Influence of Nitrogen Fertilization Rates on the Performance of Strawberry Cultivars

Abstract

Two sets of studies were conducted to examine the response of “Strawberry Festival” and “Winter Dawn” strawberries (Fragaria x ananassa Duch.) to different nitrogen (N) rates. The first set of studies consisted of two trials conducted during the 2005–06 and 2006–07 growing seasons. N rates were 0.5, 0.7, and 0.9 kg/ha per day (75, 105, and 135 kg/ha per season). The second set of studies was conducted during the 2006–07 and 2007–08 growing seasons. Nitrogen rates were 0.9, 1.4, and 2.0 kg/ha per day (75, 210, and 300 kg/ha per season) using the same cultivars. During the first set of studies, canopies of “Strawberry Festival” were 30% and 10% wider than “Winter Dawn” at 6 and 12 weeks, whereas N rates linearly increased canopy diameters of both cultivars. There was a significant cultivar by N rate interaction for total marketable fruit weight. Increasing N rates from 0.5 to 0.9 kg/ha per day linearly improved total marketable fruit weights of “Strawberry Festival,” but not those of “Winter Dawn.” For the second set of studies, N rates only influenced strawberry plant canopy diameters, but not early and total marketable fruit weight and number. There were no differences between the total marketable fruit weights of both cultivars. The data showed that the response of different strawberry cultivars depends on the range of N rates used for fertilization.