ALABAMA A&M AND AUBURN UNIVERSITIES Guide to Commercial

ANR-1098 Eggplant Production

Historical Perspective Planting Eggplant (Solanum melogena Recommendations L.), although not a major veg- etable crop in Alabama, is be- Planting Dates coming an important part of in- Eggplant is a warm-season creasingly diverse commercial crop that requires 65 to 85 days to vegetable operations. Many niche reach market maturity from trans- markets exist in Alabama for egg- planting. Following pollination, 25 plant, and an increasing number to 40 days are required for fruit to of markets are available for the reach maturity for harvesting. This more unusual specialty eggplant limits the use of direct seeding as varieties. Worldwide, China is the a means of production because leading producer and consumer spring harvest dates will be 3 to 4 Figure 1. Bare ground production of of eggplants. In North America, weeks later than with transplant- eggplants. Note: field is weed-free most commercial production is in ed eggplants. Transplanting is the with healthy, green eggplants. Florida, California, New Jersey, preferred method of production. and Mexico. Eggplants are very sensitive to Eggplant is a semitropical/ cool weather and do not perform tropical plant originating in Asia well when exposed to low tem- and India. Eggplant is a member peratures. Do not transplant until of the Solanaceae (tomato) family all danger of frost is passed. and is related to tomato, pepper, Transplant eggplants no earlier and Irish potato. Traders from the that March 10 in south Alabama, East brought seed westward April 1 in central Alabama, and about 1,500 years ago. The name April 15 in north Alabama. eggplant likely originated from an early form of eggplant that pro- Soil and Fertility duced white, egg-shaped fruits. Eggplant can be successfully Before it gained in culinary popu- grown in most soils in Alabama larity, eggplant was also termed (Figure 1). Avoid low, poorly “mala insana,” which translates to drained soils. Well-drained sandy Figure 2. Close-up of traditional, “mad apple,” owing to the belief loam, loam, or clay loam soils black, teardrop-shaped fruit that eating eggplant would lead to with a pH of 6.0 to 6.5 are best madness. By the 1860s, seed cata- for growing eggplants. A good logues in the United States listed supply of organic matter is desir- several varieties of eggplants.ARCHIVEable. Cover crops should be Nutritionally, eggplant is not a plowed under at least 1 month significant source of vitamins or before planting to allow time for minerals; however, there are only the cover crop to decompose. To 25 calories per 100 grams of raw avoid potential soilborne disease eggplant and 19 calories per 100 and nematode problems, plant grams of cooked eggplant. eggplant in soils that have not grown a crop of tomatoes, pep- pers, Irish potatoes, or eggplants in the past 2 to 3 years. Figure 3. Close-up of specialty eggplant Visit our Web site at: www.aces.edu Timely and appropriate appli- is fully decomposed before trans- vary but are often long and cations of fertilizer can make a planting eggplant. Producing smooth, ball- or bell-shaped. Fruit significant difference in the quali- transplants requires about 8 colors range from white, to green, ty and quantity of fruit and can weeks. Four ounces of seed will to purplish black, to purple. In promote earlier harvests. In the produce about 10,000 transplants. Alabama, the cultivars ‘Bambino’ winter or early spring, collect soil Soil temperatures need to be be- (miniature; small, round, purple samples from each area that you tween 75 and 90 degrees F, with fruit), ‘Little Fingers’ (straight, intend to crop, and have a soil 85 degrees F being optimal for cigar-shaped, pink fruit), ‘Short analysis performed on each sam- germination. For optimal growth Tom’ (hornlike, curving, purple ple. Soil-testing eliminates the and performance in the field, fruit), ‘Long Tom’ (oriental type; guesswork in a fertilizer program. transplants should be between 6 long, smooth, purple fruit), ‘Bride’ Apply recommended lime 2 to 3 and 10 inches tall without any (hornlike, white fruit), ‘Rosita’ months before planting. Contact flower buds, flowers, or fruits. (teardrop-shaped, pink fruit) and your county Extension agent for Space transplants 24 to 30 ‘Ghostbuster’ (teardrop-shaped, information about how to collect, inches apart within a row and 42 white fruit) have performed well. submit, and interpret the results to 48 inches apart between rows. In the United States, oriental egg- of your soil test. Use Table 1 to determine the plants constitute a niche market. If a soil test is not done, a number of plants per acre re- They are not any more difficult to general recommendation for egg- quired at various spacings. To de- grow, but they require specialized plants is to use enough fertilizer termine the number of plants re- marketing as compared to the to supply 100 to 120 pounds per quired per acre for any spacing, more traditional type. acre of nitrogen (N) and 120 to divide 43,560 (number of square Within these two groups, cul- 180 pounds per acre of phospho- feet in 1 acre) by the product of tivars also differ in earliness. rus (P2O5) and potassium (K2O). the desired