The influence of planting date, row spacing, and herbicides on the yield of soybeans in Canterbury

Abstract

Abstract A field experiment based on a 34 factorial design was used to evaluate the effects of planting times, row spacings, and herbicide treatments on the growth and yield of Adelphia, Amsoy, and Wayne soybeans (Glycine max (L) Merrill) in Canterbury, New Zealand, in 1967–68. In this location the interval between planting and maturation was extended beyond that which normally occurs in the regions for which these varieties are best suited. The earliest maturing cultivar, Amsoy, was more successful at Lincoln, and data indicate that even earlier maturing varieties may be more suitable. Soybeans sown at 20 in. row spacings in mid-November produced highest grain yields with a minimum of agronomic difficulties. Generally soybeans grown in rows 20 in. apart outyielded those grown at wider row spacings and suffered less from weed competition. Both Treflan and Amiben treatments increased grain yields, particularly where soybeans were grown at 30 and 40 in. row spacings, even though the trifluralin applications...