To identify effective fungicides for the control of gray mold in quinoa Chenopodium quinoa, the inhibitory effects and in vitro toxicity of 12 fungicides against pathogen Botrytis cinerea were determined. Two fungicides with different modes of action were selected for combination, and the optimal volume ratio and formulation of the combined fungicides were determined. The efficacy of the combined fungicides against gray mold in quinoa was comprehensively evaluated through in vitro leaf tests, in vitro pot experiments and field trials. The results showed that pydiflumetofen, azoxystrobin, tebuconazole and pyraclostrobin had significant in vitro toxicity against B.cinerea, with EC50 values of 0.49, 0.39, 0.09 and 0.03 μg/mL, respectively. When the volume ratio of pydiflumetofen to tebuconazole was 4∶6 and 5∶5, it showed a synergistic effect, with toxicity ratios of 1.49 and 1.37, respectively. When the mass ratio of pydiflumetofen and tebuconazole was 9∶2, the synergistic effect was optimal, and the synergistic coefficient was 2.85. After treatment with high and medium concentrations of the combined fungicides, the protective and treatment effect on in vitro leaves were 94.97%-97.18%, and the protective and treatment effect of indoor pot experiments were 71.45%-82.01%. The field control effects of the high and medium concentrations of the compound fungicides were 87.77% and 79.91%, respectively, which were higher than other treatments, and could significantly increase the yield of quinoa. It was indicated that the field recommended concentration of 200 g/L pydiflumetofen suspension concentrate (SC) and 430 g/L tebuconazole SC at a mass ratio of 9∶2 (200 μg/mL pydiflumetofen + 44.4 μg/mL tebuconazole and 160 μg/mL pydiflumetofen + 35.6 μg/mL tebuconazole) could not only effectively control gray mold in quinoa, but also significantly increase quinoa yield.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |