RIDGE CULTIVATION AND CULTIVAR SELECTION RELATED TO THE YIELD OF EGGPLANT AND SWEET PEPPER GROWN IN THE SUDAN
The experiments described were mainly designed to evaluate eggplant and sweet pepper cultivars and to determine their performance with respect to earliness, yield, fruit size and quality as influenced by direction of ridge side planting.
Cochran (1936) indicated that unfavourable temperatures and inadequate water supply were the basic factors causing dropping of buds, blossoms and very small fruits of pepper. Low humidity and high temperature resulted in excessive transpiration and a water deficit was induced in the plants. Under such conditions the abscission of buds, flowers and small fruits usually occurred. Low moisture supply in the soil was also an important factor in blossom drop, but under conditions of excessive transpiration a water deficit developed, even when the soil was well supplied with water.
Cochran further indicated that plants held at 50 to 60°F for six months made no appreciable growth and he noted that from 40 plants only one flower developed which dropped without setting fruit. When plants which had developed blossoms at higher temperatures were transferred to a greenhouse and held at 50–60°F at the time of anthesis, 99.3 per cent of the flowers set fruit, but all the fruits developed parthenocarpically. Knott (1956) showed that the optimum monthly average, monthly maximum average and monthly minimum average temperatures for eggplant were 70–85, 95 and 65°F, respectively. For sweet pepper these temperatures were 70–75, 80 and 65°F, respectively.