Strawberry is a kind of herbal berry with a sweet taste. It is popular among consumers because of its good taste and health care function. In recent years, the production of strawberries, especially those grown in greenhouses, has been frequently affected, which has seriously affected the planting benefits. Disease control has become a top priority for strawberry production to improve quality and efficiency. First, the common diseases of strawberries Common diseases of strawberry include powdery mildew , gray mold , anthracnose, rotten fruit disease (ultimate pyomymosis), blight , bud, virus disease, etc., but most of them are powdery mildew and gray mold. 1. Symptoms of powdery mildew: The aboveground part can be susceptible to disease. The early stage of the leaves is dark-colored lesions, which vary in size. Then, white powder is produced on the leaf back lesions, and the leaves are atrophied and dried up. After the young fruit is damaged, it stops growing and is covered with a layer of white powder. 2, gray mold symptoms: the whole growth period can be onset, especially the fruit ripening period is most obvious. 1 After the leaves are infected, brown spots form, forming a layer of light gray conidia in the case of moisture. 2 After the petiole is infested, the lesions become brown around the petiole, and finally the wilting is dry. 3 After the young fruit is infected, a single brown spot begins to form, and then the fruit is rotted, and the pulp tissue becomes soft and water-immersed. Loss of aroma and color, the late stage of the diseased gray moldy sporozoites and conidia. Conidia spread with wind and water and infect. Second, the cause 1, low temperature and high humidity: low temperature and high humidity is the main factor of disease prevalence, the onset temperature of 20 ° C -25 ° C, the lowest 4 ° C to the highest 30 ° C -32 ° C can be onset. Conidia can be inoculated at 13.7 ° C - 29.5 ° C, so the lower temperature is most conducive to disease. 2, planted too dense, partial application of nitrogen fertilizer: prolonged, insufficient light, poor drainage are conducive to the onset. In particular, fruit resistance is the weakest in the early to mid-term of fruit coloring, and it is most susceptible to illness. Third, prevention measures 1. Preventive measures: deep sorghum, mulch covered with mulch, generally 30-40 cm deep, and cover the mulch to the bottom of the ditch to reduce the incidence of fruit and soil contact, and do a good job of drainage to reduce the harm. Remove dead leaves and diseased leaves in time. Adding organic fertilizer, especially the biological fertilizer “Tudela†to improve the soil. Appropriate amount of nitrogen, phosphorus and potassium should be balanced to control the amount of nitrogen fertilizer to prevent the length of the plant. At the same time, it should be properly planted, and the number of plants per mu should be controlled within 8000 plants to facilitate ventilation and light transmission. Appropriate amount of micro-fertilizer to improve disease resistance. The fast-acting boron and copper sulfate and manganese sulfate are sprayed at the beginning of the growth of the young leaves and at the bud stage. In the growing season 7-10 days, spray the marine biological immunization preparation Haitianli 600 times liquid spray 3-4 times to enhance the disease resistance of strawberry. 2, chemical control: the principle is biological + chemical, internal resistance + external inhibition of prevention and treatment methods. Powdery mildew 25% triazolone wettable preparation 3000-5000 times + Haitian force 600 times solution, or 10% difenoconazole water dispersion granule 2000-2500 times + Haitian force 600 times solution, or 12.5% ​​myclobutanil The 1500 times solution of the emulsifiable concentrate is alternately controlled with the pesticide bactericide. In the growing season (avoiding flowering stage), gray mold can be sprayed with polyoxymycin WP 500 times + Shi Bike 600 times solution, or 50% pyrimethanil 600 times solution, pay attention to alternate medication. Optical Diffraction Gratings,Optical Grating,Diffraction Grating,Manufacturing Of Ruled Gratings China Star Optics Technology Co.,Ltd. , https://www.csoptlens.com
Symptoms and prevention methods of strawberry diseases in greenhouse