NORTH FLORIDA EXPERIMENT STATION
February 8, 1960
NFES MIMEO REPORT 60-6
COMPARISON OF SHADED AND UNSHADED VEGETABLES PLANTED IN THE SPRING, 1959.
by H. W. Young
In a field where cigar-wrapper tobacco had been grown, cucumbers tied to row
wires produced higher yields in shaded than in-unshaded plots. 'Other crops'whichr
gave acceptable yields'(higher where unshaded), were bush beans, pole beans, okra,
southern peas, peppers, squash and tomatoes. Eggplant produced high yields but
incomplete records prevented a comparison between shaded and unshaded. Beets were
unsatisfactory because of the Rhizoctonia disease.
It has been the practice in the Quincy area to grow pole beans in the fall
under shade cloth after cigar-wrapper tobacco has been harvested. As the posts and
shade cloth are already in place, the expense of constructing a shade is eliminated.
The purpose of this experiment was to determine some effects of this shading upon
pole beans as well as certain other vegetables.
METHODS AND MATERIALS
A cigar-wrapper tobacco field was divided into four blocks, each 48 feet by
80 feet. Two blocks were shaded and two unshaded. Each block consisted of 11 rows
52 feet in length, spaced 4 feet apart, with each different kind of vegetable
planted in a single row. A permanent overhead irrigation system was installed, and
water was applied as needed.
The soil analysis of samples taken on January 1, 1959 and January 5, 1960
are shown in Table 1. The plots were treated with Telone in February, 1959.
Fertilizer was applied as indicated in Table 1 to the plots in bands to the side of
the rows and covered by cultivation.
TABLE 1. Soil test-analyses and fertilizer applications during the period
January 1, 1959 and January 5, 1960.
Date pH P205 K20 CaO MgO
Shaded January 9, 1959 5.43 71 725 879
January 5, 1960 5.67 56 220 611
Unshaded January 9, 1959 5.35 79 833
January 5, 1960 5.66 60 342
Date Rate in Ibs. per acre Formula f ?
3-25-59 500 6-8-6
5-15-59 100 Ammonium Nitrate
7-1-59 100 Ammonium Nitrate
9-21-59 500 6-8-6
Note: Soil analyses were supplied by W. D. Woodward, Assistant Soil Chemist.
W T f f
The 1959 spring results, recorded in Table 2, included the crop, variety,
date of planting, days to first harvest, harvest period and marketable yields in
the appropriate market unit. Unless otherwise indicated, results are averages for
the two plots of each treatment and are expressed in yields per acre. In general
the yield and growth of the crops were satisfactory even though the season was
extremely wet. As a matter of record, the days required for emergence of the
various vegetables are listed in Table 3.
Contender bush beans were seeded March 27, 1959 and spaced three inches
apart in the row. The plants were thinned to an 8-inch spacing. On May 22, ten '
plants of each of four plots were pulled from ends of rows not in the record area,
and measurements were made on 20 plants of each treatment, as indicated in Table 4.
On the May 22 and June 5 harvests yield and additional information was
obtained (Table 4) on both plants and pods.
Foliage diseases and insect pests were controlled by weekly application of
dusts. However, every bean plant in the plots had stem or root lesions caused by
The Allgreen lima bean were harvested once, when 3 percent of the pods were
dry, as is the commercial practice. The yields (Table 2) were somewhat lower than
might be expected. This can be attributed in some degree to the stand of plants.
The average spacing of mature plants in the shaded plot was 9 inches and in an
unshaded plot 8 inches. Another factor that may have prevented higher production
was the incidence of Rhizoctonia root lesions.
It was difficult to harvest Florigreen pole beans frequently enough to
prevent over-maturity. The spacing of the plants in both the shaded and unshaded
plots was 8 inches. Foliage diseases were easily controlled and there was no
evidence of rust to which this variety is resistant. Pod measurements are given
in Table 5.
Soon after germination, the Detroit Dark Red beet plants began to succumb to
Rhizoctonia. Those that matured were unmarketable. It would appear that soil
treatment would be necessary to grow beets successfully under the conditions
encountered in this test.
