广西园林菟丝子发生危害及药剂防除筛选试验

【目的】明确广西园林菟丝子发生种类及危害规律，并筛选高效、经济、安全的药剂品种，为菟丝子防治提供科学依据。【方法】以南宁市为中心，对北海、柳州、梧州及百色市的靖西、德保、平果县的园林菟丝子发生情况进行调查，鉴定菟丝子种类，统计分析危害情况；针对主要菟丝子种类，选用9种药剂品种进行防治筛选试验，并设点记录观察菟丝子年消长动态。【结果】广西园林菟丝子以大花菟丝子为主，其次为南方菟丝子和日本菟丝子。菟丝子发生危害与空气温、湿度密切相关，每年发生危害严重期为6～9月，也是防除的重点时期。药后30d，6％菟丝特对菟丝子茎尖和藤茎的最高防效分别为100．0％和97．8％，对黄素梅和小叶榕安全；其他药剂或药效较高但有不同程度药害发生，或对菟丝子无效，效果均不理想。【结论】6％菟丝特AS对园林树木安全，具有高效、安全、经济的特点，是防除菟丝子的理想药剂，推荐用量为333．3mg／kg。

Occurrence and growth dynamics of Semen cuscutae in gardens of Guangxi and evaluation of herbicides for its control

Objective]The occurrence and damages caused by different categories of Semen cuscutae were investigated in gardens of Guangxi, and efficient, economic and environmentally safe herbicides were evaluated to control the spread of S. cuscutae. Method]The annual growth dynamics and damages caused by different categories of S. cuscutae were inves- tigated in Nanning, Beihai, Liuzhou and Wuzhou City and Jingxi, Debao and Pingguo County of Baise City. Nine different herbicides were evaluated to analyze their efficiency in controlling the spread of S. cuseutae. Result]The main categories of S. cuseutae in Guangxi gardens was found as Cuseuta reflexa Roxb., followed by C. japonica and C. australis R. Br. The damages caused by S. cuscutae were found closely related with temperature and humidity of air. It was found to harm the plants severely from June to September, which was the most important period for applying the control measures. The application of 6% bispyribac-sodium＋sdp AS on meristem-tip and cane stems showed 100.0 and 97.8% control of S. cuscutae, which was safe for the garden plants such as Ficus microcarpa and Duranta repens cv.golden leaves, while the other herbicides were found phytotoxic to garden trees or inefficient on S. cuscutae. Conclusion]It is concluded that due to non toxic effects of 6% Tusite AS on garden trees and its high efficiency, and economic and safe use, it may be recommended for controlling the spread of S. cuscutae in gardens at the concentration of 333.3 mg/kg.