First, symptoms and causes Fruit is affected during the near-mature stage. At the early stages of the disease, brownish crescent-shaped or spot-like lesions appear near the lenticels. As the disease progresses, the lesions become larger, darker, and slightly sunken. Multiple lesions can appear on different parts of the fruit simultaneously. The surface of the pear develops irregular dark brown spots, patches, or textured areas. Due to its resemblance to scratch marks made by chickens, farmers commonly refer to this condition as "Chicken Paw Disease" or "Chicken Claw Disease." In severe cases, multiple lesions may merge into nearly circular depressions around the lenticels. The formation of these lesions is primarily caused by three factors: an imbalance of calcium nutrients after bagging, thickening and cracking of the fruit peel due to lack of protection from the epidermal layer, and high enzyme activity. The microenvironment inside the fruit bag differs from that of unbagged fruit, leading to a reduction in calcium levels. This combined effect increases pericarp cracking and weakens the protective stratum corneum, which triggers enzymatic reactions and browning. A dense tissue structure forms as a protective response, acting as an immune mechanism of the Huangguan pear. Therefore, the lesions do not spread further or cause rot; they mainly affect the market value of the fruit. Several factors influence the occurrence and spread of the disease, including the type of fruit bag (such as paper bags with varying levels of transparency and air permeability), excessive nitrogen fertilizer application, fruit growth rate, and environmental conditions like climate and soil fertility. Second, comprehensive prevention and control measures 1. Fertilization: Apply organic fertilizer in autumn and maintain balanced nutrient levels. Spread 3 to 5 cubic meters of organic manure per acre. For deep soils, it's recommended to dig and mix the fertilizer into the ground. For sandy, clayey, or alkaline soils, dig trenches and apply fertilizer directly. In severe cases, 100 to 200 grams of borax can be applied before flowering. During the fruit development phase, if the tree shows signs of weakness, apply a nitrogen-phosphorus compound fertilizer early in the growing season, ensuring the amount used does not exceed 3 kg per tree during the fruiting period. 2. Pruning and thinning: Winter pruning should focus on proper branch distribution to ensure good air circulation and light penetration within the canopy. Limit the number of fruits per acre to no more than 14,000, and keep the yield between 3,500 to 4,000 kg per acre. 3. Calcium spraying on young fruit: Before bagging, spray organic calcium sources such as Ryan Calcium on young fruit. Apply the solution every 7 to 10 days, and consider applying it two or three times depending on the severity of the issue. 4. Bagging: Use breathable and light-transmitting fruit bags (with about 10% light transmission) or those lined with active materials. The optimal time for bagging is from late May to early June. 5. Watering: Ensure adequate watering before flowering and after winter. In other periods, water according to the tree’s needs and avoid overwatering. In addition, using mulching techniques can help increase soil temperature and stimulate root activity, enhancing calcium absorption and reducing the incidence of the disease to some extent. Changzhou Ziying Metal Products Co., Ltd , https://www.ziyingmetal.com