From: Brian Lo <dragon@csulb.edu>
Newsgroups: rec.gardens
Subject: Faq: Eggplant
Date: Wed, 1 Mar 1995 09:12:59 -0800
EGGPLANT
Solanum melongena
VARIETIES (approximatelyh 65-85 days from transplanting in the Willamette
Valley).
Purple and white varieties are available. Shapes range from oval to
elongated. Only the purple, medium to large oval types are of consequence in
the market. There is an increasing demand for the purple elongated types for
specialty Oriental markets.
Purple types:
Oval: Epic (10"x4"), Dusky (12"x4"), Avon (12"x4"), Black Bumper,
Tycoon, Beauty, Early Royal Hybrid, Classic.
Elongated: Vittoria (tapered, 13"x3", uniform), Vernal (12"x2 1/2"),
Little Fingers (to 12"x1 1/2"), Orient Express (very early, blotchy purple
10"x4" curved), Valentina, Ichiban, Black Shine.
Round, or nearly so: Toska (8"x6"), PS- 8280 (1 1/2" round marble)
Novelty:
White types: Easter Egg Hybrid, Ghost Buster (6x7 inch oval), Casper
(elongated to 6").
Light purple with white stripes: Bride, Pingtung Long (twisted 12"x1
1/2" with white streaks).
Purple with green stripes: Minden Early.
Purple with green and white stripes: Farmers Long.
SEED COMPANIES
Abbott & Cobb Inc. POB F307, Feasterville, PA 19047
Asgrow Seed Company, POB 5038, Salinas CA 93915
American Takii Inc., 301 Natividad Rd. Salinas, CA 93906
Ferry-Morse Seed Co. POB 4938, 555 Codoni Ave. Modesto, CA 95352
Harris Moran Seed Co. 3670 Buffalo Rd. Rochester, NY 14624
Johnny's Selected Seeds, Foss Hill Rd. Albion, ME 04910
Known-You Seed Co. Ltd. 26 Chung Cheng 2nd Road, Kaohsiung, Taiwan ROC
La Marche Seeds International, POB 190, Dixon, CA 95620
Northrup King Co. Vegetable Seed Group, POB 1827, Gilroy, CA 95021
Petoseed Co. Inc. POB 4206, Saticoy, CA 93303
Stokes Seeds Inc. POB 548, Buffalo, NY 14240
W. Osborne Seed Co. Int'l. 1679 Highway 99 South, Mount Vernon, WA 98273
Zenner Bros. Seed Co., Inc. 1311 S.E. Gideon St. Portland, OR 97202
SOIL
Choose well-drained, moderately fertile, sandy loam soils. Use soil
tests for liming and fertilization applications. Fertility requirements are
similar to those of tomato and pepper.
SEED AND SEED TREATMENT
Eggplant seed numbers approximately 104,000 per pound. Use treated
seed. Plant only after soils reach 60 F, optimum germination 75-90 F.
Advances is seed priming and coating can improve germination under cool soil
conditions. Consult your seed dealer about the availability of primed seed.
TRANSPLANT PRODUCTION AND TRANSPLANTING
Eggplant requires a long growing season, so transplants are most
commonly used. They are usually started in the greenhouse or hotbeds. Sow
seeds in shallow flats of soil mix 9 to 10 weeks before transplanting to the
field. Constant temperatures must be maintained as young plants are easily
checked by cool temperatures or droughts. Transplants grown in the greenhouse
should be kept at the following temperatures for best results:
Days: 70 to 81 F; nights: 64 to 70 F.
Use transplants grown in jiffy pots or similar containers so as to
minimize shock of field transplanting.
Use starter solution made up of 3 lbs. of 10-34-0 in 50 gallons of water
and apply l/2 pint of this solution around the roots of each transplant at
time of planting.
SPACING
Rows 3 to 4 feet apart, plants in the row 1.5 to 2 feet apart.
FERTILIZER
A soil test is the most accurate guide to fertilizer requirements. The
following recommendations are general guidelines. Adjust pH to 6.0-6.8.
