symptom
Mainly damages leaves. The initial light brown irregular spots, then expanded into large light brown wet spots, and a gray mold layer was formed on the leaf back lesions, that is, the conidiophores and conidia of the pathogen. Severe diseased leaves turn dark brown and rot, lose water and turn black under dry conditions, and a lot of gray mold can be seen.
pathogen
Botrytis cinerea Pers.: Fr., called Botrytis cinerea, belongs to the fungal kingdom Ascomycota phylum Botrytis sclerotiorum.
Transmission routes and disease conditions
The northern germ overwinters on sick debris. In the following spring, a large number of conidia are produced and spread. The conidia of the southern pathogen spread through airflow and rainwater splashing for initial infection and re-infection. Since the field hosts exist all year round, the infection occurs repeatedly, and there is no obvious overwintering or oversummering period. The disease is a disease in the low-temperature region, and the conidia have strong ability to withstand dryness. They are easy to spread under low-temperature and high-humidity conditions, and the disease spreads quickly under warm and high-humidity conditions.
Prevention method
① Select moisture-resistant varieties such as Chiwuye and Donghu spinach.
②Strengthen field management to avoid low temperature and high humidity conditions. The low temperature not only weakens the vitality of the plants, but the low temperature lasts for a long time, and the plants are in a state of immortality for a long time, and the resistance is weak. In case of high humidity, it is easy to be infected with gray mold. Therefore, it is necessary to do everything possible to increase the temperature and reduce the humidity in the field or greenhouse. , is the fundamental measure to prevent and treat the disease.
③ After the spinach is harvested, remove the sick and disabled bodies in time, and burn them together or bury them deeply.
④ Reasonable watering and fertilization, timely drainage after rain, to prevent the emergence of disease conditions.
⑤ Spray 800 times liquid of 50% cyprodinil water-dispersible granules or 600 times liquid of 55% pyrimethanil·carbendazim wettable powder, or 1500 times liquid of 50% boscalid water-dispersible granules at the early stage of the onset.
