Pear rust prevention and control method
Pear rust, also known as brachyposis, also harms papaya, hawthorn, avocado, and paste stems, in addition to harming pears. Pathogens were transferred to the main hosts of Cypress, Eucalyptus, European Cyperus, South European cypress, tall cypress, Sabina, Cypress, Cypress, Cypress, Golden Feather cypress and Cypress, of which Eucalyptus as the main host. 1, symptoms Pear rust mainly damages leaves and shoots. When severe, young fruit is harmed. When the leaves are attacked, orange-orange to orange-red and glossy round spots appear on the surface of the leaves and slowly expand to a diameter of 4 to 8 mm. After the orange-yellow black dots, the diseased part of the mesocarp thickens and hardens, the front is sunken, the back is uplifted, and 4-5 mm long hairs are produced. It is a rust device for pathogens, and there are generally more than a dozen on one lesion. To dozens. After the lesions gradually darken, if there are too many lesions on one leaf, they are often dead and fall off. The symptoms of the young fruit and the new shoot are basically the same as those of the leaves, and the diseased fruit is easy to fall off. 2, the law of occurrence Pear rust is a fungal disease that causes parasitism. After the mature rust spores formed on the pear tree, they spread to the cypress on the wind and invade the branches and leaves of the cypress, forming the teliospores. The following spring, they encounter rainwater. The winter spores germinate to produce microspores and then pass through the wind to the pear trees. A certain period of time forms a sexual organ, and after a series of changes produces microspore and invades the pear tree. Spread distance is about 2.5-5 kilometers. Microspores can easily die in dry conditions. May-June is the epidemic period. 3, control methods (1) The cypress is completely removed within 5 km around the pear orchard to eradicate the host of pear rust. In the newly established pear park, cypress should be banned. (2) In the scenic area where the cypresses cannot be cut off, the diseased branches on the cypress should be cut off before the onset of the spring rain and sprayed 1-2 times with lime sulfur. (3) The pears spray 200 times equal amount of Bordeaux mixture or 20% Triadimefon EC 4000 times in the leaf stage and after flowering, and spray 25% Rhodiola sp. 800-1000 times in the early stage of disease. Hybrid Stepper Motors,Brushless DC Motors,Linear Motor,Gear Motor,Step-Servo Motors,Brushless Motors Changzhou Satidi Import and Export Co., Ltd. , https://www.guanjiejt.com