Schillinger W F, Paulitz T C
Department of Crop and Soil Sciences, Washington State University, Dryland Research Station, P.O. Box B, Lind 99341.
Root Disease and Biological Control Unit, United States Department of Agriculture Agricultural Research Service, Washington State University, Pullman 99164-6430.
Plant Dis. 2006 Mar;90(3):302-306. doi: 10.1094/PD-90-0302.
Rhizoctonia bare patch caused by Rhizoctonia solani AG-8 is a major fungal root disease in no-till cropping systems. In an 8-year experiment comparing various dryland no-till cropping systems near Ritzville, WA, Rhizoctonia bare patch first appeared in year 3 and continued unabated through year 8. Crop rotation had no effect on bare patch during the first 5 years. However, from years 6 to 8, both soft white and hard white classes of spring wheat (Triticum aestivum L.) grown in a 2-year rotation with spring barley (Hordeum vulgare L.) had an average of only 7% of total land area with bare patches compared with 15% in continuous annual soft white wheat or hard white wheat (i.e., monoculture wheat). In years 6 to 8, average grain yield of both soft white wheat and hard white wheat were greater (P < 0.001) when grown in rotation with barley than in monoculture. Although both classes of wheat had less bare patch area and greater grain yield when grown in rotation with barley, monoculture hard white wheat was more severely affected by Rhizoctonia than soft white wheat. Soil water levels were higher in bare patches, indicating that roots of healthy cereals did not grow into or underneath bare patch areas. This is the first documentation of suppression of Rhizoctonia bare patch disease in low-disturbance no-till systems with rotation of cereal crops.
由立枯丝核菌AG-8引起的丝核菌光秃斑块病是免耕种植系统中的一种主要真菌性根病。在华盛顿州里茨维尔附近进行的一项为期8年的比较各种旱地免耕种植系统的试验中，丝核菌光秃斑块病在第3年首次出现，并在第8年一直未减弱。在前5年，作物轮作对光秃斑块病没有影响。然而，从第6年到第8年，与连续种植一年生软白小麦或硬白小麦（即单一栽培小麦）的15%相比，与春大麦（Hordeum vulgare L.）进行两年轮作种植的软白和硬白两类春小麦（Triticum aestivum L.）平均只有7%的土地面积出现光秃斑块。在第6年到第8年，软白小麦和硬白小麦与大麦轮作种植时的平均籽粒产量均高于单一栽培（P < 0.001）。虽然两类小麦与大麦轮作种植时光秃斑块面积较小且籽粒产量较高，但单一栽培的硬白小麦比软白小麦受丝核菌的影响更严重。光秃斑块处的土壤水位较高，这表明健康谷物的根系没有生长到光秃斑块区域内或其下方。这是首次记录在低干扰免耕系统中通过谷类作物轮作抑制丝核菌光秃斑块病。
