| Cotinus Coggygria Scop, is the main tree species of red autumnal leaves in Beijing Fragrance Hill and other scenic spots. The cotinus coggygria verticillium wilt, caused by verticillium dahliae, can result in the extensive death of cotinus coggygria scop. So far, no effective control method has been found. The chemical control experiment, including root irrigation and trunk injection, has been conducted so as to evaluate the effect of factors, such as different medicament or combination and different application methods, on the control of cotinus coggygria scop, and red autumnal leaves landscape, thus selecting the most reasonable and effective control technologies. At the same time, a technological demonstration center has been successfully established by carrying out the efficacy promotion tests in Ming Tombs regions with results shown as below:(1) In the control experiment of root irrigation, the four medicament or combination has certain control efficiency on cotinus coggygria verticillium wilt; among which, the compound of azoxystrobin and carbendazim has the best control efficiency, whose correction and control effect in September and October is 102.41±10.81% and 28.15±8.73% respectively. It is then followed by the compound of chitin and bacillus subtilis with a correction and control effect of 90.52±21.29% andl3.96±18.57%; the single application of azoxystrobin and the compound of trichoderma harzianum and Bihu have the poorest control efficiency with a correction and control effect from-8.33±12.67% to 24.74±5.58%.(2) In the control experiment of trunk injection, the interactive processing of 9 groups of injection at the 0,0.5 and 1 meter and 400 times,600 times and 800 times dilution of chemical combination also has certain control efficiency on cotinus coggygria verticillium wilt; among which, injection at 0 m with 800 times of dilution has the best control efficiency, which amounts to as high as 108.33±10.91%, 93.75±13.36% and 76.19±21.99% from September to November. The control efficiency of Injection at 1 meter with 800 times of dilution ranks the second place, with a correction and control effect of 91.67±12.2%,87.5±18.9% and 71.43±21.99% respectively. Injection at 1 m with 600 times of dilution ranks the third place with a correction and control effect of 100±12.2%,56.25±24.55% and 57.14±32.99% respectively. Other groups have relatively lower efficiency, as evidenced by their effect from-11.11±12.7% to 56.25±9.45%.(3) The efficacy continuity of trunk injection is better than that of root irrigation. In the control experiment of trunk injection, the correction and control effect in the 9 groups still maintains between 12.5±23.97 and 93.75±13.36% even in October. However, the same application in control experiment of root irrigation is plagued by a decrease to 28.15±8.73% in its correction and control effect in October.(4) Chemical application is conducive to enhancing the efficacy at the peak period of incidence. Compared with the chemical control experiment of root irrigation, the time for chemical application in efficacy promotion experiment has been delayed for two months. With respect to the lasting time of control effect, the treatment group in efficacy promotion experiment possesses the correction and control effect of 104.83±6.47% and 82.3±9.95% in the peak period of incidence and the following month while that of root irrigation is simply 102.41±10.81% and 28.15±8.73% respectively. In terms of enhancing the red autumnal leaves landscape, the index of treatment group in efficacy promotion experiment is higher than that of the contrast group while the treatment group and contrast group in chemical control experiment of root irrigation show no obvious difference.(5) In efficacy promotion experiment, the overall investigation of the occurrence and development of cotinus coggygria verticillium wilt from June to November shows that the correction and control effect of treatment group is 97.2±12.06%,97.2±12.06%,82.3±9.95%,7.79±5.45%,20.34±4.53% and 5.68±4.24% respectively; at the same time, the three times of investigation of red autumnal leaves landscape in October and November reveal that, the red autumnal leaves index of treatment group is 26.93±0.61,50.3±1.19 and 65±1.26 respectively, which are all obviously higher than that of the contrast group of the same period. To sum up, the compound of azoxystrobin and carbendazim with 500-time dilution is possessed of high credibility, which lays a solid foundation for the successful establishment of technological demonstration. |
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