1, symptoms and epidemic
The main damage leaves, showing three types: white point type, is the formation of water spots on the front and back of the leaf gray spots, oval or spindle, the periphery is light yellow, late lesions expand to large dead with dead spots, caused by half a leaf or Whole leaves die. When wet, sparse gray mold layer. The dry-tip type, which develops at the cutting edge, appears as water-stained, then becomes light green, and then expands to a brownish-edged streak or "V"-shaped lesion, causing the entire leaf to dry and near-surface lesions. Gray mold layer. In the wet rot type, all near-surface leaves form a deep green water-saturated soft rot under high-humidity conditions, with a foul-smelling, dense gray mold layer. Pathogenic fungi spread through airflow, irrigation, and agricultural operations, resulting in the onset of healthy leaves. The spring and spring leeks are tightly closed, the shed is warm, the shed film is dripping, and the leaves are accompanied by a water film suitable for disease occurrence. Perennial leeks, once infected, accumulate bacteria sources and tend to become more serious in the following years, especially in the conditions of low temperature, high humidity, lack of sunshine, and poor ventilation in early spring sheds. Botrytis may be endemic.
2. Control methods
(1) Agricultural prevention and control Ventilation at a proper time The reduction of humidity is an important measure for disease prevention. It controls the amount of water before the lock shed, controls the water after the shed is shed, and cannot be watered after each reaping; the bottom wind is strictly prohibited in sheds; In order to avoid damaging the leaves, we must timely harvest the leeks, and then thoroughly remove the disease and residual leaves to reduce the source of bacteria; increase organic fertilizer to prevent partial application of nitrogen fertilizer to form leaves susceptible to disease; summer leeks to weeding, top dressing, watering Keep a good root.
2 Pharmacy control In the winter and spring season, when the height of the head knife leeks is 4-7 cm, the two-knife leeks should be promptly treated with pesticides 6-8 days after the head knife leeks harvest. In the rainy days, use 10% fast-king spirit smoke agent, or 45% chlorothalonil smoke agent, use 250 grams per acre, divide 6-8 points, ignite with dark fire, close the greenhouse and fumigate for 3-4 hours. Can also be sprayed in the evening 10% moldoline dust, or 6.5% of bacteria. Mouldy Wei dust agent, 1000 grams per mu; on sunny days available 40% dimethyl pyrimidine amine suspension 1200 times liquid. Or 65% thiobacillus Wei wettable powder 1000 times, or 50% acetaminophen wettable powder 1000-1600 times spray, focus on spraying new leaves and surrounding soil, depending on the condition of continuous prevention and treatment 2-3 times. After the spraying, the weather should be ventilated and wet. 7 times a day spray, alternating with other control methods 2-3 times.
The main damage leaves, showing three types: white point type, is the formation of water spots on the front and back of the leaf gray spots, oval or spindle, the periphery is light yellow, late lesions expand to large dead with dead spots, caused by half a leaf or Whole leaves die. When wet, sparse gray mold layer. The dry-tip type, which develops at the cutting edge, appears as water-stained, then becomes light green, and then expands to a brownish-edged streak or "V"-shaped lesion, causing the entire leaf to dry and near-surface lesions. Gray mold layer. In the wet rot type, all near-surface leaves form a deep green water-saturated soft rot under high-humidity conditions, with a foul-smelling, dense gray mold layer. Pathogenic fungi spread through airflow, irrigation, and agricultural operations, resulting in the onset of healthy leaves. The spring and spring leeks are tightly closed, the shed is warm, the shed film is dripping, and the leaves are accompanied by a water film suitable for disease occurrence. Perennial leeks, once infected, accumulate bacteria sources and tend to become more serious in the following years, especially in the conditions of low temperature, high humidity, lack of sunshine, and poor ventilation in early spring sheds. Botrytis may be endemic.
2. Control methods
(1) Agricultural prevention and control Ventilation at a proper time The reduction of humidity is an important measure for disease prevention. It controls the amount of water before the lock shed, controls the water after the shed is shed, and cannot be watered after each reaping; the bottom wind is strictly prohibited in sheds; In order to avoid damaging the leaves, we must timely harvest the leeks, and then thoroughly remove the disease and residual leaves to reduce the source of bacteria; increase organic fertilizer to prevent partial application of nitrogen fertilizer to form leaves susceptible to disease; summer leeks to weeding, top dressing, watering Keep a good root.
2 Pharmacy control In the winter and spring season, when the height of the head knife leeks is 4-7 cm, the two-knife leeks should be promptly treated with pesticides 6-8 days after the head knife leeks harvest. In the rainy days, use 10% fast-king spirit smoke agent, or 45% chlorothalonil smoke agent, use 250 grams per acre, divide 6-8 points, ignite with dark fire, close the greenhouse and fumigate for 3-4 hours. Can also be sprayed in the evening 10% moldoline dust, or 6.5% of bacteria. Mouldy Wei dust agent, 1000 grams per mu; on sunny days available 40% dimethyl pyrimidine amine suspension 1200 times liquid. Or 65% thiobacillus Wei wettable powder 1000 times, or 50% acetaminophen wettable powder 1000-1600 times spray, focus on spraying new leaves and surrounding soil, depending on the condition of continuous prevention and treatment 2-3 times. After the spraying, the weather should be ventilated and wet. 7 times a day spray, alternating with other control methods 2-3 times.
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