Determining water requirements for young peach trees in a humid subtropical climate

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 (K-c) 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 K-c 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.