Eggplant is thought to have been cultivated in India and China more than 1,500 years ago. A Chinese cookbook from the fifth century mentions eggplant, and ancient Chinese brides were required to have eggplant recipes as part of their dowry. Colonialization and trade brought the fruit (though most commonly regarded as a vegetable) to Africa, Europe, and eventually to America in the 1800s.
Part of the nightshade (Solanaceae) family, eggplant was once thought to be poisonous. When eggplant arrived in Italy, it was called the “mad apple” and reputed to make people who ate it go crazy. The leaves and flowers, when consumed in large quantities, can be poisonous, but not the fruit.
As a crop, eggplant loves heat and does not like frost. Star-shaped flowers grow on thick stems, are self-pollinating, and produce various sizes of purple, black, and sometimes white or striped fruit, depending on the variety. Mature plants can reach 8 feet in height. Eggplant is related to tomatoes, potatoes, and peppers, and goes by many names including eggfruit, aubergine, brinjal, tomato-fruited eggplant, gilos, guinea squash, mad apple, and nasubi.
References: Ohio State University Extension, University of Arizona Cooperative Extension, University of Illinois Extension.
TYPES, VARIETIES & CUTS
Eggplant comes in two basic families: Solanum melongena, the traditional eggplant with a solid, fleshy inside, and Solanum integrifolium and Solanum gilo which are more like tomatoes with a soft inside and hence called “tomato-fruit eggplant.” The 7 melongena family produces varied fruits. Common eggplant is dark purple or black, 6 to 9 inches long, bulb-shaped, and 3 to 4 inches wide at the base. Common varieties include Black Bell, Black Beauty, and Black Magic. Other large-fruit varieties include Dusky, Epic, Classic, Burpee Hybrid, and Ghostbuster.
Eggplant also comes in elongated varieties such as the Ichiban, Slim Jim, and Little Fingers. There are several popular Asian cultivars including Orient Express, Orient Charm, Calliope, and Machiaw, as well as ornamental varieties including the Easter Egg. Asian varieties have softer skin and ornamental varieties are small, oval-shaped, and often whitish in color. Tomato-fruit eggplant can range in color from green to red to orange, and even be striped or bicolored.
References: Colorado State University Extension, University of Arizona Cooperative Extension, University of Illinois Extension.
PESTS & DISEASE
Eggplant is susceptible to several pests and diseases including flea beetles, aphids, and spider mites that damage leaves in young plants and can impact yield. Pests can be managed with insecticide and using row covers.
Diseases include verticillium wilt which causes yellowing and wilting and can stunt or kill plants, as well as postharvest diseases such as black or grey mold rot and hairy rot that can damage fruit.
References: Ohio State University Extension, University of Arizona Cooperative Extension, University of California Division of Agriculture and Natural Resources, University of Illinois Extension.
CULTIVATION, STORAGE & PACKAGING
Eggplant grows best in full sun and rich sandy or loamy well-drained soils with a pH between 5.5 and 7. Plants require several months of sun to bear fruit, so start seedlings inside 6 to 8 weeks before the last frost is expected. Eggplant prefers growing in temperatures between 70 and 85°F. Flowering and fruiting can slow or stop at temperatures below 60°F and above 95°F.
Fruit can be harvested when skin is firm and shiny, and is edible from about one-third of full size through maturity. Too-mature fruit can become hard and bitter. To produce larger eggplant, remove other fruit to allow the plant to send nutrients to just one or two. Harvesting by hand with clippers is best; typically the cap and a short piece of stem are left on.
Eggplant should be cooled quickly (forced air or hydrocooling after harvest) to maintain moisture and freshness. Chill to 50°F and 90 to 95% relative humidity to maintain freshness for up to 2 weeks. Cooling below 50°F for storage or transportation can result in chilling injury, leading to pitting or browning of flesh and seeds. Normal decay after 2 weeks occurs as loss of surface sheen, skin wrinkling, browning of the stem or top, and spongy pulp tissue. Waxed cartons can reduce moisture loss and decay. Stacking cartons or over packing can cause bruising and decay.
References: Clemson University Cooperative Extension, Cornell University Cooperative Extension, Ohio State University Extension, University of Arizona Cooperative Extension.