08/10/2020
EGGPLANT
Climate conditions, soil and water management
Optimum day temperatures for eggplant are in the range of 25-35degC and night temperatures from 20-27degC. Eggplant is more susceptible to low temperatures than tomato and capsicum and it does not tolerate frost. It is tolerant to drought and excessive rainfall, but struggles to grow when temperatures exceed 30degC, and where water logging occurs. When temperature and humidity are high, eggplant becomes more vegetative. Eggplant does best in well-drained, sandy loam soils. The best environmental conditions are normally found in lowland areas with relatively little temperature variation. When grown at altitudes above 800 m, growth is re****ed and yields reduced. The pH requirements range from 6 to 7 with the optimum being pH 6.4.
Propagation and planting
Eggplant is normally propagated by seed. Propagation by rooting of healthy shoots is also possible. Soaking the seeds in water for 24 hours speeds up germination. No treatment is needed when sowing fresh, vigorous seed in sterilised soil. Otherwise, soak seeds in warm water (50 degC) for 30 minutes, rinse them in cold water, and dry them before sowing.
Nursery preparation
The seeds are sown in a well-prepared raised seedbed with friable soil (soil that breaks or crumbles easily when handled) in rows 10 cm apart. Space the seeds well to make transplanting easier. Before sowing an application of 3 to 5 kg of good compost per m2 is incorporated into the nursery seedbed.
In tropical areas, seeds are sown in a shaded seedbed and watered regularly. The seedlings emerge after 8-10 days. Before planting, fertilise the field with compost or farmyard manure.
The ideal transplant is a seedling with three to four true leaves, stocky and disease-free, and without flower buds. Begin hardening plants 6 to 9 days before transplanting to reduce transplanting shock. Slightly withhold water. Thoroughly water seedlings 12 to 14 hours before transplanting to the field. Transplanting should be done in the late afternoon or on a cloudy day in order to minimise transplanting shock. Before transplanting, place a basal dose of 15 to 30 tons/ha compost or well-rotted farmyard manure in the planting furrows or planting holes and mixed with the soil.
Transplant seedlings by digging a hole deep enough to bury a plant so that its first true leaf is just above the soil surface. Press the soil firmly around the root. Irrigate furrows immediately after transplanting.
Watering newly transplanted plants well with compost tea or EM (effective microorganisms) will give the seedlings a good start. To prepare your own compost tea, mix 1 part of compost with 6 parts of water. Leave the mixture for one week. Strain and spray on seedlings to control fungal pathogens and prevent infection.
Varieties
• "Black Beauty" It takes about 100 days from transplanting to harvest. The fruit is oval to heart shaped glossy purple to almost black. Fruit size is about 10 x 8 cm. It has a good shelf life. It is unsuitable in cold wet areas.
• "Florida High Bush" From transplanting to harvest is about 100 days. Fruit shape is elongate oval. Fruit size is about 15 x 8 cm. It is unsuitable for cold wet areas.
• "Ravaya" It is an early maturing (about 80 days), high yielding variety. The fruits are slender, purple-coloured and borne in bunches of 3-4. This variety is popular for fresh export market.
• "Long Purple". It is ready for harvest about 70-80 days after transplanting. Fruit shape is cylindrical. Fruit size is about 11 x 5 cm. It is unsuitable for cold wet areas
• ."Early Long Purple". From transplanting to harvest is 90 days. Fruit shape is long cylindrical. Fruit size is about 12 x 6 cm. It is unsuitable to cold wet areas.
Crop rotation
Eggplants should not be planted after tomato, pepper, potato, or other solanaceous crops to prevent a recurrence of the same pests and disease pathogens. Rotate eggplants with other crops like onions, cereals or legumes. Planting eggplant after rice reduces the incidence of bacterial wilt and nematodes.
Husbandry
Side dressing with groundnut cake is recommended 40 days after transplanting. Also at this period, remove three nodes at the tips of the plants to improve branching and to increase the number of fruits. W**d control should be shallow, to avoid damage to the roots. Tall-growing cultivars will also require support. Supplementary irrigation is required during dry periods. Mulching with dried plant materials reduces moisture loss and w**d problems. Apply well-decomposed farm yard manure and neem cake as basal fertilisers.
Harvesting
The first harvestable fruits appear 60-90 days after planting. Harvest fruits when they are about two-thirds of their maximum size. Harvesting is done once or twice a week by cutting the fruit from the stem and leaving a short piece of stem on the fruit. For seed production, harvest only fully mature fruits from healthy and productive plants. Yields of 20 to 25 tons/ha of immature fruits can be expected.
