Biological and chemical control of sunflower basal stem rot caused by sclerotium rolfsii

الملخص EN

The studies showed significant inhibitory effects of potassium bicarbonate (KHCO₃) either on growth parameters of Sclerotium rolfsii or in sunflower root/collar.

Inhibitory effects were increased by enhancing KHCO₃ concentration.

KHCO₃ gave significant inhibitory effects against Sclerotium rolfsii caused76.6, 57.69 and 95.78% inhibition for linear growth, sclerotial formation and mycelial dry weight, respectively at 0.6g/l KHCO₃.

KHCO₃provided synergistic effects with Trichoderma harzianum, Since the antagonistic potentiality of T.

harzianum against S.

rolfsii was increased with increasing KHCO₃ concentrations.

KHCO₃ caused 80 and 76% inhibition for linear growth and sclerotial formation, respectively.

However, the most effective to prevent growth parameters and infectivity of S.

rolfsii the combinations of potassium bicarbonate and hydrogen peroxide (H₂O₂) with Trihoderma harzianum 86.25% and 97.6% inhibition for radial growth and sclerotial formation at H₂O₂ (1.2 g/l) +KHCO₃ (0.6 g/l) with T.

harzianum, respectively.

The treatments H₂O₂ (1.2 g/l) +KHCO₃ (0.3g/l) with T.

harzianum and H₂O₂ (1.2 g/l) +KHCO₃ (0.6 g/l) with T.

harzianum achieved 75% and 71% protection against sunflower basal stem rot, respectively.