Effect of shoot-tip pruning dates on yield and yield components of various brown-seeded soybean lines under shade stress

Abstract

This study aimed to determine the effect of shoot pruning dates on yield and yield components of some brown-seeded soybean genotypes under shade stress. The experiment was conducted under a shading net house in Sekarbela, Mataram, which was according to Completely Randomized Design, with three replicates and two treatment factors, i.e. brown-seeded soybean genotypes consisting of 7 lines (KH 7B, KH 7C, KH 7D, KH 9, KH 14, KH 50B and KH 35), and shoot pruning dates consisting 3 treatments (P0= without pruning, P1= pruning at 4 weeks after planting (4 WAP), P2= 5 WAP and P3= 6 WAP). The results indicated that there were significant differences in performance of those genotypes of brown-seeded soybeans and significant effects of shoot pruning, especially on grain yield, which was highest (10.99 g/plant) under without pruning but significantly reduced by different pruning dates. Among the brown-seeded soybean lines tested under shade stress, KH35 (G7) and KH50B (G6) lines performed the best as indicated by the highest 100 grain weight, grain number, and grain yield per plant. However, there was a significant interaction between the treatment factors on plant height and weight of 100 grains, in which plant height was highest n G4 without pruning (193 cm) and lowest on G5 pruned at 4 WAP (36.5 cm), while 100-grain weight was highest on G6 pruned at 6 WAP (8.59 g) and lowest on G4 pruned at 6 WAP (6.30 g), so delaying pruning date could increase weight of 100 grains, especially on G