Influence Of Several Chemical Agents On Grape Fruit Quality And Residue Analysis

We investigated the influence of CPPU, GA3and prochloraz on fruit quality, volatile compounds and residue of grape, in order to provide the basis and reference for the fair use of those chemical agents in the production. Samples from different areas were analysed and several tests were designed in our study. Moreover, we also wanted to explore the possible substances which lead to grape fruit off-odour. The main results were as follows.1. Samples from different areas showed both GA3separate treatment (50mg/kg, Taian) or GA3and5mg/kg CPPU combined treatment (Laixi) significantly increased the Fujiminori berry mass and cluster mass, also increased spike stalk, fruit stalk, and fruit brush diameter, but shortened the length of fruit brush. Both treatments significantly decreased the total soluble solids, inhibited fruit coloration. Peel anthocyanin content was decreased by57.81%and64.11%, respectively, compared with the control.For Summer Black variety, all kinds of hormone combination treatment significantly increased the fruit size, thickened the spike stalk, fruit stalk and pedicel, and reduced the content of the total soluble solids and peel anthocyanin. Among them, the anthocyanin content of Weihai two times treatment was decreased by53.15%compared with once treatment, and Pingdu TDZ treatment with high concentration (53.33mg/kg) was reduced by63.87%compared with the control.2. The verification experiment results showed that there was no significant difference in the enlargement effect of25mg/kg GA3separate treatment compared to the control on the berry diameter and length, berry mass, cluster mass of Fujiminori, while25mg/kg GA3with different concentrations of CPPU combination treatment significantly increased those indexes. The berry mass and cluster mass of5mg/kg CPPU addition treatment were increased by36.65%and96.11%, respectively, while20mg/kg CPPU addition treatment were increased by36.56%and74.01%, respectively. Spike stalk of all treatments was significantly thickened with an increase of42.02%⊥45.45%～65.62%⊥60.14%compared with the control; pedicel diameter was increased by26.43%⊥27.90%～40.16%⊥42.06%compared with the control.Two times plant grow regulator treatment significantly increased the berry diameter and length, berry mass, and cluster mass of Summer Black. The berry mass and cluster mass of two times GA3treatment were increased by62.5%and78.58%, respectively, while GA30,+CPPU10treatment was increased by107.08%and87.99%, compared with the control. Spike stalk of all treatments was significantly thickened with an increase of27.74%⊥27.42%～31.54%⊥31.65%compared with the control; fruit stalk was significantly shortened with a decrease of11.90%～40.48%.3. The verification experiment results indicated that the total sugar content of GA25+CPPU10and GA25+CPPU20combined treatments on Fujiminori grape were decreased by15.24%and11.48%, respectively, compared with the control; the anthocyanin content was reduced by71.83%and64.64%, respectively. The fruit brush of20mg/kg high CPPU concentration addition combined treatment on Fujiminori grape was shortened by8.89%compared with the control.The total soluble solid content, anthocyanin content and Vc content of all plant growth regulator treatments on Summer Black grape were decreased by5.42%～19.83%,49.71%～66.32%and27.07%～31.57%, respectively, compared with the control.4. The results of volatile compounds determination of samples from different regions showed that the relative content of esters of50mg/kg GA3+10mg/kg CPPU combined treatment on Fujiminori grape from Laixi was increased by23.11%; alcohols and acids were decreased by28.21%and56.10%, respectively, compared with the control. Moreover, there was3kinds of alcohols less than the control in this treatment. The relative content of esters, aldehydes, alcohols and acids of higher concentration plant growth regulator treatment on Summer Black grape from Nanjing were increased by41.02%,8.92%,6.41%and10.64%, respectively, compared with the lower treatment.The verification experiment results indicated that the relative content of alcohols of all treatments on Fujiminori grape was decreased by17.82%～50.56%compared with the control; the relative content of terpenes was reduced by60.15%～84.78%; ethyl acetate content of GA25and GA25+CPPU5treatment was increased by26.47%and21.00%. The total content of alcohols of plant growth regulator treatment on Summer Black grape was decreased by54.83%; terpenes content was decreased by34.82%～86.93%; esters content of GA30,+CPPU10treatment was3.69times more than the control and ethyl acetate was4.16times. 5. The anthocyanin content of Kyoho grape with prochloraz sprayed three times was decreased by18.66%compared with the control; the anthocyanin content of one time, two times and three times prochloraz sprayed treatment on Fujiminori grape was decreased by31.20%,38.58%and47.50%, respectively. Prochloraz could affect the volatile compounds of Kyoho and Fujiminori grape with the content of esters increased.6. In the verification experiment the CPPU residue was0.0137mg/kg in Summer Black grape fruit and in Fujiminori grape fruit treated with25mg/kg GA3+20mg/kg CPPU was0.0083mg/kg. The residues of GA3in Summer Black and Fujiminori grape fruit were close to which in the fruits without any plant growth regulator treatment.The prochloraz residue in Kyoho grape fruit treated with prochloraz sprayed three times was detected with the content was0.1147mg/kg.