Prevention and control techniques of diseases and insect pests in garlic

Garlic is a semiannual herb of the genus Allium in Liliaceae, which is commonly cultivated all over the country. Because garlic often has different symptoms, it can not be prevented and treated in time and correctly, resulting in serious disease and causing great losses. Let's take a look at the common pest control techniques of garlic.

Purple spot of garlic

[characteristics of the disease] most of the disease in the field began at the leaf tip or the middle of the pedicel, spread to the lower part a few days later, initially showed slightly sunken white spots, the center was slightly purplish, and enlarged into a yellow-brown spindle-shaped or oval spot. When the humidity was high, the disease part produced black mildew, that is, the pathogen conidiophores and conidia, and the disease spots had concentric wheel lines and were easy to break from the disease part. The neck of the infected bulb became dark yellow or reddish brown soft rot during storage.

[prevention and treatment methods] at the initial stage of the disease, spraying 75% chlorothalonil wettable powder 500 times or 64% chlorothalonil wettable powder 500 times, 40% Dafudan wettable powder 500 times, 58% metalaxyl manganese zinc wettable powder 500 times, 50% propofoin wettable powder 1500 times, once every 7 to 10 days, continuous prevention and control for 3 times, all have good results.

Garlic soft rot

[disease characteristics] garlic soft rot is a bacterial disease, which is beneficial to the disease with low temperature and high humidity. After garlic infection, the disease first occurs from the leaf margin or midrib, and forms yellow-white stripes along the leaf margin or midrib, which can run through the whole leaf. When the humidity is high, the diseased part is yellowish brown and soft rot. In general, the foot leaves first fell ill, and then gradually expanded to the upper leaves, resulting in the withering and yellowing or death of the whole plant.

[pest control and disease prevention] because pests cause wounds on garlic, which is conducive to the invasion of soft rot bacteria, some pests carry germs in and out of the body and directly spread the disease. Therefore, the control of insect pests is very important for the control of soft rot. Attention should be paid to the control of underground pests such as golden needle worm and mole cricket in the early stage, and yellow should be controlled from the seedling stage. Curly striped jumper beetle, maggot and other pests.

[pharmaceutical control] before or at the initial stage of the disease, 72% agricultural streptomycin 3000 × 4000 times or 47% plus Ruinong WP750 times, 50% desenamine 1000 times, neoptomycin 3000 Mel 4000 times, spray once every 5 to 7 days, continuous prevention and treatment for 2 times according to the disease. Emphasis should be placed on the mildly diseased plants and the plants around them, and attention should be paid to spraying on the base of the stems close to the surface.

Garlic leaf blight

[incidence characteristics] Leaf blight mainly occurs on leaves and pedicels, and mostly spreads from the leaf tip. The disease spot is a small white dot of flowers at the initial stage, and after expansion, it is an irregular shape or oval shape, showing a grayish white or grayish brown, producing black mildew. In severe cases, the diseased leaves die. If the pedicel is injured, it is easy to break from the disease, and give birth to many small black grains in the disease, resulting in garlic not easy to bolting.

[control methods] strengthen field management, reasonable close planting, increase the application of nitrogen, phosphorus and potassium comprehensive fertilizer, add biological multi-antibacterial fertilizer, cultivate strong seedlings, timely drainage after rain to prevent stagnant water in the field. It can be sprayed with 75% chlorothalonil or 65% Dysen zinc, 50% Ye Ku Jing powder 1000 times or 10% Chlorothalonil powder 400 times.

Garlic gray mold

[incidence characteristics] Botrytis cinerea often occurs in the later stage of plant growth, starting from the tip of the lower old leaf, the disease spot is water-immersed at the beginning, and then becomes white or light grayish brown, and develops from the tip to the in. when the disease spot is enlarged, it is called fusiform oval, and the disease spot produces gray-brown mildew on both sides. When the disease is serious, it can spread from the old leaves on the whole plant, causing the leaf sheath and even the underground bulb to collapse, then dry up and turn gray-white, and Botrytis cinerea and sclerotia can be seen in the disease part.

[control method] the control method is basically the same as that of leaf blight.

Garlic virus disease

[characteristics] garlic virus disease, also known as mosaic disease, shows dark green and light yellow irregular stripes or spots, causing plant atrophy or distortion when the disease is serious.

[control methods] non-toxic garlic species were selected to strengthen field management, pull out diseased plants, control aphids in time, apply comprehensive fertilization, apply biological multi-antibacterial fertilizer, and enhance plant disease resistance.

