Study On The Effect Of Different Leafhopper Biting On Tea Leaves

Leafhopper, as the main tea garden pests, not only effected tea quality, but also lead to deterioration of ecology environment when given a lot of pesticides. This paper study and investigated the effects of leafhopper bite which influenced the tea leaves in different extent. Finally combined prevention and control of the leafhopper, develop the new use with distinctive tea to increase economic benefits of the garden. The results are as follows:1. Through the determination of containing in Jinxuan and the Fuyun 6 fresh leaves which eaten by the leafhopper with different duration. We can found that water extract, tea polyphenols and flavonoids in Jinxuan and the Fuyun 6 tree leaves has no obvious change. The caffeine content respectively decreased by 0.98 % and 1.00 % in Jinxuan and Fuyun 6. The amino acid content showed a gradual increasing trend and increased by 0.35 % and 0.30 % in average. Sluble sugar content increased at first, then decreased slowly, and both reached maximum in the No. 2 sample. We can found that tea polyphenols, catechins, caffeine content in Jinxuan is much larger than the Fuyun 6 fresh leaves in the whole.2. The determination result show that the aroma substances was different in Jinxuan or Fuyun 6 fresh leaves which was bite by the leafhopper with different duration. Picking up different degrees of leafhopper biting Jinxuan and the Fuyun 6 fresh leaves, the measurement results show that the leafhopper biting can cause aroma change. The number of alcohols, ketones has a slightly increase. Esters and alkanes reduced. The content determination show that alkanes reduced. Alcohols and aldehydes increased. The overall content of aroma components indicates an increase at first, then decrease. With the increased of leafhopper biting levels. It also has an emergence of new aroma substances, such as xylene, ethyl hexanol, tetrahydro lavender alcohol, cetyl alcohol, tea spiro alkanes, squalene, Kashiwagi brain and 2-butyl-1-octanol.3. When the leafhopper biting was serious, not only the appearance harmed but also the internal substances influenced, leading to an decrease on the quality of tea. The measurement and analysis of the leaves which was bite by the pests demonstrate that tea polyphenols and catechins has no change in Jinxuan fresh leaves when the amino acid reduced by 0.17 % on the average and caffeine reduced by 1.20 %. The determination on the Jinxuan black tea showing that, tea polyphenols and catechins almost have little change. The amount of water extract, theaflavin and soluble sugar increased. Water extracts increased by 2.33 % and soluble sugar increased by 1.49 %. And the amount of amino acid, caffeine, thearubigins reduced. Amino acid reduced by 0.08 % and caffeine reduced by 1.50 % on the average. And theabrownin content increased at the first, then reduced in the Jinxuan black tea.4. Through the sensory evaluation of the Jinxuan black tea which was made by the different degree of leafhopper biting. We can conclude that a certain degree of leafhopper biting lead to flowers and honey appear in the tea with a mellow taste. It is more natural and harmonious on the overall taste too. In this experiment, black tea Jinxuan 2, pests performance to a lesser extent leaves have one or two obvious bite marks, fresh leaves still intact, was bright green, has the highest score 89.5. Compared to black tea Jinxuan infestation levels of expression of the lightest black tea Jinxuan 1 high 5.5 points, the heaviest damage levels black tea Jinxuan 4 high 14.5 points. The appearance of fresh leaves curl, coke side seriously with grayish green and easily broken when was made in black tea. The bottom of leaves was hard and the water has less alcohol aroma. Taste decline on the overall. Therefore, prevention of leafhopper should mainly be control-oriented. And using pest biting leaves made unique tea to achieve the purpose of improving economic efficiency of the garden.