Study On Timely Harvesting Time Of Several Main Cultivars Of Kiwifruit

This experiment studied on'Hayward','Qinmei'and'Yate'Kiwifruit which picked at eight different harvesting time,'Qinmei'and'Yate'were under cold storage, and'Hayward'was under both cold storage and room temperature storage. The physicochemical index such as respiration rate, Ethylene production rate, fruit firmness, soluble solid content, titratable acid and Vc content were determined and analyzed during storing period, the effects of different harvesting time on storage quality and physiological characteristic of Kiwifruit were studied. The results showed that:1. As fruit harvesting time delayed, the fruit firmness of all harvesting time decreased, the soluble solid content increased, Vc content of the fruits picked atâ…¢,â…£,â…¤andâ…¥were higher than the fruits picked at other harvesting time; with the storage time, the fruit firmness, titratable acid and Vc content decreased all the time, but the soluble solid content increased from beginning to end.2. The harvesting time influenced the respiration rate and Ethylene production rate of fruits during storing period. The fruits picked early had high respiration rate; the fruits picked late had low respiration rate, and the peak of respiration rate and ethylene production rate appeared earlier. All harvesting time of'Qinmei'reached the peaks of respiration rate after storing 10 days in cold storage,'Yate'after 20 days, and'Hayward'after 30 days.3. The harvesting time influenced the quality of Kiwifruit during storing period. The fruits picked early had a little low soluble solid content but a little high titratable acid, they had a little low soluble solid content and high titratable acid after storage, which lead to relative low soluble solid content/ titratable acid, the taste of the fruits were affected; the fruits picked late had relative high soluble solid content/ titratable acid, but their firmness decreased rapidly, the storage period was shorten evidently. The weight loss ratio and the rot ratio were serious; the fruits harvested timely could maintain relative high Vc content.4. The soluble solid content of'Qinmei'picked at 147DAFB-159DAFB was beyond 6.5%,'Yate'picked at 153DAFB-165DAFB was beyond 6.0%, and'Hayward'picked at 159DAFB-171DAFB was beyond 6.5%. The Kiwifruit picked at thess periods had relative high soluble solid content/ titratable acid, Vc content decomposed relative slowly, and the weight loss ratio and rot ratio were lower. Therefore, the periods mentioned above were the timely harving time for relevant kiwifruit varieties in Shaanxi province.