栽培管理對蓮霧(Syzygium samarangense Merr.& Perry)開花及品質之影響

Abstract

Currently, there are limited documented reports on effects of horticultural practice such as shading, fruit thinning and the application of naphthalene acetic acid (NAA) on fruit growth, development, and quality of wax apple (Syzygium samarangense Merr. & Perry) in Taiwan. NAA and horticultural practices are important means used in fruit production throughout the world. These means regulate several physiological and biochemical aspects of growth, development, yield and quality of fruits. In this study, three experiments were conducted to improve the potential of wax apple fruits as follows; the first experiment evaluated the effect of naphthalene acetic acid (NAA) fruit quality of Indonesia wax apple cultivar, the treatments using 10 ppm NAA, 30 ppm NAA and without spray NAA as control. The second experiment evaluated the effect of fruit thinning plus bagging (brown paper bag and white paper bag) on fruit quality of ‘Red A’, ‘Red B’, ‘Pink’, and ‘Vietnam White’ wax apple cultivars. The third experiment tried to force flowering time by shading with black cover net. NAA was sprayed at the small bud and full blossom stage, fruit thinning was controlled to 6 fruits per cluster; bagging was performed about the implementation of 20 days after flowering and shading treatment at 80%, 40% and without shading (control). The physical and biochemical quality characteristics of the fruits were recorded. The result of the first experiment showed fruit length, fruit diameter, average fruit yield, and flesh thickness were highest at 30 ppm NAA treated branches compared to 10 ppm NAA treated and control branches. Fruit cracking decreased with increasing NAA concentrations. Lowest fruit cracking occurred in fruits treated with 30 ppm NAA. Number of seeds has no significant difference between treated and untreated fruits. Total soluble solids (TSS), pH, and vitamin C were also highest in 30 ppm NAA treated fruits and lowest in control fruits. Titratable acidity acid (TA) was decreased in treated fruits. In the second experiment, the result showed that fruit thinning and bagging affected the fruit yield and quality of the four wax apple cultivars. Fruit length, fruit diameter, average fruit yield, and flesh thickness were higher in treated branch than control branches. Fruit cracking decreased with bagging treatment. Lower fruit cracking occurred in fruits treated fruit thinning and bagging. Bagging was slightly affected on fruit color (on Pink cultivar). Total soluble solids (TSS) and pH were also higher in treated fruits compared with control fruits. Titratable acidity (TA) was decreased in treated fruits. From two experiments it can be concluded that fruit thinning plus bagging and spray of NAA 30 ppm showed better effects on fruit length, size and biochemical quality in wax apple fruits under field conditions. The third experiment didn’t get the results as we expected, in the future we need to do more study about the effect of shading on flowering time and combine with other methods.