TILLER DEFOLIATION PATTERNS UNDER SHORT DURATION GRAZING IN TALLGRASS PRAIRIE

Simulated 8-pasture short duration grazing systems were studied to determine the effect of grazing schedule and stocking rate on defoliation patterns of individual grass tillers of big bluestem Andropogon gerardii and little bluestem Schizachyrium scoparium. Grazing schedule and stocking rate did not affect the percent tiller height reduction per grazing period except for the combination of 2-cycle grazing and heavy stocking which increased percent height reduction. Percent tiller height reduction per grazing period decreased over the grazing season for the 3 and 4-cycle grazing schdules. Grazing schedule and stocking rate had little effect on the height at which tillers were defoliated. Increasing the number of grazing periods reduced the percentage of tillers, defoliated per grazing period but increased the cumulative defoliation frequency over the grazing season. Grazing schedule did not affect the percentage of tillers ungrazed over the entire grazing season. Big bluestem was consistently defoliated more intensely and frequently than little bluestem. -from Authors