PRELIMINARY EVALUATION OF RUSSIAN THISTLE, KOCHIA, AND GARDEN ATRIPLEX AS POTENTIAL HIGH PROTEIN CONTENT SEED CROPS FOR SEMIARID AREAS

Abstract

An initial study of three uncultivated plants of the Canadian prairies, kochia [Kochia scoparia (L.) Schrad.], Russian thistle (Salsola kali var. tenuifolia Tausch.), and garden atriplex (Atriplex hortensis L.), suggests that kochia and Russian thistle warrant further examination as high-protein-content seed crops for semiarid areas. Plot trials gave seed yields of 2,170 kg/ha for kochia, 1,640 kg/ha for Russian thistle, but only 856 kg/ha for garden atriplex. Saponins were found in significant amounts in kochia and garden atriplex, saponin equivalent in hemolytic activity to 19.4 mg and 30.6 mg digitonin per gram seed, respectively. Most of the saponin was removed, without major loss of protein, by extracting whole seeds with hot water or ethanol. In small-animal feeding trials using mice, Russian thistle seed meal (hexane-extracted) gave weight gains of 11.5–13.6 g in 14 days, comparable to the control diet at all levels tested. The weight gains on diets containing 7–14% meals from water-washed or ethanol-extracted kochia seed, or from water-washed garden atriplex seed, were comparable to the control diet, but weight gains decreased to 6.7–9.5 g in 14 days on diets containing 28–35% of these seed meals. Correlation between feed consumption and weight gain suggested that poor palatability was the main factor affecting performance.