Industrial Sweetpotato: A viable biofuel crop for Alabama.

Abstract

Field studies were conducted evaluating selected sweetpotato (Ipomea batatas (L.) Lam.) cultivars for viability as a biofuel crop in Alabama. Industrial sweetpotato cultivars evaluated were: ‘X-1617’, ‘W-328’, and ‘Markham’ along with ‘Beauregard’, which is the most common edible-type grown in Alabama. Sweetpotato yield, dry matter and ethanol yield were measured. Sweetpotatoes were bagged according to plot and weighed in the field. Dry matter was determined using a moisture balance. Ethanol yields were established by fermenting samples then analyzing them using high performance liquid chromatography (HPLC). Statistical analysis indicated sweetpotato yield, dry matter and ethanol yield were affected by the cultivar chosen. ‘X-1617’ and ‘Beauregard’ had the highest sweetpotato yield as well as the highest ethanol yield. Field studies were conducted to assess nitrogen requirements of selected sweetpotato cultivars following a cover crop of crimson clover (Trifolium incarnatum L.). Treatments included 0, 45, and 90 lbs./A N behind crimson clover and a conventional bareground treatment receiving 90 lbs./A N. Sweetpotato yields from the treatment receiving 45 lbs./A N behind crimson clover were similar in year one and greater in year two than the conventional treatment. An increase in dry matter of storage roots was observed in all treatments behind crimson clover compared to the conventional rate. Industrial sweetpotatoes were evaluated to determine in-ground storage viability for prolonging harvest periods and reducing storage costs. A field study with ‘X-1617’ evaluated the following harvest periods: October, November, December, and January. Data collected included sweetpotato yield, dry matter, and soil temperature. As soil temperature decreased, sweetpotato yield and dry matter decreased. Reduced sweetpotato yields were observed in the December and January harvest while a reduction in dry matter was observed in the November, December, and January harvest periods.