Rhizoctonia solani damping-off on spring turnip rape and spring rape (Brassica spp.) in Finland

Abstract

Abstract. Damping-off occurred in 90 % of the spring oilseed rape fields surveyed in [1981][1982]. On the average, 10 % of the plants were infected with damping-off. 6 % of the fields were severely infected (> 30 % of the plants affected) by damping-off and 38 % were uninfected or only slightly infected ( < 5% of the plants affected). The incidence of dampingoff was higher in those fields which had been under oilseed rape in earlier years. In a crop rotation experiment, the amount of damping-off increased from 2 % to 20 %, and finally to 38 %, depending upon whether turnip rape had been grown on the same part of the field once, twice or three times. Crops other than Cruciferous ones were grown for 1 or 3 years between the turnip rape crops. Rhizoclonia solani Kiitin was isolated from 76 % of the affected plants. The R. solani isolates produced severe damping-off on rape and turnip rape in pathogenicity tests. R. sotani isolates from barley, potato and lettuce brought about only mild cases of damping-off, or else only a decrease in the growth of the plants. Fusarium avenaceum Sacc. was the only other isolated fungus which was pathogenic.

Prevalence of Plasmodiophora brassicae in a spring oilseed rape growing area in central Sweden and factors influencing soil infestation levels

“…Severe attacks of damping-off, mainly caused by Rhizoctonia solani, can disturb the bioassay test. This is particularly important to consider in soils where oilseeds are grown close to soil sampling, which agrees with the findings of Tahvonen et al (1984). Seed treatment with a selective fungicide controlled R. solani in growth chambers (Sumner, 1974).…”

Rhizoctonia solaniinjuries in oilseed crops in Finland and impacts of different crop management practices on disease incidence and severity

“…In more than 60% of the root and stem samples it was co‐occurring with different Fusarium species and T. basicola . R. solani together with Fusarium species have been reported as the main causal agents of damping off in vegetable (Linnasalmi, ) and oilseed (Tahvonen et al , ) Brassicas in Finland. Brown girdling root rot like other stem base and root rot diseases on OSR are associated with R. solani , a well‐known pathogen also causing damping‐off, root rots and stem cankers on numerous different plant species (Berkenkamp & Vaartnou, ; Petrie, ; Papavizas et al , ; Petrie, ; Petrie et al , ; Sippell et al , ; Gugel et al , ; Hwang et al , ).…”

“…When pathogenicity of the selected fungi to turnip rape was tested, none of the fungi alone caused root symptoms, while all R. solani AG 2–1 isolates originating from oilseed rape, mustard or radish caused stem base lesions. R. solani has been shown to cause severe damping off in Brassica crops in Finland (Linnasalmi, ; Tahvonen et al , ) but formation of stem symptoms in older OSR plants has not been studied before. R. solani , predominantly AG 2–1, has been shown to be the major cause of post‐ and pre‐emergence damping off of OSR crops worldwide (Berkenkamp & Vaartnou, , Gugel et al , ; Kataria & Verma, ; Verma, ; Khangura et al , ; Hwang et al , ).…”

“…Other root infecting pathogens like Rhizoctonia solani Kühn [teleomorph Thanatephorus cucumeris [(A.B. Frank) Donk] have been reported from Finland in connection with damping off on cabbage (Linnasalmi, ) and oilseed rape seedlings (Tahvonen et al , ). According to Tahvonen et al () damping‐off was present in 90% of OSR fields surveyed during 1981–82.…”

“…Frank) Donk] have been reported from Finland in connection with damping off on cabbage (Linnasalmi, ) and oilseed rape seedlings (Tahvonen et al , ). According to Tahvonen et al () damping‐off was present in 90% of OSR fields surveyed during 1981–82. Stem base and root injuries in adult OSR plants caused by R. solani have been reported to occur in low frequency in 1980s (Hannukkala, ) but no studies on their impact in current Finnish OSR production has been published.…”