Suppression of Common Scab of Potato Caused by Streptomyces turgidiscabies Using Lopsided Oat Green Manure

Abstract

Field experiments were conducted to determine the effect of green manure as fallow on common scab of potato caused by Streptomyces turgidiscabies. Significantly fewer diseased tubers were harvested from soil incorporated with lopsided oat or woolly pod vetch compared with those from oat and continuous potato cultivation in a planter experiment. Each field experiment consisted of lopsided oat cultivated during the spring and summer prior to the potato planting. Comparisons were also made with several other treatments, including cultivation of woolly pod vetch, oat, soybean, sugar beet, and potato (‘Yukirasya’, which is resistant to potato common potato scab) and soil application of Ferosand (Fe, mainly FeSO4, to decrease the soil pH). In field experiments conducted during 1999–2000, treatment with lopsided oat followed by lopsided oat or woolly pod vetch was significantly more effective at suppressing the disease severity than oat and continuous potato cultivation (P < 0.001). An increase in the marketable tuber ratio was also more significant than for oat and continuous potato cultivation (P < 0.001). In field experiments conducted during 2000–01, lopsided oat cultivation alone and with the application of Ferosand (1.8 t/ha) or resistant potato cultivar treatment were significantly more effective at suppressing the disease severity and incidence than sugar beet cultivation (P < 0.001), even under high disease intensity in the field. However, potato yield had a tendency to reduce after lopsided oat treatment with an application of Ferosand (1.8 t/ha) compared with lopsided oat alone or the application of Ferosand at 600 kg/ha, due to low pH conditions. In field experiments conducted during 2001–02, the lowest severity and incidence of common scab of potato were observed in soil treated with lopsided oat than with other treatments (P < 0.05 and P < 0.001, respectively). These findings suggest that lopsided oat used as fallow green manure can reduce the severity of common scab and increase potato yield.

Seasonal Shifts in Bacterial Community Structures in the Lateral Root of Sugar Beet Grown in an Andosol Field in Japan

“…One dominant ASV identified for Streptomyces (ASV_001) in the present study shared 100% identity with Streptomyces scabiei and Streptomyces turgidiscabies (Table S5). Consistent with these results, sugar beet has been reported as an alternate host for S. turgidiscabie, and, thus, potato production following sugar beet cultivation may cause an outbreak of potato common scab, as reported by Sakuma et al (2011). Besides Streptomyces, three genera in Actinomycetales (Kribbella, Kutzneria, and Amycolatopsis) were identified as dominant genera (Table 2 and 4).…”

Continuous Cropping Alters Multiple Biotic and Abiotic Indicators of Soil Health

“…Similarly, it may reduce soil pH and increase soil acidity in relatively acidic soils. At present, the impact of CC on soil physicochemical properties and nutrient availability is mostly tested in relatively acidic soils, while most studies have reported a reduction in soil pH and an increase in soil acidity under CC of several crops such as black pepper [240], tobacco, [241], tea [242], wheat [243], potato [244], corn [245] and soybean [246], including several other crops. A reduction in soil pH under CC is mostly attributed to the use of nitrogenous fertilizers, tillage intensity, biodegradation of crop residues, and resultantly increased production of organic acids in the soil.…”

Cultural Practices Influencing Biological Management of Crop Diseases

“…Treatment with lopsided oat followed by lopsided oat or wooly pod vetch was signi fi cantly more effective (P < 0.001) in suppressing the disease severity than oat and continuous potato cultivation. An increase in the marketable tuber ratio was also greater in this treatment than for oat and continuous potato cultivation (Sakuma et al 2011 ) .…”