Kiwifruit gray mold mainly occurs in the flowering, young fruit and storage period of kiwifruit. In the severe years, the incidence of orchards and the incidence of storage period can reach more than 50%. Kiwifruit gray mold has become one of the main diseases that affect the healthy development of kiwifruit industry.
First, the symptoms of young fruit (from the end of May to early June) when the disease, the remaining stamens and petals dense gray spores, when the initial occurrence, young fruit hairs become brown, skin infection, in serious cases can cause fruit drop. Stamens and petals are attached to the leaves. As a result, roundish lesions are formed and the lesions expand and the leaves fall off. In the event of rain, the disease occurs more severely. After the victim suffers, the surface forms ash-brown mycelium and spores, which form black sclerotia. Fruits during storage are susceptible to infection.
Second, the occurrence of regular germs with sclerotia and conidia in fruit, leaves, flowers and other diseased tissues overwintering. At the beginning of the second year of flowering to the late flowering period, in the event of rainfall or high humidity, the pathogen infested the flower arbor causing flower rot. The tainted petals fell on the leaves and caused leaf spots. The tainted petals that remained in the young pedicel invaded the pulp from the stem cut. Causes the fruit to rot. The growth and development temperature of pathogenic bacteria is 0-30°C, and the optimum temperature is about 20°C. Compared with the fruit soft rot, the gray mold-producing bacteria thrived at temperatures below 20°C. Therefore, gray mold occurs more often at low temperatures. The pathogenic bacteria are prone to spore formation under conditions of high air humidity, and spread with wind and rain.
Third, control methods
1. Agricultural control
1) Implement ridge cultivation, pay attention to orchard drainage and avoid dense planting. Well-protected ventilation and light transmission, and suitable humidity conditions are the most basic requirements for orchard management. In the fall and winter season, attention should be paid to the removal of various types of plant debris and crop stalks in and around the park, and wooden piles should be avoided as much as possible.
2) Prevent shoot shooters from being prolonged, carry out summer cuts on overgrown branches, increase ventilation and light transmission, and reduce the humidity in the park. Density of the canopy is better when the sunlight is projected onto the floor of the ground and the mesh shape is better.
2, chemical prevention
1) Pre-harvest control. Spray fungicide before flowering, such as 50% quick-inking WP 500 times, 80% WP WP 1000 times, vinyl nucleus WP 500 times, 50% acetaminophen wettable powder 1500 times liquid and so on. Spray once every 7 days and spray 2-3 times. After summer cut, spray protective biocides or biological agents.
2) Post-harvest control. One germicide sprayed one week before harvesting. When fruit is harvested, avoid and reduce fruit injury and avoid picking fruit on cloudy days and when dew does not dry. Remove diseased fruit and prevent secondary infection. After storage, extend the pre-cooling time. Efforts are made to reduce the moisture content of the fruit before it is packaged and stored.
Farming Fence,Fresh Goji Berries,Goat Fence
Triangle Bending Fence ,Related Products Co., Ltd. , http://www.chsteelmesh.com