Effect of benzyladenine on photosynthesis, floral biology characters and yield in pigeonpea (Cajanus cajan L.)

Genotypes of pigeonpea namely Paras and Manak grown under field conditions were given cytokinin benzyl-adenine (BA; 100 μM) treatment at pre-sowing (seed priming) and flower initiation stage (foliar spray). BA treatments increased the number of branches, flowers and pods in both genotypes. However, seed priming was more effective than the spray treatment. In vivo pollen germination was sufficient enough to support fertilisation of ovules in both BA treated and untreated plants. Pollen tubes could not be traced in the lower region of style and ovary due to masking effect of copious hairs. Flowers in which in vivo pollen germination was lacking resulted in abscission of flowers. BA spray at flowering stage induced pollen germination in these flowers and thus a decline in percent abscission was evident. Seed treatment with BA resulted in an increase in number of pods in Paras, however, no such increase was observed in Manak. Increase in seed yield was also observed in Paras, the increase being more with seed treatment as compared to foliar spray. However, a decline in test weight of seeds was observed with both the treatments. The relevance of these observations is discussed.