Determination of Nutrient Requirements of Peach Trees from Different Ripening Seasons

Peach trees are often fertilized without considering the amount of nutrients removed through practices such as pruning, thinning, harvesting and leaf fall. Furthermore, peach trees from different ripening seasons may have different nutrient requirements. The objective of this research was to determine the amount of nutrients removed in pruned wood, thinned fruitlets, harvested fruit and fallen leaves of peach trees from different ripening seasons. This information may be relevant for optimizing fertilization in peach orchards. We selected 18 peach trees of six cultivars from three different ripening seasons (early-season: ‘Desiree’ and ‘Spring Snow’; middle-season: ‘Sweet N Up’ and ‘Coralstar’; late-season: ‘Snow Gem’ and ‘Snow King’), and measured the amount of nutrients removed at pruning, thinning, harvesting and leaf fall. Nutrient analysis showed that early-season cultivars accumulated more nitrogen in thinned fruitlets and mature fruits, and more potassium in pruned wood and mature fruits than late-season cultivars. Fruit from late-season cultivars accumulated more calcium than early-season cultivars. Analyses of summer leaves revealed that all mineral concentrations were in sufficient levels but did not provide information on different nutritional needs of trees from different ripening seasons. These results suggest that peach trees of different ripening seasons may benefit of different fertilization programs rather than a universal fertilization program. Further research and more data are needed to evaluate the impact of different ripening season on peach nutrition but these findings are expected to help farmers to improve fertilization plans that are specific to the ripening season of their peach trees.