Garlic mosaic disease

[incidence characteristics] garlic mosaic disease is one of the common diseases in garlic, which is common in all vegetable areas, which mainly harms garlic cultivated in open field, and the disease is serious in high temperature and drought years. The serious disease often results in distorted leaves, dwarf plants, few and stiff cloves of garlic, which directly affects the yield. In the early stage of the disease, intermittent yellow stripes appeared along the leaf veins, and then connected into long yellow and green stripes, the plants were dwarfed, and the heart leaves of individual plants were surrounded by adjacent leaves, showing curly deformities, which could not be fully extended for a long time, resulting in distorted leaves. After the plant was infected, the bulb became smaller, the garlic cloves and fibrous roots decreased, and when the garlic cloves were severe, the garlic cloves were stiff, especially during the storage period. The yield and quality of diseased garlic decreased significantly, resulting in species degradation.

[control measures] strict seed selection of ①: establish the original seed base as far as possible, use garlic bulbs (cloves) from light disease areas as seeds, reduce the virus-carrying rate of bulbs, and use tissue culture virus-free seedlings if possible. ② implements rotation: avoid continuous cropping or intercropping with green onions, leeks and other crops. ③ control aphids and diseases: spraying insecticides to control aphids in garlic fields and surrounding crops to prevent repeated infection of the virus. In addition, silver-gray film strip can be hung to avoid aphids or insect-proof net can be used to cover cultivation. Strengthen the management of ④: strengthen the water and fertilizer management of garlic to avoid premature senescence and improve plant disease resistance.

[drug control] spray protection begins at the initial stage of the disease. The medicament can choose 200x liquid of 2% JK water agent, 200x liquid of 5% bacteriological clear water agent, 1000 times liquid of 1.5% Zhishanling emulsion, or 500x liquid of 20% virus A wettable powder, or 500x liquid of 20% Kangrun No. 1 wettable powder, spray control. Once every 7-10 days, 2-3 times, depending on the development of the disease.

Garlic rust

[incidence characteristics] garlic rust is one of the common diseases of garlic, which is common in all vegetable areas, which mainly harms garlic, scallions, chives, onions and so on. The disease is serious in the years of low temperature, rainy or plum rain in early spring or foggy and rainy in autumn. The serious disease often results in dense blister spots on leaves, which directly affects the yield and quality of garlic leaves and indirectly affects the yield of garlic. It mainly harms leaves and pseudostems. At the beginning of the disease, there were fusiform chlorotic spots, and then a round or oval protruding pile of summer spores was produced under the epidermis, and orange powder (germ summer spores and summer spores) was scattered after the rupture of the epidermis. There is a yellowish halo around the disease spot, which leads to the yellow withering of the whole leaf and the early death of the plant. In the later stage of growth, a black winter spore pile with unruptured epidermis was produced on the unruptured summer spore pile.

[control measures] Scientific fertilization of ①: adequate application of organic fertilizer, increased application of phosphorus and potassium fertilizer to improve disease resistance and avoid partial application of nitrogen fertilizer. ② rotation: rotation with non-onion and garlic crops for more than 2 years. ③ cleaning the countryside: remove the sick and disabled bodies in time, and take them out of the field for centralized destruction.

[drug control] spray protection begins at the initial stage of the disease. The medicament can choose 40% Fuxing EC 5000 times, or 10% high water dispersible granules 1500 times, or 15% triadimefon wettable powder 1500 times, or 70% dry suspensions 600 times 800 times, or 25% enemy demulsifiable EC 3000 times, or 1000 times of 75% rust amine wettable powder, etc., spray control. Once every 7-10 days, 2-3 times, depending on the development of the disease.

Onion fly

[hazard characteristics] the adults are small gray flies with transparent wings and larvae like fecal maggots. There are generally 4-6 generations a year in central and southern China, and the peak period of larvae is from late March to early May and from September to early October. The larvae usually feed in the bulbs of garlic and spring onions sown by humans. There are dozens of larvae in a bulb, and the damaged bulbs are eaten into holes, causing decay, leaf yellowing, withering and death.

[control methods] apply fully mature organic fertilizer evenly and deeply to prevent adults from spawning and reproduction, strictly select seeds, remove rotten garlic cloves, isolate from fertilizer when sowing, and trap adults with sugar ∶ vinegar ∶ water = 1 ∶ 1 ∶ 2.5. the ratio is sugar and vinegar ∶ water = 1 ∶ 1 ∶ 2.5. mix well with a small amount of trichlorfon, pour into a container with sawdust and cover, open the lid during sunny days. The biological multi-antibacterial fertilizer was added to the base fertilizer, and the liquid biological multi-antibacterial fertilizer was sprayed at the seedling stage. When adults lay eggs, 3000 times of deltamethrin was used to kill 6000 times or 2.5% of deltamethrin, sprayed once every 5 to 7 days for 2 times in a row.