First, disease prevention
Broken down disease Symptoms: Rotten buds before seedlings are unearthed, or water-stained lesions appear near the ground on the hypocotyls after emergence. Later, they turn yellow and contract, and the seedlings fall. The disease develops rapidly, which can cause large pieces of seedlings to die. Under high temperature and high humidity, the surface of the damaged seedlings and the nearby soil surface are covered with a layer of white flocculent mycelium.
Etiology: The disease is easy to occur under the condition of low temperature and high humidity, poor ventilation and light transmission at around 15 °C.
Control measures: select soil that has not been planted with melons and vegetables as nutrient soil, apply fully decomposed fertilizer; nutrient soil with 50% carbendazim 100g with nutrient soil 1 square, 2/3 sprinkle on seedbed, 1/3 for Cover species; do a good job of temperature and humidity control of the seedbed, pay attention to ventilation and light transmission, avoid the occurrence of low temperature and high humidity environment conditions, find the diseased plants in time to remove, and medication control.
Epidemic disease The peak period of this disease is mainly in the period from the group to the vine. Symptoms: In the early stage of the disease, the leaves produce irregular water-stained lesions, which are expanded and soft-corrosive. When dry, the lesions become brown and easily ruptured; the base of the stem of the adult plants is dark green water-stained fusiform lesions, and the surrounding Stem-based contracture eventually died.
Incidence conditions: The disease occurs at a moderate temperature of 28 ° C ~ 30 ° C, high temperature and high humidity is the main cause of the disease
Control measures: strengthen field management, timely ventilation and ventilation in the greenhouse, reduce humidity, preferably drip irrigation; in addition, less application of quick-acting nitrogen fertilizer; early stage of the disease with Jinggangmycin formulated with chlorothalonil or anti-virus sputum into 50 times high concentration of smear Vulture; can also be sprayed with 64% antivirus 矾500～600 times, once every 7 days, even spray 2~3 times.
Anthracnose Watermelon can occur in the whole growth period, and the disease is heavier in the middle and late growth stages. Symptoms: The lesions on the cotyledons and leaves are initially round yellow-brown water-stained lesions, which later become purple-brown on the edges, and the middle part of the pale brown has a purple concentric halo, which is easy to perforate. The lesions on the petiole and stem are fusiform, and the spots on the fruit are round and the brown is slightly concave. When the air humidity is high, black spots and pink sticks are formed on the lesions.
Cause: It is easy to develop in the case of high temperature, high humidity, poor drainage, nitrogen fertilizer, and weak plant growth.
Control measures: 75% chlorothalonil WP 600-800 times liquid spray can be used at the beginning of the disease
Bacterial wilt Symptoms: Most occur in the stems and stems. When the disease occurs, the stems and vines appear longitudinally cracked, and the surface produces a yellow-brown gel. The diseased part is dry and grayish white, and the surface is scattered with black dots, causing the plants to wither and die.
Etiology: The development temperature of the pathogen is 20 °C ~ 30 °C, improper management of water and fertilizer causes prolonged weakness and easy onset.
Control measures: found that the diseased plants were treated with mancozeb or Redolmir in a timely manner with 800 times 70% methyl thiophanate-methyl WP, mixed with water in a ratio of 1:1, 50 times to spread the stems, and 75% can be used. Mn-Zn wettable powder 600 times liquid spray.
Viral disease Symptoms: After the watermelon is infected with the virus, the heart of the plant is mosaic or shrunken, or the plant is dwarfed and deformed. In the early stage, the susceptible plants did not bear the melon, and the plants in the late stage were shortened, and the melons could be knotted, but the melons were small and deformed.
The law of onset: caused by aphids or poisonous seeds and artificial poisoning, high temperature and drought, strong sunshine, not only conducive to the reproduction and migration of aphids, but also conducive to the proliferation of viruses.
Control measures: use disease-resistant varieties, eradicate weeds in the field, eliminate poisonous aphids in time, use silver-gray film or black film to prevent disease, or use yellow plate oil to lure and stick aphids, or use 2.5% cyanide Pyrethroid 3000 times liquid spray; 30% virus A500 times solution and 0.2% potassium dihydrogen phosphate spray at the beginning of the disease, even spray 2 to 3 times
Powdery mildew Incidence conditions: The most common disease conditions are in the environment of 16 ° C ~ 24 ° C, high humidity in the field, excessive nitrogen fertilizer, and poor ventilation and light transmission.
Control measures: rational fertilization, timely pruning and vines, good ventilation and light ventilation; 10% high water dispersible granules 1000-1500 times liquid spray can be used at the beginning of the disease.
Second, pests
Aphids, whitefly, and leaf miners can be sprayed 2500 times or avermectin 3000 times, 25% chlorpyrifos 2000 times, and 10% beta-cypermethrin 2000 times.
Red spiders Use nymphs and adults to suck juice on the back of the leaves, so that the leaves are chlorotic, and can be sprayed with 3000 times solution of Qiqisu.
