THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF COFFEE

作者：Michael K. V. Carr · 发表于：Experimental Agriculture · 年份：2001 · DOI：10.1017/s0014479701001090 · 被引用次数：189 · 研究领域：Coffee research and impacts、Plant Water Relations and Carbon Dynamics、Irrigation Practices and Water Management

The role of water in the development and yield of the coffee crop (Coffea arabica L.) is reviewed. A period of water stress, induced either by dry soil or dry air, is needed to prepare flower buds for blossoming that is then stimulated by rain or irrigation. Although attempts have been made to quantify the intensity and duration of stress required, these have not yet been specified in ways that are commercially useful. Water must be freely available during the period of rapid fruit expansion to ensure large, high-quality seed yields. Depending on the time and uniformity of flowering this can occur at times when rainfall is unreliable, particularly in equatorial areas. Although there are differences in their responses to drought, commercial cultivars have retained many of the characteristics adapted to the shady environment of the forests in the Ethiopian highlands in which C. arabica is believed to have originated. These include partial closure of the stomata when evaporation rates are high as a result of large leaf-to-air saturation deficits (>1.6 kPa), even if the soil is at field capacity. This is thought to be an adaptive mechanism that minimizes transpiration at high irradiances when the leaves are light-saturated. Our understanding of the actual water use of coffee crops grown in diverse ways is imperfect. For mature crops, well supplied with water, the crop coefficient (Kc) appears to have a value in the range equivalent to 0.7–0.8 times the evaporation from a US Weath...