行政院農業委員會台南區農業改良場  研究彙報第34號
 

麻豆文旦植株落葉習性之探討

陳溪潭 呂俊堅 張明聰

摘  要

陳溪潭、呂俊堅、張明聰.1997.麻豆文旦植株落葉習性之探討。台南區農業改良場研究彙報34:14~25。

本研究以微噴灌之定量供水設備,並設立水分張力計,將土壤含水量設計區分為20%(-8∼-12分巴)、15%(-30∼-40分巴)、10%(-50∼-70分巴)三處理,並以一般果園為對照,分別調查對麻豆文旦植株落葉之影響。

麻豆文旦植株之落葉習性,其老化的葉片,先由葉身脫落,數日後葉柄再行掉落,落葉全日進行,而葉身日間掉落率為72%,且主要分佈於午後高溫期。植株每年於2∼3月間抽生春梢及開花期間,結果母枝的葉片有大量掉落,當春梢萌發初期落葉量較少,其後落葉量隨春梢之抽生而急速增加,且日落葉量第一次高峰期出現於抽梢後期,第二次高峰期則出現於盛花期。麻豆文旦葉片壽命最長可達24個月,每個月均有分佈,主要分佈在11∼12個月,如春梢延後萌發則分佈在12∼13個月,其次則分佈在21∼24個月。

麻豆文旦植株不論土壤水分的多寡,其葉片亦均先由葉身脫落,數天後葉柄再行脫落,葉身日間掉落率以20%土壤含水量之59.1%為最低,其次15%及10%土壤含水量則分別有68.3%及65.3%,落葉率均以午後二點為最高,而高土壤含水量之葉片則延遲掉落。冬季期間三處理之落葉率不大,當四月份春梢抽生開花後,植株母梢累積落葉率以土壤水分含量10%為最高達74.4%,其次土壤含水量15%者為56.6%,而土壤含水量20%者最低僅為41%。

關鍵詞:麻豆文旦、落葉、葉身、葉柄、土壤含水量

接受日期:1996年6月24日


The Leaf Dropping Habit in Matou Wentan (Citrus grandis)

Chen, H. T., C. J. Lu and M. T. Chang

Summary

This study is attempted to explore a micro-dripping irrigation system on the leaf-dropping of Matou Wentan trees.  The system included a certain amount of water supply unit and a tension meter.  Soil moisture included 20% (-8~-12 bars), 15% (-30~-40 bars) and 10% (-50~-70 bars), and a conventional orchard served as control.  The results indicated that leaf-dropping occurred in the aging leaves and lamina dropped first in the daytime, which counted for 72% and mainly distributed in afternoon.  The petiole dropped was found in the next few days both in the day and night times.  Large portion of the lamina on the mother fruiting shoot dropped between February and March when trees were flushing and flowering.  Less portion of leaf dropping was observed in the early flushing stage and then increased with time.  First peak of the leaves dropped/day occurred in the late flushing stage, and the second peak appeared in the full flowering stage. Leaves of the Matou Wentan trees can remain on the shoots as long as 24 months and longevity of leaf distributed in every month.  The longevity of leaf mainly distributed in the 11th~12th month of the flushing, the mainly distributed in 12~13th month when the spring flush delayed, and the next peak of distribution in the 21~24th month.  Regardless of soil moisture, leaf-dropping occurred in lamina first and then petioles dropped after a few days later.  Lowest leaf-dropping, i.e. 59.1%, in the daytime was observed in the treatment with 20% of soil moisture followed by 68.3% and 65.3%, with 15% and 10% of soil moisture, respectively.  High leaf-dropping in a day occurred around 2 p.m.  The remained leaves longer time on the shoots under high soil moisture.  Not much of leaf-dropping was observed among the treatments in the winter season.  Significant leaf-dropping started in April while flushing and flowering.  Highest dropping, i.e., 74.4%, was observed in the treatment with 10% of soil moisture, followed by 56.6% and 41%, at the soil moisture at 15% and 20%, respectively.

Keywords: Matou Wentan, leaf drop, lamina, petiole, soil water content

Accepted for publication: June 24, 1997


 

回研究彙報目錄