Cook R James, Weller David M, El-Banna Adel Youssef, Vakoch Dan, Zhang Hao
Scientist, Department of Plant Pathology.
Research Plant Pathologist, U.S. Department of Agriculture, Agricultural Research Service, Washington State University, Pullman 99164.
Plant Dis. 2002 Jul;86(7):780-784. doi: 10.1094/PDIS.2002.86.7.780.
Field trials were conducted with winter and spring wheat in eastern Washington and northern Idaho over several years to determine the benefit, as measured by grain yield, of seed treatments with rhizobacteria and formulated fungicides in cropping systems favorable to root diseases. The trials were conducted with wheat direct-seeded (no-till) in fields with a history of intensive cereals and one or more of the root diseases: take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8 and R. oryzae, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum. The seed treatments included Bacillus sp. L324-92, Pseudomonas fluorescens Q69c-80, Pseudomonas fluorescens Q8r1-96, difenoconazole + metalaxyl (Dividend + Apron), difenoconazole + mefenoxam (Dividend + Apron XL = Dividend XL), tebuconazole + metalaxyl (Raxil XT), and tebuconazole + thiram (Raxil-thiram). Controls were nontreated seed planted into both nontreated (natural) soil and soil fumigated with methyl bromide just prior to planting. Although the data indicate a trend in higher wheat yields with two rhizobacteria treatments over the nontreated control (171 and 264 kg/ha, respectively), these higher yields were not significantly different from the nontreated control (P = 0.06). Fungicide seed treatments alone similarly resulted in yields that were 100 to 300 kg/ha higher than the nontreated control, but only the yield responses to Dividend on winter wheat (289 kg/ha) and Dividend + Apron on spring wheat (263 kg/ha) were significant (P ≤ 0.05). The greatest yield increases over the nontreated control occurred with certain rhizobacteria-fungicide combinations, with three treatments in the range of 312 to 486 kg/ha (6.1 to 17.7%; P ≤ 0.05). Some rhizobacteria-fungicide combinations brought average yields to within 85 to 90% of those obtained with soil fumigation. Only soil fumigation produced a measurable reduction in the incidence of take-all and Rhizoctonia root rot, as assessed on washed roots. No reliable method exists for visual quantification of Pythium root rot on wheat.
在华盛顿州东部和爱达荷州北部，连续数年对冬小麦和春小麦进行了田间试验，以确定在有利于根部病害发生的种植系统中，通过谷物产量衡量，种子用根际细菌和配方杀菌剂处理的益处。试验在有密集谷物种植历史且存在一种或多种根部病害的田块中对小麦进行免耕直播，这些病害包括：由禾顶囊壳小麦变种引起的全蚀病、由立枯丝核菌AG8和稻立枯丝核菌引起的立枯丝核菌根腐病，以及主要由不规则腐霉和终极腐霉引起的腐霉菌根腐病。种子处理包括芽孢杆菌属L324 - 92、荧光假单胞菌Q69c - 80、荧光假单胞菌Q8r1 - 96、苯醚甲环唑 + 甲霜灵（适乐时 + 锐劲特）、苯醚甲环唑 + 精甲霜灵（适乐时 + 锐劲特XL = 适乐时XL）、戊唑醇 + 甲霜灵（敌委丹XT）以及戊唑醇 + 福美双（敌委丹 - 福美双）。对照为分别种植在未处理（天然）土壤和种植前用溴甲烷熏蒸过的土壤中的未处理种子。尽管数据表明两种根际细菌处理的小麦产量高于未处理对照有一定趋势（分别为171和264千克/公顷），但这些较高产量与未处理对照差异不显著（P = 0.06）。单独的杀菌剂种子处理同样使产量比未处理对照高100至300千克/公顷，但只有冬小麦对适乐时（289千克/公顷）和春小麦对适乐时 + 锐劲特（263千克/公顷）的产量反应显著（P≤0.05）。与未处理对照相比，某些根际细菌 - 杀菌剂组合的产量增幅最大，有三种处理在312至486千克/公顷范围内（6.1%至17.7%；P≤0.05）。一些根际细菌 - 杀菌剂组合使平均产量达到用土壤熏蒸获得产量的85%至90%。仅土壤熏蒸使全蚀病和立枯丝核菌根腐病的发病率有可测量的降低，这是在冲洗后的根部评估得出的。目前尚无可靠方法对小麦上的腐霉菌根腐病进行视觉定量评估。
