Saeed I A M, Rouse D I, Harkin J M, Smith K P
Assistant Researcher.
Professor, Department of Plant Pathology.
Plant Dis. 1997 Jul;81(7):773-776. doi: 10.1094/PDIS.1997.81.7.773.
Soil column studies were conducted to investigate the influence of soil water content and temperature on the efficacy of metham-sodium and its degradation product methyl isothiocyanate against Verticillium dahliae. The viability of the microsclerotia (MS) of the fungus in the top 30 cm of fumigated and control columns was measured. Temperatures for studies were 2 or 22°C, and the soil water content, expressed as soil matric potential, varied from -23 (wet), -113 (moist), to -2485 J/kg (dry). There was a significant interaction of soil water content and temperature on the efficacy of metham-sodium against V. dahliae MS. For the low soil temperature (2°C) the fumigant was more effective against MS of the fungus in wet than in moist or dry soil Soil water content did not affect fungicidal activity of metham-sodium when the soil columns were maintained at 22°C. These results suggest that the fumigant has a greater efficacy against V. dahliae in wet/cold soil conditions compared to the other conditions tested. Consequently, it was recommended that metham-sodium be applied to fields by chemigation in late fall or early spring to obtain efficacious results.
进行了土柱研究，以调查土壤含水量和温度对威百亩及其降解产物甲基异硫氰酸酯防治大丽轮枝菌效果的影响。测定了熏蒸柱和对照柱顶部30厘米处真菌微菌核（MS）的活力。研究温度为2或22°C，土壤含水量以土壤基质势表示，范围从-23（湿润）、-113（潮湿）到-2485 J/kg（干燥）。土壤含水量和温度对威百亩防治大丽轮枝菌MS的效果存在显著交互作用。对于低土壤温度（2°C），熏蒸剂在湿润土壤中对真菌MS的防治效果比在潮湿或干燥土壤中更有效。当土柱保持在22°C时，土壤含水量不影响威百亩的杀真菌活性。这些结果表明，与其他测试条件相比，熏蒸剂在湿冷土壤条件下对大丽轮枝菌具有更高的防治效果。因此，建议在深秋或早春通过化学灌溉将威百亩施用于田间，以获得有效的防治效果。
