Crisosto C H, Grantz D A, Meinzer F C
USDA, ARS, Hawaiian Sugar Planters' Association, P.O. Box 1057, Aiea, HI 96701, USA.
Tree Physiol. 1992 Mar;10(2):127-39. doi: 10.1093/treephys/10.2.127.
The response of coffee (Coffea arabica L.) floral buds to different water deficits followed by re-irrigation was investigated. Flower opening was stimulated by irrigation after one period of water deficit if predawn leaf water potential declined below -0.8 MPa. Similar stimulation of flowering was observed when less severe but more prolonged water deficits (ca. -0.3 to -0.5 MPa for two weeks) were imposed, even if water deficit was relieved by re-irrigation several times during this period. Consistent results were obtained in the field and in two greenhouse locations. Stimulation of flower opening by water deficit followed by re-irrigation was restricted to buds at the "open white cluster" stage of development (Stage 4). Only buds at this stage exhibited development of secondary xylem. Split-root experiments indicated that a root signal stimulated flower opening, independently of predawn or midday leaf water status. Frequent irrigation to prevent flowering, followed by a controlled water deficit and re-irrigation to stimulate flowering, may represent a practical method to synchronize flowering and shorten the harvest period in leeward coffee production areas in Hawaii.
研究了咖啡（阿拉伯咖啡）花芽对不同水分亏缺及随后复水的响应。如果黎明前叶片水势降至-0.8 MPa以下，在一段水分亏缺期后进行灌溉会刺激花朵开放。当施加不太严重但持续时间更长的水分亏缺（约-0.3至-0.5 MPa，持续两周）时，即使在此期间多次通过复水缓解水分亏缺，也观察到了类似的开花刺激现象。在田间和两个温室地点都得到了一致的结果。水分亏缺后复水对花朵开放的刺激仅限于处于“开放白色簇”发育阶段（第4阶段）的花芽。只有处于此阶段的花芽才表现出次生木质部的发育。分根实验表明，根系信号可刺激花朵开放，与黎明前或中午的叶片水分状况无关。频繁灌溉以防止开花，随后进行控制水分亏缺和复水以刺激开花，可能是夏威夷背风咖啡产区使开花同步并缩短收获期的一种实用方法。
