Greenhouse strawberry to prevent powdery mildew at seedling stage

In early November, the powdery mildew in the greenhouse strawberry seedlings has sporadically developed. The onset time is ahead of schedule and the severity of the disease has increased. The area has increased year by year, which has seriously affected the yield, quality, and food safety of strawberries. The growers should strengthen the field management of strawberries, scientifically select pesticides for prevention and control, use comprehensive prevention and control measures to control the occurrence, development and spread of powdery mildew in greenhouse strawberry seedlings, minimize the losses caused by diseases, improve product quality, and increase planting income.

In the greenhouse, powdery mildew occurred mainly in the shed after the shed. The seedling stage mainly invaded the leaves, and flower and fruit mainly infested the flowers and fruits. In the early stage of disease, there is a sparse white mold layer on the back of the leaves. As the disease progresses, the mold layer becomes thicker and forms thicker white round spots. In severe cases, the leaves roll up and infect the petioles, fruit stems, and the leaves produce reddish-brown lesions. The leaf margins are atrophic. Dry; flowers from susceptible to white to pink; young fruit after the disease can not be normal expansion, dry wilt; results of the consequences of a layer of white hair on the surface, the color is slowly uneven, the fruit loses luster and hardened to stop growing; seriously affect the strawberry The commodity value and food value.

Control measures Agricultural measures: Select disease-resistant varieties, cultivate robust and sterile strawberry seedlings, and control the occurrence of disease.

Rational management of cultivation and management of water and fertilizer; application of decomposed organic fertilizer, compound fertilizer to be appropriate, in particular, nitrogen can not be used too much to prevent burning seedlings and prosperous; timely watering to meet the water needs of the seedling period; use the tuyere to adjust the temperature inside the shed, Humidity; timely removal of old leaves, diseased leaves, clean gardens, increase the ventilation and light transmittance of greenhouse strawberries.

Chemical control of sensitive varieties, such as Hongyan, Hongxia, etc., at the seedling stage without disease and early stage of disease prevention with a protective fungicide, with 99% of mineral oil 200 times plus 1106 spores / gram of Pythium ophiopogon wettability Powder 3000 times spray, or 2% Wuyimycin water spray 200 times, or add 4% agricultural anti-120 water agent 400 times spray, or add 75% chlorothalonil WP 600 times spray, 7 to 14 days spray Once, the use of agents alternately works better.

After the onset of disease, use chemical agents with protection and therapeutic effects, use 99% of mineral oil 200 times plus 50% of oxastrobin water dispersible granules to spray 3,000 times, or add 4% of tetrafluoroether azole water to spray 1000 times, or Add 10% difenoconazole water dispersible granules 1500 times spray, 7 to 10 days spray once, the effect of alternate use of agents is better.

Pharmacy fumigation When the greenhouse humidity is high, 50m 8m sheds use 4% 2% ether oxime ester smoke agent/shed, or 20% chlorothalonil smoke agent 4/shed to smoke the shed, sulfur fumigation fumigation each time use 99.5 % sulfur powder 20 grams, fumigation every day during the prevention period of 2 hours, the onset of fumigation every day for 8 hours, after 7 to 10 times in conjunction with the recovery of the use of preventive methods; fumigant alternate use of better.