The biological control of web blight (Thanatephorus cucumeris) in common bean in Panama.
of this work was to evaluate the capacity of Trichoderma
sp., Metarrhizium anisopliae and endophytic bacteria of
T. cucumeris (Frank) Donk under fi eld conditions, for the
biological control of web blight (T. cucumeris) in beans.
Applications of Bacillus subtilis, Trichoderma sp. (Strain
2-Villa Margarita), Trichoderma sp. (Strain 1-Colombia) and
M. anisopliae (Colombia) at concentration of 2 x 107 conidia/
ml of water), B. subtilis at rates of 0.335, 0.670, 1.005 and
1.340 g ai / ml of water + 36 g ai Chlorothalonil /ha, benomyl
50 WP with doses of 250 g ai / ha and a control treatment were
conducted. Results revealed high differences (P ≤ 0.0003)
between treatments; the treatment with lower severity was M.
anisopliae, followed by B. subtilis with 1,340 g ai /ml of water
+ Chlorothalonil at 36 g ai/ha with 11.87% and B. subtilis
to 0,335 g ai /l of water + Chlorothalonil at 36 g ai/ha, with
15.0%. The treatments affected to the greatest degree were B.
subtilis with 0,670 g ai/l of water + Chlorothalonil with 36
g ai/ha, Trichoderma sp. (Strain 2-Villa Margarita) and the
control treatment with 26.2%, 22.25% and 21.85% of severity,
respectively. The regression equation for the experiment Y =
2502.91-13.021* Sev, was signifi cant and indicated losses
of 13.02 kg for each percent increase of the disease. The
marginal analysis revealed that the treatment with highest gain
was M. anisopliae, recording a net profi t of 28.34%.