spacing between Remember that the primary con- One approach would be to apply plants and the spacing between sideration in cultivar selection is 1,000 pounds per acre of a com- the rows. For example, an 18-inch market preference. Individual plete fertilizer such as 6-12-12 or between-plant spacing on 48-inch markets prefer or require specific 5-10-15. Broadcast and incor- centers would require 7,260 types of eggplants. A grower must porate one-half of the fertilizer plants per acre: (18 in. x 48 in. or identify the needs of the prospec- before transplanting. Next, apply 1.5 ft. x 4 ft. = 6 ft.2; then divide tive market or niche. After this, the second half of the fertilizer di- 43,560 by 6 = 7,260 plants per you must determine the per- rectly to the plant rows. Be sure acre). ceived demand for the product, the fertilizer placed within the the volume required by the mar- rows is banded or mixed well be- Eggplant Varieties/Types ket, the specific characteristics fore transplanting. After the first Eggplants are a botanically di- (types) of eggplant needed, and fruit set, sidedress with 20 to 30 verse group that can be divided the market window. Based on pounds of nitrogen per acre and into two groups based on fruit this information, you can deter- then twice more at 2- to 3-week shape and color. The first group mine which varieties are needed, intervals. These sidedress applica- and more traditional type are the their optimal planting dates, and tions of fertilizer do not have to teardrop-shaped, large-fruited the acreage required to supply be incorporated. eggplant (Figure 2). Fruit of these your market. eggplants are typically oval or Contact your county Seeding Rate and Spacing long and tapered in shape with a Extension agent for a copy of the Prepare the land early by black, purplish-black, or purple latest edition of the report titled turning the soil in the winter or skin color, often with a green “Spring Vegetable Variety Trials” early spring so that crop residue calyx (cap end). from the Alabama Agricultural Cultivars that have performed Experiment Station at Auburn Table 1. Numbers of PlantsARCHIVE Per Acre well in Alabama include ‘Classic,’ University. In the report, you will Required at Various Spacings ‘Black Belle,’ ‘Vernal,’ and find information about the perfor- Number of plants ‘Santana.’ The second group is mance of selected eggplant vari- required per acre collectively referred to as the “spe- eties trialed in several locations at two spacings cialty” eggplants (Figure 3), some throughout Alabama. Although Between-row of which are referred to as “orien- there are a large number of com- spacing 42 in. 48 in. tal” eggplants. Oriental eggplants mercial varieties available, grow 24 in. 7,920 5,445 generally have a purple calyx. only those adapted to Alabama. It is advisable to grow a small trial 30 in. 4,978 4,356 Fruit shapes of specialty eggplants

2 Alabama Cooperative Extension System plot of several varieties each year production costs over two crops, Since eggplant is related to to determine which varieties are decreasing the risk associated Irish potato, pepper, and tomato, best suited to your growing con- with the higher initial setup costs. it is a host for many of the same ditions and marketing outlets. Eggplant can be planted on pests that attack these related mulch that was used to produce a crops. Planting these related crops Irrigation spring crop such as cabbage, col- year after year in the same area Irrigation is an essential ele- lards, broccoli, or strawberries. Be will increase pest pressure in that ment of a successful vegetable sure that drip tape is offset 3 to 4 area. To avoid this, rotate to crops production operation. Keep in inches from the center of the bed in other plant families (such as mind that irrigation is critical to and buried 2 to 3 inches deep. the Curcurbit family—cucumbers, the production of quality pro- Contact your county Extension watermelons). Crop rotation is duce. Most vegetables are 80 to agent for more information about one of the most effective pest- 95 percent water, so any loss in using plastic mulch and drip irri- management strategies that grow- water weight is equal to a loss in gation. ers can use. Locate fields for egg- saleable weight. Whether you are plant production away from fields using overhead or drip irrigation, Two Crops from One where any related crops were provide enough water to the crop Planting grown the previous season. to ensure the production of high In Alabama, eggplants can be yields of quality fruit. In eggplant, cut back after the first crop is Controlling Weeds the most critical period for irriga- complete to allow a second crop Chemical weed-control options tion is during flower and fruit for- to develop. Depending on the lo- for eggplants are limited. Most her- mation. Any stress related to lack cation, the first crop could be bicides registered for use on egg- of water during this period can done by June (south Alabama) or plant control annual grasses, small- lead to the development of blos- July (central/north Alabama). seeded broadleaf weeds (pigweed, som-end rot and malformed fruit. Plants at this point will appear FL pursley, carpetweed, common Fruit size and yield are