Mazzola Mark, Brown Jack
USDA Agricultural Research Service, Tree Fruit Research Laboratory, 1104 N. Western Avenue, Wenatchee, WA 98801.
Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow 83844-2339.
Plant Dis. 2010 Jul;94(7):835-842. doi: 10.1094/PDIS-94-7-0835.
The efficacy of brassicaceous seed meals for the control of apple replant disease and the effects of such treatments on the causal pathogen complex were examined in conventional and organic production systems. When used in conjunction with a postplant application of mefenoxam, Brassica juncea and Sinapis alba seed meal soil amendments were as effective as preplant fumigation of soil with 1,3-dichloropropene-chloropicrin in terms of disease control, tree growth, and overall fruit yields of Gala/M26. Brassica napus seed meal amendment-mefenoxam soil drench also enhanced yields in a manner comparable to preplant fumigation, but vegetative growth was intermediate between the control and fumigation treatments. When applied alone, seed meal amendments failed to enhance tree growth or control disease to the level attained in response to soil fumigation. Postplant mefenoxam treatments revealed that failure of seed meal amendments to enhance tree growth and yield when used independently was due, at least in part, to increased apple root infection by Pythium spp. in B. napus and S. alba seed meal-amended soils, and by Phytophthora cambivora in B. juncea-amended soil. As mefenoxam treatment is not compatible with organic cropping systems, a seed meal blend was formulated which, based upon biological activity, was predicted to suppress known components of the target pathogen complex without need of additional treatment. Gala/M26 trees planted in soils treated with a 1:1 ratio of B. juncea:B. napus seed meal blend performed as well in terms of disease control and vegetative growth as trees cultivated in fumigated soil at an organic-certified orchard. Because these trials utilized the highly susceptible rootstock M26, the results demonstrate that these amendments are a viable alternative to soil fumigation for the control of apple replant disease in both conventional and organic systems.
在传统和有机生产系统中，研究了十字花科种子粕对苹果再植病的防治效果以及此类处理对致病病原体复合体的影响。当与种植后施用甲霜灵配合使用时，芥菜和白芥子种子粕土壤改良剂在病害控制、树木生长以及嘎啦/M26的总体果实产量方面，与种植前用1,3 - 二氯丙烯 - 氯化苦熏蒸土壤的效果相当。甘蓝型油菜种子粕改良剂 - 甲霜灵土壤浇灌处理也以与种植前熏蒸相当的方式提高了产量，但营养生长介于对照和熏蒸处理之间。单独施用时，种子粕改良剂未能将树木生长或病害控制提高到土壤熏蒸所达到的水平。种植后甲霜灵处理表明，种子粕改良剂单独使用时未能提高树木生长和产量，至少部分原因是在甘蓝型油菜和白芥子种子粕改良土壤中，腐霉菌对苹果根系感染增加，在芥菜改良土壤中，食根疫霉对苹果根系感染增加。由于甲霜灵处理与有机种植系统不兼容，因此配制了一种种子粕混合物，根据生物活性预测，该混合物无需额外处理即可抑制目标病原体复合体的已知成分。在一个有机认证果园中，种植在以1:1比例的芥菜:甘蓝型油菜种子粕混合物处理的土壤中的嘎啦/M26树，在病害控制和营养生长方面与种植在熏蒸土壤中的树表现相当。由于这些试验使用了高度易感的砧木M26，结果表明这些改良剂是传统和有机系统中控制苹果再植病的土壤熏蒸的可行替代方法。