The cucumbers of the Marketer variety were trained on strings which were
tied to the wires over the rows. It was necessary to periodically wrap the top
part of the vines around the string to allow the tendrils to fasten themselves to
Table 2. Comparison of shaded and unshaded vegetables grown at Quincy in the spring of 1959.
Seeding or Days to Marketable yields per acre
transplanting first Harvest period Yield Shaded Unshaded
Crop Variety date harvest First Late Days Unit (Ave./2 plots) (Ave./2 plots
Keystone Res. Giant
6-24 33 48-lb. bu.
# Cucumbers tied to string
" Plots of pepper divided into three sections to observe three varieties.
** Eggplant a very conservative estimate. Yield records were not taken during the peak harvests.
TABLE 3. Days for seedlings to emerge in the shaded versus unshaded project.
Seeding Emergence Days to
Crop Variety date date emergence
Beans; bush Contender 3-27 4-4 8
Beans; lima Allgreen 3-27 4-4 8
Beans, pole Florigreen 3-27 4-6 10
Beets Detroit Dark Red 4-9 4-18 9
Cucumber Marketer 3-27 4-4 8
Eggplant Black Beauty 4-9 4-22 13
Peas, southern Blackeye 5 3-27 4-7 11
Okra Enerald 3-27 4-6 10
Squash Frolific Straightneck 4-9 4-18 9
* No difference between shaded and unshaded plots.
TABLE 4. Measurements of Contender bush beans grown in shaded and unshaded plots.
AVERAGE OF INDIVIDUAL PLANT MEASUREMENTS (20 plants
Total plant weight - - - -
Length tip of thickened main root to first node -
Rhizoctonia root lesion rating. 0 (none) to
5 (most serious) - -- - -- -
Length of second internode - - -
Height of extended plant - - - -
Number of pods regardless of size -- ----
Number of pods with Rhizoctonia -- -----
Weight of pods - -- - - ----
Spread of first true leaves, apex to pex - -
YIELD IN 30-LB.
AVERAGE INDIVIDUAL POD MEASUREMENTS (200
Length inches -- -----
Width inches - - -
Thickness inches - -- -
Curve index inches - -
Weight pounds -- -----
pods per treatment)
--- -- 4.45
--- -- .36
- - .0130
Elevation on plant - - -
Filling - - - -
Shape - - - -
Color - - - -
* Pods drooped to ground,
TABLE 5. Pod measurements May 22 and May 28 on Florigreen pole beans.
Average of 200 pods of each treatment
Measurement Shaded Unshaded
Weight grams -- ----- - 9.36 10.57
Width cm. ---------1.2 1.2
Thickness sm. - - - -- 0.80 0.80
Length cm. - - - 15.2 15.0
During the early part of the flowering season, the shaded plots were
completely enclosed in the shade cloth; and as was expected, no fruit were set in
these plots until one end of the shade was raised and normal bee pollination
occurred. Although the unshaded plots produced fruit some ten days earlier, the
total yield for the season was much greater under the shade.
A factor not to be ignored was the Rhizoctonia problem (Table 6). Here it
can be seeh that a larger percentage of the fruits in the unshaded plots were
unmarketable because of Rhizoctonia lesions. Phizoctonia rarely affects fruits
that do not touch the soil surface. Most of the fruits damaged by Rhizoctonia set
early and therefore touched the soil. This test would suggest that losses by
Rhizoctonia could be eliminated by any type of training that would prevent the
fruits from touching the soil.
TABLE 6. Marketable and unmarketable cucumbers (Marketer variety) produced in
shaded and unshaded plots.
Marketable - - - - - 70.5 51.0
Rhizoctonia lesions - - - 12.5 35.0
Poorly shaped fruit - - - 17.0 14.O
So long as weekly dustings of Dithane Z-78 (Zineb) or a similar fungicide
was used, disease control was not a problem. However, when weekly dustings were
discontinued late in the season, downy mildew immediately became serious. Insects
were easily controlled with applications of parathion every 7 to 14 days, depending
upon weather conditions.