reduced “topped out,” not producing any purslane), and some perennial by moisture stress. more flowers and subsequent weeds, but they do not control fruits. Mow plants 6 to 8 inches large-seeded broadleaf weeds such Mulching and Drip above the soil line, being sure to as sicklepod, annual morning glory, Irrigation leave two to three leaf axils. Next, or common cocklebur. Always con- fertilize with 50 to 60 pounds of firm that the material you intend to Using polyethylene (plastic) apply will control the target pest. mulch offers several advantages nitrogen per acre and 80 to 100 pounds of potash per acre (P O ). Consult your county Extension (see Figure 4). Plastic mulch in- 2 5 This combination will produce agent to develop an effective weed- creases the soil temperature, vigorous regrowth and stimulate control program or to identify target which accelerates plant growth flowering. Plants will begin pro- pests. Refer to Extension Circular and development. It also con- ducing fruit 4 to 6 weeks after ANR-500A, Alabama Pest serves soil moisture and reduces cutting and will produce until Management Handbook, Volume 1, several common problems includ- frost. for a list of herbicides currently reg- ing soil compaction and crusting, istered for eggplant. ground rot of fruit, fertilizer leach- ing, drowning of crops, evapora- Controlling Weeds, For better weed control, select tion, and competition from Insects, Diseases, locations with low weed popula- weeds. tions and no perennial weed prob- and Other Pests lems such as nutsedge. Use me- Although using mulch in- chanical cultivation between rows, creases production costs, those Contact your county Extension agent or consult and use production practices that costs are offset by increased prof- encourage rapid development of its from earlier and larger yields Extension Circular ANR-500A, ARCHIVEAlabama Pest Management eggplant. If nutsedge is a problem, of high-quality produce. Drip irri- consult Extension Circular ANR- gation systems must be used with Handbook, Volume 1, for current information on strategies to con- 1073, “Nutsedge Control In plastic mulch. In addition, grow- Commercial Vegetables,” for infor- ers can plant multiple crops trol pests (fungi, bacteria, insects, weeds) and for materials used in mation. Use shallow cultivation to (double-cropping) into the plastic control weeds. mulch; however, you must be controlling pests in eggplant. careful to not damage the mulch Always confirm that what you are with large tears, holes, etc. applying will control the target Double-cropping will spread your pest. If you are unsure, contact your county Extension agent. Guide to Commercial Eggplant Production 3 on the species. Most species have a pair of “exhaust pipe” structures called cornicles projecting out of the hind end of their body. The presence of cornicles distinguish- es aphids from all other insects. Aphid colonies are often lo- cated on the undersides of leaves. Curled, distorted leaves and sticky honeydew (aphid excrement) on leaves indicates the presence of aphids. Black, sooty mold may grow where honeydew has been deposited. Aphids transmit viruses Figure 4. Commercial planting of egg- that can cause plant diseases, but Figure 5. Aphids (nonwinged forms) plants on white polyethylene mulch. eggplant is not as susceptible to on underside of eggplant leaf Large, vigorous plants sometimes re- these as are some other vegetable quire staking to support them as they crops. Fortunately, eggplants can of insecticidal soap are also avail- develop a heavy fruit load. To avoid generally tolerate moderate feed- able. this problem, perform a soil test, and There are several synthetic in- do not overfertilize. ing without significant damage. Young plants are more susceptible secticides registered for control of Controlling Insects to aphid damage than older aphids on eggplant. Refer to Extension Circular ANR-500A, Depending on the environ- plants. Aphid-infested seedlings Alabama Pest Management mental conditions, the potential can be killed or severely distorted. Handbook, Volume 1, for a listing. for insect pest damage on egg- When plants are growing Imidacloprid, a newer class of plant varies greatly from year to rapidly, check them twice a week systemic insecticide, can be ap- year. Regular pest-scouting of for aphids. Once aphid numbers plied as a pre-planting or at-plant- eggplant will help growers deter- are high, they are difficult to man- ing treatment (Admire) or as a mine when pests are present and age because curled leaves shelter postplant foliar spray (Provado). whether insecticide applications aphids from insecticides and nat- are needed. A good rule of thumb ural enemies. Natural enemies is to examine 50 randomly cho- can be important in controlling Colorado Potato Beetle sen plants per field on each sam- aphids, especially where broad- The Colorado potato beetle ple date. This can be done by spectrum insecticides are not fre- (CPB) adult is about 1⁄4 to 1⁄3 inch walking a “V” or “W” pattern in quently used. The most effective in length. Body color ranges from the field, choosing ten random aphid natural enemies are para- yellow to orange, with ten black sites for sampling along the pat- sitic wasps, predators