Abstract In the southern USA, low soil water holding capacity and erratic rainfall patterns create scenarios where plant water stress may occur, reducing early peach tree growth. Therefore, irrigation management is a key component to ensure adequate water supply during early tree growth stages. The objective of this study was to determine water requirements and crop coefficient (Kc) of young peach trees grown in a subtropical climate. A study was conducted in central Florida using young peach trees ‘TropicBeauty’ grafted onto ‘Flordaguard’. Daily actual evapotranspiration (ETA) was determined using weighing lysimeters. The highest daily peach water demand was recorded during the shoot development stage (23.7 L) between August and October, whereas the lowest daily ETA was 0.71 L, during dormancy in December and January. Year-round Kc values for young peach trees were obtained and ranged from 0.20 to 0.68. There was a significant correlation between plant water consumption with trunk cross-sectional area (TCSA) and projected canopy area (PCA), which can be used to estimate ETA. Peach irrigation water demand for 1–3 years old trees, expressed as daily ETA, can be estimated using daily reference evapotranspiration and PCA. The accurate determination of crop water demand allows the seasonal adjustment of irrigation scheduling avoiding water stress, or over-irrigation of young peach trees.

中文翻译：

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确定亚热带湿润气候下桃树幼树的需水量

摘要在美国南部，低土壤持水能力和不稳定的降雨模式创造了可能发生植物水分胁迫的情况，从而减少了早期桃树的生长。因此，灌溉管理是确保树木早期生长阶段充足供水的关键组成部分。本研究的目的是确定生长在亚热带气候中的桃树幼树的需水量和作物系数 (Kc)。在佛罗里达州中部进行了一项研究，使用嫁接到“Flordaguard”上的年轻桃树“TropicBeauty”。使用称重蒸渗仪测定每日实际蒸散量 (ETA)。在 8 月和 10 月之间的枝条发育阶段（23.7 L）记录了最高的每日桃需水量，而在 12 月和 1 月的休眠期间最低每日 ETA 为 0.71 L。获得了幼桃树的全年 Kc 值，范围从 0.20 到 0.68。植物耗水量与树干横截面积 (TC​​SA) 和预计冠层面积 (PCA) 之间存在显着相关性，可用于估计 ETA。1-3 年生树木的桃灌溉需水量，表示为每日 ETA，可以使用每日参考蒸发量和 PCA 进行估算。作物需水量的准确确定允许季节性调整灌溉计划，避免缺水或桃树幼树的过度灌溉。1-3 年生树木的桃灌溉需水量，表示为每日 ETA，可以使用每日参考蒸发量和 PCA 进行估算。作物需水量的准确确定允许季节性调整灌溉计划，避免缺水或桃树幼树的过度灌溉。1-3 年生树木的桃灌溉需水量，表示为每日 ETA，可以使用每日参考蒸发量和 PCA 进行估算。作物需水量的准确确定允许季节性调整灌溉计划，避免缺水或桃树幼树的过度灌溉。