Growing Eggplant In Aquaponic Units
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Eggplants require 100 to 120 days to reach maturity from seed, but choosing a faster-maturing variety and establishing optimal growing conditions can bring fresh
Eggplant, aubergine or brinjal is a plant species in the nightshade family Solanaceae. Solanum melongena is grown worldwide for its edible fruit. Most commonly purple, the spongy, absorbent fruit is used in several cuisines. Although often considered a vegetable, it is a berry by botanical definition.
- pH: 5.5–7.0
- Plant spacing: 40–60 cm (3–5 plants/m2)
- Germination time and temperature: 8–10 days; 25–30 °C
- Growth time: 90–120 days
- Temperature: 15–18 °C night, 22–26 °C day; highly susceptible to frost
- Light exposure: full sun
- Plant height and width: 60–120 cm; 60–80 cm
- Recommended aquaponic method: media beds
Growing eggplant in aquaponic units:
Eggplant is a summer fruiting vegetable that grows well in media beds owing to the deep growth of the root systems. Plants can produce 10–15 fruits for a total yield of 3–7 kg. Eggplants have high nitrogen and potassium requirements, which indicates the need for careful management choices in the number of plants to grow in each aquaponic unit in order to avoid nutrient imbalances.
Eggplants enjoy warm temperatures with full sun exposure. Plants perform best with daily temperatures in the range of 22–26 °C and relative humidity of 60–70 percent, both of which favour strong fruit set. Temperatures < 9–10 °C and > 30–32 °C are very limiting.
Seeds germinate in 8–10 days in warm temperatures (26–30 °C). Seedlings can be transplanted at 4–5 leaves. Plants can be transplanted when temperatures rise in spring. Towards the end of the summer season, begin pinching off new blossoms to favour the ripening of the existing fruit. At the end of the season, plants can be drastically pruned at 20–30 cm by leaving just three branches. This method interrupts the crop without removing the plants during the unfavourable season (winter, summer) and lets the crop restart the production afterwards. Plants can be grown without pruning; however, in limited spaces or in greenhouses, management of the branches can be facilitated with stakes or vertical strings.
Start harvesting when the eggplants are 10–15 cm long. The skin should be shiny; dull and yellow skin is a sign that the eggplant is overripe. Delayed harvest makes the fruits unmarketable owing to the presence of seeds inside. Use a sharp knife and cut the eggplant from the plant, leaving at least 3 cm of the stem attached to the fruit.