Some effects of urea and nitrate nitrogen on the growth and composition of cranberry.

Two similar greenhouse experiments wore carried out to observe the effects of 2 forms of nitrogen fertilizer, (nitrate and urea), each at 5 rates, (0, 30, 60, 90, and 120 lb N per acre), on cranberry plants, (Vaccinium macrocarpon Ait. cv. McFarlin). In the first experiment, treatments were applied to cuttings which had been rooted for a short time whereas in the second experiment, cuttings which had been rooted for 7 months as well as cuttings which had just been rooted were used. Growth measurements and foliar mineral analyses were carried out on shoots collected from actively growing plants 2 and 16 weeks after differential treatment in the first experiment and 14 weeks after treatment in the second experiment. In both experiments, N fertilization soon after rooting enhanced vegetative growth. Greater vegetative growth was obtained with nitrate in the first experiment but with urea in the second. Analysis of variance indicated that treatments which increased growth also increased foliar N and decreased foliar P, Fe, and Ca. In the first experiment, growth measurements were linearly correlated with foliar Mg or Mn or both in the first harvest, but in the second harvest, correlations were with foliar N, P, and K content. In the second experiment, cuttings which had been rooted for some time initiated more shoots and leaves, but did not respond to N treatments.Land and Food Systems, Faculty ofGraduat