Alternative fertilization effects on peach and nectarine plant and fruit characteristics

Abstract

Over- or under-fertilization is a common farmers’ practice in Greek peach orchards. During 2019 and 2020, <40% N, <50% P and >160% K were applied to ‘Onora’ peach and ‘Big Top’ nectarine mature trees, based on leaf and soil analyses, vegetative growth and expected yield, compared to farmer’s traditional practice (Control). Even though both cultivars were grown in the same orchard, soil properties were different with higher clay and pH in ‘Big Top’ compared to the ‘Onora’ planting area. All leaf macronutrients were at sufficiency levels and were not affected from the changes in fertilization practice. Soil surface temperature on tree row increased probably due to reduced vegetative growth and increased light penetration. Alternative fertilization had no effects on fruit size and yield of the two cultivars and differently affected fruit quality and antioxidant characteristics compared to control. Plant (Fv/Fm, crop water stress index, stem water potential) and leaf (specific leaf weight, chlorophyll, carotenoid and proline concentrations, relative water content, total phenols, antioxidant activity) response were differently affected from the alternative fertilization in each cultivar studied and each period of measurements (late June, early October). Reduced N and P and increased K fertilization differently affected fruit quality, and showed various positive or negative effects on plant and leaf characteristics studied. © 2022 International Society for Horticultural Science. All rights reserved.