there are still many trees which have
the outward appearance of the variety. The writer had an exactly
similar experience with this variety in the Philippine Islands where the
essential characters of flavor and aroma disappeared in a few generations.
In Hawaii, where the variety originated, it appears to have more nearly
maintained its identity through many years. For this reason a new
introduction of seed from Hawaii has just been made. An attempt will
be made to keep the variety isolated so far as possible but with many
varieties in cultivation and with wild forms in the jungle and so many
possible carriers of pollen, it may prove to be easier to grow all new plants
from imported seed.
Another most unfortunate feature of this papaya in Panama is its
susceptibility to the attack of the papaya fruit-fly because of its small
size and thin flesh. Papaya fruits with thick flesh appear the more
resistant. One of the many promising fields of effort in the breeding of
tropical fruits would appear to lie in the hybridizing of the Solo with
strong-growing and free-bearing varieties, having fruit with thick flesh
in order to combine if possible the unique flavor of the Solo with the
thick flesh and greater vigor of some other forms.
THE CASHEW (Anacardium occidentale)
During very recent years the cashew has been creating a new interest,
chiefly because of the nut which is finding its way into commerce. This
tree is native in Brazil and possibly other parts of tropical America. It
certainly became widespread on this continent and the West Indies at a
very early date and for centuries past it has been growing in warm regions
of the Eastern hemisphere also. By the native people of all of these
countries, it has been prized for the fleshy portion of its fruit and for the
seed which is very curiously placed outside of the flesh or, in common
parlance, the "nut" which growns on the outside of the "fruit." As a
fruit, the cashew is used in many ways in the countries where it is
grown, including dessert, fruit-punch and an alcoholic drink. The fruit
is very perishable and cannot be shipped long distances but finds its way
to local markets in considerable quantities. It is the seed or nut,
however, which in recent years has been bringing the cashew into
prominence. The cashew nut has always been appreciated in the
countries where the tree grows but it is only recently that it has found
its way into world commerce. This new development appears to have
been due largely to the discovery of processes of packing by which the
nuts can be transported to any country without deterioration or insect
attack. These nuts are now packed by a patented process in tight
containers from which the air is exhausted and replaced by gases, said
to be chiefly carbonic acid, in which they are perfectly preserved.
Information received from the Bureau of Foreign and Domestic Com-
merce of the United States reveals the fact that io,262,916 pounds of
cashew nuts were imported into the United States in the year 1931.
These were entered at a value of $2,052,240 which is intended to repre-
sent their market value in the principal markets of the country from
which exported, including the cost of containers or coverings and all
expenses incident to placing the merchandise in condition ready for
shipment to the United States. In 1932, the imports were slightly
under 9,800,000 pounds which represents a very small shrinkage com-
pared with the general falling off in trade in that year of general business
It is worthy of note that nearly the entire importation comes from
British India and not from its home in tropical America. Considering
the fact that the cashew grows almost as a weed in Panama and yields
abundantly even in rather poor soils, it would appear that attention
should be given to the possibilities of developing a cashew industry here
much nearer to the market. To do this it would be necessary to interest
the importing companies in stimulating trade and production here.
The climate, the soil, the proximity to market and the facilities for ship-
ping are all in favor of such an industry.
The Experiment Gardens have introduced several varieties of cashew
of unusual size and appearance all of which are doing well here and
yielding abundantly. Fruits of one of these varieties introduced from
Trinidad is represented in Plate II. We are now in correspondence with
Brazil in an effort to get some of the best varieties from that country
which is believed to be the home of this fruit and which probably makes
a wider use of it than any other part of the Western hemisphere.
TREES YIELDING ANTI-LEPRIC OILS
Our correspondent, Dr. P. H. Rolfs, Consultor Technico de Agricultura
do E. do Minas Geraes, Brazil, presented the Experiment Gardens with
seed of Sapucainha, Carpotroche brasiliensis. This is a new source of an
anti-lepric oil which is reported to be superior to the oil produced by
trees of earlier introduction, including Taraktogenos kurzii and the two
species of Hydnocarpus which have been referred to several times in
Tectona grandis.-Teak trees, nine years old.
earlier reports. Dr. Rolfs has been making careful selections of trees
of Carpotroche and believes that there are probably several distinct
species included in the forms which tentatively have been placed under
the singe designation, C. brasiliensis. This carefully selected seed
which was received by air express early in 1932 was planted promptly
and germinated well. Strong plants have been set out in permanent
position in the Gardens. There is said to be a wide variation in the oil
content among the seedlings. The species is polygamodioecious and
produces many staminate or nonbearing trees, a condition which, in
the papaya is familiar to residents of the tropics. Because of the
frequent occurance of these male or nonbearing trees and also because
of the variability in yield just referred to, grafting and budding with
scions or buds from carefully selected, high-yielding trees has appealed
to Dr. Rolfs as the most practicable means of establishing plantations
which may be expected to give a satisfactory return. Hence he is
establishing clones or pedigreed trees to be used as sources of budwood
and the basis of uniform plantations. He has offered these Gardens
budwood of his selections, if it will be possible to get it here in good
condition, by air, after our seedlings are well-established. It is of
course important that all kinds of trees yielding anti-lepric oils should be
represented in so far as each may be adapted to conditions here.
PLANT SOURCES OF INSECTICIDES
A great interest is now being taken in investigations concerning the
insecticidal properties of certain plants, as the basis for the manufacture
of effective insecticides which, as ordinarily used, are not injurious to
man and domestic animals. Plants used as fish poisons are to be found
in many parts of the world. Branches, bark or roots are crushed or
macerated and thrown into quiet or slow-flowing water. The fish
become stupified and float to the surface where they are easily caught
in scoop nets or are speared. In Panama such a fish poison is known as
"barbasco." Several native plants are so used, such as species of
Serjania and Paul/inia of the Soapberry family (Sapindaceae). In the
Orient and in some parts of tropical America, a prolific source of such
poisons is found in certain members of the family Fabaceae. Notable
among these are species of Derris, Lonchocarpus and Cracca (Tephrosia).
The principal chemical constituent of these plants which is the active
poison, is believed to be rotenone but there are others frequently
associated with it which also produce similar effects. Rotenone especial-
ly has been found to be an extremely effective insecticide and in recent
Having bisexual flowers in one tree and unisexual flowers on another tree of the same species.
years it has been extracted and used in the manufacture of commercial
products for the killing of various kinds of insects. It is claimed that
"its use as a fruit spray would make unnecessary the present expensive
machinery for washing sprayed fruit." It has also been used against
cattle grubs (Hypoderma sp.), in the backs of cattle and is reported to
have been effective in destroying these parasites, without toxic effect
upon the cattle and with no injury to the skin. The growing of
Derris elliptica especially has become an agricultural industry of some
importance in certain of the East Indies and in parts of the Malay
Peninsula, many thousands of acres being under cultivation.
Other related species are reported as having a much greater content
of rotenone than D. elliptica. D. malaccensis is one of these and accord-
ing to the Bulletin of the Imperial Institute (London), ether extract of
this species showed 34.2 percent rotenone, while D. elliptica contained
in this test only 9.7 percent. Another souce of rotenone is found in the
plant called cube (coo' bay), Lonchocarpus nicou. It is related to Derris
and is found in the wild state in South America, notably in Peru. It also
is reported as richer in the poison than D. elliptica.
Because of the prospective importance of these plants as sources of
rotenone and related compounds as the basis of new insecticides which
probably will replace some of those that have long been standard, and
because of the possibilities of the commercial cultivation of some of
these plants in this region of tropical America, some of the more import-
ant species have been introduced at the Experiment Gardens and are
under test. Seed of Derris elliptica was obtained from Buitenzorg, Java,
late in December of 1930. The plants have grown well and appear to be
well adapted to conditions here. The plant is a rambling vine which
spreads over the ground without support.
In September of 1932, through the kindness of Captain C. B. Fenton,
of Cristobal, the Gardens received ten plants which had come from
Brazil under the name of Derris guianensis. These are apparently some
species of Phyllanthus. The plant is reported as occuring in the Lower
Amazon region. These plants have maintained a healthy appearance
since their arrival in the Canal Zone, but they have not been planted out
long enough to determine their adaptability to the conditions at Summit.
Two introductions of the Peruvian cube (Lonchocarpus nicou) have been
made from the Office of Foreign Plant Introduction of the United States
Department of Agriculture. Two of these plants arrived in June 1931,
and twenty-five root cuttings in April of 1932. None of these has yet
made a very satisfactory growth. Although it is too soon to arrive at
any conclusion concerning the adaptibility of cube here, it may perhaps
be expected to do better in the higher altitudes of the interior than at
Monodora grandiflora in flower
p. 14 a.
the Experiment Gardens where the elevation at the entrance is only
254 feet above the sea. Its native habitat is understood to be in the
Another related plant introduced through the Office of Foreign Plant
Introduction is Cracca toxicaria, F. P. I. Ioi,I88. It is native to the
highlands of Bolivia and not too much should be expected of it in Panama
except in the higher altitudes. Some plants have been sent to El
Volcan for test. An effort is being made to secure propagating material
of other related species, that may yield rotenone or related compounds
in order that we may have them for comparative study here and also
that we may be able to supply material for study and analysis by the
Department of Agriculture in Washington when it may be desired.
During the fiscal year just closed, the Experiment Gardens have
responded to a request for cooperation in these investigations which
came from the Insecticide Division, Chemical and Technological
Research, Bureau of Chemistry and Soil of the United States Depart-
ment of Agriculture through the Department of State and the American
Consular Service. A letter dated November 7, 1932, was received from
Mr. Herbert 0. Williams, American Consul of Panama, reading in part
"This Consulate General is in receipt of an instruction from the Department of State,
requesting that it obtain for the Department of Agriculture a sample of a plant known as
balbec, used as a fish poison or insecticide in Panama. The following quotation from this
instruction explains in detail the wishes of the Department of Agriculture:
"In connection with investigations carried on by the Insecticide Division, Chemical
and Technological Research, Bureau of Chemistry and Soils, of this Department,
it is desired to enlist the aid of United States Consuls and other representatives in
tropical countries in securing small quantities of certain plants used as fish poisons
and as insecticides.
"Samples of not less than two pounds of the carefully dried plant material are
desired That portion of the plant reputed to have the greatest potency should be
collected. In general, it is believed that the root of the plant will be found to be
richest in toxic constituents. In case there is doubt concerning the botanical identity
of the plant collected a carefully pressed flower or leaf, or the fruit of the plant should
accompany the sample of root or other plant material."
Although inquiry of several well-informed gentlemen of long residence
here did not result in our finding anyone familiar with the name "balbec"
as applied to any plant in Panama, samples of branches and of bark of
two native plants used as fish poisons were submitted. One of these was
Salmea scandens and the other undetermined.
TEAK (Tectona grandis)
A view of a row of teak trees at the Gardens is shown in Plate Ill.
The trees were about nine years old. It will be seen that these trees
have made excellent growth and present a magnificent appearance.
The importance of teak as a timber of world-wide use can hardly be
over-emphasized because of its unique qualities and the continued and
increasing demand for it notwithstanding the present tendency towards
steel construction. Its durability and resistance to decay and to termite
and other insect attack, as cured timber, are perhaps its most important
features. In the Oriental countries where it is native, it is subject to the
attack of a borer while it is growing but after seasoning the wood appears
to be immune to most insects and very highly resistant to termites
("white ants"). Mr. James Zetek states that teak wood that has been
in the ground at Barro Colorado Island for eight years shows no injury
from termites. It is reported that ships built of teak have withstood
the elements for hundreds of years. The great demand for the wood
and its relative scarcity have kept prices high. The United States has
no supply of teak trees of its own and none is available anywhere on this
side of the world. Because of the value which such a supply would
have to the Navy, it is stated: "*that consideration has been given to
the possibility of establishing a Naval reservation for teak plantings."
At this time when reforestation is being undertaken on a gigantic scale
as a part of the Federal Government plans for rehabilitation of the
economic system and the recovery of prosperity, what could be a more
fitting use of a small part of these funds than the planting of a small
experimental forest of teak here in the Canal Zone as an adjunct to the
Experiment Gardens? Abundance of idle lands, formerly occupied as
cattle pastures and practically cleared, surround the gardens on all sides.
