Bitter gourd anthracnose occurs mostly in the spring and autumn, and the damage is serious. The pesticides are controlled in time to reduce losses. China Pesticide Network Xiaobian organizes relevant disease information for your reference:
Symptom analysis: It mainly harms melons and also damages leaves and stems. The seedlings are mostly infested from the edge of the cotyledon, and there are round to irregular lesions, which turn from grayish white to brown. The lesions are oval in shape, brown at the edges, slightly concave; the early round water stains of the fruit are brown spots. It is slightly brownish and slightly concave. When the humidity is high, there is pink mucus on the surface of the lesion. Later, the lesion changes into black, rough and irregular plaques, and the upper black spots are the conidia discs, bristles and conidia. The diseased melon is more deformed and easy to crack.
Pathogen: Colletotrichumorbiculare (BerketMont) Arx is called the genus Panicillium, belonging to the semi-known fungus. The conidia of the pathogens accumulate. Initially buried, after breaking through the epidermis, it is dark brown. The bristles are scattered in the conidia disk. The top of the bristle is light, slightly pointed, and the base is swollen, 90-120 μm long, with 1-3 separations. The conidiophores are colorless, rounded, and arranged in a shed, with a size of 20-25 μm × 2.5-3.0 μm. Conidia oblong, single cell, colorless, size 14-20 μm × 5.0-6.0 μm.
Characteristics of the disease: The pathogens mainly pass the disease in the soil or attached to the surface of the seeds for wintering, and can also survive the winter by harming other hosts. Spread by air, rain and insects. Temperature 20-27 ° C, relative humidity 80% or more suitable for onset, the optimum temperature of 24 ° C, relative humidity of 95%. Air humidity has a great impact on the disease, the relative humidity is less than 54%, and the disease hardly occurs. The soil in the field is too wet, the plant is shaded, and the melon crops are planted in conjunction with the crops.
Control method:
(1) Breeding and planting disease-resistant varieties according to local conditions.
(2) Rotation with non-melon crops for more than 3 years.
(3) Strengthen cultivation management. Covering with plastic film, using water-saving irrigation techniques such as drip irrigation, tube irrigation or sub-film submerged irrigation; scientific fertilization, application of phosphorus and potassium fertilizer, cultivation of strong seedlings; removal of diseased melons at any time during the onset period, avoiding water accumulation in the field; Minimize air humidity and control disease.
(4) Seed treatment.
Use disease-free melons to keep seeds, soak them in warm water at 80 °C for 5-10 minutes before planting.
(5) Pesticide control.
1 The melon seedlings are carefully treated with the agent one time before planting to reduce the bacterial source after transplanting.
2 soil sterilization. Use 25% charringer wettable powder, or 50% anthrax fumei WP or 50% carbendazim WP 3-5kg/667m2, mix 40-50kg of fine soil or acupoints for soil sterilization.
3 pesticide control. In the early stage of the disease, use 43% of the high-rise suspension 3000-4000 times solution, 25% of the charcoal WP 600 times, or 50% of the WP 1500 times, or 70% thiophanate-methyl wettability. Powder 600 times liquid, or 25% enemy de-euro 1000 times liquid, or 70% Antaisheng wettable powder 600 times liquid, or 80% big raw wettable powder 600 times liquid, or 30% double raw milk 2000 times liquid, or 2% agricultural anti-120 water agent 200 times liquid, or 2% added rice water agent 600 times liquid spray.
The pesticide net is recommended to use 5% chlorothalonil dust 1kg/667m2 powder spray in the protection ground.
Summary of pathogen analysis and control techniques of bitter gourd anthracnose