Comparative Response to Sugarbeet and Fodder Beet to Heterodera schachtii.

Sugarbeet and fodder beet (Beta vulgaris L.) are being considered for fuel alcohol product ion (1,2). Sugarbeet is susceptible to Heterodera schachtii Schm., and yields are adversely affected (3). T h e effect of the nematode on fodder beet is not known. T h e objective of this study, therefore, was to compare certain aspects of the host-parasite relations of H. schachtii on sugarbeet and fodder beet. Cultivars used in this study were the commercial sugarbeet cv. TASCO AH 14 and fodder beet cvs. Yellow Daeno, Oscar, and Monorosa. Nematodes for inoculum were obtained from a Utah populat ion cultured on sugarbeet in the greenhouse. Fourteen-day-old sugarbeet and Monorosa fodder beet seedlings were transplanted into bromomethane-fumigated sandy loam soil in 12.5-cm plastic pots and inoculated with 800 H. schachtii juveniles/pot of four plants. T h e plants were grown at constant soil temperatures of 5, 10, 15, 20, and 30 C. After 14 days of growth, plants were harvested; roots were stained in an acid fuschin-lactophenol solution and root penetrations by H. schacthii J2 were determined. Penetrat ion of 14-day-old sugarbeet and (Monorosa) fodder beet seedlings did not differ and was comparable to that previously reported on sugarbeet (3); it i n c r e a s e d with increasing soil temperature to 25 C, then decreased. Differences in the degree of susceptibility of sugarbeet and the three fodder beet selections were compared by inoculating ten 14-day-old seedlings of each plant selection with 1,000 H. schachtii J2/seeding. T h e plants, including 10 nonioculated controls, were grown in the greenhouse at 22 ~ 4 C in individual lS-cm containers. Day length was mainta ined at 19