Shandong garlic planting area accounts for about 50% of the total garlic planting area in the country, mainly distributed in Jinxiang, Lanling, Chengwu, Juye, Shan County, Shanghe, Laiwu and other places, the export volume accounts for about 70% of the country's garlic exports, of which Jinxiang and Lanling are named "Garlic Town" by the state.
The main pest of garlic in Shandong is garlic maggots, which are generally harmful to gray ground fly and onion ground fly alone or mixed, but the 2020 survey found that late-eyed mushroom mosquitoes (leek maggots) occurred seriously on local garlic.
For such pests, local garlic farmers generally use chemical pesticides to irrigate and control, but because the pest site of the larvae of The late-eyed mushroom mosquito is different from the seed fly larvae, it often leads to poor control effects and unreasonable use of pesticides, which threatens the quality and safety of garlic.
<h1 class="pgc-h-arrow-right" data-track="9" > is Shandong garlic root maggot serious? </h1>
In the spring of 2020, in the main garlic producing areas such as Jinxiang, Lanling, Chengwu and Daiyue in Shandong, it was found that the root maggots of Shandong garlic were serious.
Garlic root maggots found in garlic fields
Root maggots are dominated by the larvae of Theoptera rectum (commonly known as blackhead maggots), and their populations account for more than 90% of garlic root maggots, and gray ground species flies and onion ground species flies are rare or rare.
Pest characteristics: Late-eyed mushroom mosquitoes are distributed in the soil layer of 0 to 5 cm near the base of garlic stem and bulbs as larvae, mainly in the middle or upper middle part of garlic expansion, usually not harmful to the root system.
In general, the rate of garlic infested plants in the field is about 70%, and the average density of insect population per plant is about 10 heads; the rate of severe field damage plants can reach 90% to 100%, and the average density of insect populations per plant is more than 50 heads.
Late-eyed mushroom larvae gather on garlic heads to harm
<h1 class="pgc-h-arrow-right" data-track="9" > why is there an outbreak of late-eyed mushroom mosquitoes on Shandong garlic? </h1>
1. Climatic factors
With global warming, multi-chemical insects such as leek maggots have increased their generations due to the phenomenon of early spring phenology and the acceleration of life cycles. Jinxiang, Lanling and other places are autumn sown garlic area, located in the southeast or southwest of Shandong, belongs to the temperate semi-humid climate, spring rain, autumn warm, suitable for leek maggot growth and reproduction.
2. Continuous planting
Jinxiang has a long history of planting garlic, the garlic planting years in the garlic field of this survey are more than 5 years, and in previous years, "small years" occurred for leek maggots, due to the lack of attention of garlic farmers, the awareness of prevention-based plant protection is weak, and the prevention has been ineffective, resulting in a large population base of overwintering insects.
3. The level of medication is low
According to the survey, in addition to the garlic farmers in lanling area can do the rotation of drugs, Jinxiang and other places to control leeks are more focused on the use of organophosphorus pesticides or nicotinic pesticides, which have developed resistance in Shandong region, and the long-term use of prevention and control effects is poor, resulting in garlic farmers arbitrarily increasing the dosage and frequency of such pesticides in production, resulting in a vicious circle of more pesticide use and poorer control effect.
4. In areas where serious diseases occur, no pre-sowing agent seed mixing has been carried out
Seed mixing is an important measure to control garlic diseases and insect pests, which can effectively prevent the harm of leek maggots after sowing, reduce the population density of leek maggots overwintering insects, and significantly reduce the pressure of leek maggot control in the following year. It is understood that in addition to the common use of 600g/mL imidacloprid suspension seed coating agent seed mixing in Lanling area, garlic farmers in Jinxiang and other places have no pre-sowing drug seed mixing habits, which is also an important reason for the harm caused by the outbreak of leek maggots in the spring of the second year.
<h1 class="pgc-h-arrow-right" data-track="9" how to prevent and control green >? </h1>
Ecological regulation
1. Clean the countryside
After garlic harvest, remove weeds, diseased residues and diseased leaves in the field in time, destroy the wintering site of leek maggots, and reduce the overwintering base of leek maggots.
2. Fine land preparation
Before sowing garlic, it is necessary to combine deep ploughing and rotary tillage, and the ploughing depth is generally 20 to 25 cm. After ploughing, it is necessary to dry properly, and then rake through, rake flat, rake and solidify to achieve upper pine and lower fruit, so as to improve the quality of sowing and film covering.
3. Soil treatment
For plots with heavy pests and diseases, lime nitrogen can be used for soil treatment in combination with deep ploughing before sowing, and 40 to 80 kg of lime nitrogen can be evenly spread per mu. After rotary tillage, the soil surface is sealed with a transparent plastic film for about 20 days. Then the film is uncovered, and after 7 to 14 days, Bacillus subtilis containing 500 million live spores / g + Bacillus jelly-like bacteria containing 0.5 billion live spores / g are applied, with a dosage of 20 to 40 kg per mu, which can also be turned into the soil with organic fertilizer as a bottom fertilizer.
