The techniques of plant height (PH) and rising plate meter (RPM) were used to estimate the herbage mass before and after grazing in Cynodon dactylon (L.) Pears and Cynodon nlemfuensis var. nlenfuensis mixture pasture, under rotational system. Regression equations between sward surface heigth or compressed sward heigth by disk and the herbage dry weight were established. To herbage mass before grazing, the coefficients of determination (r²) ranged from 0.70 to 0.87 for RPM and from 0.58 to 0.70 for PH. The residual herbage mass was poorly associated with heights of plant or disk (r² values varying from 0.13 to 0.46). The RPM showed better results to estimate the herbage mass before grazing than PH. The techniques could not be recomended to estimated herbage mass after grazing.
sward height; double-sampling; rising-plate meter; herbage production