Changes Of Vegetable Qualities Caused By Injury Of The Bemisia Tabaci And Effects Of Photoperiod On Its Experimental Population

The Bemisia tabaci (Gennadices) is a new invaded insect in vegetable, horticuture, cotton and the other economic crops. It has caused serious economic losing. In order to explore mechamism and disaster regulation of B.tabaci, effects of photoperiod on experiment population of B.tabaci were studied in this paper. At the same time, the cabbage and eggplant qualities damaged by B.tabaci were specially studied. The major results were as following.1 The effects of the photoperiod on the experimental population of B.tabaci was studied in this paper. The results showed that the population of the B.tabaci was influenced by the photoperiod significantly. When the photoperiod was longer, the population of the B.tabaci raised faster. The population trend index of B.tabaci was the hightest under the condition of 24h light and at 27 °C per day, and the index reached 109.80. Under the condition of over 21 hours or below 3 hours light per day, the development durations of the B.tabaci increased significantly. The relationship between sex ratio, the probability of oviposition and photoperiod were linear correlation. The linear equations were y1 = 0.0547x + 0.4484 (r = 0.9263**) and y2= 10.953x - 1.5744 (r = 0.9840**) respectively.2 The influence of appearance and chemical components of cabbage injured by different population of the B.tabaci was studied in this paper.When the population of the B.tabaci was less than one individual per cm2, the rates of shrinking and the wilt of cabbage increased and the yield of cabbage decreased significantly. When the number of the B.tabaci was more than 10 individuals per cm2, the shrinking ratio and the wilt ratio of the cabbage increased by 50.95% and 35.67% as compared to the control.The chlorophyl contents of the cabbage decreased insignificantly at 2 individuals per cm2. The contents of total sugars significantly reduced when the cabbage was affected by the B.tabaci in low density. When the infection was more severe, thecontents of total sugars of the cabbage raised certaintly. The number of the B.tabaci was less than 2 individuals per cm2, the contents of the Vc and the Protain reduced. When the infection of B.tabaci was more severe, the contents of the Vc and the Protain significantly reduced . The amount of the Vc decreased above 50%. The contents of seventeen kinds of Amino Acids of cabbage were determined in this experiment, the results showed that the contents of the Met., the Tyr. and the Arg. Raised, and the Ser., the Gly. the Leu. the Phe. the Pro. reduced certainly.The appearance and chemical components the cabbage injured by the B.tabaci at 2~4 individuals per cm2 in different grown periods were affected significantly.When the B. tabaci damaged cabbage during the rosette or the folding stages, the shrinking ratio and the wilt ratio were increased markedly. The skinking ratio and the wilt ratio of cabbage damaged during the folding stage raised by 42.58% and 43.65% respectively comparable to the control. But there were on significantly decreasing in shrinking ratio and the wilt ratio at the seeding stages.The B.tabaci injured cabbage in the seeding stage or the folding stage, the contents of the chlorophyl decreased insignicantly, but the total sugars increased significantly. The cabbage was injured by B.tabaci in the rosette stage, the chlorophyl reduced 19.21% significantly, and the amount of total sugars lost certaintly. The cabbage was injured by B.tabaci in the seeding stage or in the folding stage or in the rosettle stage, the contents of Vc and the Protain of cabbage were decreased significantly. When the cabbage was injured by B.tabaci during the folding stage, the contents of the Vc and the Protain decreased by 45.34% and 29.51% respectively.3 The influence of appearance and chemical components of eggplant injured by different population of the B.tabaci was studied too in this paper.The number of the inflexible fruilt and the flowering fruilt sinificantly increased when the eggplant was affected by the B.tabaci. The ratio of inflexible fruilt and the flowering fruilt...