As the temperature decreases, the indoor temperature of the shed will also decrease day by day, and at the same time, various root anomalies will occur to varying degrees. (Tomatoes, for example) — Blight, root rot, bacterial wilt, and root-knot nematodes It is a relatively common disease in the root. In addition, various nutrient deficiency and abnormalities that occur in vegetables are also related to the absorption of roots. Bacterial wilt The onset of bacterial wilt: From the appearance point of view, the most important feature of bacterial wilt is the wilting of plants. After the onset, the upper part of the day with good days was wilting in the upper part of the day, and then the lower part was infected in the middle. In some cases, one side of the stem was wilting and some of the whole wilted. Tomatoes with wilting symptoms can be clearly seen by cutting off the base of their stems. The vascular bundle inside has become brown. It is precisely because these vascular bundles have been damaged, so that nutrients and water can not be transported upwards normally, will cause tomatoes to appear wilting phenomenon. Experts pointed out that if tomatoes can not be treated promptly with bacterial wilt, they will die after repeated wilting several times, causing great losses to vegetable farmers. To deal with tomato bacterial wilt, the best way is to use drugs to irrigate roots. Blight Symptoms: The disease is vascular bundle disease, mostly after the start of colonization, early onset, yellow leaves from the ground closer to the ground, the last brown dead, dry leaves do not fall off on the stem; also early onset, in the stem One side of the yellow leaves, the other side of the normal color of the leaves; there are individual branches on the leaves, half of the leaves yellow, and the other half normal leaves. When the morbidity is severe, the diseased leaves expand upward from the bottom, and only the top leaves are left behind, and the others die. The incidence of light, only yellow leaf from the ground near the leaves, the rest are normal, flowering, the results and healthy strains no difference. Roots of diseased plants brown rot or local necrosis. Cut stem basal vascular brown. The main difference between the disease and the symptoms of tomato bacterial wilt is that the leaves are yellow after the disease. Wet pink mold (disease conidia) often develops on the base of the stem. Occurrence and development laws: When the ground temperature is around 28°C, it is most susceptible to onset. Soil moisture content is high or soil root-knot nematodes are more. Roots are stunted, resulting in wounds and favorable wilt disease. The pathogen only infects tomatoes, and continuous crops increase the number of pathogens year by year, causing serious diseases. Root rot Symptoms: The disease damages the stem base or root. At the beginning of the disease, brown plaques were formed and the depressions gradually expanded. In severe cases, the lesions circled around the stem base or roots for a week, causing the ground to wither. In the longitudinal section of the diseased section, the catheter was dark brown, and the later rhizomes were rotten. No new roots were found and the plants died. Occurrence pattern: According to the relevant data, the pathogens of the root rot are wintering in the soil with diseased plant residues, and may also be overwintering in under-composted compost. In the following year, a large number of molecular spores are transmitted through rainwater or irrigation water, causing high temperatures. When the high humidity or low ground temperature is conducive to disease. After the planting of tomatoes, if the soil temperature is low, the soil moisture is too high, and the duration is long, or the ventilation is not possible in a continuous rainy greenhouse, the temperature in the greenhouse is high and the humidity is high. Especially after flood irrigation, the ventilation is not timely, which can lead to The occurrence and prevalence of the disease. Nematode Symptoms of injury: Occur mainly on the fibrous roots and lateral roots of tomatoes. There is a small milky white nematode in the root knot. The new roots will re-infect the disease and form root-knot neoplasms. Dwarf, stunted, and even premature death withered. When the soil temperature was 25-30°C and the soil water content was 40%, the pathogenic nematodes developed very fast. When the temperature was below 10°C, the larvae stopped their activities. Its secretion stimulates cell proliferation, forming root knots or nodules. The sunlight greenhouse with dry soil and loose soil texture is suitable for nematodes, so the disease is serious; This nematode is mostly distributed in the area where the roots of vegetables are located, in the top soil layer of 3 to 10 cm. Rushan Jinguo Food Co., Ltd , https://www.jinguofood.cn