For the pollution-free prevention and control of melon diseases and pests, the plant protection policy of “prevention-oriented, comprehensive prevention and control†should be implemented, and agricultural control must be adopted. Priority should be given to the application of biological control technologies. High-toxicity, high-residue pesticides must be banned, and scientifically efficient and low-toxicity should be used. Low-residue pesticides minimize the amount of use. In order to do a good job in the pollution-free production of melon, we need to strictly implement the following key links:
First, seedling disease prevention and treatment
1. To fall ill. The disease appeared in water-soaked spots at the base of the seedling stem, and quickly circulated around the stem for a week, allowing the seedlings to curl up and lodging. When the humidity was high, a layer of cottony mildew appeared at the lesion. The disease is mainly caused by low temperature and high humidity. Therefore, temperature and humidity should be strictly controlled to prevent the formation of a low-temperature, high-humidity, microclimate. When the disease occurs, it can be sprayed with Green Hunter No. 1 or Hymexazol 3000 times.
2. Roots. For physiological diseases, when the bed soil temperature is too low and the humidity is too high, the roots turn reddish-brown without root hairs, and the cotyledon or true leaf margins are dry and stop growing. Prevention and control mainly used to raise the temperature of bed soil, cultivating or scattering hay and wood ash to reduce the humidity, when the disease can be used to fill the roots.
Second, the growth of pest control
(I) Anthrax
1. Symptoms. In the adult stage, the leaves begin to have a yellow water-stained round lesion, which turns brown after enlargement, sometimes with concentric ring patterns, and is easily broken after drying.
2. Control methods. (1) Use disease-free seeds or seed disinfection, soak in seeds in warm water of 50°C to 55°C for 15 to 20 minutes, or soak in seeds in formalin 100 times for 30 minutes, then wash with water to kill seeds inside and outside Bacteria. (2) Spray with Nongke 120 or 150 times Wuyimycin. (3) Use 45% chlorothalonil smoke agent 200-300 grams in the evening to ignite closed smoke, ventilation the next morning. (4) In the early stage of disease, MDS 45 can be used as a 600-fold wettable powder or 80% as an 800-fold dilution of anthrax, and 1,000 times as much as mancozeb.
(b) Broom disease
1. Symptoms. The main hazard is the main vine and side vines. Most of the initial symptoms were in the visceral section, and there were light green spots and oil spots. The latter disease was cracked and secreted yellow-brown jelly. In the late growth period, the diseased part gradually became dry and depressed, appearing grayish white, and scattered with black dots on the surface. The difference with wilt is that the vascular bundle does not change color.
2. Control methods. (1) Strengthen the cultivation and management, adopt high and low ridge cultivation of large and small rows, water under the membrane, and prohibit flood irrigation. Apply adequately cooked organic fertilizer, plant dense plants, remove diseased plants in time and destroy them. Proper ventilation in the morning and evening will reduce the humidity in the booth. (2) At the beginning of the disease, 80% of Dasong M?45 WP 500 times or 60% chlorothalonil WP 500 times. (3) Use 9281 aqueous solution of 4 to 5 times or 70% thiophanate-methyl 3 to 4 times solution and add a little flour to make a paste to spread the disease vine.
(c) Powdery mildew
1. Symptoms. At the beginning of the disease, white powdery moldy spots appeared on the leaves, and they gradually expanded to form a layer of white powder. Occurred mainly in the late growth period, 10 °C ~ 25 °C can be the disease. In the late growth stage, the growth of plants is weak, and the lack of light causes severe disease.
2. Control methods. (1) Powdery mildew occurs when alternating between dry and wet conditions under high temperature conditions. Therefore, in the cultivation process should pay attention to ventilation and light, reduce the humidity within the greenhouse, timely watering to prevent drought. (2) Physical control. In the early stage of the disease, high fat film is sprayed, and the leaves can also be sprayed with 500 times of baking soda. (3) Sprayed with Nongkang 120, 150 times with Wuyimycin or 1500 times with Triadimefon.
(d) Insect pests
There are two kinds of insect pests, whitefly and leafminer, on melon. The melon farmers can adopt the following prevention and control methods:
1. Yellow traps. The fiberboard or plywood with a length of 50 cm and a width of 20 cm is painted with a yellow paint, and then a layer of engine oil is applied. The oil is placed near the growing point of the melanocarpus and used 30 to 40 pieces per acre. When the yellow plate is covered with whiteflies or latent leaves When the fly flies, a layer of engine oil is applied in time. Generally, it is coated once every 7-10 days.
2. Chemical control. Smoke is smoked with extermination smoke or cockroach smoke, 200-250 grams per acre, placed in the shed to ignite fumes in the evening, ventilation the next morning. It can also be sprayed with 0.2% aureoin water 2000 times or 75% cyromazine 5000-7000 times or 1.8% abamectin 2000 times.
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