Impact of nipping on soybean (Glycine max) plant architecture, nodulation and yield

An investigation was carried out during the rainy (kharif) season of 2011 at Raipur, Chhattisgarh to exploit suppressive apical dominance phenomenon through nipping to increase soybean [Glycine max (L.) Merr.] productivity. The experiment was laid in randomized block design with 3 replications. The treatments consisted of 7 nipping treatments, viz. nipping at 2-leaf stage, nipping at 4-leaf stage, nipping at 6-leaf stage, nipping at 2-leaf stage + nipping of lateral branches (15 days after 1 nipping), nipping at 4-leaf stage + nipping of lateral branches (15 days after 1 nipping), nipping at 6-leaf stage + nipping of lateral branches (15 days after 1 nipping) and control (without nipping). The same set of experiment was also conducted under pot culture in complete randomized design with 5 replication. Significantly higher number of branches, dry-matter accumulation and leaf-area index were obtained under nipping at 6-leaf stage + nipping of lateral branches (15 days after 1 nipping) than the other treatments. This was followed by nipping at 6-leaf stage. The number of nodules and dry weight of nodules were the maximum under nipping at 6-leaf stage + nipping of lateral branches (15 days after 1 nipping) followed by nipping at 6-leaf stage. Yield-contributing characters, viz. seed yield/plant, pods/plant, seeds/pod, 100-seed weight and seed yield, increased significantly under nipping at 6-leaf stage + nipping of lateral branches (15 days after 1 nipping) than other treatments.