Effect of boron and farmyard manure application on growth,yields, and boron nutrition of sunflower

To examine the role of organic manure on boron (B) availability, a greenhouse experiment was conducted to study the effect of B and farmyard manure (FYM) levels on growth, yields, and B accumulation of sunflower (Helianthus annuus L.). Application of B or FYM individually increased the plant height, capitulum diameter, dry matter yields of seed and stalk and their B concentration and accumulation. The interaction of B and FYM levels had a significant influence only on B concentration of stalk and total B accumulation of sunflower. In the absence of B application, use of highest level of FYM (10 g kg^‐1 soil) significantly increased B concentration of stalk and total B accumulation by the crop while with B application, use of FYM at lower rates was effective. Application of B or FYM, especially at higher rates of the latter (5 and 10 g FYM kg^‐1 soil) increased the content of hot‐water soluble soil B in the soil after crop harvest. The interaction of B and FYM levels had no significant effect on the content of hot‐water soluble soil B. Application of FYM increased apparent availability of native and added B from soil to sunflower crops.