Effect of plant regulators on flower shedding and yield attributes of Cajanus cajan L. cultivars. (66)

Abstract

Field experiments were conducted during 1989 and 1990 to study the effect of localized application of 0.1 mL plant growth regulators (0.05 mM and 0.5 mM) on flower shedding and yield attributes in indeterminate (H-77-216) and determinate (ICPL-151) cultivars of pigeon pea (Cajanus cajan L. Millsp.). Flower shedding was significantly reduced in both cultivars with indole-3-acetic acid (IAA) and ascorbic acid (AA). Treatment with 0.5 mM ethrel was most effective in promoting flower shedding followed by abscisic acid (ABA). Application of IAA and AA significantly increased pod weight in cv. H-77-216. However, benzylaminopurine (BAP) was found to be equally effective along with these two treatments in cv. ICPL-151 for increasing pod weight. Treatment 0.5 mM ABA reduced pod weight by 17.46 and 7.79% in cv. H-77-216 and cv. ICPL-151, respectively. Application of gibberellic acid (GA3) did not influence flower shedding and pod weight but significantly increased seed weight per pod in both cultivars. None of the regulators proved to be effective in improving seed number per pod. Treatment with AA (0.05 mM) was the most satisfactory for increasing 18.8% seed weight per pod in cv. ICPL-151. Differential behaviour of cultivars towards plant regulator concentrations could be due to their growth behaviour.