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期 刊 ：植物保护学报 2008年

关键词：丙森锌；苹果褐斑病；室内毒力；田间防效；叶片锌含量；

Keywords:propineb, Marssonina coronaria, fungitoxicity test in the laboratory, chemical control trial in the field, leaf zinc content,

摘 要 ：为揭示有机硫杀菌剂丙森锌对苹果褐斑病菌Marssonina coronaria的毒力,采用液体培养的菌丝干重、繁殖体产生数量、分生孢子萌发率研究其室内毒力,并在田间不同时间喷施药剂后调查病情,同时利用原子吸收法测定叶片锌含量。结果表明,丙森锌可抑制病菌分生孢子萌发和分生孢子盘产生,但对菌丝生长的抑制作用相对较弱,其EC₅₀值分别为1.07、1.70和6.76μg·mL^-1;两年的田间药效试验结果表明,丙森锌在施用浓度为875mg·L^-1时对苹果褐斑病的防治效果达90%以上,与对照药剂代森锰锌(1000mg·L^-1)相当,表现出较好的防治效果;在陕西省关中地区每个生长季节的4月下旬至6月上旬(花后至幼果期)喷施2~3次,可有效控制病害的发生和流行,防治效果达90%。喷施丙森锌2次后70多天内苹果叶片的锌含量由20.9mg·kg^-1提高到75mg·kg^-1。

Abstract:Leaf blotch is the major disease led to severe defoliation in early summer in apple orchard. To reveal the control effect of propineb to Marssonina coronaria, the dry weight of mycelia from liquid culture, fruit body production and rate of conidia germination were used as parameters to evaluate the fungitoxicity in vitro; field disease control efficacy was estimated by survey in different time after spray and effect of propineb on leaf zinc content was evaluated by atomic absorption spectrometry. The fungitoxicity test in the laboratory showed that propineb exhibited stronger inhibition on conidial germination and acervuli formation, than on mycelial growth depending on EC₅₀ of each assay 1.07, 1.70 and 6.76μg·mL^-1, respectively. The field control trial in 2005 and 2006 revealed that the good control of Marssonina leaf blotch was achieved by spraying propineb at 875 mg·L^-1 with more than 90% control efficacy, as good as mancozeb at 1000mg·L^-1. Spray at different time and different frequencies showed that apply propineb two to three times from last ten days of April to early ten days of June in a growing season, the period from post-anthesis to young fruit stage, gave more than 90% control efficacy in Guanzhong region of Shaanxi Province. In addition, propineb remarkably increased the leaf zinc content from 20.9mg·kg^-1 to 75mg·kg^-1 in apple leaves in more than 70 d after 2 time applications.

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