such as lady lines running the length of the tern, and examining five plants beetles, and fungal diseases. upper body (wing covers). The per site for insect pests and dam- One way to control aphids is adults overwinter in the soil and age. While many insects may feed to control weeds in and around emerge in the spring. Eggs are on eggplant, few species are con- fields because numbers of aphids bright orange and cylindrical, sidered to be yield-limiting pests. can build up on weeds and move about 1⁄16 inch long, and are laid Insect pests that periodically infest onto young plants. Also, avoid in groups of 10 to 40, usually on eggplant and may cause damage overfertilizing with nitrogen be- the undersides of leaves. are aphids, the Colorado potato cause high levels of nitrogen Hatching larvae are slightly larger beetle, the flea beetle, caterpillars, favor aphid reproduction. than eggs and are reddish brown and mites. Aluminum foil or reflective in color. Larvae feed on the ARCHIVEmulches have been successfully eggshells before moving off onto Aphids used to repel invading aphid pop- the leaves. Larvae go through four stages before dropping to the Aphids are small, soft-bodied ulations. In a small area, aphids ground to burrow into the soil insects that suck plant fluids with can be dislodged from plants with and pupate. The fourth-stage lar- their piercing-sucking mouthparts a strong water spray, which can vae are almost as large as the (Figure 5). They may be either be made more effective by add- adults are. Second-generation winged or wingless, and their ing 2 to 3 tablespoons of liquid adults can repeat the develop- color may be green, yellow, dishwater detergent per gallon of ment process if host plants are brown, red, or black, depending water. Commercial formulations

4 Alabama Cooperative Extension System insecticides (Foil, Novodor, Trident, etc.) are highly effective against small CPB larvae. Check the label to make sure the prod- uct contains the tenebrionis or san diego strain because these strains of Bt are effective against CPB, whereas other Bt strains are not. Good spray coverage of the foliage is important because lar- vae may be on lower foliage and on the undersides of leaves. Once Figure 6. Colorado potato beetle larvae grow to third or fourth adults feeding on eggplant stages (1⁄3 to 1⁄4 inch long), use synthetic insecticides if feeding Figure 7. In the background, charac- available. Both adults and larvae damage is significant. Plants past teristic “shotgun” feeding damage by are foliage feeders, feeding only the bloom stage can tolerate flea beetle adults. On right, close-up of on fruit when foliage is not avail- greater than 30 percent defolia- adult flea beetle. able. Severe defoliation can result tion without loss of yield, particu- in loss of yield, with the degree of larly if growing conditions are fa- yield loss depending on the gen- vorable. Imidacloprid (Admire eral health and growth stage of and Provado formulations), men- the plants (Figure 6). tioned above for aphid control, The most effective way to are also is effective against CPB. manage Colorado potato beetle is Never use foliar applications of crop rotation away from plants in Provado if Admire was soil- the tomato family. Locate fields applied at planting. for eggplant production away from fields where eggplant or re- Flea Beetles lated crops were planted the pre- Flea beetles are small, shiny, vious season. Monitor young dark beetles about 1⁄10 inch long plants at least weekly for signs of with enlarged back legs that give adult beetles and orange egg them great jumping ability. Larvae masses. Adults causing moderate Figure 8. Beet armyworm and char- usually feed on plant roots and acteristic feeding damage to heavy damage of prebloom normally do not injure eggplants. plants should be controlled with a Adult beetles feed only on fo- recommended insecticide. Do not liage, leaving tiny pits or small use the same material twice be- holes, sometimes called “shot- cause of the potential for insecti- hole” injury (Figure 7). Eggplant cide resistance. Refer to Extension is particularly attractive to flea Circular ANR-500A, Alabama Pest beetles and can be totally defoli- Management Handbook, Volume ated by them. Flea beetles move 1, for a list of recommended ma- into crops from adjacent weedy terials. Do not spray for adults un- areas or from senescing weeds less feeding damage is significant within the crop. (15 to 20 percent of foliage is lost to feeding). Continue to monitor Flea beetle adults overwinter plants for hatching egg masses. in crop and weed debris, so ARCHIVEplowing crop debris under in the Young larvae are much easier fall reduces the potential for infes- to control with insecticides than tation in the spring. Kill weeds are older larvae. If more than 10 bordering and within the field to Figure 9. Large, circular lesions on percent of plants have egg mass- remove alternate host plants for fruit. Note concentric pattern. es, apply an insecticide when at flea beetles. In areas where flea least 30 percent of the eggs have beetles are a consistent problem, hatched and small larvae are pre- consider protecting plants with sent. Bacillus thuringiensis (Bt) row-cover material.

