How to control pests, diseases and weeds during the wheat sowing period? Technical recommendations are here
Technical recommendations for the control of pests, diseases and weeds during the wheat sowing period
The wheat sowing period is approaching. In view of the occurrence in our county in recent years of the main wheat pests and diseases such as take-all, sheath blight, loose smut, root rot, soil-dwelling pests and field weeds, and in accordance with the plant protection policy of "prevention first, integrated control", technical measures for the control of pests and diseases during the 2009 wheat sowing period have been formulated.
I. Agricultural cultivation measures:
1. Crop rotation or deep ploughing: For plots where take-all and sheath blight occur severely, try as far as possible to adopt a 2-3 year rotation with non-host crops such as cotton, vegetables and sweet potato; where conditions permit, villages may carry out one deep ploughing of plots that have been continuously rotary tilled for more than 3 years, to a depth of 20-25 cm. The above measures can eradicate wheat take-all and sheath blight and can reduce the severity of other pests and diseases.
2. Select excellent varieties that are disease-resistant and disease-tolerant: The varieties promoted in our county this year are mainly: Hengguan 35, Shiluan 02-1, Ji 5265, Shixin 828, Kenong 199, etc. Wheat from fields where take-all, smut or black point occur must not be kept for seed use.
3. Apply more organic fertiliser and nitrogen fertiliser, and a suitable amount of phosphorus and potassium fertiliser and zinc and manganese micro-fertilisers: In recent years, temperatures after wheat sowing have been rather high, and plots with straw returned to the field have a large nitrogen requirement, so a suitable amount of extra nitrogen fertiliser should be applied; applying more organic fertiliser, phosphorus and potassium fertiliser and micro-fertilisers promotes wheat root development, cultivates strong seedlings and improves disease resistance and stress resistance.
4. Sow late at the appropriate time and at a suitable seeding rate: Sowing around October 10 can reduce the time for pathogen infection and lessen the severity of take-all, root rot and sheath blight; adopt the method of sowing disease-free fields first and diseased fields afterwards; a suitable seeding rate can improve the population structure and reduce the occurrence of pests and diseases.
5. Clear weeds at the edges and corners of fields: Destroy the activity sites and habitats of the small brown planthopper, soil locusts (grasshoppers) and crickets, and reduce the probability of insect damage and wheat rosette dwarf disease.
II. Chemical control:
Vigorously promote seed dressing with seed-coating agents or chemical seed dressing to control insects and eliminate diseases.
General wheat fields:
a. Seed dressing with a seed-coating agent: Use 15 ml of 2.5% Pulimeng (triticonazole) to dress 20-30 kg of wheat seed, pile and cover for 3 hours; this can effectively control loose smut and root rot.
Choose 200 g of 15% Yinmiao (phorate + carbendazim) suspension seed-coating agent or 14% Wenkuling (phorate + uniconazole + thiram) suspension seed-coating agent to dress 20-25 kg of wheat seed; this not only prevents smut, root rot and sheath blight but also controls soil-dwelling pests at the same time.
b. Before sowing, mix an insecticide with a fungicide for seed dressing, namely: 100 ml of 50% phoxim emulsifiable concentrate plus 100 ml of 2.5% Celest seed-coating agent, add 5 kg of water, dress 100 kg of wheat seed, stir evenly, pile and cover for 3-5 hours, dry in the shade and then sow (phoxim is easily photodegraded, so operate away from light and strictly avoid sun exposure). Coated seed can be sown directly.
Take-all fields: Whether or not the seed is coated, a special seed dressing agent for controlling take-all should be used for seed dressing, or measures such as mixing with insecticides should be used in combination.
(1) Use 20 ml of 12.5% Quanshijing, add 0.5-0.75 kg of water, dress 10 kg of wheat seed, stir evenly, pile and cover for 6-12 hours, dry in the shade and then sow (operate away from light and strictly avoid sun exposure).
(2) Use 10-20 ml of 2.5% Celest plus 50-100 ml of 3% Diweidan plus an appropriate amount of water to dress 10-15 kg of wheat seed, dry in the shade and then sow. Adjust the dosage up or down appropriately according to the severity of the disease.
2. Spray protective belts to control the small brown planthopper and prevent viral diseases: After the wheat emerges, immediately spray an 800-1000 fold dilution of an organophosphorus pesticide or a 2000 fold dilution of a pyrethroid pesticide; small wheat fields, especially plots near idle land or cotton fields, should be sprayed over the whole field, while for large contiguous wheat fields spray a 5-10 m protective belt at the field edges and corners.
