Effects Of Net Resistence And Shade On Little Leaf Disease And Relative Traits In The Chili Pepper

Recent years, the little leaf disease has been one of the main disease in chili pepper in Shaanxi of China. This study aimed to discover the relationships between the treatments of net covering and shading with the little leaf disease and relative traits. The two cultivars “Duojiao” and “Xinxiang No.8” were used as materials. The experiment was carried out 2 treatments, i.e. net shading treatments(T1), net totally covering(T2), and the open field as the control. The main results were as follows:1) The pepper plant height and stem width were higher than that in the control, performed in a descending order of T2>T1>CK. While the pepper fruit shape index, the number of each plant and the yield of each plant in the CK group was the lowest, and in the T2 group was the highest.2) The little leaf disease happened in each treatment. In the late of experiment observation, the disease incidence of each treatment was more than 80%, while the incidence index had ranged from 35 to 63. In the test, the disease incidence and incidence index of the CK was the highest. The order performed in a descending of CK>T1>T2. The results demonstrated that the positive relationship between the net covering and shading treatments with lowing pepper little leaf disease.3) In the stage of experiment observation, the chlorophyll content behaved lowing after rising. The CK performed highest than the other two in the early stage, and T2 performed highest in the late stage. The difference was obvious. The pepper Pn totally lowed. T2 treatments behaved lowing after rising, and the difference were significantly among the three treatments.4) In the teat, the MDA content of chili pepper was rising at first. The results showed that the content of the control group was the highest, that of the T2 group was the lowest. They had significant difference at 0.05 level. The soluble sugar behaved rising first, then lowing, performed in a descending order of CK>T2>T1. In the late stage of experiment observation, the soluble sugar content in each treatment lowing all the time, the descending amplitude of the control group was higher than the other two. In Duojiao cultivar, the protein content of the T2 treatment had larger fluctuation. In the late stage of experiment observation, the protein content of the T2 treatment was significantly higher than that in the other two treatments. Over the whole stage, the protein content of Xinxiang No.8 was lowing. The protein content in T2 treatment had increased sharply, and significantly higher than the others.5) The activities of protective enzymes(SOD, POD, CAT, APX) had increased in the early and middle stage. In the highest level, they performed in a descending order of CK>T1>T2. In the late stage of experiment observation, the SOD activities in each treatment were lowing all the time, and the T2 was obviously higher than the T1 group and CK group. In Duojiao cultivar, the POD activities were significantly higher than that in the other two. Meanwhile, the POD activities increased all the time. The enzymes activities of CAT and APX in the control group were generally lowing, while, that in the T1 and T2 groups increased. The activities in T2 group were obviously higher compared with the control.