The canopy structural traits of tanzaniagrass (Panicum maximum Jacq. cv Tanzania) pastures under three resting periods (PDs), defined as the time to complete the expansion of 1.5, 2.5, and 3.5 new leaves per tiller, along several grazing cycles (CPs), were evaluated. The following response variables were evaluated: green leaf dry matter mass (MSLV), green stem dry matter mass (MSCV), dead forage dry mass (MSFM), canopy height, leaf/stem and live/dead material ratios at pre- and post- grazing, crop growth rate (TCC) and net accumulation rate (TAC), tiller populational density (DPP) before grazing, and the residual leaf area index (IAFr). Differences among the PDs were acentuated toward the end of the experimental period for the variables canopy height, MSLV, and MSCV. The MSFM was not modified during the CPs in each PDs, but, averaging all the cycles, the 3.5 leaves PD pastures showed higher MSFM than the others. The leaf/stem and the live/dead material ratios were higher at the 1.5 and 2.5 leaves PDs pastures, than at the 3.5 leaves PD pasture. The 2.5 and 3.5 leaves PD pastures showed the highest TCC and TAC values. The DPP was higher at the 2.5 leaves PD pastures, than at the 3.5 leaves PD pasture. The PD for the expansion of 2.5 leaves per tiller is the better indication to manage Panicum maximum cv. Tanzânia pastures with sheep, because it promotes higher proportion of leaves, without decreasing the tiller population density. However, this management decision leads to higher post-grazing stubble height, which may need to be controled by manual or mechanical mowing.
grazing cycle; grass morphology; leaf; sheep
