Nitrogen and Vine-harvest Method Affect Cranberry Vine Production and Yield

Abstract

Four nitrogen (N) rates (0, 50, 100, and 150 lb/acre) were applied annually, and two spring vine-harvest methods (heavy pruning and mowing) were applied biennially in all combinations at one commercial ‘Stevens’ cranberry (Vaccinium macrocarpon) farm in southeastern Massachusetts for six consecutive years. Vine weights generated from each treatment combination were collected in Years 1, 3, and 5 (vine-harvest years). Mean vine weight across N treatments from the biennial pruning and mowing events was 1.4 and 3.6 tons/acre, respectively. Vine-harvest method affected yield components (number and weight of reproductive uprights) since mowed plots had values near zero in the vine-harvest year, and pruned vines were always productive. Increasing N rate increased overall vine weight produced. Pruned vines produced more marketable fruit than mowed vines in Year 4 and Year 6. Net income declined with increasing N rate (except Year 1). Averaged over 6 years, increasing N rate decreased net income of and had no effect on pruned and mowed vines, respectively. Although an alternate-year mowing program provides minimal opportunity for sustained vine recovery and would not be recommended for use over an extended period, mowing provided similar net income as heavy pruning (assuming income and/or cost savings from both vines and fruit) when 50 lb/acre N was applied. The incorporation of mowing, in conjunction with other cultural practices that manage the cranberry canopy and generate fruit, can be a viable economic option.