新型生物除草剂康土抑草菌的除草效果及其作用机理

Weed control effect and mechanism of a new bioherbicide AntiHerb EcoGuard

[目的]明确新型生物除草剂康土抑草菌的综合除草潜力、最优使用方法以及作用机理。[方法]通过室内试验明确康土抑草菌对马唐、稗草、反枝苋的生物活性后,以免炼山造林模式下的桉树幼林为试验对象,采用均匀试验设计布置了600、800、1200、2400 mL/hm^(2)4种剂量的田间除草试验,同时监测了康土抑草菌对植物叶绿素荧光特性的影响。[结果]施药后5 d,林地Pielou均匀度指数及Margalef丰富度指数显著降低,且剂量为800、1200、2400 mL/hm^(2)林地多样性指数显著低于600 mL/hm^(2)样地;整体而言,施药后3 d杂草防除率为50%,7 d达100%,50 d仍处82%~90%区间,能够有效控制棕叶狗尾草Setaria palmifolia、飞机草Chromolaena odorata等恶性杂草,且剂量为800、1200、2400 mL/hm^(2)林地杂草抑制率及杂草返青程度皆优于600 mL/hm^(2)处理;康土抑草菌作用机理为抑制植物光合性能,通过阻碍叶片光能捕获(TRo/CS)及光合电子传递(ETo/CS)降低杂草光合活性,进而抑制杂草生长。[结论]康土抑草菌控草效率高,效果稳定,对环境友好,符合当前新型农业需求,从经济要素出发,推荐最佳喷施剂量为800 mL/hm^(2)即稀释150倍,采取每年2次的喷施频率。

[Aims]This study aims to explore the comprehensive herbicidal potential,optimal use method and action mechanism of a new bioherbicide AntiHerb EcoGuard.[Methods]The biological activity of AntiHerb EcoGuard on Digitaria sanguinalis,Echinochloa crus-galli and Amaranthus retroflexu was determined by laboratory tests.The young Eucalyptus plantations under the non-burning arrangement was selected as the test object,and the field weeding trials with 4 doses of 600,800,1200 and 2400 mL/ha were arranged by uniform experimental design.At the same time,the effects of AntiHerb EcoGuard on chlorophyll fluorescence characteristics of plants was monitored.[Results]The experiment showed that on day 5 after treatment,the Pielou evenness index and Margalef richness index of forest land were significantly decreased,and the diversity index of forest land with doses of 800,1200 and 2400 mL/ha was significantly lower than that of 600 mL/ha.Overall,the weed control rate was 50%and 100%on days 3 and 7 after treatment,and was still in the range of 82%to 90%on day 50,which could effectively control malignant weeds such as Setaria palmifolia and Chromolaena odorata.In addition,the rate of weed inhibition and the degree of weed regreening at 800,1200 and 2400 mL/ha were better than those a 600 mL/ha.The mechanism of AntiHerb EcoGuard is to inhibit the photosynthetic performance of plants,by hindering leaf light energy capture(TRo/CS)and photosynthetic electron transport(ETo/CS),and furtherly inhibit weed growth.[Conclusions]The new bioherbicide AntiHerb EcoGuard has advantages of high weed control efficiency,stable effect,and environmental friendliness,which meets the current needs of new agriculture.Based on economic factors,the recommended optimal spraying dose is 800 mL/ha(150 times dilution),and the spraying frequency of 2 times per year is adopted.