The Occurrence Regularity Of Main Pests And Diseases And Chemical Control Tests Of Main Pests In Baise Tobacco Zones

Since tobacco was introduced into China,it has been widely cultivated in the northern and southern provinces and regions,and now the area of tobacco planting zones and production in China are the highest in the world.In the paper,the occurrence regularity of the main diseases and pests is investigated at Jingxi and Longlin,the two main tobacco production zones in Baise,and their relationship with the local meteorological factors is analyzed,combined with the local main meteorological factors.Meanwhile,the main tobacco pests chemical control experiments are carried out.The main results are shown as follows:1.The relationship between the growth of main pests in Jingxi and Longlin and the meteorological factors.In Jingxi.Prodenia litura occurs earlier than Longlin but harm slightly.The density of insect population increases with the increment of average temperature.With the increment of rainfall,the density of insect population decreases.The density of Myzus persicae in Jingxi is significantly smaller than that of Longlin,and the density of aphid gradually increases with the increment of average temperature.With the increment of rainfall,the density of insect population decreases.The occurrence of tobacco bacterial wilt disease in Longlin is more serious than that in Jingxi.With the increment of rainfall,the occurrence rate increases correspondingly.The tobacco black tibia disease occurs in Jingxi is earlier and more serious than that in Longlin.With the increment of average temperature,the occurrence of black tibia disease in both places increases gradually.With the increment of rainfall in both places,the occurrence of tobacco black tibia disease increases.The occurrence of tobacco virus disease(TMV)in Jingxi is earlier and more serious than that in Longlin.As the average temperature rises and the occurrence rate gradually increases.With the increment of rainfall,the occurrence of tobacco virus disease decreases.Since the fluctuation of sunshine duration during the occurrence of diseases and pests in Jingxi and Longlin is not obvious,the relationship between the occurrence of these diseases and the number of sunshine duration need to be further explored.2.Field test of pesticide efficacy to tobacco Prodenia litura and Myzus persicae.Among the field test of pesticide efficacy to tobacco Prodenia litura of 20%chlorine benzamide,5%abamectin suspending agent,15%emamectin indoxacarb,0.3%matrine solution,10%high-efficiency cypermethrin emulsifiable solution and 0.5%veratramine solution,20%chlorine benzamide with 3000 times dilution has higher control effect than other pesticides.The control effectiveness is 72.62%for having been sprayed for 1 day,100%for having been sprayed for 3 days and 100%for having been sprayed for 7 days.It proves to possess quick bioactivity and good durability.Among the field test of pesticide efficacy to Myzus persicae of 5%acetamiprid,70%imidacloprid,0.3%matrine solution,0.3%azadirachtin and 0.5%veratramine solution,the 0.5%veratramine solution with 1500 times dilution has higher control effect than other pesticides.The control effectiveness is 99.64%for having been sprayed for 1 day,100%for having been sprayed for 3 days and 100%for having been sprayed for 7 days.It proves to possess quick bioactivity and good durability.3.The effect of methyl jasmonate and methyl salicylate on the growth and development of tobacco Prodenia litura.MeJA and MeSA,which are regarded as induced resistances,are shown to have induced resistance properties in the Prodenia litura development period and adult life.And the induced resistance properties that induced resistances perform to young larvae are significant during the development period,while there is no significant difference in such properties in aging period and pupal period and not as effective as that in development period.However,the induced resistances perform well in significantly reducing the egg laying amount of adults,and have certain high value of promotion.4.The effect of methyl jasmonate and methyl salicylate on the activity of tobacco defense protease and secondary metabolites.The tobacco leaves have been sprayed by lmmol/L MeJA and 5mmol/L MeSA for a day,and the activity of salicylic acid(SA)and secondary metabolites is detected to be promoted significantly,compared to control treatment.After being sprayed lmmol/L MeJA for a day,the activity of peroxidase(POD)and trypsin inhibitor(TrypPI)is significantly higher than that of MeSA.After being sprayed 5mmol/L MeSA for a day,the activity of tannin and polyphenol oxidase(PPO)is significantly higher than that of MeJA.