Effect of environment and harvest date on maturation and ripening of kiwifruit in British Columbia

Abstract

Kiwifruit (Actinidia deliciosa var. deliciosa ’Hayward’ (A. Chev.) C. F. Liang et A. R. Ferguson) were harvested periodically from 10 Oct. to 21 Dec, 1990 to monitor "on-the-vine" ripening in three environments (field; greenhouse, covered for the full season; greenhouse, covered until pollination and then uncovered). Fruits were also placed in 1 °C, 97% RH storage on 19 Oct., 22 Oct., 25 Oct., and 3 Nov. and sampled periodically to monitor their "in storage" ripening. Field-grown fruit remained firmer than greenhouse-grown fruit (both treatments) on the vine, and in storage for about 7 weeks following harvest. There was little difference in the harvest maturity date of fruits from the three growing environments. In storage, fruits showed no differences in soluble solids content (SSC), and tissue deterioration (as measured with firmness and chlorophyll fluorescence) due to growing environments. The peak SSC values attained by fruits harvested prior to reaching a SSC of 6.2% were significantly lower than for fruits harvested after the SSC had reached or surpassed 6.2%. Later-harvested fruits remained firmer in storage than those harvested earlier. Changes in the fruits’ SSC and firmness were similar whether on the vine or in storage; however, fluorescence decline was more rapid in storage.Key words: Actinidia deliciosa, soluble solids content, fruit firmness, post harvest, chloroplast, temperature