The conditions of soil and climate are the same as those at the Gardens
where the teak trees are growing as shown in the illustration referred to
NOTES ON MARIJUANA (Cannabis sativa)
In cooperation with the Health Department in its study of the effects
of marijuana, the Experiment Gardens conducted some investigation
of the plant which yields this drug, as it is grown in this country in a very
small way and on an extensive scale in India and other tropical countries.
Plants were grown at the Gardens in sufficient quantity to provide the
Health Department with the plant product of uniform grade and in the
amount necessary for the department's investigation. The notes that
were made at that time on the culture of the plant in India and also in
this country are here recorded. These notes were placed at the dis-
posal of the Health Department.
Navy Department, Bureau of Construction and Repair, Technical Bul. No. 1-25: "Teak, Its
Habitat, Exploitation and Marketing" by Lt. Wendal P. Roop.
Guadua angustifolia, a giant bamboo
Marijuana is one of several common names applied to the plant
Cannabis saliva, and more particularly to the plant and its products
when used as the source of a drug which produces forms of intoxication.
Because of the fact that some of these products are being clandestinely
produced, sold, and used in the Canal Zone and that there are said to be
some addicts here, considerable inquiry has been made during the past
few years concerning the plant and the effects of the drug.
THE CULTURE OF THE PLANT IN INDIA *
The plant as grown in India was known for many years under the
botanical name Cannabis indica. This was believed to be a distinct
species but more recently the species C. indica has been reduced to C.
sativa, as no botanical characters are found to exist upon which to es-
tablish two species. The plant varies under different climatic and soil
conditions in India, and these differences are quite as marked as those
found between the plants grown in India and those grown in Europe
where the species has long been grown for its fiber known as hemp. In
India the plant is grown to some extent for fiber but also and in some
parts exclusively for its narcotic principle. The seeds are also eaten and
are a source of oil.
There are three principal forms in which the narcotic is prepared, but
of these there are many modifications. The first of these forms is that
known as charas; the second is ganja; and the third, bhang. Charas is
the resinous exudation found on the bark, the leaves, and on the pistilate
or female flowers-and even on the fruits. Ganja is an agglomeration
of the pistilate flowering stems with the exuded resin. Bhang consists
of the dried mature leaves and to some extent the fruit also, but not the
Cannabis sativa grown as a source of the narcotic has very special
treatment. The species is dioecious. t The staminate, or male plants
yield little or no resin and are not allowed to remain in the field after
their male characters become apparent, except as a few here and there
escape the eye of the "ganja doctor" as the expert is called who passes
up and down the rows to eliminate the undesirable plants. It is desired
to rid the field of all staminate plants not only because they are not
wanted in the harvest, but also because if allowed to remain and to cause
the formation of fruits, the yield of the narcotic in the pistilate plants is
Charas, the resinous substance which exudes naturally from the bark,
leaves, and pistilate flowers, is successfully produced only in the northern
Watt. Dictionary of the Economic Products of India.
t Having the staminate or male flowers on one plant and the pistilate or female flowers on another.
parts of India or in the higher altitudes as the plants do not appear to
give this natural exudation sufficiently in the lower and warmer parts of
the country. Several methods have been used for collecting this resin.
One consists in sending coolies through the rows, clad in leather coats to
which the resin adheres. Or these natives are treated to an oil on the
skin and run through the rows nearly naked. The resin is then removed
from the man's skin or his leather coat. Another, and perhaps a more
common method, is to rub the pistilate flowering stems between the
hands-the bruising process causing the exudation of the desired resin.
The resin, however collected, is pressed into the desired shape for market
purposes. Charas is smoked as a means of getting the effect of the drug.
Ganja is prepared from the pistilate flowering heads which, as already
stated, must not be allowed to form fruit if the best quality of ganja
is desired. For the gathering of this product the plants are cut quite
low at the time of full flowering, are spread out to dry for about 6 or 8
hours, after which the flowering stems are cut off and laid upon mats in a
circle with points inward, the leaves being removed. The other parts
of the plant are thrown out. These flowering heads are then tramped
upon by bare-footed natives until the desired resin is pressed out and
the mass of agglomerated flowers and resin is pressed into the desired
shape. Ganja, as charas, is used for smoking as a means of getting the
Bhang consists in the dried leaves and to some degree the dried fruits
of the plant. The resin, it appears, is not extracted from this product
which is used directly in the preparation of the products which furnish
the effect. One of these products is hashish, an intoxicating beverage.
Another is a sweet-meat known in India as majun or majum. Bhang
is made chiefly from the wild plants where the plant grows abundantly
as an excape from cultivation.
In parts of India, Cannabis sativa is so abundant as to be used as bedding
for animals. Bhang is reported to be much*weaker than ganja or charas
and is believed to be much less injurious.
The method of cultivation of C. sativa as s source of narcotic is some-
what as follows: A seed bed is most thoroughly prepared by often re-
peated tillage months in advance of the sowing of the seed. The pur-
pose of this is in part to rid the soil of weeds. The seed is planted broad-
cast without shade and the plants when 6 inches to 12 inches high are
transplanted to their permanent postion in thoroughly prepared soil.
The distances vary from less than I foot to 9 or io feet-the widest
spacing being used only when the plants are to be used for the preparation
of bhang, although, as stated above, cultivated plants are not often used
for this purpose.
MARIJUANA AS GROWN IN THIS COUNTRY
I have seen Cannabissativa growing in several places in this country.
Apparently its cultivation on a small scale is not uncommon. Some
farmers grow only a few plants to supply their own wants while others
evidently have more than could be used by themselves and their families.
There is probably no extensive cultivation.
USE AMONG THE FARMERS
It would appear that the use of this plant for its drug content is not
infrequent among the people living in certain localities. It is used
to make "tea," four or five or more dried leaves being placed in a cup
with boiling water. Among the people there is great faith in the efficacy
of this drink as a mild stimulant, giving a feeling of well-being and also
as a preventative of malaria. The smoking of the dried leaves and
flower heads seems also to be not uncommon.
MANNER OF PREPARATION
It seems very probable that the form in which they use the plant has
saved these people from the most disastrous effects of the drug because
the part used is often composed to a large degree of leaves and includes
at times the leaves of the staminate plant as well as those of the pistilate.
Also there appears to be not the same diligence that is found in other
countries in the removal of the staminate plants immediately when their
identity can be established by the presence of the flowers. Some
growers allow these plants to remain in the fields until they become
mature and show yellowing of the leaves when they are harvested, dried
and used for smoking or for "tea." It is well understood among the
people that these leaves are very much weaker and less effective that the
preparations from the pistilate plants which include the flower clusters.
It is quite possible also that these dried leaves of staminate plants may
be mixed with the harvest of pistilate plants which comes on later. It
has not been determined whether any of the growers are careful to
remove all staminate plants immediately. If this is not done, even the
pistilate plants will not yield the drug in the quantity that is yielded by
nonfecundated pistilate plants. Hence it seems not improbable that
the marijuana grown and sold locally is of very low grade judged by its
content of the drug. In fact, most samples of dried marijuana that have
come under my observation have contained a considerable quantity of
seed, indicating that the staminate plants have remained in the fields
at least long enough to fecundate the pistilate flowers. For the reason
stated above it will be seen that marijuana purchased locally is probably
of quite variable character and tests of its physiological and mental
effects in any experiments may be expected to vary likewise.
It would appear that there is no production of charas in this country.
Likewise, it is probable that there is no ganja produced here, all the
crop being disposed of entirely in the form of bhang or the dried leaves
and flower heads which have not been treated to bring out the resin.
OTHER NOTEWORTHY PLANTS OF THE YEAR
"The Miraculous Fruit." One of the most remarkable and interesting
of the plants that have come under observation during the year is the
"Miraculous" fruit, Synsepalum dulcificum (F. P. I. 75,283). This
tropical African shrub of upright and rather narrow habit, with dark
green foliage belongs to the family Sapotaceae and produces small red
fruits, oblong to oval in shape, about three-quarters of an inch long and
three-eighths of an inch in diameter. This strange fruit makes sour
things taste sweet. It is rather pleasant to the taste but after it is kept
in the mouth for a few minutes and is partly masticated, the most acid
lemon or lime tastes as sweet and pleasant as a well-sweetened fruit
punch. The cause of this remarkable reaction which has given rise
to the name "miraculous" fruit is not well understood nor has it been
determined how long the effect will last. No uncomfortable effects have
been observed. The plant is worthy of further study and it is possible
that it may be found to be of some economic importance.
The Traveller's Tree, (Plate I) Ravenala madagascariensis, sometimes
erroneously called Traveller's "Palm," is attracting much attention
because of its quite unusual and striking appearance. It is said to have
acquired its common name from the well-known fact that it accumulates
considerable water at the base of the leaf sheaths which can be tapped
by the traveller when in need of water in the forests of Madagascar
where it is native. The tree is not a palm but rather is related to the
Monodora grandiflora. The Gardens are indebted to Dr. Thomas
Barbour and Mr. Allison V. Armour for the introduction of this beautiful
and unique tree which was propagated from a tree in Trinidad, said to
be the only mature specimen in the Western hemisphere. In March
and April the young tree at the Experiment Gardens flowered profusely
and presented a handsome and unusual sight with its many large brown
pendant flowers which hang like orchids from the branches. Plate IV
shows the tree in flower.
The Waringian banyan, Ficus waringiana, gives promise of being
even stronger in growth and more handsome in appearance than its close
relative, the Chinese banyan, or laurel de India (F. nitida). The latter
Bignay.-Antidesma bunius, a fruit tree introduced from the Philippines
as seen on Roosevelt Avenue, in Balboa, is universally admired by
residents and visitors. The Waringian banyan has made a tremendous
growth at Summit during the few years that it has been planted out and
is upright and symetrical in habit. To date it has been entirely free
from thrips, the one pest which severely attacks Ficus nitida. Con-
cerning this species (F. waringiana) Dr. David Fairchild, in his fasci-
nating book on "Exploring for Plants" says: "Of all the strange avenue
trees that I have ever seen, the Waringian is the strangest. Like the
banyan but with much smaller leaves, it spreads over the ground by
hanging aerial roots, until a single tree comes to look like a whole grove."
The Waringian is very easily propagated by marcottage, sometimes
called air-layering. A few trees have been planted on the Prado area
in La Boca where it is thought there is room enough for their develop-
ment and where they may be expected to afford an excellent shade
beneath which children may play and older people may rest. There
are not many places in Balboa and Ancon where there is sufficient open
space to justify the planting of such a tree. A few have also been
planted in the rear of the new residence quarters, on Colon Beach, in
A Bamboo of giant proportions was introduced from Ecuador by Mr.
Holgar Johansen, formerly in charge of these Gardens. This has now
grown to great height and produces poles six inches in diameter with
rather short internodes. It has been tentatively identified as Guadua
angusfolia. This would be an especially useful bamboo for structure
purposes. At the Gardens, when grown in sufficient quantity it should
supply excellent plant tubes of sufficient size to hold a rather large
nursery plant. Plate V shows the lower portion of a clump of this
The Bignay, (.4ntidesma bunius) is a small tree of graceful form which
yields great clusters of small current-like fruits in wonderful profusion
and affords a magnificient sight in fruiting season. The young trees
which were grown from seed, introduced from the Philippine Islands,
are fruiting heavily at the time of this writing (July 1933) (See Plate VI).
The fruits are very highly prized in the Philippine Islands for making a
delicious fruit punch and also for jams and jellies.
Seedlings of the Brazil nut, Bertholletia excseLa, grown from seed intro-
duced from Trinidad are making good growth and it is hoped that future
years will see this famous nut tree well established in this country. Its
relative, Lecythis tuyrana, which is represented by two good specimens
in Balboa Heights, has come into fruiting. It is a beautiful tree, alwa s
clothed with rich green foliage. It was introduced into the Canal Zone
by Dr. H. Pittier. Its economic importance has not yet been determined.
Another Lecythis (L. elliptica) introduced from Colombia, has also come
into bearing at the Gardens.
Plate VIII shows one of the very handsome native orchids, Epidendrum
stamfordianum, flowering in great profusion. It is growing upon an
African Fountain Tree at the Gardens.
THE NURSERY AND THE REVOLVING FUND
It is fortunate that operations of the nursery have not been affected
by the shortage of funds. The nursery functions as a means for the
dissemination of plants of kinds that have been tested and established.
