本試驗連續三年處理台南地區黑葉品種荔枝（Litchi chinensis Sonn cv. Haak Yip），於晚秋以39.5％益收生長素（1000區∼2000倍），行葉面噴施可抑制新梢再抽生，增加植株抽穗率29.7∼36.7％，環刻處理亦可增加抽穗率31.2％，根部滴灌磷鉀肥（15％ P2O5，46％ K2O）300倍處理對次年抽穗率無顯著變化。益收處理對花性之變化隨年度而異；環刻處理其偏雌花未有明顯變化，而環刻處理花期較晚，且雄花數減少15.9％，而偏雄花數增加17.7％。益收處理對1992年及1993年荔枝果實產量增加57.1％，環刻處理則無顯著增加。
Effect of Ethrel, Girdling and Fertilizer Treatments on the Flowering and Yield of Litchi
Chern, S. T.
Experiments were conducted in three consecutive years in Tainan area to explore the effect of Ethrel, girdling, and fertilizer treatments on the flowering and yield of litchi (Litchi chinensis cv. Haak Yip). Results indicated that litchi plants sprayed with 1000~2000 dilution of Ethrel in late fall inhibited the shooting of new flushes and increased 29.7~36.7% of panicle formation. However, girdling of the trunks also increased 31.2% of panicle formation. No significant effect was observed in the treatment of dripping irrigation with 300 dilutions of P-K-fertilizer (15% P2O5, 46% K2O). Effect of Ethrel treatment on the percentage of male/female varied in years. No significant difference in hermaphrodite functioning as female flowers was observed in girdling treatment, however, it delayed the initiation of flowering and reduced about 15.9% of male flowers and increased 17.7% of hermaphrodite functioning as male flowers. Ethrel treatment increased the yield of litchi fruits in 1992 and 1993 by 57.1%, however, no significant difference was observed in girdling treatment.
Key words: Ethrel (39.5%), girdling, flower
Accepted for publication: July 5, 1994.