G. Mahajan, R.S. Sarlach and M.S. Gill
Abstract
A field experiment was conducted during June 2010 to evaluate the effect of GA (giberellic acid @ 50 and 100 ?g mL-1), CK (kinetin @50 and 100 ?g mL-1) and SA (salicylic acid @50 and 75 ?g mL-1) on growth and yield of rice. Foliar spray of growth regulating substances was done at panicle initiation and flowering stage of the crop as per treatment. Growth and yield parameters of rice were significantly increased in response to application of growth regulating substances. Flag leaf area at flowering stage increased significantly with all levels of GA, CK and SA than control except SA @ 75?g mL-1. SPAD reading of flag leaf with growth regulating substances at flowering stage was found higher than control. No variation in panicles m-2 was found in response to growth regulating substances. Number of grains per panicle increased significantly with application of CK@ 100 ?g mL-1, it was 81% higher than control. Our study confirmed that grain yield improved with growth regulating substances due to increased number of filled grains/panicle and improvement in LAI, increased flag leaf and nutrient uptake by the crop as evidenced in higher N and P content in grains and N and K content in straw. Highest yield was recorded with application of CK @100 ?g mL-1and it was 27.4% higher than control.