It operates under a revolving fund which was established for this
purpose and the receipts from all sales are returned to the fund, thus
enabling the propagation and dissemination to go on independently
without taxing the limited resources which are available for the main-
tenance of the Gardens. Some of these plants are sold to other branches
of the Canal and the Panama Railroad organizations and others go to
individuals and business concerns in the Canal Zone, in the Republic of
Panama, and in other countries of Central America and South America,
while a few go as far as the United States. Notwithstanding the
financial depression during the recent years the sale of plants has gradu-
ally increased and more have been sold during the year just closed than
in any other twelve months period. The sales for the year, consisting
chiefly of trees, plants, propagating material and prepared soil for box
and pot cultures, have approximated $5,746 in value. Although this
is not a large volume of trade from a business point of view, it represents
the distribution of a rather large number of plants, many of which would
never have become established in this country except through this
agency. While it has been stated above that the nursery is carried on
without expense to the regular Gardens funds, it must be pointed out
that it could not operate independently of the Gardens because it re-
quires careful and trained supervison which the Gardens can supply at
cost but the volume of business is too small to sustain the full time of a
man capable of supplying this necessary supervision. The revolving
fund which was initiated in 1929 with an allotment of $5,ooo now
shows a total credit of $6,634, the increase of $1,634 representing a fair
margin of safety which also is available to aid in carrying the Gardens
through any period of emergency.
THE CARE OF TREES AND PLANTS IN PUBLIC AREAS
THE AGRICULTURAL AIDE IN THE CARE OF TREES
During the fiscal year 1932, Mr. John Paul Keenan was appointed
as Agricultural Aide, in the care of trees and plants in all parts of the
Canal Zone, under the direction of the Director of the Experiment
Gardens. The urgent need for the appointment of a man who could
devote his entire time to such service had been frequently pointed out.
Trees in all parts of the Zone, some of them grand and majestic, were in
urgent need of attention, having dead and decaying branches, open
wounds, impossible of healing without treatment, and in some cases
suffering from insect attacks. Mr. Keenan came with training from
the Syracuse University School of Forestry and with experience in the
field service of the Bureau of Forestry of the United States Department
of Agriculture. He entered upon the work with a keen interest in the
problems peculiar to tropical conditions and with an enthusiasm which
has been steadily maintained. The improvement in the appearance of
the trees was manifest from the beginning and has attracted the attention
of many who are interested in the trees. Those who have observed
intimately have found not only improved appearance but also the healing
of wounds and the arrest of decay which gives promise of the saving of
many trees which otherwise would have been destroyed in a few years.
But the importance and value of the function of a tree expert lies not
only in the effort to maintain the health and vigor of old trees but also
in the training of trees that are young so as to adapt them to the special
purposes and situations for which they are desired and to encourage a
formation that will be strong and enduring. Many young trees have
been planted in towns of the Zone in recent years and it is a part of the
tree expert's duties to train these.
Mr. Keenan has been an employee of the Experiment Gardens,
operating under the Director, but his time has been devoted exclusively
to public areas and his services have been charged out to the accounts
of the District Quartermasters where the work has been done. It is
deeply regretted that it was found necessary to discontinue this service
on June 3o because the general shortage of funds in public areas, as in
other branches of the Canal organization, makes it impossible to pay
even this modest salary. It is hoped that with the return of normal
conditions, it may be possible to reestablish this position on a permanent
basis for without it valuable and handsome trees that have required
many years for their growth will be neglected and suffer deterioration,
and in many cases destruction.
LANDSCAPE PLANTING AND THE SUPERVISION OF TREES AND PLANTS
IN PUBLIC AREAS
A large share of the time of the Director of the Gardens, during the
year, has been devoted to problems concerning the new plantings for
landscape effect in public areas and in the supervision of established
plantings. The latter requires frequent inspections in the towns on the
Pacific and on the Atlantic sides of the Zone. The new and the supple-
mentary planting plans for landscape effect include those of Lion Hill
Road, some officials quarters on Balboa Heights, the Prado area includ-
ing the slope from the Administration Building, the Balboa High School
site and the patio, the triangular park facing the Balboa Post Office,
the new residence section near the Quarantine area and the Amador
Road section, all in the Gold quarters areas of the South or Pacific side
of the Isthmus. On the Atlantic side, the new residence section facing
Colon Beach, in New Cristobal, has received considerable attention.
Because of the strong and continuous winds of the dry season most
plants which prosper elsewhere are a failure on Colon Beach and efforts
are now being made to test certain plants which may endure the wind
and the salt spray. Among those that are now being tried are the
"shore-grape" (Cocoloba uvifera), icaco, (Chrysobolanus icaco), Tecoma
stans, mangrove, lilies (Hymenocallis americana and Crinum longi-
florum) Furcraea, Barleria involucrata, Wormia burbidgei, Calophyllum
calaba, Casuarina glauca, and Casuarina equisitifolia.
Blue prints covering most of these projects have been submitted, and
are now on file. In the new planting near residence quarters the aim
has been to cloth the buildings with group plantings, afford some privacy
in the open basements and preserve as much as possible of the very
limited space for lawn. No hedges have been used except where neces-
sary to screen out clothes lines or other unsightly features. I would
again strongly urge that the regular clipping and shearing of shrubbery
be discontinued, except under supervision, first for the sake of the beauty
of the plants and their free-flowering and second to avoid unnecessary
expense. A limited amount of pruning is necessary and at times a
severe but judicious pruning may be found beneficial, but regular
shearing and clipping to maintain an exact shape is objectionable in these
informal plantings. There are of course exceptions to this general
statement and in some situations in the Zone towns plants formally
trained seem to be in place.
One of the recently introduced flowering trees, being used in these new
plantings, is the Queen crapemyrtle, Lagerstroemia flos-reginae (Plate
Lagerstroemia flos-reginae.-Queen crapemyrtle
The rapid effect which it is possible to get in landscape plantings in
this country is quite astonishing to those who are familiar with such
work only in the temperate zone. Here where there is a twelve-months
growing season it is possible to produce in a few years such results as
would require a decade in the North. Plate IX shows two years growth
from bare lands in the Gavilan town site. Much of the credit for such
excellent results is due to interest which has been taken by nearly all
of the occupants of the residences. The training of the trees has been
done by Mr. Keenan.
In connection with this brief reference to landscape plantings, I
would urge that future town sites be planned with a deeper frontage
between the sidwwalks and the houses so as to provide sufficient space
to arrange a landscape and especially to allow the planting of graceful
shade trees which will neither interfere with the sidewalks nor the
houses. If lawns of liberal size are allowed and are not cut up by the
scattered and spotty planting of shrubbery, the cost of mowing them
with a power mower will not be greater than that of cutting the grass
and trimming around the many single shrubs in a much smaller yard.
Most shrubbery should be kept in well-placed groups where they require
less attention and produce more picturesque effects.
In accordance with instructions of the Chief Quartermaster, trees and
some shrubs have been planted in the residence towns occupied by
laborers of the Silver Roll. Fruit trees, chiefly mangoes, have been
chosen for this purpose and have been arranged along the streets where
there is sufficient room and also in open spaces between houses. The
West Indians who occupy these quarters are especially fond of mangoes
and other tropical fruits and the few trees that have been planted near
some of these quarters appear to have been protected and cared for.
In some places a little shrubbery of such hardy but beautiful kinds as
hibiscus and crotons has been planted. If it is found that these prosper,
under the existing conditions, more planting will be recommended for a
later date. All of the Silver towns have been included in the planting
In the laying out of all of these planting plans for the Canal Zone
towns and in the recording of them in permanent drawings, the assistance
of Mr. Keenan has been of great value, as also in the supervision of much
of the planting work.
Outside of the Canal organization, the Director of the Gardens has
acted in an advisory capacity in assisting officers of the United States
Army and Navy in connection with planting plans and the care of
SEED AND PLANT ACCESSIONS
Although the acquisition of new kinds of plants has not been pursued
as actively as in normal years, because of the insufficiency of funds,
nevertheless many valuable accessions have been added. Among these
is a collection of several new varieties of sugar cane known as Mayaguez
seedlings. The originating of new varities and their testing is a work of
outstanding importance in the sugar industry in these days and the
Puerto Rico Station at Mayaguez has developed several varieties of
much promise. The major portion of the sugar industry of today is
based upon varieties that were not in existence until quite recent years.
This collection of Mayaguez seedling varieties of sugar cane was received
from Dr. E. W. Brandes, in charge of the Office of Sugar Plant Investi-
gations of the United States Department of Agriculture. They will be
disseminated for trial under varying field conditions when propagating
material becomes available. These varieties are as follows: Mayaguez
Nos. 3, 7, 42, and 15I.
Pineapple varieties have been acquired by exchange with the Experi-
ment Station of the Hawaiian Pineapple Packers Association and with
the Department of Agriculture of the Federated Malay States. Some
of these represent new varieties which may be of value here. The
complete list of the varieties introduced is as follows:
From Hawaii: From Federated Malay States:
No. Variety No. Variety
9582-Wild Kailua 9773-Sarawak
9584-Sarawak 9775-Smooth Cayenne
9585-Wild Brazil 9776-Canning
9586-Hilo Cayenne 9777-Comte de Paris
OTHER IMPORTANT ACCESSIONS OF THE YEAR
A list of the other more important plant accessions of the year is
presented as a separate report for official records.
VISITORS AT THE GARDENS
The number and the interest of visitors to the Gardens increases each
year. In March of 1933, it was a special pleasure to welcome the
distinguished veteran and pioneer in plant introduction, Dr. David
Fairchild with Mr. Allison V. Armour and Dr. Thomas Barbour to
An orchid-clad tree at the Experiment Gardens, showing Epidendrum stamfordianum in full flower
p. 26 a.
whom these Gardens are indebted for many important plants, brought
on Mr. Armour's yacht the Utowana. Dr. Fairchild spent several days
in intensive examination of many plants resulting from the introductions
made on his tours of exploration in the tropics. The mangosteen was an
especial delight to him in its luxuriance of growth and just bursting into
flowering, for much effort and limitless enthusiasm had been expended
by him in making introductions of seeds and plants by laying a founda-
tion for establishing in America this remarkable fruit of the Orient.
The Gardens were also honored with a brief visit from Dr. C. L.
Marlatt, chief of the Bureau of Entomology of the United States
Department of Agriculture.
Congressman Edward T. Taylor made a passing visit in June, being
a passenger on the U. S. A. T. Republic. Congressman Taylor expressed
a deep interest in several features of the Gardens and was especially
surprised at the excellence of the mangoes of the Cambodiana and the
The Canal Zone College Club, on February 23, held a special session
at the Gardens at which their guest of honor was Mrs. J. Julian Souther-
land, President of the "International Tropical Flower Show." Mrs.
Southerland was on a tour by air to various points in tropical America
and the West Indies in the interests of that exhibition.
Dr. J. Horace McFarland, distinguished lecturer, author, publisher,
and expert in the art of photographing flowers and trees, spent about
a half-day in the Gardens while his ship was in port and manifested a
deep and enthusiastic interest in the treasures of tropical plant life.
The increasing number of visitors from the neighboring Republics
is especially indicative of a new interest in the cultivation of tropical
plants and many of these visitors are eager to secure planting stock of
trees, shrubs, sugar cane varieties and other economic and ornamental
THE FUTURE OF THE GARDENS
In the past these Gardens have been supported by funds received
from the rentals of Canal Zone agricultural lands. As is well known,
the present policy of the Administration, based upon health consider-
ations and the expense of controlling malaria in the Canal Zone, is to
issue no new agricultural leases or land licenses and to renew or transfer
none that expire by the death or withdrawal of the lessee. Hence the
income from land licences is steadily falling off and the resources for the
support of the Experiment Gradens are as steadily shrinking. Through
the efforts of the late Governor Harry Burgess and Governor Julian L.
Schley, an item of $s,ooo which was inserted in the Panama Canal Bill
as an aid to the work of the Gardens, was passed by Congress and will be
available during the current fiscal year to supplement the diminishing
returns from land rentals. It will be necessary to increase this amount
in each year's appropriations or to obtain money from other sources if
the Gardens are to be maintained on a basis of efficient operation. It is
recommended and urged that an item be inserted in the Supply Depart-
ment budget for 1935, providing for a sufficient increase in the appropri-
ation to bring up the total amount available for the Gardens to $24,000.
