Studies On Occurrence Regularity And Control Techniques Of Potato Virus Y Disease In Tobacco Growing Areas Of Mudanjiang

Potato virus Y(PVY)is one of the most important tobacco diseases in China,in recently years,the occurrence and damage of PVY to tobacco production have appeared sharp upward trend and caused several losses to tobacco leaf production.Although many measures have been carried out,the effect is not satisfactory.The main reason is that the disease infectious cycles and epidemic of PVY are not enough clear.By the methods of combining the field trials and experiments in the laboratory,the epidemic of PVY and the method for preventing tobacco PVY disease in Mudanjiang have been studied in this paper according to the result of investigation and research on the disease and it's environment.The main results are as follows:PVY is widely distributed in Mudanjiang tobacco production areas.Potato is the poison source and carrier of PVY.And the PVY in diseased plant residues can also lead to the occurrence of potato virus Y disease.The occurrences of tobacco PVY diseases in Mudanjiang has a close relationship with the crop layout,the fertilizer application,the meteorological factors,the tobacco growth period,the number of aphids and other factors.The investigation showed that the tobacco which near potato fields and apricot orchard have severity disease.Tobacco area should be rational fertilization.If excess nitrogen fertilizer,are likely to cause disease and potato virus Y disease outbreaks.Regardless of nitrogen is excessive or reduced,are likely to cause the occurrence of potato Y virus.Meanwhile,as the transmission mediator of PVY virus,the amount of aphids is a important factor which greatly affect the PVY disease.In Mudanjiang tobacco production areas,the PVY virus have 2 active peak(late of June and medium of July).When the temperature and rainfall from July to August for aphid growth,tobacco aphids can reached the peak aphid volume,the Potato virus Y disease can also increased.The peaks of aphid are variety with climate condition,in general,the early hatched over-winter eggs of aphids,high livability,fast multiply,early active peak and high amount of aphids when the weather is hot,drought,enough sunshine.According to the results of investigations and experiments the integrate management of PVY have been proposed:firstly,separation from the crops which is source of PVY virus such as pepper and potato etc;secondly,virus trap using the biological characteristic of aphids which attracted by yellow,rape can be planted around tobacco field to attract the aphids and kill them by spraying chemical;thirdly,avoid the aphid from tobacco fields by hanging silver gray straps around the feld;finally,spraying the virus inhibitor to decrease the occurrence and degree of PVY disease.