Source: Hebei Science and Technology News
Broken down disease Symptoms: Rotten buds before seedlings are unearthed, or water-stained lesions appear near the ground on the hypocotyls after emergence. Later, they turn yellow and contract, and the seedlings fall. The disease develops rapidly, which can cause large pieces of seedlings to die. Under high temperature and high humidity, the surface of the damaged seedlings and the nearby soil surface are covered with a layer of white flocculent mycelium.
Etiology: The disease is easy to occur under the condition of low temperature and high humidity, poor ventilation and light transmission at around 15 °C.
Control measures: select soil that has not been planted with melons and vegetables as nutrient soil, apply fully decomposed fertilizer; nutrient soil with 50% carbendazim 100g with nutrient soil 1 square, 2/3 sprinkle on seedbed, 1/3 for Cover species; do a good job of temperature and humidity control of the seedbed, pay attention to ventilation and light transmission, avoid the occurrence of low temperature and high humidity environment conditions, find the diseased plants in time to remove, and medication control.
Epidemic disease The peak period of this disease is mainly in the period from the group to the vine. Symptoms: In the early stage of the disease, the leaves produce irregular water-stained lesions, which are expanded and soft-corrosive. When dry, the lesions become brown and easily ruptured; the base of the stem of the adult plants is dark green water-stained fusiform lesions, and the surrounding Stem-based contracture eventually died.
Incidence conditions: The disease occurs at a moderate temperature of 28 ° C ~ 30 ° C, high temperature and high humidity is the main cause of the disease
Control measures: strengthen field management, timely ventilation and ventilation in the greenhouse, reduce humidity, preferably drip irrigation; in addition, less application of quick-acting nitrogen fertilizer; early stage of the disease with Jinggangmycin formulated with chlorothalonil or anti-virus sputum into 50 times high concentration of smear Vulture; can also be sprayed with 64% antivirus 矾500～600 times, once every 7 days, even spray 2~3 times.
Anthracnose Watermelon can occur in the whole growth period, and the disease is heavier in the middle and late growth stages. Symptoms: The lesions on the cotyledons and leaves are initially round yellow-brown water-stained lesions, which later become purple-brown on the edges, and the middle part of the pale brown has a purple concentric halo, which is easy to perforate. The lesions on the petiole and stem are fusiform, and the spots on the fruit are round and the brown is slightly concave. When the air humidity is high, black spots and pink sticks are formed on the lesions.
Cause: It is easy to develop in the case of high temperature, high humidity, poor drainage, nitrogen fertilizer, and weak plant growth.
Control measures: 75% chlorothalonil WP 600-800 times liquid spray can be used at the beginning of the disease
Bacterial wilt Symptoms: Most occur in the stems and stems. When the disease occurs, the stems and vines appear longitudinally cracked, and the surface produces a yellow-brown gel. The diseased part is dry and grayish white, and the surface is scattered with black dots, causing the plants to wither and die.
Etiology: The development temperature of the pathogen is 20 °C ~ 30 °C, improper management of water and fertilizer causes prolonged weakness and easy onset.
Control measures: found that the diseased plants were treated with mancozeb or Redolmir in a timely manner with 800 times 70% methyl thiophanate-methyl WP, mixed with water in a ratio of 1:1, 50 times to spread the stems, and 75% can be used. Mn-Zn wettable powder 600 times liquid spray.
Viral disease Symptoms: After the watermelon is infected with the virus, the heart of the plant is mosaic or shrunken, or the plant is dwarfed and deformed. In the early stage, the susceptible plants did not bear the melon, and the plants in the late stage were shortened, and the melons could be knotted, but the melons were small and deformed.
The law of onset: caused by aphids or poisonous seeds and artificial poisoning, high temperature and drought, strong sunshine, not only conducive to the reproduction and migration of aphids, but also conducive to the proliferation of viruses.
Control measures: use disease-resistant varieties, eradicate weeds in the field, eliminate poisonous aphids in time, use silver-gray film or black film to prevent disease, or use yellow plate oil to lure and stick aphids, or use 2.5% cyanide Pyrethroid 3000 times liquid spray; 30% virus A500 times solution and 0.2% potassium dihydrogen phosphate spray at the beginning of the disease, even spray 2 to 3 times
Powdery mildew Incidence conditions: The most common disease conditions are in the environment of 16 ° C ~ 24 ° C, high humidity in the field, excessive nitrogen fertilizer, and poor ventilation and light transmission.
Control measures: rational fertilization, timely pruning and vines, good ventilation and light ventilation; 10% high water dispersible granules 1000-1500 times liquid spray can be used at the beginning of the disease.
Second, pests
Aphids, whitefly, and leaf miners can be sprayed 2500 times or avermectin 3000 times, 25% chlorpyrifos 2000 times, and 10% beta-cypermethrin 2000 times.
Red spiders Use nymphs and adults to suck juice on the back of the leaves, so that the leaves are chlorotic, and can be sprayed with 3000 times solution of Qiqisu.
Source: Hebei Science and Technology News
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