Study On Disease Control Technique Of Exported Apple And Pear During Store Period

The store and fresh-keeping of fruits have important significance to meet the need of people's life,exploit the marketing and increase the benefit of fruit production.During the course of the store and fresh-keeping of fruits,there are a great many diseases to occur and they cause rot fruits,shorten the fresh-keeping time and reduce the quality of fruits,and often cause huge economical loss to operator and producer.To explore the epidemics and the pathogenesis,and find out the vital factor which can safely store and influence disease's occurrence and development,and research contaminated-free control technology and fresh-keeping technology in fruit storage period and establish a set of effective integrative disease management technical system will help to further improve the quality of fruits,enhance the competition of exported fruits and have huge economical and social benefit.In this research,according to the production condition of apple and pear in Longkou area,we carried out pre-clearance to exported apple and pear and cultivated latent diseases, counted the condition of disease occurrence during processing and postharvest, carried out a set of experiments including fungicide,temperature,the ratio of O₂/CO₂ and the 'Yali' pear fruit stem test,established a set of diseases control system of exported apple and pear during storage period in Longkou area,and applied it to the practical production,and achieved the good effect.The major results are as follows:1.The disease of apple and pear during storage period in Longkou area were investigated.The results showed that the major apple diseases are moudy core,ring rot,brown rot,anthracnose,blue mold,red star apple,bit pit disease and watercore apple;the major pear storage diseases are blue mold,moudy core,ring rot,brown rot,anthracnose,black spot,skin brown and pear scab. Of all these diseases,the incidence of ring rot are the most highest disease,the incidence is 0.33%-0.40%and 0.33%-0.90%,respectively.2.The effect of storage diseases due to different temperature,the different ratio of CO₂/O₂,different concentration of ozone,different chemical agents and 1-MCP were researched.The results were as followed:(1) Ring rot,brown rot,anthracnose and blue mold etc.four fungal growth are depressed along with the decrease of temperature(5～30℃),under 5℃,the growth of anthracnose was fully inhibited;but blue mold,brown rot and ring rot could not be completely inhibited,especially could not inhibit the growth of blue mold.Low temperature could obviously inhibit the incidence of apple canker,the optimal temperature is 0.5℃.(2) The inhibition effect of CO₂ has relation to the concentration of CO₂. Under the same temperature,the inhibition effect ion gradually increased with the increasing concentration of CO₂.The inhibition effect of CO₂ was enhanced with the decreasing temperature.Different ratios of CO₂/O₂ were greatly in answer to the ratio of bad fruit and disease index.The higher the concentration of CO₂,the higher the inhibition effect and fresh-keeping,but due to the damage of CO₂,the concentration of CO₂ was 1%in practical application,the relative concentration of O₂ was 5%.(3) The ozone has some inhibition effect to the mycelia of pathogens,in particular,when the concentration of ozone was 50%,the inhibition effect was especially obvious.Different concentration of ozone had obviously effect on fruit storage diseases.The experiment showed that the optimal concentration was 1 mg/l.(4) TechGreen,Rovral SC andTectoWP3 agents had better inhibition effect on the mycelium of pathogens in vitro,but the inhibition effect was lower when treated with mildew diseases;the highest control effect of Rovral SC,TectoWP3 and TechGreen was 40%,25%and 15%,respectively.As a whole,the three agents could not reach the ideal control effect without exception.(5) 1-MCP had obviously effect on sugar rigidity and some other physiological characteristics of Fuji apple,it could inhibit the decay of Fuji apple,and could effectively inhibited the red star disease of Fuji apple.The reduced diseases effect was than 92%when in Controlled Atmosphere Storage and Modified Atmosphere Storage.3.According to the results of investigation of apple and pear storage diseases in Longkou area,and the results of disease control technology,and using for reference of the new and applied results of disease management of scientific research institute in domestic and in oversea,established a engineering disease control technique system of exported apple and pear during storage period and machining process in Longkou area which gave priority to physics and chemical quality technology,and used quarantine as assist,applied it to practice,and achieved obviously economical and social benefits.The quarantine pass ratio was 99%,the fruit with disease was less-than 0.005%,and the annual economical benefit was 40%.