Biological and chemical control of rhizoctonia root-rot disease of bean under greenhouse and field conditions

Abstract EN

Effect of two bioagents, two commercial biocide products and one fungicide on the incidence of bean root-rot was evaluated and compared by seed-dip and soil drench treatment under greenhouse and field conditions.

The bioagents were Trichoderma viride and Bacillus subtilis, commercial biocide products were Plant Gaurd (a formula Trichoderma harzianum) and Rizo-N (a formula B.

Subtilis) and the fungicide was vitavax-thiram.

Through in vitro studies, B.

subtilis caused the highest percentage decrease in the linear growth of R.

solani followed by T.

viride.

On the other hand, vitavax-thiram caused completely inhibition of the growth of R.

solani at 100 ppm.

All treatments, significantly reduced the percentage of pre-, post- emergence damping-off and root-rot in both the greenhouse and the field.

B.

subtilis followed by T.

viride were more effective than Plant Gaurd, Rizo-N and vitavax-thiram in reduction the percentage of pre-, post- emergence damping-off and root-rot.

Soil drench treatment with B.

subtilis followed by T.

viride gave the highest protection against pre-, post-emergence damping-off and root-rot compared with Plant Gaurd, Rizo-N and vitavax-thiram.

Concerning of method of application data indicate seeds-dip treatments in bioagent, commercial biocide products and fungicide were less effective than soil drench treatments in reduction of the percentage of pre-,post- emergence damping-off and root-rot.

All treatments significantly increased dry seed yield of bean compared with the control treatments.

The soil drench treatment with B.

subtilis gave best results in controlling of bean root-rot disease.