The post-harvest physiology of sugarbeet (Beta vulgaris) roots was studied during controlled atmosphere (CA) storage at 35° and 50°F. Zero, 3, 6 and 10% carbon dioxide and 5% oxygen concentrations were employed to investigate the most beneficial concentrations of gases. Under the experimental conditions beets were stored successfully for 200 days. The maximum beneficial effects of CA were observed under 6% carbon dioxide and 5% oxygen at 35°F. Regardless of storage temperatures , sucrose retention was highest in the beets stored under CA, compared to conventional refrigeration (CR). Other beneficial effects include less hydrolysis of sucrose to reducing sugars and a decrease in raffinose accumulation. Fungal growth and sprouting were also inhibited significantly, under CA. In the second phase of the studies, investigations were conducted on sugarbeets to study the effects of different levels of nitrogen fertilizer on the optimum CA storage at 40°F. Regardless of the level of nitrogen fertilization, the beets stored under CA demonstrated beneficial effects as described earlier. In addition, respiration, measured on the whole beets, and amino nitrogen content of the beets were lower in the CA-stored beets than those stored under CR. Accumulation of citric acid and succinic acid was significant in the CA-stored beets.