Application & Production Technology Research Unit, US Department of Agriculture, Agricultural Research Service, Stoneville, MS, USA.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009 Mar;26(3):381-7. doi: 10.1080/02652030802441521.
While soil application of a competitive non-toxigenic Aspergillus flavus strains is successful in reducing aflatoxin contamination in certain crops, direct application to aerial reproductive structures could be more effective for maize. A sprayable, clay-based water-dispersible granule formulation was developed to deliver non-toxigenic A. flavus strain K49 directly to maize ears. The efficacy of the K49 water-dispersible granule in mitigating aflatoxin in maize (Zea mays L.) was evaluated. Field studies were conducted to compare K49 colonization and effectiveness in reducing aflatoxin contamination when applied either as a soil inoculant or as a directed spray in plots infested with toxigenic strain F3W4. Fifty percent of non-toxigenic A. flavus was recovered from non-treated controls and from plots soil inoculated with K49 on wheat. In spray treatments with formulated or unformulated K49 conidia, over 90% of A. flavus recovered was non-toxigenic. Soil-applied K49 reduced aflatoxin contamination by 65% and spray applications reduced contamination by 97%. These findings suggest direct spray application of non-toxigenic A. flavus strains may be better than soil inoculation at controlling maize aflatoxin contamination and that a water-dispersible granule is a viable delivery system for maintaining viability and efficacy of the biological control agent, K49.
虽然将竞争性非产毒黄曲霉菌株施用于土壤可成功降低某些作物中的黄曲霉毒素污染，但直接应用于气生繁殖结构可能对玉米更为有效。开发了一种可喷雾的、基于粘土的水分散性颗粒制剂，以将非产毒黄曲霉菌株 K49 直接递送至玉米穗。评估了 K49 水分散性颗粒在减轻玉米（Zea mays L.）中黄曲霉毒素方面的功效。进行了田间研究，以比较 K49 在接种土壤或定向喷雾处理受产毒菌株 F3W4 污染的地块时的定殖和降低黄曲霉毒素污染的效果。未处理对照和用 K49 接种土壤的小麦地块中，回收了 50%的非产毒黄曲霉。在含有或不含配方 K49 分生孢子的喷雾处理中，回收的黄曲霉超过 90%是非产毒的。土壤施用 K49 可将黄曲霉毒素污染降低 65%，喷雾处理可将污染降低 97%。这些发现表明，与土壤接种相比，直接喷雾应用非产毒黄曲霉菌株可能更能有效控制玉米黄曲霉毒素污染，并且水分散性颗粒是维持生物防治剂 K49 存活和功效的可行递送系统。
