Greenhouse leeks are mainly pest control technology

In order to increase the income of vegetable farmers and the supply of early spring markets, and to ensure the safety of vegetable baskets, it is necessary to strengthen the pollution-free prevention and control of leek maggot infestations and leek blight and gray mold diseases.

1. Leek maggots, also known as root maggots (adult worms called leek late-eyed mushroom mosquitoes)

1, symptoms of leek maggot adult worms are oligovorous pests, mainly harmful to lily vegetables, larvae damage when moths into leeks and other bulbs or seedlings, so that the bulbs are mothed into many holes, causing rot, the upper leaves withered yellow, wilting, resulting in lack of seedlings and ridges, and even pieces of death, if not prevented in time will reduce the yield of leeks by 50% to 70%.

2. Prevention and control methods

(1) Agricultural prevention and control: Fertilization should be done to open ditches and apply deep soil, and not to apply uncorried organic fertilizer. In the peak of adult insects, it is necessary not to pour feces thin.

(2) Pharmaceutical prevention and control: 48% Lesben emulsion 375 ~ 750 times liquid, 40% octyl thiophosphorus emulsion 750 ~ 1500 times liquid. 25% dimethoate powder, 1.5 to 2 kg of powder per acre. 80% dimethoate soluble powder 1000 times liquid along the ridge pouring or spraying coarse mist method.

Second, leek blight

1. Symptoms Fungal disease caused by fungal infestation of Phytophthora campanulum. Most of the leaf lesions start from the middle and lower parts, initially dark green water-soaked, when extended to about half of the leaves, the whole leaves turn yellow, sagging, soft rot, and when the air is moist, the disease grows a sparse white mold. The pseudostem is mostly affected by brown soft rot in the root disc, growing gray and white mold, and the leaf sheath is easy to fall off. The internal tissues become light brown. The root disease is brown and rotten, the root hair is significantly reduced, the life of the root is shortened, and the growth potential of the aboveground part is weakened.

(1) Agricultural prevention and control: crop rotation and stubble, avoid continuous cropping.

(2) Pharmaceutical control: 50% soclide 1500 ~ 2000 times liquid, 50% paraxyne 1000 ~ 1500 times liquid, 70% daisen manganese zinc 350 times liquid, 75% bacillus 500 times liquid, 50% carbendazim 300 times liquid, 25% virulence 800 times liquid, 64% virulence alum 500 times liquid, 72% Pulik 800 times liquid, etc., root irrigation or spray, 7 to 10 days once, continuous prevention 2 to 3 times, the above drugs pay attention to rotation.

Third, leek gray mold disease

1. Symptoms Fungal disease caused by infection of Staphylococcus micromonas. Mainly attacks the leaves. At the beginning of the disease, the leaves produce small white to grayish-brown dots on the front and back, and there are more on the front than on the back. Most of the spots develop from the tip of the leaf downward into fusiform or oval spots, with a size of 0.5 to 2 mm× 0.5 to 7 mm, gray-brown. When the environment is dry, the leaves are scorched, and when the environment is wet, the surface of the spots is densely covered with gray-green mold, and it is wet and rotten, and when the disease is severe, the spots are connected into pieces, resulting in the death of the upper part of the leaf or the whole leaf. Sometimes it decays downward from the knife edge of the leek cut, initially appearing as a water-stained pale green spot, semi-circular or "V" shaped, yellow-brown tissue, dense gray-green hairy mold.

(1) Agricultural prevention and control: apply fully decomposed organic fertilizer; timely ventilation according to weather changes, reduce humidity, so that the relative humidity in the shed is kept below 75%. After the leeks are harvested, the disease residue is removed in time, and the diseased leaves and diseased plants are carried out of the shed and buried or burned to prevent the spread of pathogens.

(2) Pharmaceutical control: At the beginning of the onset of gray mold disease, you can choose 50% sokrine wettable powder 1000 to 1500 times liquid, or 50% special energy (Fumei • isobacterium urea) water agent 800 to 1200 times liquid, or 40% gray mold traceless water agent (active ingredient is pyrimidine carbendazim) water agent 800 to 1200 times liquid, or 40% pyromylamine suspension agent 1000 to 1500 times liquid, or 50% fungus qing 800 to 1200 times liquid (active ingredient is lactoylamide), or 65% ash is not afraid (niacinamide• Pyrimidine) water agent 600 ~ 1000 times liquid, or 70% methylthiopyridine wettable powder 800 times liquid, or 75% Bacillus Clear wettable powder 600 times liquid, or 50% doxomycin wettable powder 1000 times liquid and so on. Spray the drug once every 7 to 10 days, and continuously prevent and treat it 2 to 3 times.