The Black Beauty eggplant seeded April 9 began producing on
produced a large quantity of high quality fruit until October 19.
insects were easily controlled, and it would appear that this crop
fully produced during the warmer parts of the year.
July 15 and
may be success-
A larger yield of Emerald okra was expected. One noticeable observation was
the scarcity of branching of the plants which may have indicated a nitrogen
deficiency or perhaps a need for a different variety.
Although the plant stand was not perfect due to poor germination, the yields
of Blackeye 5 southern peas for the unshaded plots were satisfactory. Foliage and
pod disease control was not a problem.
Southern peas are usually considered a low fertility crop; however, they
seemed to perform satisfactorily on this rather fertile soil.
In this particular test, Yolo Wonder pepper seemed superior to California
Wonder and Keystone Wonder Giant when overall average yields were considered.
However, there were some indications that Keystone Wonder Giant should be further
tested, as individual plants were outstanding.
The parathion-zineb dusts used in all the plots were satisfactory for
disease and insect control.
The quality of the peppers was excellent.
Prolific Straightneck squash were spaced about two feet in the row. Plants
in the shaded plots were rather elongated, which caused them to topple.
Rhizoctonia on the fruit resulted'in a number of unmarketable fruits.
During the wettest portion of the season, a rot (Rhizopus) appeared on many of the
fruits at the blossom scar which would have resulted in considerable loss had the
fruit been'intended for shipment. Although foliage diseases were easily controlled
with Zineb, the Rhizopus disease was not fully controlled.
The Manalucie variety was selected for its high quality, disease resistance
and large size of fruits. Its known susceptibility, under some conditions, to
fruit cracking when harvested in a pink stage of maturity was of special interest
to this study. The fruits were harvested in a pink or slightly later stage of
maturity to obtain expression of fruit cracking.
Manalucie seemed quite tolerant to Rhizoctonia damage. Foliage diseases
were easily controlled as long as weekly fungicide applications were made. Small
immature tomato hornworms were in evidence in great numbers at several times during
the season but were controlled with parathion.
Table 7 compares yield of marketable fruits to those unmarketable because of
cracking. Fruits considered culls for other reasons, such as blossom end rot,
catfacing, insect damage, etc., were negligible and are not listed. There was a
small difference between the two treatments in overall yield; however, the unshaded
plots produced a larger quantity of early June fruit. It should be pointed out
that Manalucie is not considered an early variety.
TABLE 7. Yield of staked Manalucie tomatoes in shaded and unshaded plots
harvested in the pink stage of maturity. (Plants pruned to two stems).
Marketable fruit (No. 1 grade)
Average yield pounds per acre - 13,470 19,710
Average weight of fruit pounds - .425 .477
Unmarketable fruit because of cracks
Average yield pounds per acre - 14,339 12,616
Average weight of fruit pounds -- --- .482 .488
Total No. 1 and Cracked Fruit
Average yield pounds per acre - 27,809 32,326
Average weight of fruit pounds - .453 .482
Early Yield (June) Marketable Fruit
Average yield pounds per acre - 3,229 10,101
Average weight of fruit pounds - .433 .499
In the spring crop of vegetables only cucumbers trained to strings produced
increased yields in the shaded plots. It should be remembered that this report is
for only one year and is concerned only with crops planted in the spring. Summer
or fall crops may produce entirely different results.
This test indicates that spring planted bush beans, pole beans, cucumbers,
eggplants, southern peas, okra, squash, and tomatoes might be expected to perform
satisfactorily in fields previously cropped to shade-grown cigar-wrapper tobacco.
Beets, which are susceptible to root rots, may be difficult to produce unless
suitable varieties or soil treatments are found.
It is evident that more work of this type is needed to determine the
reaction of various varieties to shading in these tobacco shades. It should be
possible to select varieties that will perform even more satisfactorily under the
conditions of the experiment.