Badania nad chorobami podsuszkowymi owsa (Avena sativa L.) z uwzględnieniem temperatury i opadów [Investigations on root and stem rot diseases of oat (Avena sativa L.) with a special regard to temperature and rainfalls]

Abstract

Investigations were carried out in 1996–2000 in the Experimental Station of Cultivars Evaluation in Uhnin. Disease symptoms were recorded twice – in the seedling stage (18 in the Tottman's scale) and in milk ripe stage (77 in the Tottman's scale) of oat. The seedlings with root and sheath necrosis or plants with diseased stem base were obtained every year. The percentage of diseased seedlings ranged from 6,0 to 39,5. and percentage of older plants with necrotic stripes on lower internodes ranged from 11,5 to 50,0. Results of mycological analysis of diseased plants showed that Fusarium spp., especially F. avenaceum and F. culmorum were isolated the most frequently, F. avenaceum was obtained in the seasons with different weather conditions. This indicates great tolerance of this fungus to temperature and humidity. In the seasons with high temperature F.culmorum was predominant. This species also can be tolerant to changing weather conditions. Warm and wet weather was favourable for oat infection by Bipolaris sorokiniana. Rhizoctonia solani was isolated from plants in milk ripe stage in each vegetation seasons. and from seedlings in years 1998 and 1999.