Study On The Occurrence Characteristics And Prevention Of Tobacco Virus Disease In Sanming Of Fujian Province

Tobacco virus diseases, which are one of the most serious diseases damaging the tobacco production in our country, distributed across all over the tobacco areas. The virus diseases not only cause the loss of tobacco production,but also cause the serious drop of tobacco quality, Economic losses occupy half of the losses from all tobacco diseases. The virus disease causes a loss of 420,000 kg of its Yield and about 6.08 million yuan of its output value each year in Sanming of Fujian province, which severely restricts the tobacco production to develop healthily and sustainably.Therefore, it is very important and has practical significance to analyze and research epidemic regularity of the tobacco virus diseases in Sanming, pointedly work out integrated and restraining measures about the virus diseases in the district and improve the control effect of it.On this background, the paper studied the occurrence characteristics and prevention of tobacco virus diseases in Sanming of Fujian province. For the full occurence period of the virus diseases in the field, the diseased leaves of different symptoms are collected and the method of ELISA is adopted to identify the types of the virus diseases in order to analyze the population structures of the virus diseases. The systematic observation field is established in Ninghua in 2007, which is a representative selection in tobacco-producing areas. The purpose is to monitor the regularity between tobacco aphid migration and its population dynamics, comprehensively analyzing the regularity of the tobacco virus diseases occur. Besides, the method of ELISA is also used to test the rate of stumpy tobacco residue carrying the diseases in the field, and track to survey the relationship between the virus diseases and the tobacco plant debris. Additionally, the domestic antiviral agents is collected to make comparative trial about their effect in the field with the purpose of screening out the effective and stable antiviral agents applied to the production demonstration。The network about the prediction and forecast of the diseases and insect pests being made full use of, Chui Pik-1, a special breed in Sanming, is planted in Anle, Ninghua for setting up a 66.7hm2 demonstration plot of the integrated control technology with the object of controlling the tobacco virus diseases.The results indicated that:For types and structures of virus diseases in Sanming tobacco areas, that TMV and CMV constituting the dominant populations of the virus diseases, virus spread by aphids CMV,PVY,TEV and the complex infection have an increasing trend. Their detection rates are respectively 36.7%,9.2%,5.1%,31.6%, which proves the more serious harm in the field. Secondly, the field epidemic of tobacco virus disease in Sanming tobacco areas is more typical "S" curve. That is to say, the cold weather in earlier stage has greater impact on the seedlings quality and their adverse resistance, and the virus diseases are easy to break out and prevail if it is hot and droughty in the first third of April. The main cultivars in Sanming tobacco areas are different in the disease resistance of the virus diseases-- Chui Pik-1> Yunyan 85> K326. After decaying for 200 days, the stumpy tobacco residues collected randomly still contain living donor TMV with the virus carried rate as much as 100%. What's more, the tracking investigation about the field virus diseases also indicates that the virus diseases are serious in the field with poor hygiene and abundant stumpy tobacco residues. 8%Ningnanmycin with the rate from 57.2%～62.0% has best control effect in the seven antiviral agents, which can effectively control the virus diseases to some extent. In addition, the control demonstration in the large areas has the same control treed with the rate from 65.3%～77.7%. It is obvious that scientifically integrated control technology and efficient technology implementation is effective in controlling the disease and insect pests. As a result, the yield in the demonstration plots is up to 2190.2kg/hm2 and the average values is about 33687.6元/hm2, which is obviously higher than that in non-demonstration areas. Finally, the demonstration areas achieve farmers income.