Foliar Supplementation of Boron Enhances the Performance of Inbred and Hybrid Boro Rice Varieties

A field experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University during November 2021 to April 2022 to investigate the effects of foliar supplementation of 0.1% aqueous solution of boron (B) to inbred and hybrid boro rice varieties. The experiment was laid out in completely randomized block design (RCBD) with two factors, viz. variety (inbred ‘BRRI dhna29' and hybrid ‘Lal Teer'), and foliar B supplementation in addition to the recommended basal dose (6 kg ha-1 boric acid) which was applied during the final land preparation. The later factor had four levels, viz. (i) no additional B supplementation (B1), foliar supplementation of B (ii) at tillering stage (B2), (iii) at panicle initiation stage (B3), and (iv) at both tillering and panicle initiation stages (B4). The experiment was replicated four times. The results revealed that hybrid (Lal Teer) variety outperformed the inbred variety (BRRI dhna29) in all yield related parameters, and grain and straw yields. All plant characters, yield contributing characters and yields were significantly affected by B supplementation. Although there were yield differences between inbred and hybrid cultivars, their response patterns to foliar supplementation of B were similar. In both varieties, the highest grain yield was recorded when the crops received foliar doses of B twice (tillering and panicle initiation stages) in addition to the recommended basal B fertilizer. However, a single foliar application of B at the tillering stage produced statistically similar results as two foliar applications. The control treatment (no boron application) produced the lowest grain yield and performed poorly in terms of both plant characters and yield related traits. Therefore, a single foliar application of B during tillering stage is recommended for both inbred and hybrid varieties.