Soil‐boron affects straw quality and other agronomic traits in two cultivars of barley

Abstract

Boron (B) toxicity in crops occurs in many dry areas. However, the effect of high external B levels on straw quality is not known. In this greenhouse study, the responses of straw yield, straw quality, and other characters to high soil B levels were investigated in barley. Two cultivars, Galleon and Harmal, were tested. In Experiment I, three B levels were prepared by mixing 0, 25, and 50 mg B kg‐1 soil‐mix (designated as B0, B25, and B50, respectively). Straw yield, straw quality (nutritional value), and other characters were measured. In Experiment II, an additional soil B level, prepared by adding 12.5 mg B kg‐1 soil‐mix (designated as B12), was used. Shoots and roots were harvested at tillering and after heading. In Experiment 1, the B50 treatment improved straw quality, had no effect on straw yield, but decreased grain yield, and harvest index. Considering the shoot B concentrations and B uptake at the tillering stage at moderate to high levels of soil B in both experiments, Galleon was able to restrict B uptake better than Harmal. However, Harmal, unlike Galleon, had a better growth and more tillers at moderate levels of soil‐B than at BO. Since Harmal had higher or similar B concentrations as Galleon, Harmal appeared to tolerate higher tissue B concentrations than Galleon. The limitation of selecting genotypes tolerant to high‐B soil was pointed out, and the need to study adult performance after the initial selection was suggested. The finding on straw quality and yield would be a positive finding for sheep owners in dry areas, where barley straw and stubble are a valuable ruminant feed.