EFFECT OF DENSITY OF PLANTING ON YIELD OF 2 SOYBEAN CULTIVARS

The yield and yield components of two varieties of soybean [Glycine ma x (L.) Merrill], Bossier and Improved Pelican were compared in two exp eriments in 1987 and in 1988 at a range of planting densities from 10 to 40 plants/m. The experimental design was a split plot randomized bl ock with three replicates; plant density formed the main plot treatmen ts and the cultivars formed the sub plot. The optimum density of plant ing for Bossier, a determinate type was 20 plants/m while that of Impr oved Pelican, an indeterminate type, was 10 plants/m. Improved Pelican which was more susceptible to lodging showed greater yield reductions at higher densities than Bossier which was lodging resistant. Althoug h number of branches per plant generally increased with increasing den sity, there was no significant density effect on the number of nodes p er plant. Number of pods/plant, seeds/pod and seed weight decreased at high densities in 1987 as well as in 1988, indicating a consistent re sponse across years.