2017 ASHS Annual Conference

Fertilization guidelines for peach tree orchards during tree establishment vary among growing regions and, in many cases, for a given region. In this field study, we applied three fertilization treatments to peach trees during the first two years: 1) grower standard rates (control; first year: 1 lb 10-10-10 in March, and 1 lb Ca₂NO₃ in May and in July; second year: 2 lb 10-10-10 in March, 1.25 lb Ca₂NO₃ in May and July); 2) split applications: previous fertilization rates were split into monthly applications (March, April, May, June and July); 3) reduced applications: 70-75% of the fertilization rates in the control treatment were monthly applied, between March and June. Two cultivars, ‘Juneprince’ and ‘Scarletprince’, grafted onto Guardian^TM rootstock were used. There were 15 trees per fertilization treatment and cultivar in a split-block design with three blocks (five trees per fertilization treatment and cultivar in each block). At the beginning of the third year after planting, trunk cross-sectional area of trees fertilized with split or reduced rates was similar to that of trees fertilized with the grower standard rates. Trees of all treatments showed similar fruit set and leaf nutrient concentration on their first year in production. These results suggest that a considerable amount of fertilizer could be saved and orchard sustainability could be improved if fertilizer rates are optimized for specific growing areas.