Nitrogen: 75-120 (N) lb./acre
Phosphate: 100-150 (P205) lb./acre
Potash: 50-150 (K20) lb./acre
Sulfur: 20-30 (S) lb./acre
Side-dress with 30-50 lb./acre of nitrogen after the first flowers are
set. In wet years apply an extra side dressing. Where mulching and trickle
irrigation are practiced, additional nitrogen can be fed through the trickle
irrigation system at 15 lb./acre when the first fruit begins to set and an
additional 15 lb./acre four weeks later. To prevent clogging or plugging from
occurring, use soluble forms of nitrogen (Urea or Ammonium nitrate) and
chlorinate the system once a month with a 10 to 50 ppm chlorine solution.
Chlorinate more frequently if the flow rate decreases.
IRRIGATION
Maintain uniform growth. Eggplant may require 14-16 inches of water in
western Oregon, depending on seasonal variation and variety. Approximate
summer irrigation needs for the Hermiston area have been found to be: 3.5
inches in May, 5.0 in June, 7.5 in July, and 7.0 in August.
Soil type does not affect the amount of total water needed, but does
dictate frequency of water application. Lighter soils need more frequent
water applications, but less water applied per application.
GROUND MULCHES AND ROW COVERS
Black plastic ground mulches increase soil temperature, control weeds,
and conserve moisture increasing yield and earliness. Black plastic ground
mulch is recommended for Western Oregon in particular. A new generation of
plastic mulch films allows for good weed control together with soil warming
that is intermediate between black plastic and clear film. These films are
called IRT (infra-red transmitting) films. They are more expensive than black
or clear films, but appear to be cost-effective where soil warming is impor-
tant.
Spun bonded polyester and polypropylene, and perforated polyethylene row
covers may be used for 4 to 8 weeks immediately after transplanting. Covers
should be removed when plants begin to flower to allow proper pollination.
Row covers increase heat unit accumulation by 2 to 3 times over ambient. Two
to four degrees of frost protection may also be obtained at night. Soil
temperatures and root growth are also increased under row covers as are early
yields, and in some cases total yields.
POLLINATION
Although eggplants have perfect flowers, and self-pollination would not
be expected to be a problem, bees are required for good pollination. Usually,
wild bees are adequate, but if they are not present, bees should be provided.
HARVESTING AND HANDLING
Approximate average yields of eggplants are 190 cwt./acre with good
yields about 250 cwt./acre.
Harvest eggplant fruit when they have developed full bright color for
the variety, but while they are still firm to touch. At this stage, the seeds
will be young, white, and tender and the flesh firm and white. As the fruit
passes the prime stage for eating and becomes over-mature, the fruit surface
becomes dull, the seeds harden and darken, and the flesh becomes spongy.
Prompt picking increases fruit set and yields.
STORAGE (quoted from USDA Ag. Handbook #66):
Eggplants should be stored between 45 and 55 F with a recommended humi-
dity of 90-95%. Eggplant fruit are chilling sensitive at 50 F and below and
deteriorate rapidly at warm temperatures, so they are not adapted to long
storage. Pitting, surface bronzing, and browning of seeds and pulp are sym-
ptoms of chilling injury, and loss of sheen and wilting are symptoms of normal
deterioration. Sensitivity of eggplants to chilling differs with cultivar,
maturity, size of fruit, and season of harvest. Fruit harvested at optimum
maturity or in midsummer are more sensitive than those harvested at an
over-mature stage or in the fall, when the growing temperature is cool. Thus,
eggplants harvested in midsummer can be held about a week at 55 F, whereas
those harvested in fall can be held about 10 days at 48 F. Exposure to
ethylene for 2 or more days hastens deterioration.
Wrapping eggplants with shrink film reduces weight loss and maintains
firmness, due to the high relative humidity. However, wrapped eggplants decay
rapidly if the film is not perforated. Shrink-film wrapped eggplants are
susceptible to decay caused by Botrytis cinerea and Phomopsis vexans, whereas
chilled eggplants are susceptible to decay by Alternaria when removed from
chilling temperature.
PACKAGING
Eggplants are commonly packaged in: 33 lb., 1-1/9 bushel containers or
wirebound crates; or cartons packed 18s and 24s, weighing 20-23 lbs.
