| Agricultural production, pesticides play an irreplaceable role. As awareness of environmental protection does not improve the segment, resulting in a number of highly toxic organophosphorus pesticides banned, this low toxicity of organophosphorus pesticides chlorpyrifos has become a substitute for increasing the amount, may in the crop become a new source of pollution. This experiment, cucumber and tomato as test material, cucumber and tomato were selected "Jinyou36and" the Bei Dou Xin Fen "these two varieties, planting in the greenhouse.1A study of different concentrations of chitosan (50mg/L,100mg/L,200mg/L and400mg/L) of chlorpyrifos degradation. Test results as follows:chlorpyrifos degradation half-life of cucumber plants5.05d, the safety interval (≤1mg/kg)6.98d, when the spraying chitosan concentration of50mg/L,100mg/L,200mg/L,400mg/L processing half-life were5.05d,4.27d,4.26,4.63d,4.52d, the safety interval (≤1mg/kg) were6.03d,6.32d,6.58d,6.50d. Tomato plants on chlorpyrifos degradation half-life of5.15d, the safety interval (≤1mg/kg)7.01d, when the spraying chitosan concentration of50mg/L,100mg/L,200mg/L,400mg/L treatment half-life of4.25d,4.36,4.67d,4.50d, the safety interval (≤1mg/kg)6.10d,6.45d,6.59d,6.52d. Chitosan on the half-life impact from the two crops of cucumber and tomato small interval of50ml/L chitosan effect the best control than a single spray of chlorpyrifos shortened from0.91to0.95days.2Different concentrations of chitosan (50mg/L,100mg/L,200mg/L,400mg/L) role in mitigation of chlorpyrifos under cucumber and tomato plants physiological and biochemical indicators were used to detect superoxide dismutase (SOD) activity, peroxidase (POD), catalase (CAT) activity, malondialdehyde (MDA), proline, accumulation of soluble sugar and soluble protein accumulation. Test results:performance indicators in cucumber plants and tomato plants are basically the same, chlorpyrifos chitosan on superoxide dismutase (SOD) activity of longer, can ease the SOD activity in a relatively short period of time back to the control level In particular, low concentrations of chitosan (50,100mg/L), the best performance. Chlorpyrifos existence a long time the Cucumber POD activity in the stress, performance is still very obvious in the7th day, eased only in14d, the performance difference was not significant. Chitosan on the mitigation of chlorpyrifos POD in0d,1d,3d chlorpyrifos mitigation performance, especially in the first5d,7d, followed by the14th day basically removed. CAT activity in spraying finished the pesticide chlorpyrifos and spraying finished chitosan1d to14d performance is not too obvious. Description of CAT activity less affected. Chitosan on proline accumulation in a certain ease to do, and chlorpyrifos with shorter proline. About the spraying finished chlorpyrifos within5d to7d, the proline content on the restoration of normal levels. Chlorpyrifos inhibition of the soluble sugar content increased, the chitosan to inhibit the accumulation of soluble sugar content of chlorpyrifos eased. Chlorpyrifos inhibition time to lift14th day, indicating that the role of chlorpyrifos or a longer period of time. Chlorpyrifos, the role of time or longer, the7th day, performance is still very obvious. Chitosan can relieve stress on soluble protein content of cucumber plants to chlorpyrifos. Chlorpyrifos is a very long time on MDA content in cucumber plants, there are also differences in the first14d was highly significant. Chitosan on cucumber plants the content of MDA in chlorpyrifos stress relief. Overall,50mg/L chitosan Alleviation of the best,100mg/L chitosan, followed by chlorpyrifos.3different concentrations of chitosan (50mg/L,100mg/L,200mgl/L and400mg/L), chlorpyrifos stress in cucumber and tomato plants, quality and yield. The results show that the impact on quality and yield of cucumber plants or tomato plants are small, soluble protein accumulation in the accumulation of soluble sugar content, have minimal impact on the vitamin C content. Compared with the control there was no significant difference. Also no significant difference in yield. There are some small effects that may be the role of chitosan alone. |
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