Study On The Prevention And Control Of Plant Diseases Of Oligosaccharins

The subject of this paper is to study the oligosaccharins prevention and control of resistance to plant diseases which were viral disease of tomato and watermelon, downy mildew of cucumber, epidemic disease of tomato and verticillium wilt of cotton, so as to work out methods and concentration of making use of oligosaccharins rationally. Effects of oligosaccharins on the seed germination percentage of the crops listed above, the length of root after seed germination and the growth of tobacco seedling were determined. The application technology of oligosaccharins was investigated by using field standardization test. In addition, in order to explore function mechanism of oligosaccharins, effect of oligosaccharins on inhibition of tobacco TMV virus was discussed tentatively .The results showed:(1) It was no effects to soak seeds in oligosaccharins for seed germination . The oligosaccharins had bio-activity which was similar to growth hormone. Soaking seeds in 50ug/ml oligosaccharins could improve the elongation of cotton root. Spraying could improve the growth of tobacco.(2) The oligosaccharins not only could improve plant resistance to virus infection and reproduction , but also had characteristics of inactivation infection activity of virus.(3) To a certain degree , the oligosaccharins had inhibition to viral disease and fungous diseases including downy mildew of cucumber , epidemic disease of tomato and verticillium wilt of cotton . The ways of prevention and control of plant diseases were different. The diseases spread in soil were controlled by combining soaking seeds with spraying. The concentration of soaking seeds was 100ug/ml. The time of soaking seeds was different on the basis of different varieties. The concentration of spraying of prevention and control of other plant diseases was 40ug/ml~100ug/ml. The frequency was above 3~4. The intermission of spraying was 5~7 days. The time of spraying was different on the basis of plant diseases. The liquid state quantity of the oligosaccharins per mu was 50kg.(4) The effects of the oligosaccharins of prevention and control of cucumber downy mildew , tomato viral disease and tomato epidemic disease were respectively 73.48%—79.70% , 69.3%~81.6% and 66.20%~81.76% . The effect of prevention cotton verticillium wilt was above 64% when cotton seeds had been sowed 90 days. Moreover, the oligosaccharins could inhibit the diseases of cotton seedlings and viral disease of watermelon. (5) According to the ways of the listed above , the oligosaccharins had inhibition to viral disease and fungous diseases including downy mildew of cucumber , epidemic disease of tomato and verticillium wilt of cotton .Soaking seeds or spraying continually at seedling stage could prevent plant diseases effectively or lighten diseases to a certain extent and reduce the frequency and quantity of making use of pesticide.