Row Spacing and Plant Density Effects on Smooth Root Sugarbeets

Agronomic performance of smooth root (SR) type sugarbeet genotypes was compared with that of standard commercial cultivars under different row spacings and plant densities during the years 1988-1990. In one experiment smooth root types SR 87 and 87H1-00 were compared with commercial cultivars MH E-4 and ACH 176 in plant population densities of approximately 69,200 ; 96,800 ; and 79,100 plants ha-'. Individual plant spacings were 71 cm (between rows) x 20 cm (between plants within rows), 56 x 20 cm, and 46 x 46 cm respectively. In a second experiment in 1989, SR 87 was compared with MH E-4 at six plant spacings of 71 x 30 cm, 56 x 30 cm, 46 x 30 cm, 71 x 15 cm, 56 x 15 cm, and 46 x 15 cm. This experiment was repeated in 1990 with these six plus two additional plant densities, 51 x 30 cm and 51 x 15 cm. Although SR sugarbeets have a different fibrous root system than today's standard root type, there were no adverse effects of SR plants when grown in narrow rows under higher plant densities compared with present conventional 71 cm row width. Smooth root sugarbeet genotypes responded to plant density in different environments similarly to adapted standard root commercial cultivars. SR productivity was enhanced when sugarbeets were grown at the higher density of 71,760 plants ha -1 (46 row width x 30 cm plant spacing).