Occurrence and Control Techniques of Nectarine Scab

Peach scab disease mainly harms peach fruit and also harms shoots and leaves. The fruit was mostly attacked at the top. The victim was only in the part of the skin. The diseased part had a dark green round spot, and gradually expanded into a purple-black or reddish-brown spot. It was slightly sunken with a layer of black mold on top. As the disease department is corky and the fruit enlarges, the diseased part often cracks or deforms. Branches were first seen in light brown round spots, the edge of purple brown, dark brown later, slightly elevated, often flow phenomenon occurs. The leaves were damaged, and the primary polygonal or irregular gray-green lesions gradually expanded to become brown or purple, and finally the diseased part fell off and became perforated.
Temperature and humidity are the main conditions for the onset of infection by Peach smear. The pathogenic bacteria used the hyphae to overwinter on the lesions of the branches that year, and when the spring temperature reached 10°C and the air humidity was more than 80%, the disease began to infect and was reinfected by wind and rain. Rain and high temperatures are conducive to disease. The incubation period of the scab pathogen is as long as 40 days or more. It usually begins 6 weeks after the petals fall off. The early-middle-maturing peach varieties have a lighter incidence, and the late-maturing varieties suffer more.
The early symptoms of peach scab are not obvious, only dark green dots are often overlooked. When the lesions appear, the germs have already invaded the peels. It is difficult to control the spraying and the prevention and cure should be mainly prevention. Spraying 3 Baumide Lithosulfurous Mixtures during flower buds, spraying 5 Baume Degree Limestone Sulfur Mixtures when the buds are slightly exposed. Xie spend 70% when spraying 80% spray grams of 600 to 800 times the liquid, or 50% of the US 500-500 times the level of Fumei zinc, or 40% Fuxing 8000 to 10000 times EC 1 times, and then spray 1 time interval 15 days.