3. At the seedling stage, pay attention to inspecting and controlling soil locusts and crickets: Soil locusts and crickets mainly threaten early-sown wheat fields. After the wheat emerges, for plots with 5 locusts and crickets per sq m, apply pesticide immediately. Specific methods:
(1) Broadcast poisoned bait: Use 80-100 ml of 40% chlorpyrifos emulsifiable concentrate or 50 ml of 4.5% beta-cypermethrin per mu, add 3 kg of water, mix with 2.5 kg of stir-fried fragrant wheat bran to make poisoned bait, and scatter it in the wheat field in the evening.
(2) Spray control: Spray a 1000 fold dilution of an organophosphorus pesticide or a 2000 fold dilution of a pyrethroid pesticide.
4. Vigorously promote winter control of weeds in wheat fields: Weeds in wheat fields greatly affect wheat yield; spring control requires large doses and easily causes phytotoxicity to the following crop, so winter and autumn control of weeds in wheat fields is vigorously promoted.
(1) For wheat fields dominated by grass weeds, the control time should be at the 3-leaf stage of wheat (late October to early November), as follows: For wheat fields where brome grass and shortawn foxtail are the dominant species, use 3 g of 70% Biaohu per mu plus 10 g of a special adjuvant, add 30-40 kg of water and spray evenly; for wheat fields dominated by jointed goatgrass, use 30-40 ml of 3% Shima per mu plus a special adjuvant, or 20-25 g of 3.6% Kuoshima water-dispersible granules plus a special adjuvant, add 30 kg of water and spray.
(2) For wheat fields dominated by broadleaf weeds, from late November to early December, when watering the freezing water or taking advantage of moist soil after rain, generally use a tribenuron-methyl type herbicide for ordinary plots; for wheat fields dominated by corn gromwell and cleavers, use 7-10 g of 36% Benteng per mu or 2 g of 40% Kuaimieling plus 8 g of 10% tribenuron-methyl, add 30 kg of water and spray.
Precautions:
1. When preparing pesticides, use the double dilution method, that is, first prepare a stock solution with a small amount of water, then add water according to the dilution factor, stir thoroughly and spray evenly; choose clear, windless weather for application, with 30 kg of water per mu.
2. Wheat fields to be sprayed, especially those using Kuoshima and Shima herbicides, require sufficient base fertiliser and strong wheat seedlings; do not flood irrigate heavily within 2 days before and after application; when spraying, it is best to use a fan nozzle, without overlapping or missing sprays; after using Shima, wheat will show yellowing, and the symptoms disappear after 3-4 weeks without affecting yield; stop application when the minimum temperature is below 4°C.
I. Agricultural cultivation measures:
1. Crop rotation or deep ploughing: For plots where take-all and sheath blight occur severely, try as far as possible to adopt a 2-3 year rotation with non-host crops such as cotton, vegetables and sweet potato; where conditions permit, villages may carry out one deep ploughing of plots that have been continuously rotary tilled for more than 3 years, to a depth of 20-25 cm. The above measures can eradicate wheat take-all and sheath blight and can reduce the severity of other pests and diseases.
2. Select excellent varieties that are disease-resistant and disease-tolerant: The varieties promoted in our county this year are mainly: Hengguan 35, Shiluan 02-1, Ji 5265, Shixin 828, Kenong 199, etc. Wheat from fields where take-all, smut or black point occur must not be kept for seed use.
3. Apply more organic fertiliser and nitrogen fertiliser, and a suitable amount of phosphorus and potassium fertiliser and zinc and manganese micro-fertilisers: In recent years, temperatures after wheat sowing have been rather high, and plots with straw returned to the field have a large nitrogen requirement, so a suitable amount of extra nitrogen fertiliser should be applied; applying more organic fertiliser, phosphorus and potassium fertiliser and micro-fertilisers promotes wheat root development, cultivates strong seedlings and improves disease resistance and stress resistance.
4. Sow late at the appropriate time and at a suitable seeding rate: Sowing around October 10 can reduce the time for pathogen infection and lessen the severity of take-all, root rot and sheath blight; adopt the method of sowing disease-free fields first and diseased fields afterwards; a suitable seeding rate can improve the population structure and reduce the occurrence of pests and diseases.
5. Clear weeds at the edges and corners of fields: Destroy the activity sites and habitats of the small brown planthopper, soil locusts (grasshoppers) and crickets, and reduce the probability of insect damage and wheat rosette dwarf disease.
II. Chemical control:
Vigorously promote seed dressing with seed-coating agents or chemical seed dressing to control insects and eliminate diseases.