The amount that would be necessary to insert in the budget would
depend upon the Auditor's estimate of the prospective net return from
land leases. In consideration of the large amount of money that has
already gone into the Gardens to bring together and establish so valuable
a collection of plants; and in further consideration of the growing interest
and importance of the work which has attracted wide attention of
scientists and other visitors, it is hoped that adequate support will be
forthcoming. Neglect would mean ruin to most of this collection.
Lands( ape ecO s ('at tained in two years growth
I 28 a
........... .... . . .I II//ff]. . T/11 ] / I III II II [
Annual Report of the
Canal Zone Experiment Gardens
FOR THE FISCAL YEAR
LETTER OF TRANSMITTAL
CANAL ZONE EXPERIMENT GARDENS,
Summit, Canal Zone, v.7ul 7, 1934.
SIR: I have the honor to transmit herewith a Report of the Canal Zone
Experiment Gardens for the year ending June 30, 1934. Publication is
recommended when funds become available. *
J. EDGAR HIGGINS,
Mr. Roy R. WATSON,
Balboa Heights, Canal Zone.
Through Mr. J. H. K. HUMPHREY,
Assistant Chief Quartermaster.
Publication authorized February 19, 1938.
Teak, Tectona grandis----------------------------------------------------35
A New Guava Variety---------------------------------------------------37
An Experiment in Apprenticeship------------------------------------------.38
Report of a Trip to Chiriqui Province:
Inspection of Earlier Distributions--------------------------------------40
Locating Homes for New Plants----------------------------------------42
Cub6, Lonchocarpus nicou------------------------------------------43
Cracca toxicaria.------------------------------------------------- 44
Eugenia floribunda-------------------------------------------- 44
Asparagus, Asparagus oJflcinalis------------------------------------ 44
Bamboo species.------------------------------------------------- 45
Bambusa polymorpha------------------------------------------ 45
Nut-bearing Trees.--------------------------------------------------- 45
Macadamia nut, M acadamia ternifolia ------------------ ------ ------ 45
Brazil nut,Bertholletia excelsa----------------------------------- 45
Lecythis zabucajo--------------------------------------------- 4;
Lecythis tuyrana and L. elliptica------------------------------------ 46
Waringian Fig, Ficus waringiana--------------------------------------46
Hawaiian Cooking Bananas-------------------------------------------- 46
The Coffee Situation--------------------------------------- -------- 46
Coffee Diseases------------------------------------------------- 47
Control Measures------------------------------------------- 49
The Coffee Trees Themselves as a Source of Infection ------------ 4
Bordeaux Mixture----------------------------------------- 54
General Soil Management and Fertilization--------------------------
Vegetable Tests.----------- --------- ----------------- !
Report of Vegetable Tests, by W. R. LINDSAY, Supervisor of Cultures --
Plate I Figure i.
Plate II Figure i.
Plate III Figure i.
A Guava Variety (Psidium guajava var.)
Breadfruit Tree, Twenty Months After Planting
Avacado Trees at Blanco, Chiriqui
Coffee Plantation Center in the Mountains Above Boquete
Coffee Tree, Said to be a Hybrid
Coffee Tree Defoliated by the Leaf Spot Disease
ANNUAL REPORT OF THE
CANAL ZONE EXPERIMENT GARDENS FOR 1934
By J. EDGAR HIGGINs, Director
For another depression year, the work of the Canal Zone Experiment
Gardens has been conserving rather than expanding. With shrinking
resources, it has not been possible to pursue plant introductions with the
same activity which has been attempted in the predepression years.
Nevertheless, some progress has been made even in the introduction of
new species; and the natural progress of the established trees and other
plants has brought to attention some things of interest and importance.
Also such improvements in appearance and accessibility as could be
carried on with the limited resources have been in progress.
Through the medium of seed and plant exchanges some valuable
accessions have been made during the year. The United States Depart-
ment of Agriculture has been the largest contributor. Sixteen species
of orchids were received from the Bureau of Science, Manila, Philippine
Islands, in exchange for a shipment of Panama orchids from the Gardens.
Exchanges received from the Royal Botanic Gardens, Trinidad, B. W.
I., included about 24 different species and varieties. A half-dozen or
more items came from Mr. W. P. Phillips of Orlando, Vla. Scions of
seven Hawaiian varities of mango were received from the Hawaii Agri-
cultural Experiment Station, Honolulu, T. H. From the Atkins Insti-
tution of the Arnold Arboretum at Solidad, Cienfuegos, Cuba, seeds or
plants of upwards of 40 kinds were received. Dr. E. B. Stilz, of Lusai-
bo, Belgian Congo, Africa, contributed a number of interesting items,
including selected seed of the African Oil Palm F/ads guineensis. Seed
of several cover crops was received from the I)epartment of Agriculture,
Rabual, New Guinea. Mango scions of five varieties were contributed
by Dr. Wilson Popenoe from the Lancetilla Experiment Station of the
United Fruit Company in Tela, Honduras. ,ratonia siliqua seed \.as
sent by Dr. Thomas W. Brown of the Agricultural I)epartment, (i/a,
Egypt. Exchanges were received also from Mr. Holger Johansen of
Puerto Rico, formerly Agronomist in charge of these Gardens; from the
Director of Forestry, Manila, Philippine Islands; from the Puerto Rico
Agricultural Experiment Station; and one or more species from each of
many other contributors. It is desired to express the thanks of the
Canal Zone Experiment Gardens to all of these who have continued to
cooperate freely in seed and plant exchanges.
A few explanatory notes regarding some of these introductions may
be of interest. The longan, Dimocarpus longan, was received through the
United States Department of Agriculture. It is a relative of the litchi
and is a fruit-bearing tree of the Orient where it is highly prized although
not equal in importance to the litchi. Trees of the litchi are well estab-
lished in these Gardens but never have flowered. However, seedling
litchi trees are very erratic in their bearing habits and usually very tardy
in coming into bearing. Even where litchi trees bear abundantly, the
seedlings may produce no fruit until they are over 25 years of age.
Hence it is the custom to propagate them by air-layering or what is
known as the gootee method and thus to produce bearing trees in only
a few years. By this method a branch from a fully mature bearing tree
of known quality is made to produce roots and later is removed to form
a new tree. Up to the present time it has not been known whether the
entire lack of fruit on the litchi trees at Summit has been attributable to
their seedling character or to the tropical conditions under which they
are growing. The native habitat of the species is not strictly tropical.
It has produced well in Hawaii and Cuba and we are advised by Dr.
Wilson Popenoe that the trees of the United Fruit Company in Honduras
have come into production.
Hence it is hoped that even in the tropical climate of the Canal Zone
the litchi trees may be expected to produce in due time. Girdling may
aid in bringing about fruit-bearing, as was described in the case of mango
trees in the Annual Report of these Gardens for the year 1928. As the
longan is native of the same regions as the litchi it is also hoped that this
species will yield fruit here.
Lonchocarpus domingensis, as its relative, "Cube," L. nicou, is under
trial as a possible commercial source of rotenone, now attracting much
attention as an ingredient in the manufacture of effective insecticides
that are comparatively innocuous to man and domestic animals.
Awa, Piper methysticum, is a narcotic plant formerly much used by
the ancient Hawaiians and probably other Polynesian races. It is now
under investigation as a medicinal plant.
A variety of sugar cane designated as Mayaguez No. 28 is one of the
new seedling varieties originated at the United States Agricultural Ex-
periment Station at Mayaguez, Puerto Rico. It is a variety of out-
standing promise in Puerto Rico and may prove to be of importance,
among the other varieties introduced by the Gardens, in aiding the
Panama sugar cane industry.
The nutmeg, Myristica fragrans, is represented at the Gardens by
mature specimens, but only of the pistillate or female tree. Without
staminate trees there can be no fruit production. Some of the seedlings
from this introduction, if they mature, should be staminate trees.
tegle marmelos is a relative of citrus, which is of some possible value as
root-stock. It is one of the collection of citrus relatives being cared for
here, primarily for the investigations of the citrus specialists of the
United States Department of Agriculture.
The African violet, Saintpaulia ionantha is a very beautiful little house
plant that was introduced by Mr. L. E. Burdge who presented the
Gardens with several plants. The foliage is handsome and the flowers
resemble violets in form and color. It is becoming very popular.
Acacia koa is the Koa tree of Hawaii which produces a very valuable
lumber, often sold under the name of "Hawaiian mahogany." It is
much used for fine cabinet work.
The sweet corn variety, Maypuertotres, is a new hybrid produced at
the Puerto Rico Agricultural Experiment Station at Mayaguez, Puerto
Rico, under the United States Department of Agriculture. It represents
an attempt to breed a variety having the characters of sweet corn, but
adapted to growth under tropical conditions. None of the standard
varieties of sweet corn appear to be suited to the lowland tropics.
Ceratonia siliqua, the Carob or St. John's Bread, is valued as a stock
feed and is of considerable economic importance in the Mediterranean
region. This strictly tropical climate may be unsuited to it but it should
be given a trial.
TEAK, Tectona grandis
Reference has been made in earlier reports to the progress of the teak
trees in the Gardens. This year measurements of growth have been
recorded and one tree was cut down as a test of the timber.
Thirty-nine trees of this species in various parts of the Gardenis are
apparently the product of about one ounce of seed received from iD,.
David Fairchild and Mr. Dorsett when in Ceylon. It came through
the Office Seed and Plant Introduction and is S. P. 1. Number 66,242.
These are recorded as having been received April 8, 1926. As this is the
only record of the planting of teak seed at the Gardens prior to 192-, all
of the large trees of teak now on the place must have come from this
introduction. Later plantings of teak trees have been from seed of
these older trees. These trees therefore were eight years old in April
of this year (i9,34).
Cutting and testing. One of these trees was cut down for a timber test
on February 2i, 1934. It was the second tree from the south end of the
row west of the propagating house. When the trees were later marked
with permanent numbers this stump was inadvertantly omitted from
the series and hence has been designated as tree No. i-A. The tree
marked No. 3 was girdled in accordance with the Burma method of har-
vesting and will be allowed to stand until dead and partly seasoned.
The measurements of the tree that was cut down (tree No. i-A) under
the supervision of the Garden staff and of Mr. F. W. Braddy, timber ex-
pert for the Panama Canal, were as follows:
Height, 54-feet, 7-inches; mean diameter i-foot above ground, where
cut, 14 inches; mean diameter of heart-wood at the same point, I21
inches. It cut a 13-foot bole of 14 inches diameter at the base and io
inches at the top. It was quite unexpected that so large a part of the
trunk of this very young tree would be found to be heart-wood.
Rings. It is interesting to note that the bole of this tree showed rings
corresponding to the annual rings of temperate zone trees and that the
number of distinct rings appears to be nine, or one more than the number
of years that the tree has been growing.
The 13-foot log was delivered at the Mechanical Division of the Pana-
ma Canal, on Friday, February 23, for seasoning, for observation, and
for sawing. The remaining portion of the tree trunk and main branches
are being kept at the Gardens where they will be exposed to weather and
to termites for future observation.
Remaining trees. The height of all of these trees in the row referred
to is approximately uniform as was shown in Plate IV of the Report for
1933. The circumference of i6 of the trees, 18 inches above the ground
surface, on June II, 1934, taken in consecutive order and measured in
inches, were as follows: 62.5, 52, 55, 59.5, 44.5, 6o, 64.5, 6i, 62.5,
59, 51-5, 62.5, 45.25, 52, 65.5, 70.5. The mean circumference was
thus 57.9 inches.
The above trees have all received considerable water in dry season
during recent years due to their proximity to nurseries from which they
doubtles: appropriated also some fertilizing elements. It will be inter-
esting to compare the above measurements of circumferences with those
of other trees of the same introduction but located in other parts of the
Gardens where conditions were different.
Trees numbered 17 to 34 inclusive, are located in comparatively dry
places and where irrigation water is not usually applied. It is possible
that they may have received some irrigation in dry season during their
first year or two. There are no records of such. The circumference
measurements of these trees at i8 inches above ground expressed in
inches were as follows: 44, 43, 43, 42, 36, 71.5, 55, 49-25, 58-5,57,
41, 39, 34-75, 37, 43, 38, 30, 42.5. This represents a mean circum-
ference of 44.69 inches.
