Nitrogen Fertilizer Management for White Potato Production in Virginia. (S04-phillips466751-poster)
Authors:
S.B. Phillips* - Virginia Tech G.L. Mullins - Virginia Tech
Abstract:
Field studies were conducted at eight sites in Virginia from 2000 through 2002 to identify the optimum rate and timing of N fertilizer application for white potato production. Fertilizer treatments ranged from 0 to 268 kg N/ha and were applied at planting, split between planting and bloom, or as a 3-way split between planting, drag-off (just prior to emergence), and bloom. Whole-plant samples from each treatment were collected 2 to 3 times during the season, separated into roots, tubers, and leaves, and analyzed for N content to evaluate N uptake and translocation throughout the season. At maturity, tuber yield and grade was determined for each treatment. The standard VA recommendation for applying N to white potatoes (1/3 of the recommended rate applied at planting and 2/3 as sidedress) did not consistently affect yield at any site compared with applying the entire N rate at planting. However, applying N using a 3-way split resulted in increased yields at 4 of 8 sites suggesting that in higher yielding environments (greater than 28 Mg/ha), a 3-way split may be the most efficient method of applying N to white potatoes. However, applying more than 1/6 of the recommended rate at bloom delayed maturity and decreased yield. Not surprisingly, optimum N rate was directly related to tuber yield with each Mg of tuber yield requiring approximately 7 kg N/ha, averaged across sites.
Speaker Information: Steve Phillips, Virginia Tech, 33446 Research Drive, Painter, VA 23420; Phone:
757-414-0724; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1319)
Keywords: nitrogen fertilizer; nitrogen use efficiency; white potato; nitrogen rate and timing