Guide to Commercial Eggplant Production 5 Since flea beetles are highly Mites Leaf spots can occur at any mobile, foliar insecticides will Mites are not insects but are time during the season, though only decrease flea beetle num- more closely related to spiders. older leaves are most susceptible. bers, not completely control They are tiny, about 1⁄20 inch or Spots are circular with a distinct them. Admire, the formulation of less in length, and can be light narrow brown margin about 1 imidacloprid registered as an at- cream (some with dark spots on inch in diameter. Lesions are typi- planting application, will provide the sides) or red in color. They cally gray to brown, developing a approximately 5 to 6 weeks of feed on the leaf undersides with light-colored center as they age. protection after planting. needle-like mouthparts that re- Black, pimplelike structures devel- move sap from the leaf. Affected op in the center of old lesions; Caterpillars leaves first appear “stippled” with these are pycnidia, which are the fungal reproductive structures Several caterpillar species are white spots on the upper surface, where spores are produced. occasional pests of eggplant in then leaves take on a bronze ap- These can easily be seen with a Alabama. These include army- pearance, finally turning brown hand lens or magnifying glass. worms, loopers, fruitworms, and and dying. Mite infestations are Diseased leaves may turn yellow cutworms (see Figure 8). usually found near field edges and drop prematurely. Lesions can Depending on the species, they and are most commonly found also form on stems and branches. may feed on foliage and/or fruit, or during hot, dry weather. With reg- they may feed on young stems ular monitoring of fields, mite in- Fruit spots are similar to those near the soil line (cutworms). festations can be detected on field on leaves but are much larger, Foliar-feeding caterpillars cause the borders or in hot spots, and con- leaving diseased fruit unmar- most damage to young plants. trolling sprays can be directed ketable. Symptoms first appear as Older plants can tolerate greater onto these areas to keep the in- pale, sunken, circular to oval levels of defoliation (Figure 8). festations from spreading. Soap areas on the fruit surface (see Fruit-feeding caterpillars like fruit- sprays as discussed above for Figure 9). These later turn brown worms are the greatest threat dur- aphids are also moderately effec- and enlarge up to 2 to 3 inches in ing the fruiting period. tive for controlling mites. The diameter; often, two or more le- miticide dicofol is registered for sions merge to cover much of the The best management ap- mite control on eggplant and fruit surface. Affected fruit be- proach for armyworms, loopers, several other vegetable crops. come soft and watery at first; and fruitworms is to monitor decay may penetrate rapidly plant foliage for young larvae or throughout the fruit, causing a signs of feeding damage on fo- Controlling Eggplant light-brown discoloration of the liage, flower buds, and fruit. The Diseases flesh. Under dry conditions, fruit biological insecticide Bacillus There are a number of plant shrivel and become mummified. thuringiensis (Dipel, Javelin, diseases that can limit eggplant Black pycnidia arranged in a con- Mattch, Agree, and Xentari) is ef- production in the Southeast, centric, targetlike pattern can usu- fective if targeted against small including Phomopsis blight, ally be seen in the center of fruit worms just after they hatch. Phytophtora blight, southern lesions (Figure 9). Pyrellin, a mixture of natural blight, and early blight. pyrethrins and rotenone, is anoth- The fungus can survive from season to season in plant debris in er material that is effective against Phomopsis Blight young larvae. Synthetic insecti- the soil as well as in or on seed. cides such as Asana XL may be Phomopsis blight is caused by The fungus can survive for more used to control large larvae. If the fungus Phomopsis vexans and than a year in fields where a dis- cutworm feeding has severed can infect aboveground plant parts eased crop was grown. The disease stems of young plants, a synthetic at all stages of development. is favored by warm, wet weather insecticide such as Asana XL ap- Generally, spots first appear on and is spread by splashing water. plied as a directed sprayARCHIVE to the seedlings shortly after they emerge. Controlling Phomopsis blight base of the plants might help Dark, sunken lesions (cankers) starts by destroying the crop im- prevent further damage. form on the stem slightly above the mediately after the final harvest to soil line. Eventually, these cankers reduce fungal inoculum that encircle the stem, resulting in the could carry over to the next sea- collapse and death of the plant. son. Carefully inspect transplants for symptoms of Phomopsis