Trees numbered 35 to 39 inclusive are located in soil that is naturally
more moist and in rainy season is inclined to be wet and not well
drained. The circumference measurements of these trees at 18 inches
above ground and expressed in inches were as follows: 54.5, 62.5, 46,
57, 38. The mean circumference of this group was 51.6 inches.
To summarize, it will be noted that the 16 trees which in the last few
years have had access to some water and fertilizer, applied to adjacent
nurseries, show a mean circumference measurement of 57.9 inches. The
group of I8 trees in the drier location without irrigation or fertilizers
present a mean circumference measurement of 44.69 inches, or 13.3
inches less than the first group. The group of five trees in a more moist
location without irrigation or fertilizer have a mean circumference meas-
urement of 51.6 inches or only 6.3 inches less than the favored group.
It would appear therefore, that even on the dry hillside a very satisfac-
tory growth has been made while on the more moist places the growth
has been better.
The small mangosteen orchard continued to prosper and produced
about fifteen hundred fruits in July and August. This made possible
the giving of several mangosteen demonstrations at the Gardens at
which some of the residents of the Canal Zone and of the Republic of
Panama were given the opportunity to try this fruit, as yet quite new
and rare in the Western hemisphere. By this means also it was possible
to save the seed for planting. There is a limited supply of very excellent
seedlings resulting from earlier plantings now ready for planting out and
the younger stock from the 1934 plantings is making good progress.
Mr. Walter R. Lindsay has conducted experiments in grafting mango-
steens on mangosteen roots for the purpose of devising means for the
multiplication of any especially good clones which may appear and also
with a view to bringing trees into bearing earlier in their development.
Another good crop of fruit is about to mature at the date of this writ-
ANEw GUAvA ARITY
A new guava, Psidium guajava var., from the Experiment Gardens
introductions, fruited for the first time in June, in the gardens at Albrook
Field under the care of Mr. J. B. Shropshire. This is apparently the
progeny of F. P. 1. No. 81,849 which was introduced from Peru ib\ the
United States Department of Agriculture through l)r. \ilson Popenoe.
The fruit is shown in the accompanying illustration (Plate I, Figure i).
It is of outstanding interest first because of its unusually large size but
more particularly because of its very thick pericarp which may offer
resistance to the fruit fly (Anastrepha sp.). This insect is found in almost
every ripening guava fruit in this country. Of the several fruits of this
variety that have been gathered none has contained any larvae.
AN EXPERIMENT IN APPRENTICESHIP
In the first half of the fiscal year, the suggestion was offered by the
Executive Secretary of the Panama Canal that a mutual advantage
might be attained if the Experiment Gardens would offer the opportuni-
ty to a group of young Panamanians to come to Summit in the capacity
of student laborers. The Department of Agriculture of the Republic
of Panama expressed interest in the proposal and after several confer-
ences between Director H. D. Sosa and the representatives of the Canal,
a plan was worked out under which a group of about IO boys and young
men varying in age from perhaps 17 to 23 years, began work at the Gar-
dens on December I I, 1933. The group has varied in size by the drop-
ping out of a few who did not seem adapted to the work and by the com-
ing in of others. They were given subsistence and experience in many
different kinds of horticultural operations and in turn they performed any
kind of labor that needed to be done. They remained at the Gardens
for about six months when most of them were needed by the Government
of Panama and were given positions as assistants in connection with the
extension service carried on by the Department of Agriculture. Even
with this very brief period of training they appeared to the Department
to be the best material available for the work to be done.
During their stay at the Gardens these young men gained some ex-
perience in such operations as collecting, preparation, and planting of
seed, establishing of seedling nurseries, budding, grafting, training of
nursery stock, balling trees, transplanting, pruning of nursery and or-
chard trees, preparation and application of sprays, operation of spray-
pumps, propagation by layering and air-layering, collecting and prepara-
tion of banana propagating material, harvesting grass seed, potting and
handling'of greenhouse plants, operation of gasoline lawn-mowers, laying
small water pipe-lines, grading and many other operations incident to
the work of the gardens. They also have had opportunity to make
observations upon and to become more or less familiar with several
varieties of oranges, grapefruit, lemons, limes, mangoes, and other fruits.
The amount of information acquired under such circumstances depends
chiefly upon the students eagerness to learn. If the period of residence
could be increased such would be advantageous for the students.
Fiut 1, .A Guava variety (Psidium guajava var.)
FIG -RE 2. -Breadfruit tree twenty months after planting
After this first group was called to service in Panama, a new group of
somewhat larger size was placed at the Gardens. The number at the
date of this writing is 14. They appear to be interested and desirous of
acquiring information and experience.
Until the recent inclusion of an item of $5,ooo for the Experiment Gar-
dens in the Congressional appropriations, the Gardens have been de-
pendent entirely upon the net revenues from agricultural leases or land
licenses. At the beginning of the fiscal year 1934 it was estimated by
the Land Agent and the Accouting Department that the net revenues
of that office, above expenses, would be approximately $9,922. This,
with the $5,ooo above mentioned,-would make a total of S14,922 available
for the Gardens operations for 1934. This is about $9,0o0 short of the
normal needs. At the date of this writing the accounting for the
entire I2-month period is not available but the expenses from these funds
for the ii months ending May 31 have amounted to $13,779. If the
i2th month is at the same rate the total operating costs will be I 5,031.
However, the land revenues, although much less than those of any pre-
ceding year, appear to have exceeded the estimates and it is believed that
there will be a small surplus which should be obligated to meet the needs
of 1935 when it is expected that there will be a further shrinkage in
revenues. It has been possible to keep the expenditures within the
income only by neglecting many things that ought to have been done
and by further suspending the publication of annual reports. It will
be necessary to have increased allotments from Congressional appropria-
tions each year or to have funds from other sources to meet the shrinkage
in land revenues, in order to meet the needs of maintenance alone, with-
out reference to the natural growth which should be made.
The nurseries carried on by the Gardens for the dissemination of
valuable plants have continued to operate upon a self-supporting basis
under the revolving fund. The sales for the II months ending May
31 have amounted to $3,879.45. June is usually the month of largest
sales, amounting to $i,6o3 in 1933. It is thus estimated that the 1934
total sales will approximate $5,ooo. There remained a balance of about
$8,247 in this fund on May 3 1, representing an increment of approxi-
mately $3,250 over the $s,ooo originally set up for these operations.
In the Equipment Replacement account which is maintained by a
monthly charge against the operating funds there was a balance of about
$i,823 on May 3i. This will be reduced in the immediate future by
approximately $3oo by the installation of much needed grinding equip-
REPORT OF A TRIP TO CHIRIQUI PROVINCE
In January 1934, the Director of the Gardens made an official trip to
the Province of Chiriqui. A copy of the report of this trip, which has
already been submitted, is incorporated herewith as a part of the year's
activities. It is as follows:
REPORT OF TRIP TO THE PROVINCE OF CHIRIQUI
Balboa Heights, C. Z. (Through the Assistant Chief Quartermaster).
SIR: In accordance with the letter of authorization of the Governor, on recommendation
of the Chief Quartermaster, I visited the Province of Chiriqui, leaving Balboa on Sunday,
January 14, and returning to the Canal Zone on Thursday, Feburary I.
The purposes of this trip were as follows:
Inspecting the condition of plants which the Gardens have placed in Chiriqui for
experimental purposes; selecting suitable locations and cultivators for the placing of
other plants requiring higher elevations than those at Summit; familiarizing the people
of the region with the facilities which the Experiment Gardens are offering in the
matter of plant introduction and distribution; and attaining familiarity with the
conditions of the Chiriqui region and other matters in the interests of the Canal Zone
INSPECTION OF EARLIER DISTRIBUTIONS
The trees of avocado from the Gardens, now growing in the very deep,
rich soil in the banana district, a few miles inland from Puerto Armuelles,
have made a remarkable growth and have begun to bear fruit. (Plate II,
Figure I.) Some were in flower at the time of my visit to the orchards
and gave promise of producing quite heavily this year. The soil of that
region appears to be ideal for avocado culture and this may be said of
extensive areas in the Chiriqui Province. I saw none of the failure of
avocado trees which is so prevalent in the heavy and tenacious soils of
the Canal Zone towns. With the further dissemination of grafted and
budded trees of these choice, selected varieties, this most fertile province
should take an important part in supplying the markets of Panama City,
Colon, and the interior towns with avocados that will compare favorably
with those of any part of the world and should entirely replace the non-
descript lot of seedlings which are so frequently seen in the markets.
Doubtless there are also choice seedlings of Panama origin which also
should be multiplied by budding or grafting. Even with the present
facilities for shipping there is no reason why avocados from Chiriqui
should not be safely placed in the markets of Colon and Panama.
In the higher altitudes of the Province had been placed some of the
varieities of the race of avocados which is found in the highlands of
Guatemala and is known as the Guatemalan race. These were seen in
different localities at 4,ooo to 5,ooo feet elevation and were reported to
have begun to produce fruit. Some were in flower at 5,ooo feet at the
time of my visit and looked very promising. Avocados of these varieties
may be expected to supply fruit at seasons when the lowland varieties
of the so-called West Indian race are out of the market.
The mango trees seen at Blanco, near to sea-level, are making a very
vigorous growth and are in a healthy condition. It is yet too soon to
determine what these may do in the matter of fruit production. They-
were planted about the middle of October in 1929 and thus were a little
more than four years in the orchard. Some were in flower in January of
1934 which indicates rapid maturing. In this rich, deep soil, abundantly
supplied with moisture during a long rainy season, I was rather surprised
to see flowers while the trees were so young. Mangoes are naturally
strongly vegetative until the trees become quite old, and I should not be
surprised if it be found necessary to adopt some such measures as girdling
of some of the branches to arrest growth and encourage production of
Observations of citrus fruit trees both on the lowlands and also in the
coffee districts, indicate that a large assortment of varieties of oranges,
grapefruits, lemons, limes, and others may' be expected to prosper in the
Chiriqui Province. The observations covered not only the citrus trees
sent out from the Experiment Gardens, but also the old seedling sweet
oranges that have been in the country for a very long period, and the
Bahia or Washington Navel orange introduced many years ago from
California. Mr. W. J. Wright is authority for the statement that this
introduction was made in 1896 by Mr. Frank Tedman of Alto Lino. Mr.
Wright has a small orchard budded from the Tedman tree and this is one
of the special attractions of the town of Boquete. These Navel oranges,
in flavor, texture, and appearance, would do credit to any, market. These
and other trees of the variety scattered through the district hear strong
testimony to the fact that Panama should produce all its own oranges
and also become an exporter of this high quality fruit. The Bahia
(Washington Navel) orange in the tropics has so far appeared to be strict-
ly a highland variety and its production on a commercial scale should
not be attempted on the lowlands as the fruit in these localities tends to
be of poor quality. It is possible that special clones may be found that
will be adapted to these conditions. The Canal Zone Experiment (Gar-
dens have introduced budwood of one of the best strains of Bahia grown
in California. This budwood was from trees whose production records
have been kept for many years past. This is propagated at the Gardens
and the trees are shipped to the high elevations, but are not yet on our
recommended list for the lowlands.
Grapefruit in several varieties also prosper in Chiriqui on the lowlands
and at altitudes up to at least 4,000 feet. The fruit, whenever found, was
of good quality.
Breadfruit thrives like a weed in the rich, moist soils of the lowlands
of Chiriqui. Plate I, Figure 2, shows a breadfruit tree which was received
from the Experiment Gardens about May of 1932 and was planted out
by the Chiriqui Land Company at Blanco. The photograph taken in
January of 1934, shows the tree when it had been planted for less than
two years. The breadfruit furnishes a staple food supply for thousands
of the inhabitants of the Pacific Islands and should be planted by every
farmer on the lowlands of Chiriqui and in many other parts of Panama.
The trees yield abundantly a most nourishing food and require almost
no attention in the conditions to which they are adapted. Under such
conditions, it also is one of the most handsome shade trees that can be
found anywhere, with its huge, deeply lobed leaves which present amag-
nificent tropical effect. A few trees would keep a family supplied with
the necessary starchy food throughout the entire fruiting season.
