Cucumber Scab in Greenhouse and Its Control
2021-08-10 10:05:06
The occurrence of cucumber scab in the greenhouse is widespread, and the damage is serious. In recent years, there has been a trend of development. Therefore, we must pay attention to strengthening prevention and control.
First, the symptoms of black spot disease and the conditions of seedlings infected, yellow and white round spots on the cotyledons, the development of the whole leaf after the dry; stems and vines infected with water-immersed dark green spindles, depressions, cracks, when the humidity grows black Mold layer, the conidial stems and conidia of pathogens; brownish rot in tendrils; rotted into bald piles of inadvertent sprouts in 2 to 3 days; diseased leaves in early dark green near-round spots, perforation The edge of the hole is not neatly tinged with jagged edging, and the perforations of the hole are collapsed; the pale yellow rubber on the melon stalk gradually expands into a dark green depression, and the black moldy layer grows on the surface. The diseased spot is sore and the growth stops. Malformed melons. ?
Scabs are caused by the infection of the fungus A. melitensis and fungi of the subphylum Subgermanium. In addition to harming cucumbers, it also infects zucchini, pumpkins, watermelons, melons and so on. It overwinters with mycelium in diseased or field soils, and the seeds can carry bacteria. Temperature 15 ~ 25 °C, long-term condensation of melon leaves is an important condition of the disease. ?
Second, prevention and treatment methods?
1. Rotation. Rotate with non-cucurbit vegetables. ?
2. Seed treatment. Soak in 15 to 20 minutes with 55°C hot water. ?
3. The greenhouse smoked with sulfur powder. In the greenhouse planting or nursery before turning to the ground, with 2.5 kg of sulphur per acre mixed with 1 times the amount of dry sawdust, ignited smoke 24 hours, 7 to 10 days after nursery or colonization, can effectively kill the bacteria. ?
4. Cultivate strong. Increase phosphorus and potash fertilizers to increase seedling disease resistance. ?
5. Strengthen the temperature and humidity management. In the management of temperature and humidity, we must pay special attention to the management of humidity. During the production period, it is forbidden to flood irrigation, and the method of humidity increase and humidity reduction and high temperature ventilation should be adopted. The specific approach is: every morning after the dumplings, the humidity in the canopy can reach 90% to 100%. At the same time, there is fog. At this time, it is impossible to take ventilation and venting. One of the reasons is that the growth period of cucumber in greenhouse must be the most suitable high-yield temperature at 28-33°C every morning. The early air temperature is low, which is not conducive to the high yield of cucumber. The second reason is that the indoor humidity can be reduced by 2% to 3% for every 1°C increase. Therefore, in the morning, when the cold air is released, it is not as good as a warming and humidifying effect. In addition, low-temperature dehumidification due to small temperature difference between indoor and outdoor, moisture can not be discharged. Therefore, the correct approach is to open the scorpion every morning, can not immediately release the wind, it should be closed all vents, so that when it warms to 33 ~ 35 °C and then suddenly open the vents (must be the top vents) for air release dampness. However, when the temperature drops to 30°C, the air outlet must be closed again, and when the temperature exceeds 33°C, the air is released again. Every morning, 2 or 3 times of high-temperature ventilation is performed, and in the afternoon, the temperature is reduced to 25 to 28°C by amplifying the wind. In this way, the humidity can be greatly reduced, especially the nighttime humidity, which is conducive to high production, good humidity control, reduced nighttime condensation, and effective control of the occurrence of scab and various diseases. ?
6. Drug control. To observe frequently, when a diseased plant is found in the shed (the diseased plantlet should be removed in a timely manner), the “Smoke No. 3†produced by Shenyang Agricultural University should immediately be smoked once a night, and 40% of new stars can be sprayed 10,000 times at the same time, or 50% Starlight 600 times liquid, or 50% mancozeb WP 400 to 500 times, or 50% acetaminophen wettable powder 1000 times foliar spray, once every 7 days, pay attention to several drug alternations Use can receive better results.
First, the symptoms of black spot disease and the conditions of seedlings infected, yellow and white round spots on the cotyledons, the development of the whole leaf after the dry; stems and vines infected with water-immersed dark green spindles, depressions, cracks, when the humidity grows black Mold layer, the conidial stems and conidia of pathogens; brownish rot in tendrils; rotted into bald piles of inadvertent sprouts in 2 to 3 days; diseased leaves in early dark green near-round spots, perforation The edge of the hole is not neatly tinged with jagged edging, and the perforations of the hole are collapsed; the pale yellow rubber on the melon stalk gradually expands into a dark green depression, and the black moldy layer grows on the surface. The diseased spot is sore and the growth stops. Malformed melons. ?
Scabs are caused by the infection of the fungus A. melitensis and fungi of the subphylum Subgermanium. In addition to harming cucumbers, it also infects zucchini, pumpkins, watermelons, melons and so on. It overwinters with mycelium in diseased or field soils, and the seeds can carry bacteria. Temperature 15 ~ 25 °C, long-term condensation of melon leaves is an important condition of the disease. ?
Second, prevention and treatment methods?
1. Rotation. Rotate with non-cucurbit vegetables. ?
2. Seed treatment. Soak in 15 to 20 minutes with 55°C hot water. ?
3. The greenhouse smoked with sulfur powder. In the greenhouse planting or nursery before turning to the ground, with 2.5 kg of sulphur per acre mixed with 1 times the amount of dry sawdust, ignited smoke 24 hours, 7 to 10 days after nursery or colonization, can effectively kill the bacteria. ?
4. Cultivate strong. Increase phosphorus and potash fertilizers to increase seedling disease resistance. ?
5. Strengthen the temperature and humidity management. In the management of temperature and humidity, we must pay special attention to the management of humidity. During the production period, it is forbidden to flood irrigation, and the method of humidity increase and humidity reduction and high temperature ventilation should be adopted. The specific approach is: every morning after the dumplings, the humidity in the canopy can reach 90% to 100%. At the same time, there is fog. At this time, it is impossible to take ventilation and venting. One of the reasons is that the growth period of cucumber in greenhouse must be the most suitable high-yield temperature at 28-33°C every morning. The early air temperature is low, which is not conducive to the high yield of cucumber. The second reason is that the indoor humidity can be reduced by 2% to 3% for every 1°C increase. Therefore, in the morning, when the cold air is released, it is not as good as a warming and humidifying effect. In addition, low-temperature dehumidification due to small temperature difference between indoor and outdoor, moisture can not be discharged. Therefore, the correct approach is to open the scorpion every morning, can not immediately release the wind, it should be closed all vents, so that when it warms to 33 ~ 35 °C and then suddenly open the vents (must be the top vents) for air release dampness. However, when the temperature drops to 30°C, the air outlet must be closed again, and when the temperature exceeds 33°C, the air is released again. Every morning, 2 or 3 times of high-temperature ventilation is performed, and in the afternoon, the temperature is reduced to 25 to 28°C by amplifying the wind. In this way, the humidity can be greatly reduced, especially the nighttime humidity, which is conducive to high production, good humidity control, reduced nighttime condensation, and effective control of the occurrence of scab and various diseases. ?
6. Drug control. To observe frequently, when a diseased plant is found in the shed (the diseased plantlet should be removed in a timely manner), the “Smoke No. 3†produced by Shenyang Agricultural University should immediately be smoked once a night, and 40% of new stars can be sprayed 10,000 times at the same time, or 50% Starlight 600 times liquid, or 50% mancozeb WP 400 to 500 times, or 50% acetaminophen wettable powder 1000 times foliar spray, once every 7 days, pay attention to several drug alternations Use can receive better results.
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