What Causes Wheat Leaf Blight? Cause Analysis and Disease Control
Wheat Leaf Blight and Disease Control
Wheat rust 15 to 20 days after wheat emergence, select wheat fields with conditions favorable for disease development and conduct an investigation. When the rate of diseased leaves reaches 10%, and the autumn temperature is on the high side with more rain than usual, immediately spray Heguoli or triadimefon for control, that is, use 15 to 20 grams of 12.5% Heguoli wettable powder or 75 grams of 15% triadimefon wettable powder per mu, mix with 50 kg of water, and spray. When one plant is found, protect a whole patch; when one patch is found, protect a whole field.
Wheat sharp eyespot Wheat sharp eyespot can occur from the seedling stage to the heading stage of wheat. Symptoms at the seedling stage mainly appear on the underground parts. After emergence, it damages the underground stems of wheat, producing brown lesions or elliptical lesions, and spreads upward. Use 75 grams of 20% triadimefon wettable powder or 40 grams of 20% jinggangmycin per mu, mix with 50 kg of water, and spray along the rows; the effect is very good.
Wheat take-all The pathogen of wheat take-all can infect wheat at the seedling stage, and 20 to 30 days after emergence is the peak infection period. For plots where wheat take-all has occurred in the past, use 15 to 20 grams of 12.5% Heguoli wettable powder or 120 to 200 milliliters of 20% triadimefon emulsifiable concentrate per mu, mix with 40 to 50 kg of water, and spray the seedlings along the rows, which can significantly reduce the incidence of the disease at the heading stage of wheat.
Wheat aphids Besides directly causing damage that reduces wheat yield, wheat aphids can also transmit wheat yellow dwarf disease and others. When the rate of aphid-infested plants exceeds 5% and there are about 10 aphids per 100 plants, chemical control should be carried out. Use 25 milliliters of Yashijing or 20 grams of Dagongchen or 20 grams of imidacloprid per mu, mix with 40 to 50 kg of water, and spray along the rows; the effect is very good, and it can also control wheat red spider mites at the same time.
Underground pests The underground pests that damage wheat at the seedling stage are mainly three kinds: mole crickets, white grubs, and wireworms. According to observations, when mole crickets cause damage, they bite the tender stems of wheat seedlings into a tangled mess, with uneven break points; when white grubs cause damage, they bite off the root crown of wheat seedlings, with neat break points; wireworms bore into and eat the tender heart of wheat stems, and the damaged part appears tangled like hemp, but the outer skin remains connected. By carefully observing these damage symptoms on wheat seedlings, you can determine which kind of underground pest is present in the wheat field without digging into the soil for investigation. 30 days after wheat emergence, select representative plots for investigation, and when the dead seedling rate reaches 3%, immediately apply pesticide for control. Apply trichlorfon bait through the rows: use 75 grams of 90% crystalline trichlorfon per mu, first dissolve it with warm water, then add water to 1.5 kg to make a medicinal solution, spray and mix it onto 10 kg of crushed and roasted sesame cake or rapeseed cake, and let it stand for 4 to 6 hours to make bait. Use a drill to apply the bait through the rows in the wheat field. This method can achieve a 95% effect in killing pests and protecting seedlings. Broadcast poisoned soil: use 2 kg of 2% isofenphos-methyl powder per mu mixed with 30 to 40 kg of fine soil, mix evenly, then open furrows and apply it into the wheat rows, which can effectively control damage from white grubs and wireworms. Spray or irrigate with pesticide water: for plots with scattered, patchy damage, use 0.5 kg of 40% isofenphos-methyl or 50% phoxim per mu, mix with 60 to 75 kg of water, and spray or pour along the rows at the wheat roots; it has a special effect on white grubs and wireworms.
Locusts and crickets In recent years, these two types of pests have occurred in large numbers and often damage early-sown wheat seedlings. Use 75 grams of 90% crystalline trichlorfon per mu, first dissolve it with hot water, then add water to 1.5 kg, spray and mix it onto 5 to 7 kg of crushed and roasted wheat bran to make poisoned bait, and broadcast it along the rows to trap and kill them; the effect is very good.
Wheat sharp eyespot Wheat sharp eyespot can occur from the seedling stage to the heading stage of wheat. Symptoms at the seedling stage mainly appear on the underground parts. After emergence, it damages the underground stems of wheat, producing brown lesions or elliptical lesions, and spreads upward. Use 75 grams of 20% triadimefon wettable powder or 40 grams of 20% jinggangmycin per mu, mix with 50 kg of water, and spray along the rows; the effect is very good.
Wheat take-all The pathogen of wheat take-all can infect wheat at the seedling stage, and 20 to 30 days after emergence is the peak infection period. For plots where wheat take-all has occurred in the past, use 15 to 20 grams of 12.5% Heguoli wettable powder or 120 to 200 milliliters of 20% triadimefon emulsifiable concentrate per mu, mix with 40 to 50 kg of water, and spray the seedlings along the rows, which can significantly reduce the incidence of the disease at the heading stage of wheat.
Wheat aphids Besides directly causing damage that reduces wheat yield, wheat aphids can also transmit wheat yellow dwarf disease and others. When the rate of aphid-infested plants exceeds 5% and there are about 10 aphids per 100 plants, chemical control should be carried out. Use 25 milliliters of Yashijing or 20 grams of Dagongchen or 20 grams of imidacloprid per mu, mix with 40 to 50 kg of water, and spray along the rows; the effect is very good, and it can also control wheat red spider mites at the same time.
Underground pests The underground pests that damage wheat at the seedling stage are mainly three kinds: mole crickets, white grubs, and wireworms. According to observations, when mole crickets cause damage, they bite the tender stems of wheat seedlings into a tangled mess, with uneven break points; when white grubs cause damage, they bite off the root crown of wheat seedlings, with neat break points; wireworms bore into and eat the tender heart of wheat stems, and the damaged part appears tangled like hemp, but the outer skin remains connected. By carefully observing these damage symptoms on wheat seedlings, you can determine which kind of underground pest is present in the wheat field without digging into the soil for investigation. 30 days after wheat emergence, select representative plots for investigation, and when the dead seedling rate reaches 3%, immediately apply pesticide for control. Apply trichlorfon bait through the rows: use 75 grams of 90% crystalline trichlorfon per mu, first dissolve it with warm water, then add water to 1.5 kg to make a medicinal solution, spray and mix it onto 10 kg of crushed and roasted sesame cake or rapeseed cake, and let it stand for 4 to 6 hours to make bait. Use a drill to apply the bait through the rows in the wheat field. This method can achieve a 95% effect in killing pests and protecting seedlings. Broadcast poisoned soil: use 2 kg of 2% isofenphos-methyl powder per mu mixed with 30 to 40 kg of fine soil, mix evenly, then open furrows and apply it into the wheat rows, which can effectively control damage from white grubs and wireworms. Spray or irrigate with pesticide water: for plots with scattered, patchy damage, use 0.5 kg of 40% isofenphos-methyl or 50% phoxim per mu, mix with 60 to 75 kg of water, and spray or pour along the rows at the wheat roots; it has a special effect on white grubs and wireworms.
Locusts and crickets In recent years, these two types of pests have occurred in large numbers and often damage early-sown wheat seedlings. Use 75 grams of 90% crystalline trichlorfon per mu, first dissolve it with hot water, then add water to 1.5 kg, spray and mix it onto 5 to 7 kg of crushed and roasted wheat bran to make poisoned bait, and broadcast it along the rows to trap and kill them; the effect is very good.