6 Alabama Cooperative Extension System blight before plants are set in the of the disease. Growing eggplant Early Blight field. A protective fungicide spray on plastic mulch greatly reduces Early blight, also known as program will substantially reduce the chance of spores splashing Alternaria leaf spot, is most often damage from this disease. Consult from the soil to the fruit. caused by the fungus Alternaria Extension Circular ANR-500A, solani. This disease is more Alabama Pest Management Southern Blight common on tomato and Irish Handbook, Volume 1, for a list of The soilborne fungus potato, in which it can severely materials labeled for controlling Sclerotium rolfsii causes southern reduce yields. On eggplant, it is Phomopsis blight. blight, which is a common prob- responsible for damaging the lem on eggplant as well as most leaves and fruit. Phytophthora Blight other broadleaf crops. Southern Leaf spots, which typically The same fungus, Phyto- blight develops where it is moist form on older leaves first, begin phthora parasitica, that is respon- and hot (85 degrees F or more). as small, dark, irregular spots that sible for buckeye rot of tomato Generally, the first symptoms are enlarge to form zonate spots up and a fruit rot of pepper, causes leaf yellowing and wilting of in- to 1⁄2 inch in diameter. On egg- Phytophthora blight on eggplant. fected plants. Stems at the soil plant, these lesions are lighter in Other species of Phytophthora line often appear soft and sunken, color, and the concentric ring pat- can also cause blight of eggplant. developing a brown to black in- tern may not be as noticeable as Symptoms of Phytophthora blight ternal and external discoloration. that seen on tomato or Irish pota- include damping-off of seedlings Under moist conditions, a white, to. When spots are numerous, in seedbeds, spotting of leaves, fanlike fungal growth can be seen leaves die prematurely and drop, and a collar rot of the main stem on the lower stem near the soil which exposes the fruit and that often results in death of in- surface (see Figure 10), on fruit in makes it more likely to be dam- fected plants. The most important contact with the soil, and on crop aged by sun scald. damage, however, occurs on fruit. debris on the soil around the base Lesions may also develop on Fruit rot can affect fruit at any of the plant. Spherical, light- the fruit. These spots are dark, stage of maturity. Spots from brown, mustard-seed-sized (1 to 2 leathery, and sunken and usually Phytophthora are dark brown, mm) sclerotia often form in the have distinct concentric rings. water-soaked with a light-colored mycelium (Figure 10). Under dry Spots on the fruit slowly expand border. These spots expand conditions, fungal mycelium and until they decay much of the sur- rapidly and can cover mature fruit sclerotia may not be visible. face area and the internal flesh of in 3 to 4 days. There is often a The fungus is spread as the fruit. The fungus survives from whitish mold on the fruit surface. mycelium in infested organic mat- season to season on crop debris in The fungus penetrates deeply ter or as sclerotia in infested soil. the soil and grows well in warm, within the fruit, resulting in a Infection usually takes place at wet conditions. Spores are spread brown discoloration of the flesh. the soil surface but can occur by wind and splashing water. Diseased fruit drop prematurely. below the soil line. The fungus Control early blight by follow- Spores of the fungus are splashed can spread through the soil more ing a crop-rotation program that from the soil to fruit. The disease than 3 feet and from plant to allows for a 3-year break between is usually spread from field to plant within a row. It is common Solanaceous crops. Destroy a dis- field on contaminated tools or to see several infected plants eased crop immediately after har- farm machinery and thrives in hot within a row killed. Sclerotia pro- vest to reduce the chance of the (86- to 90-degree F), wet weather. duced by the fungus on plant de- fungus overwintering. To reduce Controlling Phytophthora bris and dying plants serve as in- spread of the disease, maintain blight consists of hand-removing oculum and spread the disease to plant vigor, limit leaf-wetness pe- diseased plants when practical, the next crop. riods, and follow a protective deep-plowing to bury crop debris Controlling southern blight fungicide spray program. Consult after harvest, and providingARCHIVE a consists of following long rota- Extension Circular ANR-500A, 3-year rotation between Solan- tions (3 to 4 years) with grass Alabama Pest Management aceous crops (crops within the crops such as corn, small grains, Handbook, Volume 1, for a list of tomato family). Growing plants on or grass forages; deep-plowing materials labeled for controlling raised beds and wide plant spac- the soil to bury crop debris; using early blight. ings will also help reduce spread wider plant spacings to improve air movement; and removing and destroying infected plants.

