| Abstrakt: |
Insect populations and feeding damage among five combinations of birdsfoot trefoil, Lotus corniculatus L., and companion grasses were compared. Trefoil was seeded in 1983 alone and in binary combination with tall fescue (Festuca arundinacea Schreber), orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), and timothy (Phleum pratense L.) at two locations in West Virginia. Three cutting treatments, one three-cut schedule and two two-cut schedules, were used in 1984 and 1985. The pyrethroid cyfluthrin was applied to half of all treatments. The influence of forage mixture, cutting schedule, and insecticide on insect populations and herbage yields and quality were studied. The most abundant insects collected in biweekly sweep net samples were Cercopidae, Cicadellidae, Delphacidae, Aphididae (Homoptera), and Miridae (Hemiptera). Numbers of nymphs and adults from the five families varied among forage mixtures and cutting treatments. Cyfluthrin effectively controlled all insects except adult mirids, and biweekly insecticide application increased overall forage yields by approximately 6.0%. The effect of insects on the crude protein and in vitro dry matter digestibility of the trefoil and grass components of the swards did not differ consistently among the five forage mixtures but did vary among the three cutting schedules. |
