Control of Leather Rot of growing Strawberry

In recent years, with the optimization and adjustment of planting structure, the cultivation area of strawberry in Laizhou City has expanded rapidly. due to continuous cropping, the occurrence of strawberry diseases tends to be aggravated, especially the appearance of strawberry leather rot, which has a great impact on the yield and quality of strawberries. serious plots even lead to extinction. The symptoms and control methods of strawberry leather rot are introduced as follows:

First, symptoms. Strawberry leather rot mainly occurs in fruits and roots, and can also occur on stolons.

1. Root: the root occurs first, and the diseased root turns black from outside to inside, leathery and rotten. Field observation: there were no symptoms in the early stage, poor growth and slight dwarfism in the middle stage, and water loss in the aboveground part at the flowering and fruiting stage, and gradually wilted until the whole plant died.

2. Fruit: the damaged fruit shows a light brown hot spot, and can quickly spread to the whole fruit, the diseased part fades and loses luster, it has the feeling of leather-like hard hair gently pinched by hand, and white hyphae grow on the fruit surface when the humidity is high.

3. Seedlings: the disease can also occur during the breeding period, and the main symptom is that the stolon is dry and wilted and finally dried to death.

Second, pathogenic bacteria. The pathogen causing strawberry leather rot is flagellum Alternaria oryzae, also known as Phytophthora apple. The hyphae are colorless, branched, unseparated, sporangia terminal, subglobose or ovate, papillae more prominent. The sporangium exfoliated has a short stalk. The temperature range of mycelium formation is 10-30 ℃, and the optimum temperature is 25 ℃.

III. Conditions for onset of disease

1. Soil and seedlings. The disease is a soil-borne fungal disease. Using disease-free seedlings planted in disease-free fields generally will not cause disease. Therefore, whether there is a bacterial source in the soil and whether the strawberry breeding materials carry bacteria are the prerequisites for the occurrence of the disease.

2. Climatic conditions. The disease is a medium-temperature disease, and the temperature and humidity rise greatly in the middle and late May, which is beneficial to the occurrence and epidemic of the disease.

3. Cultivation factors. The disease is aggravated by continuous cropping or continuous cropping in diseased fields, and it is easy to occur in plots with poor drainage and night tide land.

Fourth, prevention and control methods: ⑴ to establish a disease-free seedling base, the implementation of a unified seedling supply. ⑵ leveled the land and ditches to prevent stagnant water. Irrigation should be carried out from 10:00 to 2 p.m., in order to dry in the evening. Once the disease occurs during the growth of ⑶, chemical control can be carried out in time, 64% disinfectant alum, fulvic acid, etc. can be used for root irrigation, and foliar spraying with 72.2% Prike 600x solution, 72% Klu 600x solution, etc., can achieve better control effects.