SI C(71 -L' BIG BEND HORTICULTURAL LABORATORY
Big Bend Hort. Lab. imeo Report BBL 67-6 March 31, 1967
S APR 18 1967
S8REJUVENAT ON OF A NEGLECTED PECAN ORCHARD IN NORTH FLORIDA.
by H. W. Young
Assoc. Horticulturist and Head
In North Florida many of the pecan trees were planted in the early 1900's.
These trees were reasonably productive during the period when the varieties were
resistant to scab. At the present time these trees are of considerable age and
most of the varieties are susceptible to scab and insect damage often severely
reduces yield. In addition, many of the plantings are spaced between 40 and 50
feet apart which means that soil nutrients and moisture are limiting factors in
production. Most of the trees are not being sprayed for pest control and in some
cases have been inadequately fertilized. The big question owners of pecan groves
have asked is, "should they attempt to rejuvenate these orchards by entering a
complete fertilization and spray program".
In 1963 a neglected orchard near Monticello was purchases as part of the Big
Bend Horticultural Laboratory. These trees were probably planted about 1908, had
been topworked to a number of varieties, and had reportedly produced few commer-
cial crops in recent years. The entire orchard was in centipede sod, and because
of the long steep slope of the land it was the recommendation of the Soil Conser-
vation Service that this sod be retained. The trees had been inadequately fertil-
ized and pest control had not been practiced. Although the original tree spacing
was about 45 feet apart, about 50 percent of the trees had died, or were removed.
This resulted in an irregular number of trees per acre.
A careful review of literature including many reports in the Proceedings of
the Southeastern Pecan Growers Association seemed to indicate that the orchard
could be rejuvenated. The many references reviewed will not be listed here as
L. M. Ware in the Proceedings of the 59th Annual Convention of Southeastern Pecan
Growers Association did a splendid job in reviewing and citing many of the appli-
cable references. The author's experience with an orchard at the North Florida
Experiment Station at Quincy, Florida further strengthened the idea that rejuve-
nation was possible. Very few new plantings have been made in North Florida and
it is obvious that if the pecan industry in Florida is to grow and if the State
pecan production is to be increased, both in quantity and quality, the older or-
chards must be brought into profitable production.
From the available literature it appeared that if proper varieties are planted,
insects and diseases can be controlled, if adequate fertilization is provided,
and the trees are on. land which has a depth and drainage desirable for pecans -
the critical problem is moisture. In the work reported here moisture was not
200 cc 3/24/67
Beginning in 1963, approximately 800 pounds per acre of 10-10-10 was applied
broadcast each year. Zinc was applied twice, once as a soil application and once
as a foliage spray. Except in 1965 when a fungicidal test was conducted in the
orchard, the entire orchard was sprayed approximately as suggested in Big Bend
Horticultural Laboratory Mimeo BBL 67-4.
Parathion, Guthion, Cyprex and Du-Ter were the most used materials. An ad-
joining orchard, a part of the original orchard, was not fertilized or sprayed
and acted as a check plot. Since this project was begun, production in this check
orchard has been negligible.
Visibly the trees in the controlled orchard have improved in vigor, growth
and appearance, but are still not outstanding specimens.
With all data presented it should be noted that an estimated 4000 pound crop
of nuts in 1964 were never harvested. Other orchards in the area had few nuts
that year and an influx of squirrels and birds removed the pecans from the trees
in the test orchard before they could be harvested. Some losses were caused by
these pests in 1965. Some degree of control was exercised in 1966.
Table 1 presents the total yields of pecan varieties from the orchard.
In Table 2 the average yield per tree is presented. Because of variable tree
spacing, a presentation by pounds per acre would have little significance. Yield
records of all trees are included even though some of the trees were in such poor
condition originally that no yields have thus far been obtained.
The average price per pound (Table 3) gives some tangible evidence of quality.
Data on kernel quality was taken, but will not be included here because of space
limitation. The high price of the Mahan variety indicated that these nuts moved
into the tourist trade. In 1966, Mahan nuts were retailing successfully in
Monticello at $1.00 per pound.
Because some of the trees were spaced 10 to the acre (because of previous
tree deaths) it was possible to calculate (Table 4) the yields of Mahan pecans
from trees at two spacings (10 trees and 20 trees per acre). From available data
indications are that more plants per acre, even with a lower yield per plant, may
produce higher yields. This relationship has been found in several field crops
and may be applicable to:pecans. It should be considered, however, that excessive
crowding of plants per acre would eventually result in moisture becoming the
TABLE 1. TOTAL YIELDS OF PECAN VARIETIES FROM THE BIG BEND HORTICULTURAL
Total pounds of nuts
1In 1964 it was estimated that the entire crop of approximately 4000 pounds
was lost to rodents and birds.
2An undeterminable yield was lost to rodents and birds.
TABLE 2. AVERAGE YIELD PER TREE OF PECAN VARIETIES FROM THE BIG BEND HORTI-
CULTURAL LABORATORY ORCHARD.#
Variety Pounds of Nuts per tree
1963 1965 1966
Stuart 7 6 22
Mahan 41 23 51
Moneymaker 13 31 21
Moore 31 17 45
Schley 5 7 11
Teche 6 18 40
Seedlings or unknown
varieties 16 6 32
Two varieties on tree 33 25 35
*'Some of the trees were used in a fungicide test in 1965, but all trees are
included in average. All trees included regardless of orchard spacing.
TABLE 3. AVERAGE PRICE PER POUND RECEIVED FOR PECANS OF VARIOUS VARIETIES
SOLD FROM THE EXPERIMENTAL ORCHARD.
Price in cents per pound
*In 1963 all nuts were sold as mixed and price based on average quality.
TABLE 4. YIELDS OF MAHAN PECANS FROM TREES AT TWO SPACINGS (10 TREES AND
20 TREES PER ACRE) AT MONTICELLO, FLORIDA.*
Number of Trees
Yield in Pounds of Nuts per Tree
10 93 24 87
20 20 21 82
Yield in Pounds of Nuts per Acre
10 936 245 874
20 410 432 1640
*All trees were fertilized and sprayed for insect and disease control.