Low temperature, high humidity, low light conditions, cucumber prone to scab
Black spot disease is one of the major diseases on cucumbers. In recent years, it has been seriously affected in cucumber production areas such as Weifang and Shouguang in Shandong Province. The symptoms, occurrence rules, and prevention and control measures are described below. Cucumber scab, also known as scab, can harm multiple parts of the cucumber. Leaves suffer, first appear chlorotic small spots, after the lesions expand and rupture perforation, round or star-shaped cracking, some lesions with yellow halos, high humidity when the lesion on the back of gray spots and amber layer of plastic Species (mycobacterial spores and conidia) often cause leaf margins to shrink and deform. The stems were damaged, and the lesions were mostly ellipsoidal in the oval shape. The lesions in the later stages were cracked and the gray mold layer appeared when the humidity was high. The squash was damaged and there were small water-stained spots. After the lesions expanded, the sulci was cracked and scab-like. The diseased part overflowed from milky white to amber-colored jelly and became yellow-brown granules. Cucumber scab is a fungal disease. The pathogenic bacteria overwinter on mycelia in the soil, or winterize with conidia and mycelium on the seed. The following year, the germs produced conidia and spread through air currents or rain. Germs can directly penetrate the plant's epidermis and can also invade from natural orifices or wounds. The incubation period is generally 3 to 8 days. The higher the temperature, the shorter the incubation period. The suitable temperature for disease onset is 20～23°C, and the suitable humidity is more than 90%. It is likes weak light. Therefore, the temperature of greenhouses with low temperature, high humidity and poor light transmission is early and serious in spring and autumn. To prevent cucumber black spot disease, comprehensive measures should be taken. (1) Seed disinfection. Can be used 2.5% Bromofluonitrile suspension seed coating agent 10 ml water 150 ~ 200 ml, mix and mix 5 ~ 10 kg of seeds, after sowing seeds. Can also use 50% carbendazim wettable powder seed dressing, pure drug dosage is 0.3% of the seed weight. (2) Strengthen field management. Scab is a low-temperature and high-humidity disease. Protected cultivation can reduce the humidity by releasing air, controlling the amount of water and the frequency of watering, and controlling the temperature of the greenhouse at 30-35°C to create environmental conditions that are not conducive to the development of the disease. (3) Chemical control. Before the onset of illness, 10% chlorothalonil smoke agents can be used to prevent smoke. 250-300 grams of medicine can be used per acre. Immediately after the onset of disease removal and spraying control, Fuxing 40% fluosilazole EC or 50% isoprenil wettable powder 1000 times spray, once every 7 days, continuous control of 3 to 4 times. The spraying time should be 9-10 o'clock in the sunny morning or 4-5 o'clock in the afternoon. When the temperature is high at noon, it is not suitable for spraying so as to avoid phytotoxicity. 4564567567567567 Empire Wedding Dresses,Empire Western Wedding Dresses,Empire Boho Wedding Dresses,Empire Sexy Wedding Dress Bosgoo(China)Tecgnology Co., Ltd , http://www.laohuang.com