From 1997 to 1999, Schizaphis graminum (Rondani), intensity (number per tiller) was estimated on 115 occasions from hard red winter wheat fields located throughout the major wheat growing regions of Oklahoma. A total of 32 and 83 fields was sampled during the fall and spring, respectively. The parameters of linear regressions relating the mean number of greenbugs per tiller (m) and the proporti...

Sward structure affects herbage growth, pasture species dynamics, and herbage utilization. Defoliation management has a major impact on sward structure. In particular, tiller size-tiller density compensations allow for the maintenance of herbage growth. Tiller size and tiller density are determined by several major morphogenetical components. Defoliation affects these morphogenetical components...

In this paper we steer wheeled nonholonomic systems that can be represented in a so called chained form Su cient conditions for converting a multiple input system with nonholonomic velocity constraints into a multiple chain single generator chained form via state feedback and a coordinate transformation are presented along with sinusoidal and polynomial control algorithms to steer such systems ...