Currently, autumn celery (usually open field production) has entered the heart and leaf erect period or heart rate of hypertrophy. During this period, the growth of celery is large, the plants are ridged, the field is closed, and the ventilation and light transmission are poor. In addition to leaf damage caused by leaf spot disease, another kind of celery soft rot that causes whole rot disease is also very serious. According to investigations, at present, the disease occurs sporadically in lightly-affected areas, and severely-infected lands occur in patches. Should cause the vegetable farmer to pay close attention to.
The main symptom of this disease is that it occurs at the base of the petiole or on the stem. The appearance of water-soaked, light-brown spindle-shaped or irregular-shaped depressions followed by a wet rot. After the onset of disease, the entire rhizome connection or the petioles on the ground become dark and stinky, and the whole pod becomes soft due to the decay of the epidermis and vascular bundles. Death on the ground. There are also half soft rot plants.
"This disease is caused by the soft rot of Carrot Carryola rot, which is a kind of bacterium. The optimal temperature for growth and development of this bacterium is 25-30°C, it is not light and dry, and it is exposed to sunlight for 2 hours, and most of them died. In the soil from the host, it can only survive for about 15 days. In addition to celery, the fungus also infects Cruciferae, Solanaceae, Liliaceae and Asteraceae vegetables.â€
From the perspective of the route of transmission and onset of disease, this celery field can clearly see the onset of the disease, but the whole field appears sporadically, apparently related to excess water and fertilizer. The pathogenic bacteria spread through the diseased plants or in the soil without decaying diseased bodies and pests, and is transmitted through rainwater, irrigation water, fertilisers, and insects. Large amount of fertilizer, high concentration of soil solution, soil viscosity, poor permeability, poor root development or more wounds, bacterial infection is easy. "Watering is large, rainfall is high, and soil moisture is conducive to the growth and development of pathogens. Partial application of nitrogen, phosphorus and potassium fertilizers, cracks caused by deficiency of boron and calcium, ground locusts, etc., and wounds and other diseases caused by underground pests, and agricultural operations in the field. The mechanical wounds created the conditions for the invading germs.†Mr. Du Zihai emphasized that in addition to this, early planting, low-lying, and suitable host vegetable continuous cropping can also cause the disease to become more severe.
Control methods:
1. Agricultural control: strengthen field management, rational watering and fertilization, soil moisture content of 60% -70% of the water capacity in the field is appropriate, should not flood irrigation, timely drainage after the rain. Pay attention to the application of medium and small fertilizers and organic microbial fertilizers to enhance plant disease resistance. Top dressing can be used when Xin Zhinong has 1 billion live spores/grams of Bacillus subtilis 1 kg/mu plus Huafu Love Fertilizer 500 ml/mu or An Run Bio-organic Fertilizer 1.5 kg/mu. Dilute with water pouring.
2. Chemical control:
1) Immune control method: In case of non-invasive fields, 0.136% erythromycin B (Bai Hu) wettable powder 15000-5000 times solution plus 0.5% amino oligosaccharide water agent 500 times solution plus 25% azoxystrobin suspension The agent 2000 times liquid added chelated boron calcium fertilizer spray, can induce celery to produce immunity to the disease, Jianmiao strong seedlings, disease prevention and prevention of petiole cracking.
2) Control after onset: 72% agricultural streptomycin 3000-times, 6.5% bacteriostatic water-purifying agent 450-times or 47% wang copper-depleted WP 500-fold plus 60% difenoconazole ( Kaimeilai) water dispersion granules 5000 times spray control. Pay attention to the stem base. Intermittently 5-7 days again, spray 2-3 times.
3) When the ground pests are serious, use 20% octopine (1000mg/kg) EC with water; when ground locusts and beet armyworms occur, use 10% extinction (虱蚜锉) wettability 1000 times liquid powder plus 5.7% Emamectin benzoic acid dispersible granules 1500 times liquid control.
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