接木對於生長週期的影響

EFFECTS OF ROOTSTOCK ON CYCLES OF SHOOT GROWTH OF DECIDUOUS FRUIT TREES

本試驗自1962年11月開始至1964年5月結束。所用的樹種是烏梨（Pyrus lindleyi, Rehd.）與20世紀梨（Pyrus serotina, Rehd.）的實生苗。試驗用的苗木是1962年11月播種，1963年2月嫁接成活，並在1963年3月起到1964年5月止進行觀察。其目的在求知不同嫁接組合對於新梢生長量、生長週期、落葉、萌芽及休眠反應的影響。試驗結果摘要敘述如下：鳥梨組的共砧（free stock）區，全年新梢生長有4個高峰期，但無明頓的生長分隔階段；20世紀梨砧區，全年有6個生長高峰期，唯生長曲線變化的幅度較小。20世紀梨組，不論共砧區與鳥梨砧區，全年新梢的生長，均有2個生長高峰期，但二者生長曲線的變化幅度較鳥梨組為大。部分的20世紀梨有明顯的生長分隔階段。全年新稍生長的總長度，鳥梨組與20世紀梨組的共砧區殆無統計上的差異。鳥梨組中的20世紀梨砧區較共砧區的生長為矮。而且達到差異顯著的地步。20世紀梨組中的鳥梨砧與共砧區之閶，新梢的生長總長度無差異。鳥梨組的20世紀梨砧區與20世紀梨組的鳥梨砧區來比較時，前者較高，後者較矮，差異非常顯著。20世紀梨的節間較長，長度的變化較大；鳥梨的節間較短，長度旳變化較小。不同嫁接組合間無差異。不論任何嫁接組合，鳥梨與20世紀梨均在11月上旬自新梢基部開始落葉。此點與同種的成年型樹（mature form）迴乎不同，是否為一年生的實生苗的幼年型（juvenile form）的樹的影響，尚待進一步的比較觀察。落葉開始時期雖然大致相同，但落葉完結的時期卻各相異：鳥梨較早，20世紀梨較遲，同組不同嫁接組合區間無差異。在萌芽時，部分的樹仍有少許近於乾枯葉片附於樹上。鳥梨的萌芽期較早，20世紀梨的萌芽期較遲。不論嫁接組別，二者的差異均顯著。鳥梨組的不同砧木區間無差異；但20世紀梨組中，鳥梨砧區較共砧區提早10天萌芽，差異顯著。

This experiment was conducted from November 1962 through May ]964 in the Department of Department of Horticulture, College of Agriculture, National Taiwan University, Taipei, Taiwan, China. Potted one year-old seedlings of Pyri,s lindleyi, Rehd. and Pyrzes serotina, Rehd. were grafted on to each other to determine the effect of rootstocks on cycle of shoot-growth of the scions. Results obtained from this experiment are summarized as follows: The rate of growth of the Pyrus lindleyi, which found no distinct growth cycles during the growing season had four peak periods of growth on free stocks and six peak·periods of growth on Pyrus serotina stocks. While P. serotina, a few number of them which recorded two growing cycles in growing season had two peak periods of growth both on free stocks and on P. lindleyi stocks. As for the total amount of shoot-growth in the current year, no significant difference were observed between P. lindleyi and P. serotina when they were grafted on free stocks. Trees of P. lindleyi grafted on P. serotina were smaller than those of P. lindleyi on free stocks. Differences in height of trees of P. serotina on free stocks and on P.lindleyi stocks were insignificant. By com­paring shoot-length between P. lindleyi P. serotina and P. serotina P. lindleyi graft combinations highly significant differences were found. The average length of internode of P. serotina was longer and more variable than those of the P. lindleyi. Stock varieties are shown to have no significant influence on the length of internode in all of these grafted combinations. Leaves of the scion varieties of all grafted conbinations began to fall gradually from the base of the shoot in the first part of November during 1963. On contrast of old trees, they are much difference between the mature form al).d the juvenile form trees observed in this experiment. It was not clear whether the difference was made by the age of trees or the weather conditions. Time of the leaf -fall finished of P. lindleyi was earlier than those of P. serotina. No difference were found in same scions grafted on different stocks. From the results secured in this experiment the number of days from growth ceased till bud-burst, scions of P. serotina need more days than scions of P. lindleyi graft combinations. Difference in days of P. lindleyi were in significant. But ten days earlier in scions of P. serotina grafted on P. lindleyi, than on free stocks were observed.