Analysis of Russian thistle (Salsola species) selections for factors affecting forage nutritional value

Abstract

The need for forage plants that are productive in, and adapted to, semiarid conditions prompted us to examine the range and independence of assortment of nutritional qualities of wild stands of Russian thistle (Salsola species). Seventy selections from a 5-state area of the southwestern United States were planted in observational plots and analyzed for crude protein, acid detergent fiber, lignin, nitrate, water-soluble oxalate, in vitro digestibility, and ash content at 2 stages of maturity. Values on a dry matter basis of crude protein (5.4 to 22.3%), acid detergent fiber (20.1 to 48.8%), acid detergent lignin (3.1 to 10.4%), nitrate (0.1 to 5.1%), water-soluble oxalate (0.2 to 9.1%), plant height (40 to 180 cm at second harvest), stage of development (midbloom to complete seed development at second harvest), and degree of prickliness (soft to extremely prickly at second harvest) were determined for each of the 70 selections at 2 harvest times. The color, branch density, and degree of leafiness were examined at the second harvest only. Values for in vitro digestibility (45.1 to 66.3% organic matter disappearance) and ash (12.7 to 30.5% of dry wt) were determined for a subset of 22 samples. About 10% of the selections had a composite of properties which would suggest they they would make moderate to good forages.