環狀剝皮與勒束對‘黑葉’荔枝生長與發育之影響

Abstract

本試驗第一部份以‘黑葉’荔枝盆栽植株為試驗材料，探討環狀剝皮與勒束對荔枝樹體之影響。結果顯示兩種篩管阻礙技術均會抑制根系生長，但勒束處理於123天及解除勒束後，已不會影響根系之生長。此外，環剝與勒束均會降低營養芽萌發之比例，及抑制頂芽萌。兩處理亦可改變樹體內營養要素與碳水化合物之分配，如葉片中磷、鈣、鎂等要素含量於處理後會降低，鉀則會堆積於葉片中；碳水化合物則會累積於處理部位上方之葉片中，根內碳水化合物因篩管運輸受阻，而導致含量下降。環剝與勒束處理兩週內，可使葉片之光合作用速率下降。 本試驗第二部份以經濟生產果園內之‘黑葉’荔枝為試驗材料，探討環剝與勒束對荔枝果實品質之影響。結果顯示，於盛花期行篩管阻礙處理，尤其是環剝，會抑制果實發育；於假種皮發育初期環剝與勒束均可提升果實品質。

The materials for the first section of this experiment were potted ‘Haak-Yip’ litchi and the purpose was to discuss the effects of girdling and strangulation on ‘Haak-Yip’ litchi tree. Results indicated that both of two phloem disruption techniques restrained root growth, but root growth will not be affected 4.5 months after strangulation and after removal of the strangulating wire. Either girdling or strangulation reduced the proportion of vegetative bud burst and raised the proportion of quiescent apical bud. Two treatments also affected the allocation of nutrient and carbohydrate contents. Nutrient contents in leaves such as phosphorous, calcium and magnesium were reduced after treatments, whereas potassium was accumulated. Carbohydrates were accumulated in leaves above treating site but were reduced in roots due to phloem disruption. Reduction of photosynthetic rate occurred within two weeks after girdling and strangulating treatments. The materials for the second section of this experiment were ‘Haak-Yip’ litchi grown in economic orchard. The purpose was to discuss the effects of girdling and strangulation on fruit quality of litchi. Results showed that phloem disruption treatments, especially the girdling treatment, during full bloom stage inhibited fruit development. Girdling and strangulation executed at aril-occurring stage promoted fruit quality.