Objectives : Control of Verticillium wilt of the smoke tree in the forestry farm of Badaling by studying the effect of different combination of chemicals and application techniques, we are exploring effective methods for the prevention and control of Verticillium wilt to ensure the health of smoke tree and the safety of the red leaf landscape in Beijing.
Methods : We selected five fungicides including Bacillus subtilis, 50% Azoxystrobin, 156 g/L Propiconazole, 50% carbendazim and 45% Prochloraz and set up 12 treatments to control Verticillium wilt in Badaling Forest farm by using injecting root and trunk or a combination of both.
Result : Analysis of the 2021 control data showed that the combination treatment 12 (root injection of propiconazole combined with trunk injection of carbendazim and azoxystrobin) was the most effective, with a corrective disease index of only 5, significantly different from the control (p < 0.05) and a corrective control effect of 88%. By comparing the disease indices of each treatment for the period 2021-2022, it was found that the most efficacy control combination for that year was root injection of propiconazole combined with trunk injection of carbendazim and azoxystrobin, with a corrected disease index of 5 and control effectiveness was 88%. Moreover, 26.67% of trees in this combination treatment remained healthy and had the highest number of healthy trees. The combination with the lowest disease index in May of the following year was a combination of Bacillus subtilis with root irrigation combined with trunk injections of carbendazim and azoxystrobin, which showed a good treatment efficacy with the highest number of healthy trees, and the severely diseased sample trees from previous years all turned to be healthy or lightly diseased. And, the combination has a disease index of only 3.33.
Conclusions : This study suggested that the combination of propiconazole in root irrigation and trunk injections of carbendazim and azoxystrobin was most efficacy, and that the combination of Bacillus subtilis in root irrigation and trunk injection of carbendazim and azoxystrobin performed well in terms of disease treatment and control, both of which can be used as control options for Verticillium wilt.