Studies on the growth of soybeans on the Darling Downs, Queensland

Abstract

Soybean seed yields of up to 1,655 lb per ac were produced over a 3-year period on chernozem type soils at Hermitage Research Station. The highest yielding varieties were Nanda, ECR 973 Congo, and selections from Delsta and Mammoth Biloxi hybrids. Flowering time was accelerated by delayed planting up to the end of December. In a plant population trial, 14, 21, and 28-in. spacings gave higher yields than 42-in. spacing. Where soybeans were grown for the first time, nodulation did not occur even after inoculation of seed. Improved nodulation was noted in second-year soybean ground without further inoculation. Nodulation was also improved through the use of a second strain of Rhizobium on a humus base. Marked response to foliar applications of zinc were observed in some varieties. The need for fungicidal seed dusting at planting was demonstrated.