General wheat fields:
a. Seed dressing with a seed-coating agent: Use 15 ml of 2.5% Pulimeng (triticonazole) to dress 20-30 kg of wheat seed, pile and cover for 3 hours; this can effectively control loose smut and root rot.
Choose 200 g of 15% Yinmiao (phorate + carbendazim) suspension seed-coating agent or 14% Wenkuling (phorate + uniconazole + thiram) suspension seed-coating agent to dress 20-25 kg of wheat seed; this not only prevents smut, root rot and sheath blight but also controls soil-dwelling pests at the same time.
b. Before sowing, mix an insecticide with a fungicide for seed dressing, namely: 100 ml of 50% phoxim emulsifiable concentrate plus 100 ml of 2.5% Celest seed-coating agent, add 5 kg of water, dress 100 kg of wheat seed, stir evenly, pile and cover for 3-5 hours, dry in the shade and then sow (phoxim is easily photodegraded, so operate away from light and strictly avoid sun exposure). Coated seed can be sown directly.
Take-all fields: Whether or not the seed is coated, a special seed dressing agent for controlling take-all should be used for seed dressing, or measures such as mixing with insecticides should be used in combination.
(1) Use 20 ml of 12.5% Quanshijing, add 0.5-0.75 kg of water, dress 10 kg of wheat seed, stir evenly, pile and cover for 6-12 hours, dry in the shade and then sow (operate away from light and strictly avoid sun exposure).
(2) Use 10-20 ml of 2.5% Celest plus 50-100 ml of 3% Diweidan plus an appropriate amount of water to dress 10-15 kg of wheat seed, dry in the shade and then sow. Adjust the dosage up or down appropriately according to the severity of the disease.
2. Spray protective belts to control the small brown planthopper and prevent viral diseases: After the wheat emerges, immediately spray an 800-1000 fold dilution of an organophosphorus pesticide or a 2000 fold dilution of a pyrethroid pesticide; small wheat fields, especially plots near idle land or cotton fields, should be sprayed over the whole field, while for large contiguous wheat fields spray a 5-10 m protective belt at the field edges and corners.
3. At the seedling stage, pay attention to inspecting and controlling soil locusts and crickets: Soil locusts and crickets mainly threaten early-sown wheat fields. After the wheat emerges, for plots with 5 locusts and crickets per sq m, apply pesticide immediately. Specific methods:
(1) Broadcast poisoned bait: Use 80-100 ml of 40% chlorpyrifos emulsifiable concentrate or 50 ml of 4.5% beta-cypermethrin per mu, add 3 kg of water, mix with 2.5 kg of stir-fried fragrant wheat bran to make poisoned bait, and scatter it in the wheat field in the evening.
(2) Spray control: Spray a 1000 fold dilution of an organophosphorus pesticide or a 2000 fold dilution of a pyrethroid pesticide.
4. Vigorously promote winter control of weeds in wheat fields: Weeds in wheat fields greatly affect wheat yield; spring control requires large doses and easily causes phytotoxicity to the following crop, so winter and autumn control of weeds in wheat fields is vigorously promoted.
(1) For wheat fields dominated by grass weeds, the control time should be at the 3-leaf stage of wheat (late October to early November), as follows: For wheat fields where brome grass and shortawn foxtail are the dominant species, use 3 g of 70% Biaohu per mu plus 10 g of a special adjuvant, add 30-40 kg of water and spray evenly; for wheat fields dominated by jointed goatgrass, use 30-40 ml of 3% Shima per mu plus a special adjuvant, or 20-25 g of 3.6% Kuoshima water-dispersible granules plus a special adjuvant, add 30 kg of water and spray.
(2) For wheat fields dominated by broadleaf weeds, from late November to early December, when watering the freezing water or taking advantage of moist soil after rain, generally use a tribenuron-methyl type herbicide for ordinary plots; for wheat fields dominated by corn gromwell and cleavers, use 7-10 g of 36% Benteng per mu or 2 g of 40% Kuaimieling plus 8 g of 10% tribenuron-methyl, add 30 kg of water and spray.
Precautions:
1. When preparing pesticides, use the double dilution method, that is, first prepare a stock solution with a small amount of water, then add water according to the dilution factor, stir thoroughly and spray evenly; choose clear, windless weather for application, with 30 kg of water per mu.
2. Wheat fields to be sprayed, especially those using Kuoshima and Shima herbicides, require sufficient base fertiliser and strong wheat seedlings; do not flood irrigate heavily within 2 days before and after application; when spraying, it is best to use a fan nozzle, without overlapping or missing sprays; after using Shima, wheat will show yellowing, and the symptoms disappear after 3-4 weeks without affecting yield; stop application when the minimum temperature is below 4°C.