The influence of plant population on the yield of cotton at Katherine, N.T

Abstract

In 1957-58 and 1958-59, cotton was grown under dryland conditions on Tippera clay loam at Katherine, N.T., at plant populations of 4, 8, 16, 32 and 64 thousand plants per acre, under three nitrogen fertilizer treatments and at two dates of planting. In 1960-61, cotton was grown at 8, 16, 24, 32, 40 and 48 thousand plants per acre at one date of planting and at a standard nitrogen fertilizer level. The 1957-58 and 1958-59 results showed that 8, 16, and 32 thousand plants per acre gave a higher yield of seed cotton than 4 and 64 thousand plants per acre, with no interaction between population and nitrogen fertilizers. No significant yield differences were recorded in 1960-61. The combined data indicated an optimum population of 8 to 32 thousand plants per acre, with only a 5 per cent yield difference across the population range. High populations encouraged early boll development.