How to prevent and cure tobacco virus disease?

How to prevent and cure tobacco virus disease? Virus disease is the most serious disease of tobacco in China, and it is becoming more and more serious. According to the characteristics that tobacco virus diseases are mainly transmitted by aphids, and in view of the current situation that there is still no effective drug for the control of tobacco virus diseases, we use non-woven cloth to cover tobacco to control tobacco virus diseases transmitted by aphids. Good results have been obtained, which are summarized as follows. 1. Usage: after transplanting tobacco seedlings, cover the tobacco seedlings with 10~13g/ square meters, 1.0-1.5m wide non-woven fabric, wait until after the aphid migration peak, uncover the non-woven fabric. 2. The principle of disease prevention tobacco virus disease is mainly transmitted by aphids. Covering tobacco plants with non-woven cloth on the ridge after tobacco transplanting can effectively prevent winged aphids from migrating to tobacco and prevent aphids from spreading tobacco virus diseases when eating tobacco leaves. so as to effectively reduce the occurrence of virus diseases transmitted by aphids and reduce the harm of virus diseases. Third, the disease control effect of covering non-woven cloth has a significant effect on the control of tobacco virus diseases transmitted by aphids. The virus disease incidence and disease index of tobacco plants treated with non-woven cloth were significantly lower than those of the control. The control effect is more than 50% about 10 days after opening the non-woven fabric. With the extension of the time after the opening of non-woven fabric, the incidence and disease index of tobacco plant virus disease increased in varying degrees, and the control effect of non-woven fabric was also weakened. This is the result of aphids migrating to tobacco plants after uncovering the non-woven fabric. This problem is inevitable, but because most of the tobacco plants have entered a prosperous period when uncovering nonwovens, the impact of the virus has obviously weakened, and from this point of view, the period of covering nonwovens should be prolonged as far as possible. At the same time, non-woven fabric has the same effect as plastic film: increasing ground temperature and reducing water evaporation. Tobacco plants can also play a significant role in preventing frost injury and early flowering under non-woven cloth, especially in the areas of early transplanting. Fourth, the yield-increasing and value-added effect of non-woven mulching is used to control tobacco virus disease. the average yield of tobacco field is increased by 0.63%-12.29%, and the output value of tobacco field is increased by 9.6%-132.5 yuan per 667m2 tobacco field, with an increase rate of 0.74%-14.59%. The proportion and average price of high-quality tobacco are also increased in varying degrees. 5. effects on the growth and quality of tobacco the results of chemical analysis and evaluation of tobacco leaves covered with nonwovens showed that there was no consistent change trend and no significant difference between the treatment and the control. the results showed that the covered non-woven cloth had no adverse effect on the internal quality of tobacco leaves. In the application, some deformities such as shrinkage and distortion may occur when the tobacco plant grows under the non-woven fabric because of the narrow non-woven fabric and covering technology, but it will recover 5-7 days after the non-woven fabric is removed. In addition, non-woven fabric had no adverse effects on tobacco growth and agronomic characters. Points for attention 1. Tobacco plants are generally covered with non-woven cloth for about 30 days, and the covering time can be appropriately extended according to the size of tobacco plants and the peak period of aphid migration, so that the effect of aphid prevention and disease prevention of non-woven cloth will be better. Uncover a part of the nonwovens every day from 5 to 7 days before the nonwovens are opened, until they are completely removed. After removing the non-woven fabric, the bottom leaves are removed and the soil is cultivated to strengthen the field management. two。 In order to reduce the number of agricultural operations such as weeding and disinfestation of non-woven fabrics during the coverage period, 40% phoxim or trichlorfon was used as poison bait to prevent underground pests. 3000 times 90% Wanling wettable powder was sprayed on the leaves of tobacco plants before covering the non-woven fabric to control pests. 3. The earlier the nonwovens were covered after transplanting and the later the nonwovens were opened, the lower the incidence of tobacco virus disease was, and the more significant the disease prevention effect of nonwovens was. It is best to cover it in time after transplanting, at least on the day of transplanting, so as to reduce the chance of aphid migrating before covering non-woven fabric. 4. If the nonwovens are removed at one time, the tobacco is very prone to the symptoms similar to climatic plaques, which is mainly due to the great difference in temperature and humidity inside and outside the nonwovens, and the tobacco does not adapt to this change after uncovering the nonwovens. It is also found that if the nonwovens are gradually opened before uncovering the nonwovens (it takes 5 to 7 days), in order to reduce the sudden change of temperature and humidity caused by the nonwovens, the problems can be avoided. 5. The longer the tobacco plant is protected by the wider non-woven fabric, the higher the disease prevention effect of the non-woven fabric is, and the tobacco plant will not be seriously wrinkled and deformed by extrusion. Using a wide (1.50m) non-woven fabric, improving the covering technology, combined with the local climatic conditions, accurately grasp the time to uncover the non-woven fabric, and then gradually uncover the non-woven fabric as far as possible after the aphid migration peak. In the case of not scalding the leaves, the longer the time to uncover the non-woven fabric, the lower the incidence of virus disease, and the higher the disease prevention effect of the non-woven fabric. 6. The cost of single use of nonwovens is higher. Because the non-woven fabric is made of polypropylene (PP) granule, it is produced by high temperature melting, spinneret, laying, hot pressing and coiling. High toughness, good air permeability, strong wear resistance, moderate soft and hard, uniform thickness, acid and alkali resistance, non-toxic, non-moth, easy to wash. The used non-woven fabric can continue to be used after the lotion, if used properly and pay attention to protection, it can be used continuously for at least 2 years, which can greatly reduce the use cost and improve the economic benefit. Click to get more tobacco planting techniques click to get more flower planting techniques