Cicer Milkvetch Forage Yield, Quality, and Acceptability to Insects

Abstract

AbstractCicer milkvetch (Astragalus cicer L.) has shown potential as a forage legume. A study near Ames, IA, was conducted to determine its herbage yield, forage quality, and acceptability to insects in relation to alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.). Averaged over 2 yr, cicer milkvetch harvested three times each year (3‐cut) had 40 and 18% lower herbage yield than alfalfa and birdsfoot trefoil, respectively. The 2‐cut cicer milkvetch had 20% lower yield than 3‐cut alfalfa, but had similar yield to that of 3‐cut birdsfoot trefoil. Seasonal neutral‐detergent fiber (NDF) concentration for 3‐cut cicer milkvetch was 31 and 20% lower than for alfalfa and birdsfoot trefoil, respectively. Seasonal acid‐detergentlignin (ADL) concentration expressed on an NDF basis for 3‐cut cicer milkvetch was 20 and 37% lower than for alfalfa and birdsfoot trefoil, respectively. Seasonal crude protein concentration was greater for 3‐cut cicer milkvetch than for the other treatments, and seasonal in vitro digestible dry matter was similar for the three species when harvested similarly. Compared with alfalfa, average host acceptability of cicer milkvetch was 98% lower for alfalfa weevil [Hypera postica (Gyllenhal) (Coleoptera: Curculionidae)], 89% lower for potato leafhopper [Empoasca fabae (Harris) (Homoptera: Cicadellidae)], and 84% lower for pea aphid [Acrythosiphon pisum (Harris) (Homoptera: Aphididae)]. Cicer milkvetch has favorable yield and forage quality and should be considered for problem areas prone to these insects.