Influence of Prohexadione-calcium on Photosynthetic and yield parameters in basmati rice (Oryza sativa L).

Abstract

Basmati rice cultivars grow taller due to longer internodes but possess shallow rooting system and are thus prone to lodging during panicle development that may reduce yield and efficiency of mechanical harvesting. The main objective of the study was to make use of Prohexadione-calcium (Pro-Ca) to reduce internode elongation to avoid lodging without negatively affecting its yield potential. A field experiment was conducted on three cultivars of basmati rice (Punjab Basmati 2, Punjab Basmati 3 and Pusa Basmati 1121) with treatment allotted in split plot design and foliar application of Pro-Ca @5,10 and 20mg/l were sprayed at vegetative and anthesis stage. Yield contributing parameters (grain yield and plant height) were recorded at maturity. Pro-Ca had promoted the formation of total chlorophyll and carotenoid content in leaves at vegetative and anthesis stages. Plant height significantly decreased in Pro-Ca treated plants and subsequently decreased with increase in the concentration. Pro-Ca treated sets had significant increase in number of spikes/plant and grain/m2. Pro-Ca (20ppm) hindered gibberellins formation reducing plant height in selected basmati rice cultivars, though had positive effect on photosynthetic rate and yield.