Effect of boron application time on yield of wheat, rice and cotton crop in Pakistan

Boron (B), one of the essential micronutrients, plays vital role in plant growth. Thirty one field experimentswere conducted to evaluate the response of wheat, rice and cotton to B application throughout Pakistan during2005-08. Boron was applied at 1 kg ha-1 as Borax decahydrate (11.3% B) at different times along withrecommended doses of N, P and K. The results revealed that B application at sowing time to wheat increasedsignificantly the number of tillers plant-1 (15%), number of grains spike-1 (11%), 1000-grain weight (7%) and grainyield (10%) over control. Among the treatments, B application at sowing time showed best results followed by Bapplication at 1st irrigation and at booting stage. In rice (coarse), B application before transplanting substantiallyincreased number of tillers hill-1 (21%), plant height (3%), panicle length (10%), and number of paddy grainspanicle-1 (17%), 1000-grain weight (11%) and paddy yield (31%) over control. Response of fine rice to Bapplication was similar for all yield parameters as in coarse rice. In cotton, B application considerably increasedplant height (3%), number of mature bolls plant-1 (12%), seed weight boll-1 (8%) and seed cotton yield (9%) overcontrol. Although, B application at all stages significantly increased yield parameters tested but B application atsowing time was best among all treatments.