Boron (B), one of the essential micronutrients, plays vital role in plant growth. Thirty one field experiments were conducted to evaluate the response of wheat, rice and cotton to B application throughout Pakistan during 2005-08. Boron was applied at 1 kg ha -1 as Borax decahydrate (11.3% B) at different times along with recommended doses of N, P and K. The results revealed that B application at sowing time to wheat increased significantly the number of tillers plant -1 (15%), number of grains spike -1 (11%), 1000-grain weight (7%) and grain yield (10%) over control. Among the treatments, B application at sowing time showed best results followed by B application at 1st irrigation and at booting stage. In rice (coarse), B application before transplanting substantially increased number of tillers hill -1 (21%), plant height (3%), panicle length (10%), and number of paddy grains panicle -1 (17%), 1000-grain weight (11%) and paddy yield (31%) over control. Response of fine rice to B application was similar for all yield parameters as in coarse rice. In cotton, B application considerably increased plant height (3%), number of mature bolls plant -1 (12%), seed weight boll -1 (8%) and seed cotton yield (9%) over control. Although, B application at all stages significantly increased yield parameters tested but B application at sowing time was best among all treatments.