PEST CONTROL FOR EGGPLANT
THE PESTICIDES LISTED BELOW, TAKEN FROM THE PACIFIC NORTHWEST PEST
CONTROL HANDBOOKS, ARE FOR INFORMATION ONLY, AND ARE REVISED ONLY ANNUALLY.
BECAUSE OF CONSTANTLY CHANGING LABELS, LAWS, AND REGULATIONS, OREGON STATE
UNIVERSITY CAN ASSUME NO LIABILITY FOR THE CONSEQUENCES OF USE OF CHEMICALS
SUGGESTED HERE. IN ALL CASES, READ AND FOLLOW THE DIRECTIONS AND PRECAUTION-
ARY STATEMENTS ON THE SPECIFIC PESTICIDE PRODUCT LABEL.
USE PESTICIDES SAFELY!
Wear protective clothing and safety devices as recommended on the label.
Bathe or shower after each use.
Read the pesticide label--even if you've used the pesticide before. Follow
closely the instructions on the label (and any other directions you have).
Be cautious when you apply pesticides. Know your legal responsibility as a
pesticide applicator. You may be liable for injury or damage resulting from
pesticide use.
WEED CONTROL
When black plastic ground mulch is not used, cultivate as often as
necessary when weeds are small. Proper cultivation, field selection and
rotations can reduce or eliminate the need for chemical weed control.
ACTIVATED CHARCOAL SEED PROTECTION
Several Pacific Northwest grass seed crops are protected from herbicide injury
with the use of activated charcoal which adsorbs and detoxifies or inactivates
the herbicide. In vegetables, activated charcoal can be mixed with horticul-
tural grade vermiculite and applied as an anticrustant/seed protectant. The
activated charcoal vermiculite mix is placed within the seed furrow using a
positive feed device. Herbicides must not leach excessively or move readily
from crop roots into the plant. Although crop safety can be enhanced, weeds
emerging from within the treated area also are protected.
Another use for activated charcoal involves seed protection from herbicides
that leach into the seed zone from excessive rainfall. Seed coatings of
activated charcoal would reduce the active concentration of herbicide at or
very near the seed during the germination process.
Activated charcoal/vermiculite mix: Thoroughly mix 1 lb activated
charcoal/ft3 of number 2 or 3 grade horticultural
vermiculite. If severe dustiness is a problem, add a
small amount of water. Apply 1 ft3 of mixture/600 ft.
of seeded row or approximately 15 cu.ft/A. Fill the
seed furrow using a positive feed applicator and press
with a press wheel.
THE WEED TREATMENTS LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST
WEED CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS
FOR CURRENTLY LEGAL REGISTRATIONS, RATES, AND COMPLETE INSTRUCTIONS.
STALE SEEDBEDS FOR VEGETABLE PRODUCTION
Stale seedbeds are sometimes used for vegetable production when other selec-
tive weed control practices are limited or unavailable. The concept depends
on controlling the first flush of emerged weeds before planting or emergence
of the crop followed by minimal soil disturbance which reduces subsequent weed
flushes during establishment of the crop. Following establishment, other weed
control practices including cultivation or use of other herbicides can be
used.
1. Prepare a seedbed, preferably 2 to 3 weeks before planting to achieve
maximum weed seed germination near the soil surface. Soil temperatures
and moisture must be reasonable or results will be erratic.
2. Plant the crop with minimum soil disturbance. Otherwise, new weed seed
will be exposed to favorable germinating conditions.
3. Just before or after planting but before crop emergence, treat the
field by flaming or with herbicide to kill all germinated or exposed
weeds.
Weed Treatment Active Ingredient Per Acre and Application Comments
---------------------------------------------------------------------------
Flaming
Use liquid propane or similar fuel-burning equipment to quickly sear the
weeds, but not consume them with flame.
------------------------------------------------------------------------
paraquat 0.625 to 0.94 lb ai/A
Gramoxone Extra
(see remarks)
Restriced-use pesticide. Do not ingest or inhale spray mist. Wearing
protective face shields, respirators, and clothing is advised. Apply
during or after planting, but before crop emergence. Add a nonionic
surfactant or crop oil concentrate according to label specifications,
taking care to avoid anionic formulations that react in the tank to form
insoluble precipitates. Exposed crop plants will be killed. Do not
apply preplant or preemergence to soils lacking clay minerals, such as
peat, muck, pure sand, or artificial planting media. (Acts as contact;
absorbs energy produced by photosynthesis forming peroxides that disrupt
living cells.)
