閉合環刻與螺旋環刻對糯米茲（73-S-20）荔枝開花、結實與樹勢之影響

Effects of closed cincturing and spiral cincturing on flowering, fruit production and tree vigor of '73-8-20' litchi

傳統之間合環刻（ c10sed cincturing ）有利於茄枝控梢與促進開花、結實，惟過度施用易造成植株樹勢衰弱。為暸解螺旋環刻（ spiral cincturing）能否代而取之，以彰化縣、芬園鄉簡氏之平地、土壤濕洞之呆圓植株為材料，於98年11月下旬停梢（ quiescence ）期分別對植株施以螺旋環刻（ spiral cincturing ）與閉合環刻（ closed cincturing ） （對照組），並於童年盛花期再對同一植株環刻一次，桐比較對日後抽梢、花序品質、著呆數、果實品質與樹幹截面積（ Trunk Cross-Section Area ' TCSA）相對生長率之影想，俾為栽培管理之參考。實施螺旋環刻者，其於抑制當年停梢期萌發營養梢比率、翠年開花之品質（帶葉花序比率）及結實（留果率及每呆穗呆數、呆重）等均較閉合環刻者為低，而果實生育期間萌發營養梢比率較之為高，但採收時二者呆實之品質並無差異。此外，螺旋環刻處理者，其自採後修剪至停梢期止之當年生（c叮rent season ）枝條生長量及TCSA相對生長率卻均較對照組為高。結果顯示，平地果園進行螺旋環刻處理者，其於開花、結實等表現均較閉合環刻者為差，尚不能取而代之，惟其下半年之營養生長較佳，有利於樹勢之恢復及植株之續管理。本研究未來值得於坡地、乾燥之果園另行評估。

Closed cincturing (CC) has been reported to remarkably inhibit vigorous vegetative growth of canopy in the autumn and thus could enhance flowering and fruiting in the following year on litchi. However, excessive usage of CC could result in decay of the tree. The purpose of this study is to document the effects of spiral cincturing (SC), an improved cincturing, on flowering, fruiting and tree vigor in '73-S-20' litchi, a branch line of‘No Mai Tsz' over 2009-2010 season. SC and CC (as the control) were conducted two times, when the trees were during quiescence period (around mid to late November of2009) and flowering period (around early April of2010) respectively, on 9-10 year-old trees grown in plain field in Fenyuan, Changhua, central Taiwan. Flushing, flowering，fruiting，yield and fruit quality were examined, and relative growth rate of tree trunk cross-sectional area (RGTCSA) was measured. SC resulted in inferior inhibition of vegetative flushing during quiescence, less quality of inflorescence, more vegetative flushing during flowering and poorer yield per c1uster when compared with CC. No difference was recorded of fruit quality between the treatments. Nevertheless, SC appeared higher current growth off lushes from harvest pruning to quiescence and ITCSA. We conc1uded that SC treated plants grown in the plains and wet orchard of '73心-20' litchi leads a deteriorated generative performance than that of CC, indicating that CC might be sti11 a better practice for fruit production currently. On the other hand, a superior current vegetative growth resulted from SC, speculating that a greater recovery potential of tree vigor from cincturing injury might be obtained. Evaluating the effects of SC in the trees grown on the sloping and dry orchard is needed in the future.