Pear ring rot. At the onset of leaf disease, the lesion is nearly round, with obvious brown concentric wheel lines, and the later color is lighter with small black spots. First, select disease-resistant varieties, strengthen seedling quarantine, and prevent the introduction of diseases. Secondly, orchard management should strengthen the management of soil, fertilizer and water, increase the application of organic fertilizer and avoid partial application of nitrogen fertilizer; Pruning reasonably, thinning flowers and fruits reasonably, and then applying bagging technology to control diseases. When the diseased fruit is found in the field, it should be removed and buried in time, and the source of the disease should be removed in late autumn and early winter. Spraying bactericide on diseased tissues after winter shearing, and painting the whole stem white. Before pear trees germinate, the whole tree should be sprayed with 3~5 degrees sulfur mixture once. From the 7th day after flowering to the closing period of pericarp pores, 65,438+0,000 times of 70% mebuzin wettable powder or 600 times of 50% carbendazim wettable powder can be sprayed, and then double-layer bags can be used in time. From bagging to one month before fruit harvesting, 80% mancozeb wettable powder 1000 times, 70% thiophanate-methyl wettable powder 1000 times or 70% thiram water dispersible granules 1~2 times a month can be sprayed. After the fruit is harvested, the branches can be smeared with 5 Baume's mixture of stone sulfur and silicon powder (stone sulfur mixture: silicon powder = 10∶4) to control the spread of ring rot.