No abstract

This study was prompted by the special interest in sugar crops, at a time of high petroleum prices and fuel shortages, as potential renewable resources which would supplement non‐renewable fossil resources. Four to six sweet sorghum [Sorghum bicolor (L.) Moench] cultivars were evaluated 4 yr for fermentable sugar production potential at eight locations in the continental USA and at one location in Hawaii. Latitudes represented ranged from 21 to 47° N with the average number of frost‐free days ranging from 120 to more than 350. Data were collected for biomass yield, percent lignin, percent cellulose, stalk sugar yields, and other agronomic characters. Total sugar yield for the continental USA ranged from 4 Mg ha‐1 to 10.7 Mg ha‐1 during 3 yr of the study and up to 12 Mg ha‐1 at the Hawaiian location. Accordingly, theoretical ethanol production in the continental USA ranged from 2129 L ha‐1 to 5696 L ha‐1. Results of the study demonstrated that sweet sorghum is far more widely adapted than was anticipated for a plant of tropical origin and certainly has the potential for providing a good source of fermentable carbohydrates across a wide geographic area.

Casein, casein-starch, casein-sucrose, and casein-glucose mixtures were heated under conditions modeling storage, autoclaving, baking/ broiling and charring (37-3OO'C). Losses in total and chemically available lysine content were measured by fluorodinitrobenzene (FDNB) and dye-binding methods. The lysine and arginine content decreased up to 99%. Changes in amino acid profiles were accompanied by the appearance of at least five new nhrhydrin-positive compounds. The relative potencies of the three carbohydrates in effecting these changes were different at the four temperatures studied. The available lysine contents of the samples measured by the two independent methods were identical within experimental error. The results show different susceptibilities of casein to heatinduced damage in the presence of different carbohydrates.

Narrow-sense hcritability estimates, adjusted to account for inbreeding of parental lines, wcrc compared with realized hcritabilitles obtained by actual selection for high and low resistance to Cercospo~a beticola in sugarbeet (Beta vulgaris). Parental, F1, F~, F~, and polycross populations from high and low selections were field grown under an artificially induced leaf spot epidemic. Heritability estimates, in percent were 24.3___2.9 and 24.3___2.4 for each of two resistant X susceptible crosses. These values were compared with realized heritabilities of 20.47 and 26.71 for the same two resistant X susceptible crosses. Environmental variation accounted for 44 to 62% of the total variation for leaf spot resistance.