Evaluating the Synergistic Effects of Foliar Boron and Magnesium Application on Mitigating Drought in Wheat

Grain yield of wheat is primarily limited by water stress. Therefore, to increase the productivity under drought conditions, a pot experiment was carried out at Maru Agricultural Research Station (MARS), Jordan during the year 2021 to investigate the effect of foliar fertilizer by boron and magnesium under drought at either tillering or anthesis stages on some physiological parameters and yield components of two varieties of durum wheat. Foliar application by combined boron and magnesium had improved significantly the transpiration rate by 23% and 28%, and also relative water content (RWC) by 8% and 17% of wheat varieties at tillering and anthesis growth stage, respectively when compared with controls. RWC was significantly the highest (79%) by foliar boron at tillering drought. Meanwhile, total chlorophyll content by SPAD was significantly the highest by combined boron and magnesium during anthesis drought. In general, the results indicated that var. Maru 1 had significantly 66% higher grain yield than var. Hourani may due to differences in genetic makeup. Foliar application by combined boron and magnesium had significantly increased grain weight of wheat varieties at tillering and anthesis drought by 25% and 36%, respectively. However, foliar application did not significantly improve the grain weight under well-watered conditions. Our findings showed the significance of foliar application at anthesis drought rather than at tillering for improvement of grain yield and also the importance of foliar magnesium in increasing total chlorophyll, and thus yield under different drought conditions.