LOCATING HOMES FOR NEW PLANTS
I took with me to Chiriqui 145 plants for the purpose of placing them
for trial in locations where the environmental conditions are quite differ-
ent from those prevailing at the Experiment Gardens or anywhere else
in the Canal Zone. Some of the plants are not suited to the comparative-
ly low elevations on the Canal Zone and others will probably benefit by
the rich and more friable soils of some parts of the Chiriqui lowlands.
These plants were as follows:
25 Grape cuttings, Isabella variety
2 Lonchocarpus nicou
20 Derris elliptica
3 Cracca toxicaria S. P. I. ioi,i88
3 Macadamia ternifolia
'24 Eugenia floribunda
30 Asparagus officinalis
2 Sasa variegata pygmaea F. P. I. 52,614
2 Sasa pumila F. P. I. 52,673
12 Bambusa tulda (suckers)
3 Bertholletia excelsa
3 Lecythis sapucaya
2 Lecythis tuyrana
3 Lecythis elliptica
3 Ficus waringiana
8 Banana suckers (2 of each variety) Eleele, Manaiula, Maoli,
THE ISABELLA GRAPES
This is a strain of the Isabella variety of grape which appears to be ac-
climated to the cooler tropics. It was introduced at the Experiment
Gardens from Hawaii where it has prospered for many years since its
introduction from Madeira. In Hawaii, under irrigation, it produces
two crops per year of excellent grapes. The conditions at Summit ap-
pear to be unfavorable for it, and it is therefore being tried at various
places in Chiriqui. In El Volcan these are located with Messrs. J. G.
Macoubrey, J. L. Miller, and C. A. Escoffery. In Concepcion, which is
perhaps the more promising location, cuttings have been placed with Mr.
Walter Spalding. In the Boquete district, they are with Messrs. W. J.
Wright, Paublino Ruiz, Nicholas Taylor, and Dr. J. H. Talboy.
CUBA (Lonchocarpus nicou)
Cube' is a plant that is now attracting considerable attention because of
its content of rotenone, a substance highly poisonous to insects but not
dangerous to man and the domestic animals. Hence it is being used in
the manufacture of some of the newer insecticides and is under further
investigation for such purposes. If rotenone is found to be an economi-
cal and highly effective insecticide capable of displacing to a considerable
degree the arsenical compounds which have been the standard stomach
poisons in insecticides, there may be a large demand for it. Cube, being
one of the possible sources of rotenone, is under trial in several countries.
As the plant is native of the highlands of Peru and probably other parts
of South America, it is doubtful whether it will prosper in the heat of the
lowlands. It is under test at the Experiment Gardens, but to date has
not given much indication that it will flourish here. Hence, of the few
plants that we have, two were placed with Mr. J. L. Miller in the Volcan
coffee district at an altitude well above 4,000 feet and also with Mr.
Wright and Dr. Talboy in the Boquete district.
Derris elliptica-Another source of rotenone
This climbing or trailing plant is native in parts of the Oriental tropics
where it is used as a fish poison and is now under study as a source of
rotenone. It appears better adapted than Cube to the conditions at
Summit, in the Canal Zone. The seed was introduced at the Experiment
Gardens direct from Java and the plants have made good growth, but
it seems desirable to test this species under other conditions in Panama.
Hence plants were placed with the Chiriqui Land Company, withMr.
Escoffery and Mr. Miller in El Volcan, and with Messrs. Wright, Ruiz,
Monniche, Jose Yenez, and Dr. Talboy in the Boquete district and the
Cracca toxicaria-Another source of rotenone
This is a leguminous plant, native in the higher altitudes of Bolivia,
which was introduced by the United States Department of- Agriculture
from which source it came to the Canal Zone. It is another of the plants
under investigation as possible sources of rotenone. It has not been
under cultivation at the Canal long enough to determine its adaptability
here but considering its source, it seemed desirable to place a part of the
very few plants in the higher elevations of Chiriqui. Hence they were
placed with Messrs. J. L. Miller and W. J. Wright. Also, to ascertain
the effect of entirely different soil conditions combined with altitudes
not widely different from those at the Experiment Gardens, one plant
was paced with Mr. H. S. Blair, Manager of the Chiriqui Land Company
plantation at Puerto Armuelles.
This is a small fruit which has been introduced from the Virgin Islands
where it is much used for making jam. The tree is of medium size and
is adapted to low altitudes, but its adaptability to higher places should
be tested. The young trees were placed with the Chiriqui Land Com-
pany for lowland planting and with Messrs. Jennison, Macoubray,
Wright, and Dr. Talboy in the higher altitudes.
This is the ordinary garden asparagus, grown as a vegetable and for
decorative purposes. It is not suitable to lowland conditions in the
tropics, but at altitudes of 4,ooo to 5,000 feet in the friable soils of the
Volcan and Boquete regions it should prosper. A few plants were left
with Messrs. Jennison, Miller, Escoffery, Paublino Ruiz, Nicholas
Taylor, and Mrs. J. F. Keiser.
Two species of small bamboo, Sasa variegata pygmaea, F. P. I. 52,614
and Sasapumila, F. P. I. No. 52,673, were placed in the Volcan with Mr.
Miller; and S. variegata was placed also in Boquete with Mr. Wright and
with Dr. Talboy.
Bambusa polymorpha *
This is a bamboo that has proved very succesful in the Canal Zone and
is one of the most beautiful among the many species now under cultiva-
tion at the Experiment Gardens. It is without thorns and being very
compact in habit of growth it is not so hard to control in limited space
as are some of the other species. It was placed for trial in the rich low-
land soils of the Chiriqui Land Company.
The macadamia nut tree, also called the Queensland nut, (Macadamia
ternifolia) is native of Queensland, Australia, but has been established
in various parts of the tropics. The production of these nuts has become
a small but growing industry in Hawaii. Several introductions of seed
from Honolulu have been made and the trees at Summit are making good
progress. As this is one of the most excellent of all the nuts, it will doubt-
less become widely disseminated in Panama if it succeeds here. It is
believed that the macadamia will not require much altitude but it should
be tested from sea-level to 5,000 feet. Plants were placed with Mr.
Miller and Mr. Monniche and also with Mr. Blair. It is regretted that
the supply was quite limited.
The Brazil nut (Bertholletia excelsa), known also by various names as
Para nut, butter nut, nigger-toe, etc., is so well known in the market
that no description is necessary. It is native to the warm, moist parts of
Brazil and may be expected to do well in the rich soils of the banana
region about Puerto Armuelles where three plants were left with the
Chiriqui Land Company.
The Sapucaia nut or Paradise nut (Lecythis zabucaio), a close relative
of the Brazil nut, is also native to Brazil where it is said to be more highly
prized than its better-known relative. The reason for its being less
widely known may lie in the fact that the "monkey-pot" or capsule in
which the nuts are contained has a natural opening or lid through which
the nuts when ripe are dropped to the ground and are immediately the
objective of a wild scramble of monkeys and other animals of the forest
so that man has a poor chance to collect and market them. The Brazil
Through an error this bamboo was culturtd and di;svminated under the nam Biambwsa tnlda.
It has since been detennined as IB pdymorpha,.
nut is difficult to open and man has a better chance in competition with
the beasts of the forest. Both of these excellent tropical nut trees have
been introduced at the Experiment Gardens, and the sapucaia has made
very good growth. The Brazil nut trees have been slower. It is believed
that both species will do better in Chiriqui than in the Canal Zone.
Three sapucaia trees were placed with the Chiriqui Land Company.
Lecythis tuyrana and L. elliptica are two other nut-producing trees
related to the two just mentioned. The first of these is native to Darien,
Panama, and the second comes from Colombia. They also have been
placed in the lowlands for trial in rich soil.
THE WARINGIAN FIG (Ficus Waringiana)
This is a tree of the banyan type and is sometimes referred to as the
Waringiana banyan. It is one of Dr. David Fairchild's introductions
from Java and of it, in his book Exploring For Plants, he says, "Of all the
strange avenue trees that I have seen, the Waringian is the strangest."
He adds: "Little plants of it are now struggling with the lime-stone soils
of Florida and with the clay soils of Cuba, the Panama Canal Zone, and
At the Experiment Gardens in the Canal Zone, there appears to be no
longer any struggle, for the Waringian has become an easy victor and is
expanding upwards and outwards more rapidly than almost any other
tree in the Gardens. It resembles the "Chinese Banyan" or "Laurel de
India" (Ficus retusa Linn.) F. Nitida Thunb, which is so much admired on
Roosevelt Avenue, in Balboa. It is even more handsome and, unlike its
relative, it is apparently not subject to attack by thrips which cause
much leaf curling on F. retusa. At the Chiriqui Land Company's plan-
tation it will doubtless become a remarkable tree. Three small trees
were left there.
HAWAIIAN COOKING BANANAS
These, from horticultural and culinary standpoints, are essentially
like the plantains of the West Indies and tropical America, but they are
of exceptional quality and appearance. In the opinion of the writer,
these cooking bananas have considerable possibilities of development
into an export fruit. It is desired to have them tested in the banana soils
of the Chiriqui Province. They include the varieties Eleele, Maoli,
Manaiula, and Popoulu. Two of each variety were placed with the
Chiriqui Land Company for testing and report.
THE COFFEE SITUATION
Coffee production has become the leading industry in the district
about Boquete and on the slope of the mountain and in recent years a
FIGURE 1.-Avocado trees at Blanco, Chiriqui
FIGURE 2.- Coffee Plantation Center in the mountains above Boquete
p. 4 -a.
coffee industry has sprung up on another shoulder of the mountain in
what is known as the Volcan region. In Plate II, Figure 2, may be seen
part of the lay-out of a very successful coffee plantation above Boquete
at an elevation of about 5,000 feet. The coffee growers in and about
Boquete are Panamanians and foreigners including several Americans,
while in the Volcan, Americans and Scandanavians seem to predominate.
Some quite large plantations have been made by joint stock companies
and there are many good-sized plantations owned and operated by indi-
viduals or partnerships. Plate III, Figure I, shows a hybrid coffee tree
in the Volcan region, heavily laden with fruit. This coffee belt is located
at altitudes ranging from 3,000 to 5,000 feet, on the mountain slope, be-
low the extinct crater, El Volcan de Panama, on soil that is of volcanic
origin. In general the soil of the virgin forest consist of a surface layer
of varying depth and rather well supplied with humus, below which is a
thin stratum of rather coarse volcanic ash, subtended by a very deep
stratum of black powdery material. The surface soil is known locally
as "la crema," the second stratum as "ceniza," (ashes) and the third as
"negro,' because of its very dark color. No soil survey of the region is
on record and the writer has failed to find authentic, reliable, and repre-
sentative soil analyses.
In the Volcan coffee region and also in Boquete my attention was
solicited concerning several coffee diseases. The most important of
these and the one which has caused deepest concern among some of the
planters is a leaf spot disease which causes defoliation, suspension of
growth, the destruction of young branches, injury to the cherry and bean,
and sometimes almost complete loss of crop. In some instances this
disease has caused the abandoning of the plantations and certainly will
do so on many plantations if it is not brought under control. Hence
the deep concern among some growers is well founded, although other
plantations have so far been kept rather free from the disease and the
owners do not seriously fear it. There are, however, few if any fincas
that are entirely free from it and none that are not endangered by it if
There has been much misapprehension among planters as to the identi-
ty and the cause of this disease which locally has been confused with the
devastating coffee "Rust" of the Orient that caused the ruin of the plan-
tations of Arabian coffee in Java, Ceylon, the Philippines, and other parts
of the Oriental tropics. The latter is also a leaf spot disease and is caused
by a fungus known to science as 11milcia 'axtarix, but the spots are so
entirely different that the two are easily distinguished by general external
appearance. It was possible, therefore, to assure the planters at once
that their trouble is not that of the Orient.
The chief leaf spot disease found in the Chiriqui Province and the one
that we are now discussing is that which has been variously known as the
"American Leaf Disease" of coffee, "Viruela" (small-pox),"Leaf-Spot,"
"Mancha de Hierro" (iron stain), etc.
The disease is characterized by spots one-quarter inch to one-half
inch in diameter on the leaves, at first dark in color but later turning
gray or almost white, and showing equally on both surfaces of the leaf.
