Phytopathology. 2001 Feb;91(2):221-7. doi: 10.1094/PHYTO.2001.91.2.221.
ABSTRACT All pesticides used in United Kingdom glasshouse lettuce production (six fungicides, four insecticides, and one herbicide) were evaluated for their effects on Coniothyrium minitans mycelial growth and spore germination in vitro agar plate tests. Only the fungicides had a significant effect with all three strains of C. minitans tested, being highly sensitive to iprodione (50% effective concentration [EC(50)] 7 to 18 mug a.i. ml(-1)), moderately sensitive to thiram (EC(50) 52 to 106 mug a.i. ml(-1)), but less sensitive to the remaining fungicides (EC(50) over 200 mug a.i. ml(-1)). Subsequently, all pesticides were assessed for their effect on the ability of C. minitans applied as a solid substrate inoculum to infect sclerotia of Sclerotinia sclerotiorum in soil tray tests. Despite weekly applications of pesticides at twice their recommended concentrations, C. minitans survived in the soil and infected sclerotia equally in all pesticide-treated and untreated control soil trays. This demonstrated the importance of assessing pesticide compatibility in environmentally relevant tests. Based on these results, solid substrate inoculum of a standard and an iprodione-tolerant strain of C. minitans were applied individually to S. sclerotiorum-infested soil in a glasshouse before planting lettuce crops. The effect of a single spray application of iprodione on disease control in the C. minitans treatments was assessed. Disease caused by S. sclerotiorum was significantly reduced by C. minitans and was enhanced by a single application of iprodione, regardless of whether the biocontrol agent was iprodione-tolerant. In a second experiment, disease control achieved by a combination of C. minitans and a single application of iprodione was shown to be equivalent to that of prophylactic sprays with iprodione every 2 weeks. The fungicide did not affect the ability of C. minitans to spread into plots where only the fungicide was applied and to infect sclerotia. These results indicate that integrated control of S. sclerotiorum with soil applications of C. minitans and reduced foliar iprodione applications was feasible, did not require a fungicide tolerant isolate, and that suppression of Sclerotinia disease by C. minitans under existing chemical control regimes has credence.
摘要 在英国温室生菜生产中使用的所有农药（六种杀菌剂、四种杀虫剂和一种除草剂）均在体外琼脂平板试验中评估了其对小球腔菌菌丝生长和孢子萌发的影响。只有杀菌剂对测试的三种小球腔菌菌株有显著影响，对异菌脲高度敏感（50%有效浓度 [EC（50）] 为 7 至 18 微克 a.i.毫升（-1）），对福美双中度敏感（EC（50）为 52 至 106 微克 a.i.毫升（-1）），但对其余杀菌剂的敏感性较低（EC（50）超过 200 微克 a.i.毫升（-1））。随后，所有农药均在土壤托盘试验中评估了其对作为固体基质接种物施用的小球腔菌感染菌核的能力的影响。尽管每周以推荐浓度的两倍施用农药，但小球腔菌仍在土壤中存活，并在所有施药和未施药对照土壤托盘中同等程度地感染菌核。这证明了在环境相关测试中评估农药兼容性的重要性。基于这些结果，在温室种植生菜作物之前，将标准和异菌脲耐受菌株的固体基质接种物分别单独应用于受菌核病侵染的土壤中。评估了单喷异菌脲对小球腔菌处理中病害控制的影响。无论生物防治剂是否耐受异菌脲，小球腔菌均可显著减轻由核盘菌引起的病害，并增强单喷异菌脲的效果。在第二个实验中，证明了将小球腔菌和单喷异菌脲相结合的组合控制可达到与每两周预防性喷施异菌脲等效的效果。该杀菌剂不会影响小球腔菌在仅施用杀菌剂的地块中的扩散能力和对菌核的感染。这些结果表明，采用土壤施用小球腔菌和减少叶面异菌脲施用量的方法来综合防治核盘菌是可行的，不需要使用耐受杀菌剂的分离株，并且在现有的化学防治方案下，小球腔菌对核盘菌病害的抑制作用是可信的。