______________________________________________________________________________
PREEMERGENCE SOIL-APPLIED
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
napropamide 1 to 2 lb ai/A
Devrinol
Apply and incorporate uniformly 1 to 2 inches deep. Use lower rates on
light, sandy, or coarse-textured soils. Following harvest, deep mold
board plowing or disk plowing must be completed before planting succeed-
ing crops. (Inhibits roots of seedlings).
------------------------------------------------------------------------
DCPA 9 lb ai/A
Dacthal
(transplants only)
Apply 4 to 6 weeks before transplanting to weed-free soil. Soil should
be moist and additional water applied for activation. Performs poorly
in western Oregon and Washington. Consult label forplanting sensitive
crops within 12 months. Results can be improved with overhead irriga-
tion applied immediately after spraying. (Inhibits mitosis).
______________________________________________________________________________
POSTEMERGENCE
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
Sethoxydim 0.29 lb ai/A
Poast
Identify susceptible grasses and apply at optimum growth stage listed on
the label. Add 2 pints/A nonphytotoxic crop oil concentrate to improve
leaf absorption. Erratic control often occurs when grasses are stunted
or stressed from drought, high temperatures, or low fertility. Resistant
grasses include annual bluegrass and all fine fescues, whereas quack-
grass can be suppressed. Do not apply within 20 days of harvest, nor
exceed 4.5 pints/A per season. (Inhibits fatty acid production, cell
membranes, and new growth.)
______________________________________________________________________________
______________________________________________________________________________
INSECT CONTROL
Proper rotations and field selection can minimize problems with insects.
THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST INSECT
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS FOR
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.
Insect and Description Control, Active Ingredient Per Acre
---------------------------------------------------------------------------
Aphids endosulfan - 0.5 lb
Different species
Metasystox-R - 0.5 lb
Yellowish-pink to pale green
plant lice. Suck plant juices. Phosdrin - 0.25 lb
Lannate - 0.225 - 0.9 lb
malathion - 0.6 lb
Vydate L - 0.5 to 1.0 lb
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Colorado potato beetle Rotenone - 0.3 lb
Leptinotarsa decemlineata
carbaryl - 0.5 to 2 lb
Adult is robust beetle with five
yellow and black stripes on endosulfan - 0.5 lb
back. Larva is reddish-orange,
humpbacked with two rows of Vydate L - 0.5 to 1.0 lb
black spots on each side.
Asana - 0.03 to 0.05 lb
permethrin - 0.1 to 0.2 lb
---------------------------------------------------------------------------
Spider mites Dibrom - 1 lb
Tetranychus spp.
malathion - 0.6 lb
Tiny spiderlike animals located
on undersides of foliage. Feed Phosdrin - 0.25 to 0.5 lb
on plant juices and cause yel-
lowing and browning of leaves. Metasystox-R - 0.5 lb
Vydate L - 0.5 to 1.0 lb
Vendex 1-2 lb
---------------------------------------------------------------------------
Western potato flea beetle Asana - 0.03 to 0.05 lb
Epitrix subcrinita
methoxychlor - 1 to 2.25 lb
Small, oval, shiny, bronze,
jumping beetle. Feed on foliage. azinphosmethyl - 0.5 lb Do
not apply after fruit set.
carbaryl - 1 lb
endosulfan - 0.5 lb
Metasystox R - 0.5 lb
permethrin - 0.1 to 0.2 lb
---------------------------------------------------------------------------
Wireworms Telone II - preplant
Limonius spp.
Telone C-17 - preplant
Brown, jointed larvae of click
beetles. Kill young plants,
weaken older ones.
______________________________________________________________________________
______________________________________________________________________________
DISEASE CONTROL
Proper rotations, field selection, sanitation, spacings, fertilizer and
irrigation practices can reduce the risk of many diseases. Fields can be
tested for presence of harmful nematodes. Using seed from reputable seed
sources reduces risk from seed born diseases.
THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST DISEASE
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS FOR
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.
EGGPLANT -- ANTHRACNOSE
Cause: Gloeosporium, a fungus found on both peppers and eggplants. This
fungus (like many other anthracnose fungi) is saprophytic during part of its
life cycle and may survive from year to year in the soil crop refuse.
Symptoms: Round sunken spots appear on both green and ripe fruits. Spores
develop on the infections often in radiating circles around the center, which
later may contain masses of pink spores. The seed may be infected and often
seedlings have the disease, which later moves into the developing foliage.
Such infections are often unnoticed until the fruits start to grow, at which
time the fruit rot phase may become serious.
~Control:
1. Dust all plant refuse by burning or deep plowing.
2. Rotate crops.
3. Spray fixed copper fungicide. See product label.
--------------------------------------------------------------------------
EGGPLANT -- CERCOSPORA LEAF SPOT
Cause: Cercospora melongenae (mostly on eggplant), Cercospora capsici (mostly
on pepper), fungi. These organisms survive the winter on dead plant parts.
Symptoms: Leaf spot infections on eggplant are small, chlorotic, gray turning
to brown, with tiny, dark specks containing spores arranged in circular
fashion. Eggplant fruits are not attacked. Leaf spot on pepper is at first
water-soaked and up to inch in diameter, later becoming tan in shade with a
dark marginal ring. Centers may often drop out as they age. Spots develop on
stems and petioles. When numerous, the leaves turn yellow and may drop or
wilt. Defoliation is often serious, exposing peppers to sunscald.
~Control:
1. Destroy by burning or deep burying old pepper and eggplant refuse.
2. Use seed from disease-free areas.
3. Rotate crops.
4. Spray fixed copper fungicide. See product label.
------------------------------------------------------------------------------
EGGPLANT -- LATE BLIGHT
See Potato and Tomato - Late Blight
------------------------------------------------------------------------------
EGGPLANT -- ROOT ROT
Cause: Phytophthora capsici, a fungus. This soil-inhabiting organism causes
root rot in pepper and eggplants and is most active in moist, warm weather.
Symptoms: At soil level, dark-greenish, water-soaked spots occur which often
girdle the stem, causing the plants to wilt and die. Foliage leaf spots
develop, which are often water-soaked and irregular in shape, later becoming a
light-brown shade. The fruit shows similar spots often enlarging to cover the
entire fruit, which later dries and becomes mummied.
~Control:
1. Plant only in clean soil where the disease has not occurred.
2. Use disease-free seed.
3. Practice light irrigation and crop rotation.
4. Ridomil 2E can be used to control this problem. A full program consists
of a preplant application followed by two postplant applications. See product
label.
---------------------------------------------------------------------------
EGGPLANT -- VERTICILLIUM WILT
Cause: Verticillium dahliae, a fungus organism. The Verticillium wilt organism
is a widespread soil inhabitant which affects a wide range of herbaceous and
woody plants.
Symptoms: Infected plants show a stunting of growth accompanied by yellowing
and inward rolling of the leaves. The disease development on eggplant begins
with a yellowing of the lower leaves, reduced size and vascular discoloration.
It is seedborne in the eggplant. The fungus gains entry through the root
system, and progress in the plant is primarily through the vascular system.
~Control:
1. Old crop remains should not be left on the field or added to the compost
pile, as this encourages future infections.
2. Crop rotation with nonsusceptible grasses and grains may be of some small
value, but nothing can really be done to eradicate this disease.
3. Avoid tomatoes and potatoes in any rotation, as these are favorite hosts.
4. There are as yet no resistant varieties.
______________________________________________________________________________
______________________________________________________________________________
---------------------------------------------------
---------------------------------------------------
This information was adapted by the Oregon State
University Extension Service from Oregon and
Pacific NW publications as well as other vegetable
production guidelines from public institutions
in the U.S. and Canada. These guidelines are
intended as a general guide for Oregon commercial
vegetable producers. Address comments or questions
to your County Extension Agent or Dr. N. S.
Mansour, Department of Horticulture, Oregon State
University, Corvallis, OR 9733l.
---------------------------------------------------