Interaction between a biostimulant and cyazofamid in the control of clubroot of crucifers under conditions of high disease density

ABSTRACT Clubroot of crucifers is a root disease caused by the fungus Plasmodiophora brassicae, responsible for causing more than 40% economic damage to brassica crops. This disease has led to a gradual decline in brassica production in several countries, including Brazil, where an approximate volume of 50 thousand tons are marketed every year. There are few studies involving the control of this disease, which led to the development of an experiment with four treatments: T1. negative control, T2. biostimulant (phosphorus + auxin + fulvic acid), T3. biostimulant + fungicide (phosphorus + auxin + fulvic acid + cyazofamid) and T4. fungicide (cyazofamid). The lowest incidence value obtained in the last evaluation was 21% (79% control) with the mixture of biostimulant and fungicide; the biostimulant alone did not significantly differ from the negative control, considering the condition of high inoculum density, which serves as a basis for future studies with a mixture of new compounds and biocontrol agents compatible with the fungicide.

摘要：十字花科根肿病（Clubroot of crucifers）是由芸苔根肿菌（Plasmodiophora brassicae）引发的根部病害，可对十字花科作物造成超过40%的经济损失。该病害已导致包括巴西在内的多个国家十字花科作物产量逐步下滑，巴西每年十字花科作物的上市量约为5万吨。目前针对该病害的防治研究较少，为此本研究设置了4组处理开展试验：T1为空白对照，T2为生物刺激素（磷+生长素+黄腐酸），T3为生物刺激素+杀菌剂（磷+生长素+黄腐酸+氰霜唑（cyazofamid）），T4为杀菌剂（氰霜唑（cyazofamid））。末次调查结果显示，生物刺激素与杀菌剂复配处理的发病率最低，为21%（防治效果达79%）；在高接种体密度条件下，单独施用生物刺激素与空白对照无显著差异，该结果可为后续筛选与该杀菌剂兼容的新型化合物及生防制剂的复配研究提供参考依据。