Control of Alternaria black pod disease of bean in Southwestern Ontario, Canada
1992
Tu, J.C. (Agriculture Canada, Harrow, Ontario (Canada). Research Station)
Alternaria black pod fungus, Alternaria alternata (Fr.) Keissler, causes grey and black discoloration of seeds. The disease occurs in navy bean crop every year because the fungus has a wide host range and can survive in overwintering hosts and in plant debris. During the growing season, it grows on bean as an epiphyte by anchoring its hyphae in the cavities of stomata and living off the leached substances. The present research shows that several cultural practices could help to alleviate this disease. Beans planted early tend to develop more of this disease later. Thus they should be planted late and harvested early. Matured bean plants should not be left in the field to allow them to dry. Instead, they should be harvested as soon as possible and dry in the elevator to avoid rain and moisture. Overhead irrigation reduces the establishment of epiphytic population on the leaves during the growing season and consequently reduces the disease severity as the plants senesce. Among the number of chemicals, only iprodione is effective, others such as benomyl,chlorothalonil, dichloran, BAS 436 and CGA 64250 are ineffective against the fungus. Effective control by iprodione could be achieved by foliar spray just prior to the senescence of plants. A matured bean crop subjected to rain(s) enhances rapid disease development
显示更多 [+] 显示较少 [-]