| Scale insects are one of the most important pests in kiwifruit orchards in Xiuwen County,Guizhou Province.At present,chemical control is the main measure of fruit trees scale insects,however,the long-term unreasonable use of chemical agents is likely to lead to resistance,residues,resurgence,pollutio problems.Reducing the use of chemicals is a great significance for improving the quality of kiwifruit and ensuring the safety of fruits.This experiment,Guichang kiwifruit Pseudaulacaspis pentagona,was taken as the research object,exploring its spatial distribution in Xiuwen kiwifruit orchard and fruit trees,25.5% oil film of colophony & lime sulfur was developed to control the scale insects of kiwifruit,exploring its indoor biological activity and field control effect,then the safety of the film agent to trees and fruits was clarified,the purpose of all study is to provide new ideas for the green control of scale insects in kiwifruit orchards.The main results are as follows:1.The species,habits and spatial distribution of Pseudaulacaspis pentagona in kiwifruit Guichang in Xiuwen County were found out.Using “parallel jumping”,“random investigation” and “five point sampling” to explore the spatial distribution and harm of scale insects in kiwifruit.The results showed that the main scale insects in the kiwifruit of Guichang in Xiuwen County was Pseudaulacaspis pentagona,which occurred two generations in one year and its peak from May to August,the most serious direction was in the south of the garden and trees;its spatial distribution is aggregative;the orchard with high management level has less damage.2.The 25.5% oil film of colophony & lime sulfur agent has good physicochemical performance.The formula of the natural film agent: rosin 12.5%,soybean oil 10%,emulsifier 2.5%(AEO:OP-15=1:3),lime sulfur 3%,sodium alginate 2%,sodium benzoate 1%,water 69%.When the dilution times of 25.5% oil film of colophony & lime sulfur agent is between 125 and 2000,pH value is between 7.80 and 8.03,which is lower than the 29% lime sulfur with the same dilution times,the viscosity value is 71.66-51.33 mPa.s,the average solid content is over 80%,and the average solid content loss rate is 3.81%.3.The results showed that 25.5% oil film of colophony & lime sulfur agent had high indoor activity and good field control effect on the scale insects of Kiwifruit.The results of indoor bioassay showed that the corrected mortality of this film to scale insects was 65.71%,higher than 34.29% of 29% lime sulfur(commercial preparation)and 48.75% of the self-developed rice planthopper film inhibitor.The field experiments showed that 7 days after the application of the film agent,the average control effect of 1000 and 2000 times diluted with the film agent was 59.03% and 49.82% respectively,on the 14 th day,the average control effect of 1000 and 2000 times solution of the film agent on scale insects was 65.25% and 59.83% respectively,which was higher than the 42.22% and 35.22% of the control effect of 29% lime sulfur at the same dilution,46.90% and 37.24% of the control effect of self-developed rice planthopper film inhibitor.4.The safety of 25.5% oil film of colophony & lime sulfur agent on trees and fruits quality was clarified.When it's in 500,1000 and 2000 times of solution were significantly lower than the same dilution times of 29% lime sulfur.There weren't significant differences in VC,soluble sugar,titratable acid,fruit quality,transverse diameter,longitudinal diameter,lateral diameter,fruit shape index,single fruit volume,fruit hardness between the each treatments after spraying film agent.It can be seen that 25.5% oil film of colophony & lime sulfur agent in 1000~2000 times solution hasn't adverse effects on trees and fruits,which is more safe than the application of lime sulfur alone. |
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