A Method for Screening the Fungicide Efficacy on Sclerotinia sclerotiorum (Lib.) de Bary

I. KIRYAKOV

Institute for Wheat and Sunflower “Dobroudja”, BG-9700 General Toshevo, Bulgaria

Abstract

KIRYAKOV, I., 2000. A method for screening the fungicide efficacy on Sclerotinia sclerotiorum (Lib.) de Bary. Bulg. J. Agric. Sci., 6: 633-635

A method for preliminary screening of fungicide efficacy on Sclerotinia sclerotiorum in vivo was developed. The method included spraying of bean plants with fungicide 24 h before inoculation, cut of the main stem of three weeks old plants 25 mm above the node of the first trifoliate leaf, and inoculation by the straw method. The size of diseased tissue under the straw was recorded 8 days after inoculation. The fungicide benomyle (0.1% of product), procimidone (0.1%), and tebuconazole (0.08%) restricted the S. sclerotiorum growth in both the in vitro and the in vivo tests. The procimidone was the fungicide most effective to the pathogen in the in vivo test, followed by tebuconazole and benomyle. The obtained data showed that the straw method is easy to apply and provided an effective technique for preliminary screening of fungicide efficacy to S. sclerotiorum. The main advantage of the straw method is that it thus not ignore the host-pathogen interaction. Since the pathogenesis of the S. sclerotiorum on bean is identical to that in the other hosts, the bean plants could be used as testers.

Key words: Sclerotinia sclerotiorum, chemical control, common bean