SEED SPACING FOR NONTHINNED SUGAR-BEET PRODUCTION

Irrigated sugarbeet growers traditionally overseed their crop to assure adequate stands, then hand thin to a final population. The extra seed and hand labor costs may possibly be eliminated. The objective of this study was to determine optimum seed spacing for the greatest sucrose production in nonthinned sugarbeet. 'AC-102' sugarbeet (Beta vulgaris L.) was planted at 10-, 15-, 19-, and 23-cm intrarow seed spacings for 4 yr in Sidney, MT, to determine optimum seed spacing for greatest sucrose production of nonthinned sugarbeet. The fall ridging/spring deridging system was used to assure sufficient moisture for emergence. Successful stands were established without supplemental irrigation in 1984, 1985, and 1986, but in 1987, rains after planting and before emergence caused severe crusting of the soil which reduced stands. Seedling and harvest plant densities decreased with wider seed spacing in all years. Sucrose content decreased and impurities increased as seed spacing increased. Yields varied across years, but increased sucrose content and decreased impurities of beets planted with the 10- and 15-cm spacings generally resulted in highest gross sucrose and estimated recovered sucrose yields.