Plant Growth and Physiological Responses to Improved Irrigation and Fertilization Management for Young Peach Trees in the Southeastern United States

Abstract

New peach orchards in the southeastern United States are often not irrigated until 3 or 4 years after planting. During those years, the only water comes from rainfall. Droughts in the region are becoming more common, making irrigation more important. At the same time, fertilization practices follow recommendations developed decades ago and may not be optimal for current production practices. This research aimed to investigate the effect of different irrigation and fertilization practices on young ‘Julyprince’ trees grafted onto ‘Guardian™’ rootstock. The treatments consisted of irrigated vs. nonirrigated trees, drip- vs. microsprinkler-irrigated trees, and four different fertilizer levels (25%, 50%, 100%, and 200%; with 100% = current fertilizer recommendations). Responses to the treatments varied by year. In 2016, below-average rainfall (severe drought as classified by the U.S. Drought Monitor) was recorded throughout the year. This severe drought reduced the growth of nonirrigated trees compared with irrigated trees (average reductions of 56% in canopy volume, 39% in trunk cross-sectional area, 39% in leaf and stem water potential, and 40% in leaf photosynthesis). The adverse effects on tree growth and physiological responses of the 2016 season carried over to 2017, which was characterized by a short period of below-average rainfall in early spring. Nonirrigated trees displayed advanced budbreak progression; reduced commercial yield (10.9 vs. 13.4 kg/tree for nonirrigated vs. irrigated trees); and smaller trunk cross-sectional area (54.0 vs. 70.1 cm2) and canopy volume (8.9 vs. 10.9 m3) compared with irrigated trees. In 2018, rainfall was like the historical average throughout the year. Major differences continued to be trunk cross-sectional area (103.4 vs. 126.7 cm2) and canopy volume (15.8 vs. 17.8 m3), with nonirrigated trees being smaller than irrigated trees. No major or consistent differences were found between drip vs. microsprinkler irrigation or among fertilizer levels during the 3 years of the experiment. During the first years of orchard establishments, irrigation resulted in increased plant growth, commercial yield, and superior water status (higher values of water potential) compared with no irrigation, especially when rainfall was below the historical average. Although no major differences were found between the irrigation systems, drip irrigation used 35% less water than microsprinkler irrigation. While different fertilizer levels did not induce major differences in young trees’ growth and yield, potential economic savings and long-term effects of reduced fertilizer applications are being monitored as trees mature.

Annual compost amendments can replace synthetic fertilizer, improve soil moisture, and ensure tree performance during peach orchard establishment in a humid subtropical climate

“…Additions of straw mulch have also been shown to improve water infiltration and slow water movement in comparison to bare soil ( Keesstra et al., 2019 ). Improving water status during orchard establishment could prove beneficial for growers, especially those growers that do not irrigate trees prior to when fruit production occurs, as improving tree water status during the early years increase young tree TCSA, canopy volume, and initial yield ( Casamali et al., 2021 ). Although buffered soil moisture conditions may account for larger TCSA in the 2x compost rate, additions of compost largely did not change SWP during the growing season, except for a single point in 2020 when the 2x rate had less water stress than the control.…”

“…Adding stable compost amendments have shown promise in mitigating replant disease ( Forge et al., 2016 ) and the creation of berms provides an opportunity for growers to incorporate soil amendments prior to tree planting. Fruit growing is also often subject to climatic variations of extreme rainfall and temperature ( Eck et al., 2020 ) and improving soil carbon using compost may assist with production despite detrimental weather scenarios ( Droste et al., 2020 ); for instance, peach tree growers in the southeastern U.S. often do not irrigate trees until the third year (first crop), and young trees rely exclusively on rainfall ( Casamali et al., 2021 ). Therefore, understanding how increasing OM may improve the water status and initial growth of young trees could have an impact on orchard management.…”

Effects of Fertilization Approaches on Plant Development and Fertilizer Use of Citrus

“…In comparison with conventional fertilization approaches, drip fertigation has the advantages in promoting the use efficiencies of water and fertilizer and improving crop yield and quality [ 9 , 10 ]. Drip fertigation increases the leaf N and stem diameter of peach trees with a N fertilizer saving for 25% to 50% [ 11 ]. Drip fertigation of potato fields reduces NO 3 − -N leaching [ 12 ].…”

Optimizing Nitrogen, Phosphorus, and Potassium Fertilization Levels for Container Plants of Lagerstroemia Indica ‘Whit III’ Based on the Comprehensive Quality Evaluation

“…Therefore, an evaluation of the appropriate amount of fertilizer is critical for optimizing fertilization programs. Precision fertilization for plants relies on the nutrient requirements of a species or cultivar, plant growth stage, climate conditions, and substrate composition (Casamali et al 2021;Davis and Strik, 2022;Shreckhise et al 2020). Few studies have investigated the effects of different fertilizer amounts on different crape myrtle cultivars, and the available studies mainly focused on N fertilizer.…”