ABSTRACT The root parasitic weed Striga hermonthica , a member of the Orobanchaceae family, is a major constraint to cereal production in sub‐Saharan Africa. Its germination is triggered by host‐derived stimulants, which are upregulated under phosphorus (P) and nitrogen deficiencies. This study evaluated the effects of the arbuscular mycorrhizal fungus Glomus mosseae , the phosphorus‐solubilizing bacterium Bacillus megaterium var. phosphaticum (BMP), and inorganic phosphorus (P 2 O 5 ), applied individually and in combination, on S. hermonthica incidence and sorghum ( Sorghum bicolor ) growth. Uncontrolled S. hermonthica parasitism reduced sorghum height by 48%–54% and shoot biomass by 71%. G. mosseae alone reduced S. hermonthica emergence and biomass by 87%–100% and 93%, respectively, while increasing sorghum height by 89%–115% and shoot biomass by 351%. The combination of G. mosseae with BMP increased sorghum height by 116%–139% and shoot biomass by 314%. BMP alone reduced S. hermonthica emergence and biomass by 57%–65% and 68%, respectively, and phosphorus alone reduced S. hermonthica emergence and biomass by 29%–42% and 51%, respectively. The combinations of G. mosseae with BMP, G. mosseae with phosphorus, and G. mosseae with BMP and phosphorus achieved reductions in S. hermonthica emergence of 93%–100%, 82%–100%, and 87%–100%, and reductions in biomass of 93%, 87%, and 65%, respectively. Phosphorus suppressed arbuscular mycorrhizal fungus colonization, while BMP had no significant effect. These findings highlight the potential of G. mosseae and Bacillus megaterium , individually and in combination, as biocontrol agents for reducing S. hermonthica and improving sorghum growth in low‐fertility soils.
Elhag et al. (Sun,) studied this question.