In 1957-58 and 1958-59, Virginia Bunch and Natal Common peanuts were sown on Tippers clay loam at Katherine, N.T., in a multifactorial experiment at two inter-row spacings (2 ft and 3 ft), four plant populations (10, 20, 40 and 80 thousand per acre) and two dates. In 1960-61, Natal Common only was sown at the same inter-row spacings, at two dates, and at populations of 10, 20, 30 and 40 thousand per acre. Over two seasons, the yield of Virginia Bunch kernels was not significantly influenced by variation in population, though the yield of hay was 42 per cent higher at 80,000 plants per acre than at 10,000 plants per acre. Kernel yields from 2 f t rows were 14 per cent higher than from 3 f t rows. In the first two seasons, the yield of Natal Common kernels was lower at 80,000 plants per acre than at 40,000 plants per acre. Over three seasons, maximum kernel and h g yields were achieved at 40,000 plants per acre ; the kernel yield at this population was 35 per cent greater than at 10,000 plants per acre. With early-planted Natal Common, 2.ft rows gave an 11 per cent higher yield of kernels than 3 f t rows, but with later planting there was no significant effect of inter-row spacing. The optimum economic seeding rates were estimated approximately as 30 lb an acre for Virginia Bunch and 45 lb an acre for Natal Common.
Increasing population density reduces soybean yield components and productivity
