荔枝樹新梢之生長及其與抽穗之關係

Investigation on the Growth of New Shoots and Flower Clusters of Lychee Tree

為瞭解荔枝樹新梢之發生情形及其與抽穗開花結果之關係，以謀荔枝栽培之改進，作者於51-52年在臺中太平鄉以黑葉繻米糍等品種作此項觀察獲知（1）在台中氣候環境下荔枝樹年中各月皆有抽生新梢之可能，比例上以6,7,8,9月為多。（2）10月以前所抽新梢，次年仍有相當之抽穗率，10月以後者則須延緩一年開花結果。（3）新梢次年之抽穗率，以春秋二季所生新梢較高，10月所生新梢，次年仍有37%可抽生花穗。（4）抽穗率之高低與枝條所在之方向及部位有關，頂生枝及西南二方之枝抽穗率較高，花穗亦較大。（5）病蟲發生程度與枝條所在之方位關係不明顯，但蔭蔽處之枝，病蟲滋生最多。（6）枝梢年中生長次數，在臺中氣侯環境下，4,5月所生枝條，當年內多者可繼續生長四次，但以二次三次者為多，9月所生枝條，當年內可再生新梢一次，朝南及朝外生長之枝，因光照充足，年中生長次數亦較多。

In order to understand the appearing of new shoots and their relation to the flower cluster formation of Lychee tree, the author has carried out some investigations with the varieties of Hak Ip and No Mai Ts.e at Taiping Hsiang, Taichung Hsien, Taiwan, Republic of China, in 1962-63. The results are as follows: 1.Under the climate condition and the general orchard management in Taichung, the Lychee shoots appear each month, but the amount differs with the nutrient condition of the tree. They appear mostly in June, July, August and September. 2.The flower clusters are formed more or less in the following spnng on the new shoots in condition that they appeared before October. 3.The percentage of flower cluster formation is found higher for the new shoots appearing in spring and autumn than those appearing in other seasons. However, thirty-seven percent of the shoots, even appeared in October, may form flower clusters the following year. 4.The percentage of flower cluster formation is found related to the exposure and location of new shoots. The topmost or western and southern shoots have higher percentages than the eastern ones. The northern ones, however, are the weakest and have the lowest percentage. 5.No significant relation is found between pest and disease occurrence and the location of new shoots. Nevertheless, pests and diseases are often found in the interior shady portion of the crown. 6.The growth of Lychee shoots varies with growing month, their location and exposure. Under the climate condition in Taichung, those shoots appeared in April or May may continuously grow twice or thrice even four times. Those appeared in September may continuously grow just once in the same year. Because of abundant sunshine, the southern shoots or outmost shoots may grow many times more than others. According to above statements, the following suggestions are offered by the author: 1.In order to preserve many latent buds for forming fruiting shoots the next year, the harvester should be as careful as possible to prevent from injuring the basal portion of shoots below the fruit clusters when harvest. 2.Cleaning orchard and trees right after harvest, fertilizing earlier and irrigating if needed, the trees may restore soon and grow more shoots from August through October. 3.It is important to plant Lychee trees wider in distance, so they can have ample space, better ventilation and more sunshine for tree growth in the orchard. 4.The shoots located closely in the interior of crown should be pruned. They gcow weakly, fruit poorly and cause diseases and pests and bad ventilation also. 5.In order to regulate the growth of the shoots, the fertilizing should be scheduled. Don't fertilize too much in spring and summer, while the tree is blooming and bearing, so that the growth of the flowers and fruits will not be hindered by the overgrowth of new shoots. However, to fertilize abundantly after harvest is important.