Peach trees grow rapidly in their first few years and it is important to get the trees well established for best production. Irrigation and fertilizer are important components to good tree growth. In Florida young peaches are put on irrigation at planting because of our sandy soils, but in Georgia they are often not irrigated until the third or fourth year. Fertilization may have a big influence on early growth as well and may interact with irrigation. University of Georgia researchers wanted to compare young peach growth with varying levels of irrigation and fertilizer to see if the traditional techniques and amounts could be improved upon for recommendations.
‘Julyprince’ trees grafted onto ‘Guardian™’ rootstock were planted into treatments of irrigated vs. nonirrigated, drip- vs. microsprinkler-irrigated, and four different fertilizer levels (25, 50, 100, and 200 percent of the current fertilizer recommendations). The current Georgia recommended rate (100) for peaches is 59 lbs N/acre for the first year of growth and 86 lbs N/acre the second year. Soil probes were used to control the irrigation amounts based on soil moisture, keeping soil moisture midway between permanent wilting point and field capacity during the growing season and less during the fall. Researchers measured canopy volume, trunk cross-sectional area, leaf and stem water potential, leaf photosynthesis, and yields (once the trees produced).
Drought the first year and varying levels of precipitation in following years had significant effects on results. Non-irrigated trees had reduced growth the first year and continued effects in later years with advanced budbreak progression, reduced commercial yield, smaller trunk cross-sectional area, and canopy volume compared to irrigated trees. They found no differences in plant growth with drip vs. microsprinkler irrigation or among fertilizer levels during the three years of the experiment. Drip irrigation used 35% less water than microsprinklers however. The canopy volume was greatest with the highest fertilizer level in the first year but was not different in following years. Fertilizer levels will continue to be monitored as the trees mature to consider potential economic savings with reduced fertilizer rates.
Florida recommendations for peach nutrition are lower than the traditional Georgia recommendations and more along the lines of what this research discovered.
Drip irrigation used 35% less water with the same growth and yield results as microsprinkler. Georgia soils are different than Florida soils, but if using soil moisture probes to determine when to irrigate, similar results may be obtained.
Casamali, B., M.W. van Iersel, D.J. Chavez. 2021. Plant Growth and Physiological Responses to Improved Irrigation and Fertilization Management for Young Peach Trees in the Southeastern United States. HORTSCIENCE 56(3):336–346.