排序方式: 共有3条查询结果,搜索用时 15 毫秒
1
1.
Yigal Cohen Avia Rubin Dror Gotlieb 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(1):169-183
Four carboxylic acid amide (CAA) fungicides, mandipropamid (MPD), dimethomorph (DMM), benthiavalicarb (BENT) and iprovalicarb
(IPRO) were examined for their effects on various developmental stages of Bremia lactucae, the causal agent of downy mildew in lettuce, in vitro and in planta. Spore germination in vitro or on leaf surfaces was inhibited
by all CAA fungicides (technical or formulated). MPD was more effective in suppressing germination than DMM or BENT, whereas
IPRO was least effective. CAA induced no disruption of F-actin microfilament organisation in germinating spores of B. lactucae. CAA applied to germinating spores in vitro prevented further extension of the germ tubes. When applied to germinated spores
on the leaf surface they prevented penetration. Preventive application of CAA to intact plants inhibited infection. MPD was
more effective in suppressing infection than DMM or BENT, whereas IPRO was least effective. Curative application was effective
at ≤3 h post-inoculation (hpi) but not at ≥18 hpi. CAA (except IPRO) applied to upper leaf surfaces inhibited spore germination
on the lower surface and hence reduced infection. CAA suppressed sporulation of B. lactucae on floating leaf discs and when sprayed onto infected plants two days before onset of sporulation. BENT and DMM were more
effective in suppressing sporulation than MPD or IPRO. Epidemics of downy mildew in shade-house grown lettuce were suppressed
by CAA. A single spray applied to five-leaf plants before transplanting controlled the disease for 50 days. The results suggest
that CAA are effective inhibitors of spore germination and therefore should be used as preventive agents against downy mildew
of lettuce caused by B. lactucae. 相似文献
2.
[目的]研究杀菌剂双炔酰菌胺在马铃薯上施用后的残留动态并以此制定其合理的使用方法。[方法]在吉林和南京同时进行了残留动态试验,利用液相色谱法分析测定。[结果]双炔酰菌胺在马铃薯植株中半衰期为4.5~7.5d,在土壤中半衰期为7.8~11.7d;试验条件下,双炔酰菌胺在最后1次施药后间隔3、7、14d均未在马铃薯中检出残留量。[结论]25%双炔酰菌胺悬浮剂在马铃薯上合理使用方法为:以75~150ga.i./hm^2喷施3次,安全间隔期3d;双炔酰菌胺在马铃薯中最高残留限量推荐值为0.01mg/kg。 相似文献
3.
Zheng-He TangYi-Ping Hou Si-Ping ZhangJian-Xin Wang Ming-guo Zhou 《Crop Protection》2011,30(3):354-359
Litchi downy blight caused by Peronophythora litchii is a devastating disease of litchi plants in China. Control of litchi downy blight requires numerous fungicide applications. A new carboxylic acid amide (CAA) fungicide, mandipropamid, was examined for its in vitro effects on multiple asexual stages of four single-sporangium P. litchii isolates and protective activity against downy blight in detached fruit assays. Though mandipropamid did not affect discharge of zoospores from sporangia, it strongly inhibited mycelial growth (mean EC50 = 0.0048 μg ml−1), sporangia production (mean EC50 = 0.0032 μg ml−1), germination of encysted zoospores (mean EC50 = 0.0023 μg ml−1), and germination of sporangia (mean EC50 = 0.0061 μg ml−1). On detached fruit, 0.39, 1.56 and 6.25 μg ml−1 of mandipropamid were superior in reducing downy blight compared to metalaxyl and flumorph, however, the 25 μg ml−1 application rate was necessary for all three CAA fungicides to completely inhibit the disease. In 2007, 100 isolates from Fujian, Guangdong, and Guangxi Provinces of China were characterized for the baseline sensitivity to mandipropamid. The isolates obtained from different provinces showed similar baseline sensitivities to mandipropamid. Baseline sensitivities formed a unimodal curve with mean EC50 values of 0.0055 ± 0.0012 μg ml−1 for inhibition of mycelial growth. The described baseline sensitivities of P. litchii populations will be useful for monitoring possible shifts in sensitivity to mandipropamid. 相似文献
1