Effects of Cultivar and Planting Arrangement on Eggplant Yield in

Effects of Cultivar and Planting Arrangement on Eggplant Yield in
Missouri
Lewis W. Jett1*
Department of Horticulture, University of Missouri, Columbia, MO 65211-7140.
Introduction:
Eggplant (Solanum melongena L.) is native to India and China and is botanically related
to other solanaceous vegetables such as tomato, pepper, pepino and potato. As consumers
desire more diverse vegetables, many producers in the Midwest have noted an increase in
demand for eggplants, especially the “nontraditional” or specialty types.
Eggplant is typically established as a single row planting arrangement in the Midwest.
However, using a twin row may increase marketable yields. The objectives of this
research were to evaluate eight specialty eggplant cultivars planted in either a single or
twin row planting arrangement.
Methods:
Eight eggplant cultivars were chosen for evaluation (Table 1).
Table 1. Eggplant cultivars evaluated in Columbia, MO-2005.
Cultivar
Days to
Fruit appearance
Seed Vendor
z
maturity
Caliope
64
White/purple; oval
Johnny’s Seeds
Ghostbuster
70
White; oval
Seigers Seeds
Millionaire
60
Elongated black
Seigers Seeds
Megal
64
Slender; black
Seigers Seeds
Nadia
67
Purple/black; oval
Seigers Seeds
Orient Charm
65
Pink/white; elongated;
Johnny’s Seeds
Oriental
Rosa Bianca
73
Round, Italian heirloom
Johnny’s Seeds
Tango
60
White; cylindrical
Johnny’s Seeds
z
Days from transplanting.
1
State Vegetable Crops Specialist; Phone 573-882-7511; Email: [email protected].
* To whom correspondence should be addressed.
Eggplants were seeded in 50-cell trays filled with ProMix media and placed in a
greenhouse. The transplants were fertilized weekly with 600 ppm of nitrogen. Six weeks
after seeding, the plants were transplanted on 5 June 2005. Research was conducted at
the University of Missouri Bradford Farm located near Columbia, MO. Prior to planting
the soil was tilled and pressed into a raised bed (6” height x 26” width). White on black
plastic mulch and drip irrigation was placed over each bed using a Model 2600 mulch
layer (Rainflo Irrigation, East Earl, PA). Plants were spaced either as a single row with
18 inches between individual plants or as a staggered twin row with two rows per bed, 18
inches between rows and between individual plants. Beds were centered 48 inches apart.
Each plot was 15 feet long and contained either 10 plants (single row) or 20 plants
(double row). The experiment was replicated three times in a randomized complete block
design.
Prior to transplanting, 50% of the required seasonal nitrogen (50 lbs/acre) and all the
recommended phosphorus and potassium were top dressed as a granular fertilizer (13N13P-13K) to the raised beds. The remaining nitrogen .was injected weekly through the
irrigation system starting one week after transplanting (5 lbs N/acre/week).
The
eggplants were staked to keep the fruit off the ground and improve fruit shape. Flea
beetles and cucumber beetles were controlled with Admire insecticide (18 oz/acre)
applied immediately after transplanting. Spider mites were controlled with Capture (5.2
oz/acre) and Acramite 50WS (0.75 lb/acre). No herbicides or fungicides were applied.
Harvest commenced on July 21. The eggplants were harvested weekly for six weeks.
Fruit were harvested that had glossy, tender skin. Each fruit was cut from the plant with
clippers, weighed and examined for quality.
Figure 1. Eggplant fruit was harvested at peak quality.
Results:
Table 2. Marketable yield and number of eggplants as affected by cultivar and planting
Arrangement.-Columbia, MO 2005.
Cultivar
Row type
Marketable yield
Culls
(lb/plant)
lb/plant
Bu/acrez Fruit/plant Fruit/acre
Caliope
Single
5.0
1102a
17
124872a
0.7
a
a
Twin
2.4
1074
9
131164
0.2
Ghostbuster
Single
4.3
948ab
10
68728cd
2.0
ab
cd
Twin
2.0
882
4
61952
0.2
Megal
Single
3.8
845a
11
78892bc
1.4
a
bc
Twin
2.3
992
7
97768
0.2
ab
ab
Millionaire
Single
3.1
681
12
86636
2.5
Twin
2.3
1003ab
8
117128ab
0.2
a
cd
Nadia
Single
4.4
972
9
61468
1.4
Twin
2.7
1163a
5
73568cd
0.3
b
bc
Orient Charm Single
3.1
689
10
74536
1.9
Twin
1.6
698b
7
95832bc
0.2
a
d
Rosa Bianca Single
4.9
1075
8
60500
1.4
a
d
Twin
2.2
945
3
50336
0.2
Tango
Single
3.7
820b
12
86152bc
2.2
b
bc
Twin
1.9
838
6
93412
0.2
Significancey
Cultivars
NS
*
*
*
*
Row type
*
NS
NS
NS
*
z
A bushel of eggplants = 33lbs.
y
Significant * at P =0.05. Means with different letter superscripts are significantly
different at P ≤0.05.
Cultivar Performance:
‘Caliope’ is a purple and white streaked, Indian-type eggplant with no spines on the calyx
(fruit cap). Yield of this cultivar was very good (>1000 bushel/acre) with excellent fruit
size (5 oz/fruit). ‘Rosa Bianca’ is a round, Italian-type eggplant with excellent fruit size
(9 oz/fruit). ‘Rosa Bianca’ thrives in hot weather and does not tolerate cool weather.
‘Nadia’ is an attractive dark purple, Italian-style eggplant that tolerates cool weather.
However, ‘Nadia’ has some spines on the calyx. ‘Megal’ is a purple to black, elongated
eggplant (5oz/fruit) with good yield. ‘Megal’ has spines on the calyx. Ghostbuster’
produced excellent yield of egg-shaped, white fruit (6 oz/fruit) with an attractive, green
calyx.
‘Millionaire’ is a dark purple, elongated fruit.
Fruits averaged 4 oz/fruit.
‘Millionaire’ planted as a single row had a significantly higher amount of cull fruit
primarily due to sunscald damage. ‘Millionaire’ did not produce a large plant which
would have shaded the fruit from solar damage. ‘Tango’ is an early, white-skinned
eggplant, but did not yield as well as ‘Ghostbuster’. ‘Orient Charm’ is an elongated
Oriental-type eggplant with a fusion of pink and white streaks. ‘Orient Charm’ has a
very attractive fruit (4.5 oz/fruit), but should be staked for maximum fruit yield and
quality..
Planting Arrangement:
Twin rows doubled the area plant population. Planting the field as single rows has 7260
plants/acre while a twin row arrangement has 14520 plants/acre.
Yield per plant
decreased with increasing plant population (Table 1). The twin row did not consistently
increase yield per acre even with a larger number of plants.
Planting arrangement did not affect fruit set per plant. However, with a larger plant
population, twin rows produced more fruit per acre relative to a single row.
The
individual fruit weight was less with a higher plant population. Since single rows had less
fruit per acre and less canopy shading, the cull weight was higher. The majority of culled
fruit was late season cucumber beetle feeding damage and sun scalded fruit.
The decision to use a single or twin row for eggplants should hinge on the marketing
method. If eggplants are sold by weight (bushels), a single row of a vigorous cultivar
will produce excellent yields. However, if eggplants are being sold by the count, a larger
plant population with twin rows may be the best choice.
Acknowledgements:
The author wishes to thank Mr. James Quinn and Chris Prenger for assistance in data collection.