碩士 / 國立中興大學 / 園藝學系所 / 101 / Kiwifruits (Actinidia spp.) are deciduous vines that mostly indigenous to temperate areas with the following problems when cultured in subtropical low lands: inadequate winter chilling may cause limited budbreak in the next season, high temperature may induce abnormal growth in summer and delay natural defoliation and onset of dormancy in autumn. Therefore, the main goals of this study are to overcome the the problem of inadequate winter chilling by grafting and bud-forcing of low-land kiwifruit vines, to evaluate the effect of high temperature on the growth of kiwifruits, and to test the potential of artificial defoliation to induce onset of bud dormancy. Results from this research may possibly be applied to culture kiwifruits in subtropical low lands.
The plant materials include eight cultivars or individuals in three species(A. deliciosa: ‘Abbott’, ‘Bruno’, ‘Chung-Hsing No. 3’, ‘Tomuri’, ‘Matua’, and a female individual‘E’. A. chinensis: a male individual‘F’. A. setosa: ‘An-Ma No. 9’). The stock plant species is A. rufa. Our results indicated that the grafted scions start to bud two weeks after grafting. The period between budbreak and flowering is 1-4 weeks shorter in low-land trees than that of high-land trees. The high-land flowering often encounters the rainy season, causing the subsequent poor fruitset. The flower number of the low-land grafted scion is fewer, but the percentage of fruitset is higher. As to the fruit quality, the total soluble solids were less in the fruit grown at low land. No significant differences in fruit weight, firmness, and titratable acid can be observed between low- and high-land trees. Treatment of 10 fold diluted DormexR alone or in combination with nicking has no significant effect on budbreak of high-land kiwifruits. For the low-land trees, the best treatment for budbreak was nicking followed by treatment of 20% calcium cyanamide hydrolyzed solution, the second was nicking followed by treatment of 20% garlic extract, the third is nicking and then treated with 10 fold diluted DormexR, next is the 10 fold diluted DormexR treatment without nicking. All these treatments showed a positive effect on budbreak relative to the control. For the bud-forcing in a low-land greenhouse, nicking treatment showed a stronger effect on budbreak than treatment with 10 fold diluted DormexR. The time required for budbreak of low-land trees is about 20 days earlier than that of high-land trees. The period between budbreak and flowering is about 20 days less for low-land trees compared to that of high-land trees. Flowers per shoot in most cultivars were significantly less for low-land trees in contrast to that of high-land trees. Results from bud analysis indicated that respiration rate of the bud increased 18-36 hours after treatment in all treatments. An ethylene peak was also observed after treatment with 10% 2-chloroethanol or 20% calcium cyanamide hydrolyzed solution. Ascorbate peroxidase activity was elevated 24 hours after most of the treatments. For catalase activity, except for the buds treated with 10 fold diluted DormexR showing a decline 48 hours after treatment, the rest first showed a decline followed by an increase. In terms of peroxidase activity, an increase followed by a decrease was observed in most treatments.
The low-land kiwifruit plants grown under high temperature have a 25-60% fruit drop. The low- and high-land shoot length was not significantly different from each other. For the net photosynthetic rate, most cultivars grown at low land had a lower rate than those grown at high land. Total soluble sugar of leaves was higher in low-land trees, but the starch content was similar between low- and high-land trees. For the artificial defoliation timing, January is better than December or February. The earlier the plants were defoliated, the more soluble sugars can be accumulated in the buds.
| Identifer | oai:union.ndltd.org:TW/101NCHU5378016 |
| Date | January 2013 |
| Creators | Chen-Hsuan Wu, 吳承軒 |
| Contributors | 林慧玲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 90 |
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