NITROGEN, POTASSIUM, AND PLANT SPACING EFFECTS ON YIELD, TUBER SIZE, SPECIFIC GRAVITY, AND TISSUE N, P, AND K OF NETTED GEM POTATOES

Abstract

Netted Gem potatoes (Solarium tuberosum L.) were grown at seed-piece spacings of 28, 38, and 46 cm with 90, 134, and 179 kg N/ha and 46, 93, and 139 kg K/ha. Prior to planting, 100 kg P/ha and 56 kg Mg/ha were broadcast. At planting 74 kg P/ha was combined with the N and K treatments and banded. Increased spacing resulted in increased yields of "A" size tubers (113–454 g) and the percentage of A size tubers in the total yield, whereas total yield was unaffected as spacing increased. Increased rates of N and K resulted in increased total yields and percentage of A size tubers. Specific gravity decreased slightly as N rates increased, but decreased markedly (from 1.099 to 1.091) as K increased. Spacing had no effect on specific gravity. Applied N and K had significant effects on leaf and petiole N, P, and K levels. Increased spacing had no effect on tissue nutrient levels.