4. Seed treatment
Choose garlic cloves that are large, neat, harmless and mold-free. Before sowing, choose sunny days to dry seeds for 2 to 3 days to break the dormancy, enhance the germination potential, and promote the emergence of garlic seedlings, even and strong. In early to mid-October, 27% phenyl ether, chlorinated thiamethus suspension seed coating agent 75mL can be mixed with 2.5 to 3.0 kg of water to mix garlic seeds 150 kg, or 60% imidacloprid suspension seed coating agent 60 mL with water 2 kg of garlic seeds, dried and sown; or 7 days after sowing, 5% fludilurea emulsion of 750 to 1000 g per mu is applied. Each mu can also be mixed with 100 g of Bacillus subtilis containing 10 billion spores/g of wettable powder to mix seeds or soak seeds to prevent soil-borne diseases.
5. Sowing at the right time
Suitable sowing The suitable germination temperature of garlic is 15 to 20 °C, and it is advisable to sow seeds from September 25 to October 15 in Shandong. After sowing, the edge of the mulch film is pressed into the soil when the mulching is covered, and attention is paid to flattening the mulch as much as possible and sticking to the ground.
6. Reasonable irrigation
Garlic root system is shallow, not tolerant of drought and flood, watering requires water to be able to seep down in time, no clear water overnight. Grasp the key watering period, do not water the winter water when freezing in early and mid-November; when watering the green water in late March of the following year, it is necessary to water small water or sprinkler irrigation, and apply the rejuvenating fertilizer according to 800 to 1000 kg, 10 kg of ammonium sulfate and 5 kg of potassium sulfate per mu of organic fertilizer; in late April, when watering "hypnotic water", the amount of water should be large, and the "hypnotic fertilizer" should be applied with the water, and the quick-acting potassium and 10 to 15 kg of nitrogen fertilizer should be applied per mu. Timely watering increases soil moisture to be detrimental to the hatching and feathering of leek maggots, so as to achieve good control effects.
Physical control
1. Booby traps the armyworm board
Adult late-eyed mushrooms have a certain tendency to color, and the black armyworm plate has a good effect of attracting insects, and 30 to 40 black armyworm plates can be placed per mu at the garlic seedling stage.
2. Booby trap with sweet and sour liquid
In the mother stage of garlic rot, sweet and sour solution can be used to trap adult late-eyed mushroom mosquitoes. The cotton sugar (g), acetic acid (mL), absolute ethanol (mL) and tap water (mL) are mixed according to the ratio of 3:3:1:80, packed in a pot with a diameter of 30 cm and mixed well, each pot is 300 to 500 mL, 10 to 15 pots per mu of garlic field, evenly placed on the furrow, every 7 days to remove the dead insects in the basin, and replenish the sweet and sour solution.
Biocontrol
1. Prevention and control of biological fungal agents
From the end of March to the beginning of April (garlic rot mother stage), watering once permeable, and then immediately sprinkle with 200 million spores /g of Scarab beetle green zombie granules with an amount of 5 kg per mu, or when watering, 200 mL of beetle green zombie dispersible oil suspension containing 8 billion spores/mL per mu, or 8000 IU/mg Officinalis thuringiensis Subspecies Israel subsp. (Bti for short) wettable powder 6 kg, flushed once every 7 to 10 days, 3 times continuously.
2. Pathogenic nematode control
In early April, 100-200 million pathogenic nematodes per mu were flushed with water (Zhao Guoyu, 2013), or mixed with Bti (1200ITU/mg) wettable powder 200 times liquid for control.
Scientific medication
1. Pesticides of plant origin
Per mu, 1.1% matrine powder can be mixed with 50 to 60 kg of water, or 1.8% avermectin emulsion oil 30 ~ 60 mL with water 50 ~ 60 kg, or 15% castor oil nicotine emulsion 2.5 kg with water 50 ~ 60 kg of irrigation roots. Prevention and treatment once every 10 to 15 days, and continuous prevention and control twice.
2. Chemical pesticides
Per mu, use 10% insect mite nitrile suspension agent 1000g with an appropriate amount of water to irrigate the roots, or in the early stage of adult occurrence the following year (that is, after stinging), 60g of 20% fly-killing amine wettable powder per acre with 90kg of water, and spray evenly at 10:00-14:00. Prevention and treatment is carried out once every 7 to 10 days, and 2 consecutive prevention and treatments are carried out.
3. Mixture of agents
When leek maggots occur severely, 1000g + 200 million heads of pathogenic nematodes can be used per mu with 10% insect mite nitrile suspension agent, or 25% thiamethiazide wettable powder 250 g + containing 8 billion spores / mL scarab beetle green zombie dispersible oil suspension 200 mL, or 10% insect mite nitrile suspension agent 1000 g + pathogenic nematode 200 million heads + Bti (1200ITU/mg) wettable powder 200 times liquid irrigation root control. Prevention and treatment once every 10 to 15 days, and continuous prevention and control twice.
(Source: "The Occurrence of Shandong Garlic Late-Eye Mushroom And Green Prevention and Control Technology" in the 4th issue of China Vegetables; authors and units: Shi Chaopeng, Yin Shanshan, Wang Dan, Liu Cunhui, Yang Jiutao, Liu Kuicheng, Jin Xin, Sun Zuowen; Shandong Provincial Plant Protection Station, Jinxiang County Agricultural and Rural Bureau, Lanling County Agricultural and Rural Bureau)