Guide to Commercial Eggplant Production 7 Fruit can be harvested by Eggplants are not suited for breaking them from the plants. long-term storage. Fruit are chill- However, to avoid damaging the ing-sensitive, meaning that low plants and to produce a cleaner temperatures will cause pitting, product, it is best to cut fruit off surface bronzing, and browning with a knife or pruning shears, of seeds and pulp. Sensitivity to being sure to leave the calyx (cap chilling differs with the eggplant end) attached to the fruit. Because cultivar, maturity, fruit size, and the fruit bruises easily, eggplant is season of harvest. Fruit harvested not run across a grading line. Fruit at optimum maturity or in mid- Figure 10. White fanlike fungal are generally sorted by size and summer are more sensitive to growth (mycelium) on lower stem and color and field-packed into bushel chilling than those harvested at an surrounding soil. On right, close-up of baskets or cartons, depending on overmature stage or in the fall mycelium and sclerotia. the market. when growing conditions are cooler. As a result, eggplants har- Cooling and Storing vested in midsummer can be Harvesting Eggplant stored at 54 degrees F with 90 to With proper cultural practices, Eggplant 95 percent relative humidity for eggplant can produce about 500 The following recommenda- up to 1 week. Fruit harvested in to 700 bushels per acre, with tions are adapted from The the fall can be stored for up to 10 bushels weighing 28 to 32 Commercial Storage of Fruits, days at 46 degrees F with 90 to 95 pounds. The fruits of the eggplant Vegetables, and Florist and percent relative humidity. If egg- can be harvested any time after Nursery Stock, 1986, USDA, plants are stored too long, dis- they have reached sufficient size Agricultural Handbook No. 66. eases can develop during storage for your intended market. In any Remove eggplants from the and retailing. Never store egg- case, be sure to harvest fruit be- field immediately after harvest plants with tomatoes, bananas, fore their flesh becomes tough since eggplants lose water (which watermelons, or other ethylene- and their seeds begin to harden. can cause shriveling) and their producing fruit. Plan on harvesting at least once quality suffers when they are not per week, although two harvests cooled promptly. Forced-air per week would ensure harvest- and/or room cooling are suitable ing most fruit at the optimal stage for eggplant. Never use ice or of maturity. chilled water to cool fruit.

J.M. Kemble, Extension Horticulturist, Assistant Professor, Horticulture, E.J. Sikora, Extension Plant Pathologist, Associate Professor, Plant Pathology, E.H. Simonne, Extension Horticulturist, Assistant Professor, Horticulture, G.W. Zehnder, Extension Entomologist, Associate Professor, Entomology, M.G. Patterson, Extension Weed Specialist, Agronomy and Soils, all at Auburn University Use pesticides only according to the directions on the label. Follow all directions, precautions, and restrictions that are listed. Do not use pesticides on plants that are not listed on the label. The pesticide rates in this publication are recommended only if they are registered with the Environmental Protection Agency ARCHIVEand the Alabama Department of Agriculture and Industries. If a registration is changed or cancelled, the rate listed here is no longer recommended. Before you apply any pesticide, check with your county Extension agent for the latest information. Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guar- antee any product and does not recommend one product instead of another that might be similar. For more information, call your county Extension office. Look in your telephone directory under your county’s name to find the number. Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability. ANR-1098 UPS, 5M58, New June 1998, ANR-1098