With the increase in the area of ​​strawberry replantation in greenhouses, the incidence of powdery mildew is ahead of schedule, and the incidence of disease increases and the area of ​​occurrence increases. Strawberry powdery mildew occurred mainly in the greenhouse after the shed, which mainly invaded the leaves at the seedling stage, and flower and fruit were mainly infected in the flower and fruit stage. 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 become infected with petioles, fruit stems, and leaves with reddish-brown lesions and leaf margin atrophy. Dry. After January, when strawberries entered the flower and fruit stage, the flower changed from white to pink. After the disease, the young fruit can't grow normally and dry and wilting. The result is a layer of white hair, slow coloration, and fruit loss. Hardening stops growth; it seriously affects the commodity and food value of strawberries. Therefore, the following measures must be taken for prevention and control:
Select disease-resistant varieties and cultivate robust and sterile strawberry seedlings to control the occurrence of disease.
Application of organic fertilizer to maturity, compound fertilizer to be appropriate, in particular nitrogen fertilizer can not be used too much to prevent burning seedlings and prosperous; timely watering, control of soil moisture, greenhouse humidity, to meet the water requirement of the fruit flowering period; reasonable cultivation Density can increase the ventilation and light transmittance of greenhouse strawberries; timely removal of old leaves, diseased leaves, and diseased fruits.
The use of high-temperature stuffy greenhouse technology in greenhouse strawberry continuous cropping can eliminate bacteria in soil and diseased bodies, and can comprehensively prevent and treat various soil-borne diseases and other diseases of strawberries.
In the production of susceptible varieties such as Hong Yan, Hong Xia, etc., in the absence of disease before flowering with a protective fungicide for active prevention, with 1106 spores / g oligo-androgen wettable powder 3000 times spray, 2% Wuyimycin Aqueous 200 times spray, 4% Agri 120 water spray 400 times spray, 75% chlorothalonil wettable powder spray 600 times, sprayed once 7-14 days, better use of alternate agents.
After the onset of the disease, it should be controlled by the use of agents with protection and treatment effects. It should be sprayed with 50% carbendazim water dispersible granules 3000 times, 4% tetrafluoroether azole water solution 1000 times, and 10% difenoconazole water dispersible granules. 1500 times spray, spray once 7-10 days, the effect of alternate use of agents is better.
When the greenhouse humidity is high, a greenhouse of 50 meters and 8 meters in each shed is used to smoke 4 sheds of 2% ethericides or 20% chlorothalonil smokers. Sulfur fumigation device fumigation, each with 99.5% sulfur powder 20 grams, fumigation every 2 hours during the prevention period, the onset of fumigation every day for 8 hours, 7-10 times after continuous use to prevent the use of methods of recovery; fumigant alternate use of better.
Issues that require special attention:
The focus of strawberry powdery mildew is prevention. The control effect is limited after serious illness.
The azole drugs are commonly used in the prevention and treatment of strawberry powdery mildew in the greenhouse. A large dose or multiple doses of the drug may inhibit the growth of the strawberry.
Spraying any medication must avoid blooming and avoid producing berries and malformed fruits.
Frequent and extensive use of pharmaceuticals can also cause malformed fruit to contaminate the fruit surface. Wang Junxia Chen Haiming
At present, the incidence of Botrytis cinerea in the greenhouse is widespread, and a few infected green fruits have significant impact on tomato yield and quality. Due to the shortest temperature in the whole year, low-temperature and high-humidity micro-environment can easily cause tomato gray mold.
Botrytis cinerea mainly damages flowers and fruits, and also damages leaves and stems. Young fruit was heavier, and most of the stigma and petals were infested first and then transferred to the fruit. Fruits spread from the stalk to the fruit surface. The diseased skin was pale and soft rot. The disease minister produced a large number of gray green mold layers. In severe cases, the fruit fell off and became rigid after losing water. Leaf disease, mostly from the tips of the leaves, the lesions showed a "V" shape inward expansion, the initial water stains, light brown, there is no obvious shade between the dark and the phase, when wet, the lesion surface can produce gray mold, leaves withered . The stalk is infected, resulting in water-stained spots, and then rapidly expanding into an oval shape. When wet, the surface is brown and brown and the mold layer can cause death of plants above the diseased part.
Prevention:
Agricultural control: should be based on warming, water control, air release, and dehumidification, and should not be flooded to reduce the amount of condensation in the field; remove the diseased fruit and diseased leaves, and pay attention to using plastic bags to cover the diseased fruit and diseased leaves. Can be removed in order to avoid improper operation of pathogenic bacteria, disease transmission, especially after the tomato pull the pot to thoroughly clean the garden, thoroughly sterilized before planting the next crop, prevent Botrytis cinerea invasion of the crop.
Spraying and preventing disease should change the smoke-enhancing drugs during the continuous snowfall. The humidity in the shelter under the condition of continuous cloudy snow is very large. If the method of spraying the liquid is adopted to prevent the occurrence of diseases, the humidity in the shelter will be further increased, and the occurrence of the disease will be aggravated. Secondly, the tomato will be tender after spraying. Ye Yi Chinese medicine harm, not worth the candle. Change the spraying to smoke, not only can avoid the adverse effects caused by spraying, but also for the characteristics of the large number of pathogenic spores of Botrytis cinerea, spray easy to spread the spores of pathogens, disease prevention effect is poor. Take smoke-prevention and disease prevention can use 100-speed smoke agent, Botrytis sclerotiorum nuclear net again, fumigation time is 7-8 hours, 5-7 days, rotation of medication, to avoid pathogenic bacteria resistance, and thus improve drug efficacy.
On sunny days, chemical control is performed in the early stages of the onset of Botrytis cinerea. The medications are as follow: 50% SulfoMax 1000x, 50% Piohaiin 1000x, Vanyalin 800x, 40% Scarlet Suspension 1200x , 65% Tamyroxin WP 1000-1500 times, sclerotium net 800 times, 75% thiophanate-methyl 800 times, 45% Tektronix suspension 3000 times, 60% anti-mildew Po Supermicro 500 times liquid powder, 2% Wuyimycin agent 150 times liquid, the above agents are used alternately, once every 5 days, continuous spraying 2-3 times.
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