This diseased tissue frequently falls out as the spots become older, leav-
ing perforations in the leaf. Many of these spots may occur on a single
leaf. Partial or complete defoliation follows if the disease is not con-
trolled. Similar spots but inclining to be elongated in shape, appear
upon the cherries (coffee fruits) and upon the twigs. These young shoots
may be killed and the coffee beans within affected berries are likely to
The tree, seriously affected, thus presents a generally distressed ap-
pearance although it may retain its crop of fruit more or less diseased.
Without leaves the tree cannot make new growth and hence is not pre-
pared to produce the next crop of cherries, as fruit of the coffee tree is
yielded chiefly on the growth of the preceding season. Also, without
leaves there can be no root growth and without new rootlets little food
can be taken up. Thus the vicious circle continues. A typical tree
thus defoliated is shown on Plate III, Figure 2.
The organism which causes this disease is a fungus. Its decription will
be found in the literature of the subject under various names that have
been given it during the progress of the study that has been made of it.
The students of the subject will look for it under the names Stilbumflavi-
dum, Stilbella flavida, Sphaerostilbeflavida, and Omphaliaflavida. Which
of these determinations is best founded from a purely mycological point
of view will not concern the planters but with a knowledge of the several
names it will not be difficult for planters to avoid confusing this disease
with others in reading of its history and treatment in other countries.
This fungus is propagated by vegetative parts which appear as small
round heads on yellowish thread-like supports resembling very small
pins. They arise in wet weather out of the brown spots on leaves,
branches, or berries. The rounded heads drop off and are carried by
wind, water, gravity, on the clothing of laborers, or otherwise until they
find a lodging place. If this happens to be upon the vulnerable parts of
a coffee tree or upon some other favorable host plant, it begins to grow
and soon produces another spot which in turn becomes a new source of
infection. Under dry atmospheric conditions the disease makes no
!j1wI1 H1 2. ( I ,' t, (' d i( t t cd by tile 1 'a Sp t( diseaisc
I I,, I I I ( : , , I , I i d i I t Itybrid
progress but with the arrival of wet weather or dense fog it immediately
springs into activity.
From the standpoint of control of the disease, it is most unfortunate
that there are many host plants upon which it thrives and these include
wild plants of the forest and several kinds of weeds which spring up every-
where among the coffee. McClelland lists under their local Puerto
Rican names at least 24 different species of host plants, commonly found
in coffee fincas in Puerto Rico, and although coffee appeared to be the
preferred host there were several almost as susceptible. The guava,
Inga vera, used as a shade tree for coffee, was found to have numerous
spots but in only one instance was a fruiting body found and hence it was
concluded that the danger of infection from this source is very slight.
This tree must not be confused with the fruit-yielding species, Psidium
guajava, which is commonly known as guava where English is spoken.
Another species of Inga (Inga laurina), commonly known in Puerto Rico
as guama, and much used as coffee shade, was reported as entirely free
from infection. Some of the Ingas seen in the Volcan had spots on the
leaves but, it being dry season and there being no propagation of the
fungus in evidence anywhere, it was impossible to determine whether
these trees are in any way responsible for the spread of the disease.
Unfortunately there are many weeds upon which the disease does multi-
ply and which are important factors in its spread. This fact must be
taken into consideration in any discussion of methods of control. No
accurate list of such plants could be prepared during the dry season but
many of them are known to the planters.
"Coffee Leaf Spot" or "Viruela" is not a new malady of this crop in
Panama, having been known here for many years and has taken its toll
from many plantations periodically with varying seasons and destroyed
others completely as profitable fincas. Its greatest devastations are in
seasons of continuous and prolonged rainfall as in 1933-34, when the
rains continued for more than a month later than usual. Little scientific
study of the disease has been made in this country and I find no record
of any exact experiments in methods of control, but some of the growers
have applied control measures more or less successfully while others feel
helpless to stem the tide of its progress. As the disease is wide-spread
in the American tropics, Panama may benefit from the experiences of
other coffee-growing countries in which this disease has received consider-
able attention. In discussing control measures, reference will be made
to some of the experimental and demonstration work done in these
countries. The disease is reported in the Central American States, in
Mexico, Colombia, Venezuela, Dutch Guiana, Brazil, Puerto Rico,
Dominica, Trinidad, Jamaica, and, doubtless, others of the Antilles.
When confronted with any serious fungus disease of plants, the cultiva-
tor naturally thinks first of fungicides of which bordeaux mixture, bur-
gundy mixture, and forms of sulphur are the standards. As remedies for
leaf spot or viruela on coffee in Panama, they must be considered of very
limited applicability, although they may serve a special part in a control
campaign. The limitations of fungicides are due to several practical
considerations. First, in wet season, the rains are so frequent and so
heavy that it is usually difficult to get the fungicides on the trees and
dried before the next shower washes them off, even though there are now
quite effective stickers that will keep the protective covering on the leaf
a long time if well dried. Each day new growth is made and these new
leaves require protection which increases the difficulty. The use of
fungicides in dry season, except just at its close, in preparation for the
rainy weather is of no value whatsoever, as the disease is dormant at
that time, and no application can penetrate to destroy it where it lies
within the tissues of the plant. Then the practical difficulties and ex-
pense of spraying large plantings, frequently located on steep and
rough hillsides, including the transportation of water and machinery, are
so great as to render spraying impracticable except in very limited areas.
The most important control measures must consist in avoiding infec-
tion and in establishing conditions unfavorable for the spread of the
disease. These sources of infection may be diseased coffee trees in the
plantation or in an adjoining one over which the grower may have no
control; or they may be in one or many of the different species of weeds
that cover the ground if uncontrolled; or the requisite shade trees, if not
well-chosen, may breed the fungus and shower the propagating parts
everywhere; and finally the wild growth of surrounding fields or forests
may multiply the offending organism.
I observed one very good finca into which the disease seemed to be
advancing from a badly infested and neglected adjoining plantation. In
such situations the planter may do much to protect his plants by cutting
down a few rows and replacing them with a thick stand of some rapidly
growing plant which will form a barrier immune to viruela. Bananas
have been reported as effective for this purpose but the planter must
make sure that his variety is immune and in making the selection must
not be deceived by the presence of such brown or gray spots on the'leaves
as do not produce the propagating parts of this disease. I have nowhere
found any record of bananas serving as a host but it would not be safe
to state that all varieties are immune. If the disease appears on the
coffee inside the barricade, steps must be taken to eradicate it but this
control of the disease within the plantation must be discussed later.
It is often observed that the disease enters the plantation from an ad-
joining forest. Obviously it would be impracticable to eradicate all the
possible host plants from the forest. If any special offenders are found
in the nearby forest, and particularly high trees from which infection
would be carried by winds, such trees should be cut down, but the entire
clearing of the forest is not indicated.
Sometimes special locations are found where the disease enters from
the forest and in such localities the banana or other barricade might be
effectively and economically used if the offending host plants are low.
If not too far from market the banana fruit has a sale value and in any
case is valuable as food and as feed for livestock. In these locations
close to the edge of the forest, the coffee trees are especially vulnerable
because of the dense shade cast by the forest trees. Shade and the con-
sequent atmospheric humidity are especially favorable to the disease
When the disease has already entered at the edge or, as sometimes
occurs, on isolated trees well inside the plantation where it may have been
carried by wind, water, birds, men, or other agencies, what methods must
be adopted to arrest its spread? First, it must be remembered that
shade favors the disease and excessive shade should be removed but the
coffee trees themselves require some shade and to go beyond the limit
of the demands of the coffee, in the removal of shade, would involve fur-
ther trouble. But more active measures than the adjusting of shade
must be adopted. The sources of infection within the plantation must
be removed. All weeds that act as hosts must be kept down and insofar
as possible must be destroyed at least in and about the infected area.
Under present conditions this implies the cutting of all weeds and grass
rather close to the ground. Some planters shave the ground with a hoe
or a very sharp, especially devised shovel so as to remove every vestige
of living vegetation above the surface, except the coffee trees. This
cannot be recommended for general practice and is seldom advisable.
It exposes the soil to the excessive heat of the sun during dry season and
to the serious effect of erosion during wet weather. Fortunately it is
very difficult to maintain such a practice during continuous and prolongd
rainy weather when weeds spring up persistently. The practice, unless
maintained by a ver great amount of labor, tends to establish a grass
cover for the soil which is undesirable.
On the one hand, the planter is beset with the dangers of disease-breed-
ing weeds and on the other with serious soil erosion and the risk of the
carrying of the disease on the clothing of laborers engaged in the cutting
the weeds. It would appear that, ultimately, the wyi out of these diffi-
culties must lie in the selection of some low-growing immune species of
plants, preferably legumes which can be used as cover crops during wet
season and as a dry mulch during dry season in infested areas. It is
impossible to predict in advance which of the many legumes might prove
to be immune to the disease and otherwise adapted to the location and
the need. Experiments should be begun at once with all promising
varieties of which seed may be obtainable. In selecting cover-crop seed
for this purpose, climbing legumes should be avoided and those of low-
growing habit should be tested. Those that are too quick in maturing
will not be best as it is desirable to find one whose period of growth will
extend through the wet season. It is also essential that the legume shall
be vigorous in growth and able to contend with the weeds. No attempt
can be made here to list all the legumes that should be tested out for
this purpose. Among them may be mentioned Pueraria phaseoloides,
Indigofera endecaphylla, Dolichos hosei, Centrosema pubescens, Jack Bean
(Canavalia ensiformis), the Crotolaria in several species, the Yam Bean
(Pachyrhizus angulatus), Dolichos uniflorus, Melilotus alba, Tephrosia
species, Calapogonium mucunoides, Lespedeza striata, L. sericea, L. stipu-
THE COFFEE TREES THEMSELVES AS A SOURCE OF INFECTION
Thus far we have been discussing the avoidance of infection from host
plants other than coffee. But the coffee trees themselves are preferred
hosts. The methods that may be followed to rid the plantation of cen-
ters of infection in the coffee trees themselves, depend in part upon the
extent of the infestation.
In plantations that have been extensively devastated by the disease
so that the most of the trees in certain areas have become affected, dras-
tic measures are necessary. In Trinidad, Briton-Jones has reported a
successful experiment in the restoration of a plot which had been heavily
infested with the disease. It was severely pruned so as to remove such
tender growth as would be most susceptible to the disease and all leaves
were removed. The leaves and prunings were allowed to remain where
they dropped as it was claimed that earlier experiments had shown that
the burning or even the gathering in heaps of all this material was un-
necessary, because the disease did not seem to propagate itself on this
decaying material. This severe pruning and defoliation was accom-
panied by clean culture to rid the place of weeds and was followed by
fertilization to stimulate new growth. The treatment resulted in the loss
of about one year's crop but on badly infested trees the crop is almost
negligible without any treatment.
This defoliating and heavy pruning involves very much work and
many planters will think it best to follow the Puerto Rican method de-
scribed by McClelland and adopted on many fincas on that island. This
consists of cutting back all trees in badly infested spots to a stump about
six inches high. The cut should be clean with no ragged edges and should
be diagonal in direction so as to shed water and to heal. The trees are
chopped into pieces and allowed to lie on the ground and rot. It is im-
portant to leave not a single tree in the treated areaassuch would quickly
infect the new growth. This stumping is preceded and followed by
clean culture and a close watch is kept for local reinfection in order to
remove any disease as soon as it appears. It is admitted, the trees can
produce no coffee worth picking until the third year after treatment is
begun and not a full crop until the fourth year, but it is claimed that
the method, where faithfully followed, has resulted in the rehabilitation
of the plantation which otherwise would soon have become worthless.
It will always be necessary for coffee planters in Chiriqui to maintain
a constant watchfulness against the inroads of this disease. Whenever
it is found it must be promptly treated and where the disease is well es-
tablished one or other of the methods described above should be applied.
But even after the plantation has been cleaned there will be new infec-
tions from time to time. When a few diseased leaves have been dis-
covered on a tree these should be removed at once and if a tree appears
with extensive infestation, either very severe pruning with complete de-
foliation or cutting to a six-inch stump will probably prove to be the
safest and the most economical method of treatment. I do not consider
it necessary or economical to cut down an entire tree for no other reason
than that a diseased leaf has been found upon it. The disease is not
bacterial and does not travel within the tree from the leaf to other parts.
