Effects of Foliar Application of Boron (B) on the Grain Set and Yield of Wheat (Triticum aestivum L.)

Abstract
Aims: The objective of this study was to evaluate the effect of foliar application of boron (B) on the grain set and yield of wheat (cv. Shatabdi). Study Design: The experiment was designed with six boron treatments, arranged in a randomized complete block design (RCBD) with three replications. Place and Duration of Study: The field trial was conducted at Bangladesh Agricultural University (BAU) farm, Mymensingh during 27 November 2010 to 24 March 2011. Methodology: The B treatments were (i) B control, (ii) soil application of B, (iii) seed priming into boric acid solution, (iv) foliar spray of B at primordial stage of crop, (v) foliar spray of B at booting stage and (vi) foliar spray of B at primordial and booting stages. The rate of B for soil application was 1.5 kg B ha-1 from boric acid (17% B) and the rate for each foliar spray was 0.4% boric acid solution. Seed priming was done by soaking wheat seeds into 0.1% boric acid solution for 10 hours and then seeds were dried before sowing. Every plot received 115 kg N, 25 kg P, 75 kg K and 15 kg S per hectare from urea, TSP, MoP and gypsum, respectively. Results: The treatment receiving foliar spray of B at both primordial and booting stages of the crop performed the highest yield (3630 kg ha-1) which was statistically similar with the yield recorded with foliar spray of B at booting or primordial stage of crop and with soil application of B before crop (wheat) was sown; all the yields were significantly higher over the yield noted with seed priming or control treatment. The control treatment (no B application) had the lowest grain yield (2600 kg ha-1) which was significantly lower than the yield observed with the seed priming treatment. Conclusion: Wheat yield was affected due to grain set failure induced by boron deficiency and it was possible to overcome this element deficiency by soil application at 1.5 kg B ha-1 or foliar application of 0.4% boric acid solution at primordial or booting stage of crop.