Fungus diseases of field bean in Finland during 1975—1977

Authors

• Anna-Liisa Ruokola University of Helsinki, Department of Plant Pathology, SF-00710 Helsinki 71
• Mauritz Vestberg University of Helsinki, Department of Plant Pathology, SF-00710 Helsinki 71

DOI: https://doi.org/10.23986/afsci.71992

Abstract

During 1975—1977, studies were carried out on the fungus diseases of field bean and attempts were made to find, through seed-dusting trials, suitable methods for their control. The fungal flora in a total of 43 seed lots containing 140—200 seeds each were determined. In addition, plant samples collected from farms where field beans were under cultivation and field bean cultivar trials in seven localities were analysed. The weather conditions in the growing seasons of 1975 and 1977 were rather exceptional, the former being dry and warm and the latter rainy and cool. Ripe crops were obtained from the control experiments, in which the seeds of 3—4 field bean cultivars were dusted with thiram and benomyl preparations, only in 1975 and 1976. Ascochyta fabae Speg. was rare in all the seed samples apart from those from Länsi-Hahkiala, where the degree of infection varied, depending on the cultivar, from 1.3—20 %. Botrytis fabae Sard. was rare in the seeds, B. cinerea Pers. ex Fr. quite common in 1976 and especially in 1977. The frequency of the Fusarium fungi were very great on the seeds in 1977, F. culmorum (W. G. Sm.) Sacc. and F. avenaceum (Fr.) Sacc. being the most common. A. fabae was quite common in the stand samples collected at Länsi-Hahkiala in 1975 and 1976. The chocolate spot-causing agents, B. fabae and B. cinerea, were relatively rare in all years except 1977, when some cultivars were heavily infested by B. cinerea.