Integrated Management of Striga hermonthica in Sorghum Using Glomus mosseae, Bacillus megaterium, and Phosphorus

TL;DR

This study shows that using Glomus mosseae and Bacillus megaterium, alone or together, can reduce the parasitic weed Striga hermonthica and improve sorghum growth in poor soils.

Contribution

The study demonstrates the effectiveness of combining biocontrol agents and phosphorus to manage Striga hermonthica in sorghum cultivation.

Findings

Glomus mosseae alone reduced Striga hermonthica emergence and biomass by 87%–100% and 93%, respectively.

Combining Glomus mosseae with Bacillus megaterium increased sorghum height by 116%–139% and shoot biomass by 314%.

Phosphorus suppressed arbuscular mycorrhizal fungus colonization, while Bacillus megaterium had no significant effect.

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 (P2O5), 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.

Glomus mosseae,
Bacillus megaterium
, and phosphorus significantly suppress
Striga hermonthica
, enhance sorghum growth, and improve soil fertility, offering a sustainable biocontrol strategy against Striga in nutrient‐deficient soils.

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