In recent years, the occurrence of root rot in fruit trees has become more severe in some fruit-producing areas, especially in the early days of fruit tree growth, and in the middle and late periods of frequent rainfall, the occurrence of root rot is more serious. In order to reduce the harm caused by root rot, the symptoms, causes and prevention measures of the disease are described below for reference.
One, field performance symptoms
Root spot root rot is found in both the upper and lower parts of the orchard. Roots from the roots of the fibrous root disease, light round red or brown round spots formed around the fibrous roots, the disease root rot, light patella can fall off, serious lesions expand, plaques connected to each other, so that the entire root rot, lesions From the fine root to the thick root gradually expands. The most obvious feature of the disease is that the roots can repeatedly produce callus and regenerate new roots. With the occurrence of root diseases, the aboveground parts also show symptoms. The symptoms of the aboveground parts are usually acute and chronic. Acute symptoms: There was no obvious abnormality before the onset. The leaves of the diseased section suddenly lost water and dried and withered. The shoots also withered and drooped. They seemed to be burned by boiling water. Severe leaves fell off. Apples and grapes showed symptoms of this disease; chronic symptoms: the site of the disease The chlorosis began to appear, and the leaves gradually wilted and died. After the diseased leaves were shed, new leaves could be issued again. However, the leaf color was not normal and the peach saplings showed more symptoms. Because the diseased plants have the function of callus and the function of a new root, the development of the disease shows a state of ups and downs. When the water and fertilizers and management conditions are good, and the plants grow robustly, some of the diseased branches can even recover completely.
Second, the cause of the disease
According to many years of field observations and disease investigations, the cause of round spot root rot disease: First, the pathogen. Root spot root rot is caused by infection with three sickle fungi. All three species of bacteria are soil-accommodating bacteria. The pathogens are widely found in soil and can survive in the soil for long periods of time. Only when the roots of fruit trees are weak, will they be affected by Fusarium infestation. The second is the texture of the soil. There are many factors affecting the root growth of fruit trees, but the soil (including soil texture, structure, organic matter content, soil pH, etc.) is the main reason affecting root growth. For example, apple requires organic matter content of 2% to 3%, and soil pH is The acidity and neutrality are appropriate, and the soil is sandy loam. Therefore, soil is the major constraint to the occurrence of root rot in fruit trees. Third, management is not scientific. Most fruit growers use a large amount of chemical fertilizers, blindly increase the amount of nitrogen fertilizers, and concentrate or apply organic fertilizers that are not decomposed to cause root damage and root burning, resulting in weakening of the root system. Unfair girdling and ring-cutting methods are used to overload the trees. Load, resulting in extreme decline in tree vigor, root potential; flood irrigation, soil compaction, extensive management, pests and other serious damage to the impact of the normal development of roots, are conducive to the infection of bacteria. The fourth is unfavorable weather conditions. When dry and little rain occurs and the soil water content reaches the withering coefficient, the growth of roots is hindered and the infection of pathogenic bacteria is conducive. Overcast and rainy, the relative water holding capacity of the soil and the lack of oxygen in the soil will lead to asphyxiation and debilitation of the roots, which will facilitate the pathogenic bacteria infection.
Third, prevention advice
According to many years of investigation and practice, the comprehensive management principle of "prevention first and prevention and control supplement" should be adopted in the prevention and control of round spot root rot. One is not planting seedlings with pathogens. Before the establishment of the garden, the nursery shall be investigated and the seedlings shall be selected. If brown rot is found in the roots, it shall be burnt and concentrated. The selected seedling shall be immersed in liquid with 600 times carbendazim or 0.5 Baume degree lime sulfur for 4 to 5 hours. Eradicate the source of the disease. The second is to deepen the hole and change the soil. Remove the diseased soil from the root neck or the large root and replace it with sterile sandy soil. Replace it six months to one year later. Or refilling coal residue, grass ash, and composting rotted straw, weeds, etc. can relieve the waste of root rot. For the replanting of dead plants where root rot occurs, the soil is treated with a bactericidal agent during deep filling and refilling. The third is to improve soil properties. Deeply apply organic fertilizer in autumn to deepen the living soil layer; cover the straw or take grass and natural grass to increase soil organic matter content and improve soil ventilation; increase humic acid fertilizer and adjust soil ph; scientific application Nitrogen, phosphorus, and potassium fertilizers supplement trace elements. The fourth is to strengthen scientific management. According to the growth conditions of new shoots, timely artificial or chemical control, standard tree tree structure, improve ventilation and light conditions, reasonable tree load, reduce nutrient consumption; timely control of pests and diseases; change flood irrigation to drip irrigation, sprinkler irrigation, improve the soil environment The conditional implementation of water and fertilizer integration.
Fourth, prevention and control measures
1. For the diseased trees, dig up the root soil, scrape the roots of the disease to dry roots, and then apply 2.5 to 5 kilograms of plant ash to each tree (the tree is large and the disease is heavy enough), add a little soil, 1 to 1 Two months later the disease tree can issue new roots.
2. Spring and autumn air soil. The root of the disease was dug out and dried for 7 to 10 days. During the air-drying period, avoid rain and irrigation water entering the pit so as not to affect the rooting effect.
3. Chemical control. For the control of round spot root rot, 50% carbendazim 1000 times solution or 75% thiophanate-methyl 1000-1500 times solution can be used. It is also possible to use agricultural anti-120 water agent 200 times solution and double effect elixir 200-300 times solution. , pentachloronitrobenzene and so on. When using the trunk as the center, excavate 34 to 45 cm, depth 50 to 70 cm, 3 to 5 radiation channels, each with 75 kg of liquid. The frequency and time of application are preferably twice a year in early spring and late summer. For the acute bacterial wilt tree, dinizol 3000 times can be used to irrigate the roots. Each dry plant uses 50 to 70 grams of water to 200 to 250 kilograms of water to infuse the tree plate. The water is sprinkled with 75 to 100 grams per plant, and the irrigation is 1 to 2 After days of loose soil, irrigate 1 time at 1 month intervals. Applying humic acid on the basis of applying organic fertilizer, 8 kg of large trees and 5 kg of small trees per plant will be watered after application to reduce the occurrence of diseases.
Curtain motor of smart hotel guest control system
Smart Home automation curtain motor is a part of home automation system, which is used to control the curtains of home and office. Support mobile phone real-time remote control curtain close or open. You don't have to go to the place near the window and use your mobile phone to control the curtain anytime and anywhere. It really makes your home intelligent. It is also suitable for smart hotels to control the opening and closing of the curtain system, so that you can have a better use experience
Curtain Motor,Smart Curtain Motor,Home Curtain Motor,Automation Curtain Motor
Shenzhen Zhuohao Intelligent Electronic Development Co., Ltd. , https://www.szactop-smart.com