The influence of sowing date on the yield of peanuts in a short summer rainfall environment

Abstract

In an experiment conducted under natural rainfall at Katherine, peanuts were sown during one wet season every day for 81 days between December 8 and February 27. There was a subsidiary experiment comprising 41 daily sowings, between December 16 and January 25, to confirm any trends in the main experiment. There was an almost linear decline in yield from over 3000 kg/ha in the early sowings to nil in the last few sowings, but mean individual kernel weight remained constant at about 0.39g for most of the growing season. The store of available moisture at depth in the root zone was considered adequate until mid-April. It is suggested that a decline in surface soil moisture was the major feature in determining this trend and that declining minimum temperatures after the wet season initially retarded, and eventually prevented, further development and maturation of fruit. The number of peanut pods bearing mature kernels on a single plant declined from 51 in the first sowing to 2 in the 70th, but the weight of a mature pod remained at about 1.1g.