Recently, readers of Mr. Ma of Xiping County, Ms. Li of Shangshui County, and Mr. Zhu of Linzhou City called the newspaper's Technology Hotline 110 to inquire about the problem of cucumber bacterial angular spot. On this issue, the reporter interviewed experts from the expert advisory group of the newspaper. Experts pointed out that cucumber bacterial leaf spot disease is a bacterial disease, mainly harmful to cucumber, gourd, gourd and other cucurbit crops. The disease is the main disease of cucumber.
First, the harm symptoms
Cucumber bacterial angular spot disease mainly damages leaves and fruits, but also can harm stems, petioles and tendrils. Seedlings and adult plants can be infected.
The infected leaves were infected with the leaves of the lower mature leaves and gradually developed toward the upper leaves. The lesions initially developed water-stained spots, which were limited by veins. The lesions were polygonal, pale yellow to brown, and the edges were yellow halo. When the air humidity is high, the back part of the disease produces milky opaque mucus, called bacilli, which is a characteristic symptom of bacterial diseases. When the air is dry, the back pyome is dehydrated and forms a white mark. The diseased part is brittle, and the rupture causes perforation. (Cucumber downy mildew, and when the back spot is in high humidity, an off-white mildew layer appears). When the disease is severe, the lesions are covered with leaves, and the leaves dry and curl off.
Cotyledon was infected at the seedling stage, and it was water-stained like a small round spot at the beginning of the disease. It was slightly sunken and then became yellow-brown.
The fruit was infected and the skin began to appear watery spots, and after the enlargement, the lesions were light brown and sunken. In severe cases, the lesions are connected and become irregular. The diseased part produces a large amount of opaque mucus that is bacillary pus. The old lesions are gray and white and form an ulcer-like crack. When the disease is severe, the pulp tissue may be impregnated, the pulp may be discolored, and the seeds may be impregnated to carry the bacteria. Young fruit is infected, often causing fruit drop or malformed fruit.
Second, prevention and control measures
(A) Seed and seed treatment. Seeds were collected from disease-free seedlings and disease-free seeds were selected. When seeds are introduced, they must be seeded before sowing, and soaked in warm water at 50°C for 20 minutes.
(b) Passage rotation. It is advisable to implement a year round rotation with non-cucurbit crops in order to reduce the source of field germs.
(c) Strengthen field management. To cultivate cucumbers in pipe sheds and multi-span greenhouses, fertilizer and water management should be strengthened, and ventilation and ventilation should be carried out at appropriate times. The management of the fertilizer and water should be lightly poured, and the watering and fertilizing should be on sunny mornings, and ventilation and dehumidification should be started in a timely manner. In the rainy days when the temperature is not lower than 12°C, it is still necessary to maintain adequate ventilation every day.
(D) clean up the pastoral. In the period of disease, timely removal of old leaves, increase air and light in the fields, clean the pastoral areas after harvest, remove diseased bodies, and bring them out of the fields to be deeply buried or burned, deepen the soil, and accelerate the decay and decomposition of the diseased bodies. Re-infect the pathogen source.
(e) Hypohydration and disease control. Clean up the ditch system to prevent accumulation of water after the rain, reduce the groundwater level and the humidity in the greenhouse, and control the disease environment.
(6) Chemical control. The spraying began at the beginning of the disease. The interval between medications was 7-10 days, and the spraying was continued 3 or 4 times. Severe disease field development as the disease, if necessary, increase the number of spraying. The agent can be selected from 47% Garethon WP 600-800 times (125-165 grams per mu), 50% Daisen Aqueous Solution 1000 times (100 grams per mu), 72.2% Precise Liquid agent (100 grams per acre), Fenghuo amine wettable powder 800 times fluid (mu dose 125 grams), 30% DT wettable powder 600 times fluid (mu dose 165 grams), 77% can kill Wet powder 1000 times (100 grams per mu) and so on.
(+)Sparteine
Natural Sparteine,Plant Therapy Sparteine,Sparteine Cas 492-08-0,Sparteine Extract Powder
Shaanxi The River Pharmaceutical Co., Ltd. , https://www.dahepharma.com