If this were the case, then the removal of the entire tree would be indi-
cated, but the facts are quite otherwise. It is quite true that where the
disease has been found it may appear again as a result of the same in-
fluence that caused the first appearance, but it is as likely to appear upon
the immediately surrounding trees. The same agency which brought it
to the one tree is quite likely to have brought it to others in the immediate
vicinity where it may appear soon after. The tree, when it has been
found and those surrounding it, should be marked in some way So that
they can easily be found and should be especially examined periodically
until the planter is satisfied that he has exterminated the disease in that
locality. It is quite possible that here bordeaux mixture might be made
to serve a useful part in the control of viruela. A goIod coating of a
tightly adhesive fungicide upon the tree which leaf spot has been found
and upon others in the immediate vicinity, would give all the covered
parts protection from attack.
Although much has been written about bordeaux mixture, not all
planters know how to prepare it and it will therefore not be out of place
to repeat some of the formulae, state simple essentials in its preparation,
and call attention to adhesives which are more important on coffee foliage
than on the leaves of many other trees.
A standard formula for bordeaux mixture is expressed as 4-4-50,
which signifies 4 pounds of copper sulphate, 4 pounds of quicklime, and
50 gallons of water. It is important that these ingredients be properly
mixed. The copper sulphate is placed in a sack and suspended in a
wooden tub containing about '25 gallons of water. It is usual to leave
this over-night, as in cold water several hours may be required to dissolve
the chemical. The 4 pounds of quicklime are slaked in another tub by
slowly adding water and after the slaking is completed more water is
added to make a total of 25 gallons. These two stock solutions are then
poured, simultaneously in a uniting stream, through a strainer into a
5o-gallon barrel or spray-tank where they are thoroughly mixed and are
then ready for use. It is important to thus strain the mixture to avoid
the frequent clogging of the spray nozzle. It should be applied at once
as the mixture quickly breaks down. Stock solutions of the lime and
of the bluestone may be kept almost indefinitely in closed containers
which prevent evaporation of the water. When necessary, the mixture
may be preserved by adding a heaping tablespoonful of sugar, dissolved
in a little water, to every ioo gallons of mixture. It is often difficult,
expecially in this country of humid atmosphere, to get quicklime or to
hold it because it rapidly acquires the moisture from the air and becomes
hydrated lime. This hydrated lime can be used but the amount must
be increased by using 6 pounds of the hydrated lime for every 4 pounds of
In this country of torrential rains, the adhesiveness of a spray mixture
is most important and a so-called "sticker" is generally used under such
conditions. One of these is resin soap prepared by boiling 4 pounds of
finely broken resin with 2 pounds of washing soda in 2 gallons of water
until the mixture is clear. This is sufficient for one 5o-gallon tankful of
bordeaux mixture and should be added to the mixture and thoroughly
agitated. It should not be added to either of the ingredients separately.
Glue is also used as a sticker in the proportion of one-half ounce to 50
gallons of spraying material.
For spraying on an extensive scale, a concentrated stock solution con-
taining I pound of copper sulphate in each gallon of water is prepared
and another stock of the lime solution containing I pound to each gallon.
These are diluted as needed and the diluted solutions are mixed to prepare
bordeaux mixture. For large operations special equipment is set up.
Every coffee grower should have a good bulletin on bordeaux mixture
and these can be obtained for a few cents on application to the Superin-
tendent of Documents, Washington, D. C.
GENERAL SOIL MANAGEMENT AND FERTILIZATION
Some program of soil management for the maintenance of fertility is
important throughout these coffee districts. Such a program, if well-
planned and carried out, would also aid the trees in overcoming the
effects of disease. One of the most important matters is the maintenance
of a supply of decaying organic matter. In some of the older fincas this
appears to have become much reduced and low-growing grasses have
become established. Even in some of the newer plantations, the error
of burning over the land before planting has been made, thus consuming
much of the humus. In the newer plantings, there is a natural growth
of vigorous weeds and if these are not breeding the leaf spot disease,
they can be made to serve a useful purpose in maintaining the humus
supply if they are cut and allowed to cover the ground. I believe it to
be a better practice to leave this vegetation where it falls than to gather
it all up and place it in the rondas or circles about the trees, not because
it does any injury in the rondas if kept from immediate contact with the
trees but it is needed, especially in dry season, to cover all the ground
surface and at all times to build up the humus supply. The value of an
immune leguminous plant in the places infested with viruela has already
been emphasized. If a suitable legume, adapted to the location and need
can be found and established throughout the plantations, such would be
a tremendous achievement in coffee growing in Chiriqui. The ideal
would be a permanent legume which could be allowed to grow through
the wet season, and be cut back as needed and especially at the begin-
ing of the dry season, thus furnishing a ground cover. Some of the leg-
umes tend to reseed themselves. But even a legume that would require
plantingat thecloseof each dryseason wouldprobably well pay for thecost,
not only in humus supply but in the direct increase in nitrogen brought
about by their root nodules. Also if the legume is not too high in habit
of growth but dense enough to hold down the weeds, it would reduce the
cost of labor in cleaning which many careful planters do from three to
five times per year. As emphasized above, it is impossible to predict
which of the many legumes would best fit into such a program and the
most adaptable could be determined only by experiment with a large
number of kinds.
The judicious application of chemical fertilizers, as supplementary to
other good management, would doubtless give beneficial results on many
of the fincas and would probably prove very profitable on some. But
here again only careful experiments in the plantations can determine
just what combinations of fertilizing elements can be most economically
used to supply the need. There is a popular belief prevalent in Chiriqui,
as elsewhere, that all that is necessary to determine the right fertilizer
formula is a chemical analysis of a few samples of the soil. Nothing
could be farther from the facts. In corroboration of this statement I
quote from Lyon and Buckman of Cornell University as follows:
"The conclusion that chemical analyses are of but little direct practical
value as a guide to soil productivity is unavoidable. In spite of the
great importance of chemistry in research and teaching it fails to indi-
cate either the permanent or the immediate fertility of the land."
This is typical of what might be quoted from many authors. These
and similar statements are in no sense intended to detract from the well-
recognized position of chemistry as a basal soil science or its value to
soil scientists but analyses of samples, especially those collected by men
untrained in this work, cannot be regarded as more than suggestive of
possible fertilizer needs and are likely to be misleading.
Therefore, the only means of determining formulas for fertilizers that
may prove profitable in coffee growing in Chiriqui are by carefully con-
ducted fertilizer tests in the plantations. However, in the absence of
such experimental data and of any plans for conducting such experiments,
the planters themselves by trial on a small scale can at least determine
something of the results to be expected by the use of different fertilizers.
Small quantities of ready-mixed fertilizers can be tested but some of the
principal fertilizing ingredients should be tried alone.
For example a dressing of I oo to 200 pounds per acre of nitrate of soda
or of 75 to i5o pounds of sulphate of ammonia applied at the beginning
of the rainy season would indicate whether there may be a decided in-
sufficiency of available nitrogen. An application of 200 to 400 pounds
of dissolved phoshpate rock or of dissolved bone-black might indicate
improvement by the use of phosphoric acid. The use of ioo to 20o
pounds of sulphate of potash per acre might show a response due to the
supply of potash. However, these responses are not always immediate
and sometimes are difficult to evaluate. Also planters can secure ready-
mixed fertilizers of different formulas and by trial get some suggestions
at least as to their relative usefulness. But carefully planned experiments
in fertilization, scientifically carried on for a period of years, are the only
means of determining the most economical fertilizer formulas for the
coffee crops on a given soil. An application of 150 to 2o0 pounds of
nitrate of soda is likely to be especially beneficial in the rehabilitation
of the parts of plantations which have been injured by viruela.
The Gardens have never undertaken much work with vegetables but
the new arrangement for apprenticeships has made possible and desirable
a limited amount of work in the culture of vegetables. There is some
demand for information as to the varieties of vegetables that will suc-
ceed under conditions existing in and near the Canal Zone. Mr. Walter
R. Lindsay, Supervisor of Cultures has conducted a considerable number
of tests with the student labor group. His report of such work follows:
REPORT OF VEGETABLE TESTS
By WALTER R. LINDSAY, Supervisor of Cultures
Part of the instruction work given the student laborers during the past
year consisted of the maintenance of an experimental vegetable plot.
The seed was offered and supplied by commercial seed houses in the
United States with request that they be supplied with reports of tests.
The following were the seeds tried:
13 varieties of Bush Beans
2 varieties of Dwarf Bush Lima Beans
7 varieties of Pole Beans
4 varieties of Cantaloupes
2 varieties of Egg Plant
4 varieties of Peppers
i variety of Spinach
2 varieties of Squash
15 varieties of Tomatoes
The students were very enthusiastic about their work and not only
learned modern methods of gardening but also accumulated valuable
data concerning the varieties of vegetables under test. Brief mention
may be made regarding the results obtained.
Very little difference was noted in the yield between the different
varieties of bush beans tried. "Full Measure" and Landreth's "xtra
Early Stringless," however, were slightly more resistant to mildew and
damping off in the young stages than the other varieties and were slightly
A marked difference was noted in the fruiting habits of the two
varieties of dwarf bush lima beans. Henderson's "Dwarf Bush Lima"
produced an abundance of delicious beans while the variety "Fordhook,"
planted beside them, failed to produce a single fruit. Both varieties
received the same amount of fertilizer and care but the former variety
had the ability for setting fruit under wet humid conditions while the lat-
ter variety did not. Possibly reverse results might be had if these
varieties were grown during the dry season.
"Nancy Davis" variety of pole bean has repeatedly shown its superiority
as a green bean in this region and is about the only variety grown in
the local Chinese gardens. It is resistant to most common bean dis-
eases of Panama and produces an abundance of excellent, long, tender
green beans which are practically fiberless.
In wax beans "McCaslan," Landreth's "Tennessee Wonder," and
"Golden Cluster Wax" all did fairly well but were more subject to diseases
and produced less uniform fruits than the green pod variety "Nancy
Davis." It may be noted that one authority stated that he had never
tasted a more delicious bean in this country than the "Golden Cluster
Wax." This variety far surpassed the other varieties of wax beans in
both yield and hardiness.
No success was achieved in the growing of any variety of cantaloupe
during the rainy season although excellent crops were produced during
the dry season. Seeds should be sown during the latter part of Decem-
ber or early January thus allowing the plants plenty of time to mature
their fruits before the May rains commence. "Hearts of Gold," "Rocky
Ford," and "Hale's Best" have all given satisfactory results here in dry
Practically the same things may be said about raising summer squash
as was said about cantaloupes. The varieties "Patty Pan" and "Golden
Summer Crook Neck" produced a few fruits when planted during the
Excellent results were obtained from the varieties of lettuce, "New York
Green" and "White Big Boston." The latter however, was not as good as
the New York Green variety because it started to flower too early.
Salamander and Black Seeded Simpson both started flowering before
they were large enough to harvest. None of these varieties showed any
sign of heading.
The results obtained from tomato experiments this year were better
than in any former years. Several varieties matured excellent fruits but
no one variety was entirely free from wilt (probably some form of Fus-
arium wilt). Some of the varieties which have been reported as most
wilt-resistant in the United States proved to be most susceptible to the
disease in this region. The only variety found to be highly wilt-resistant
here is the native tomato which produces small and very irregular fruits.
"No Substitute," "Landreth," "Norton Certified," "Improved John
Baer," and "Walter Richards Extra Globe," were the five varieties least
attacked by wilt this year.
An excellent substitute for spinach may be found in the plant Tetra-
gonia expansa, commonly called New Zealand spinach. It was intro-
duced into the United States from New Zealand in 1932. Two years'
trial here with this variety has proved very satisfactory and we feel
that eventually this variety will replace the so-called Chinese or "slipper-
spinach" (Bassella alba) grown by the Chinese gardeners.
The egg plant and peppers are growing nicely at the date of this writing
but have not yet matured their fruits.
Sweet corn is usually not succesful in the tropics. None of its varie-
ties have succeeded here. This year we received a small sample of seed
of the variety "Mayaguez Sweet Corn" from the Puerto Rico Experiment
Station of the United States Department of Agriculture, located at Naya-
guez, Puerto Rico. This seed represents their latest achievement in
hybridizing to create a sweet corn suitable for tropical conditions. It
is too early to state how this variety will yield here but so far excellent
growth has been attained and one to two ears are appearing on each
MR 60229-Panama Canal 10-15-38 -1,500
UNIVERSITY OF FLORID
3 1362 0979 7142