Ecofisiologia de azevém anual manejado sob diferentes frequências e intensidades de corte em solos hidromórficos

Abstract

The objetive of the experiment was to verify the response of Italian ryegrass (Lolium multiflorum Lam.), cultivate BRS Ponteio, subjected to different frequencies and intensities of defoliation from cuts. The experiment was carried out at the Experimental Station of Embrapa Temperate Lowlands (31° 80 and 52° 40 ' W), in the municipality of Capão do Leão/RS. Were tested three different defoliation frequencies determined from the number of fully expanded leaves, and three different defoliation intensities, determined from the height of the plants at the time pré-desfolha. The desfolhas occurred when expanded fully 2, 3 and 4 (2F, 3F and 4F). The intensities of defoliation were equivalent to residues of 0% (± 3 cm, simulating "shaved"), 25% and 50% of the height of the plants. The experimental design was randomized blocks in 3 x 3 factorial (3 3 frequencies and intensities), with 3 replications. The variables studied. The variables studied were: density, tiller alive (DPV), emission rate, tiller (TxEP), number of tillers alive and dead (PfV; PFM), number of initial and final plans (Pli; Plf), number of leaves per tiller live (NFV), total length and medium of living leaves (CtFV and CMF), living in forage harvested leaf blades and the residue (MLFVfc and MLFVr), vivid leaves residue (RFV), residual stem + sheath (RCB), residual dead material (RMM), forage harvested culm + sheaths (MBCfc), hems + stem + spikes (MBCEfc), percentage of foliar blades alive (pLFVfc), percentage of hems + stem + spikes (pBCEfc), accumulation of living leaves; dead; and as in forage harvested hems (aFV; aFM; aCB), forage harvested dry mass; bright leaves; dead leaves; stem + sheath; and spikes (MSfc; MSFVa; MSFMa; MSCBa; MSEa), relegation of thatched roofs (RC), crude protein content (PB). DPV were verified between 5 and 7 tillers. plant-1, TxEP up 0.0072 tiller. GD-1, between 40 and 60 cm CtFV. sheet. 1, RC-tiller between 15 and-0, 27 cm, pLFVfc between 24 and 99%, pBCEfc between 76 and 1%, MSFVa between 2,600 and 3,700 kg ha-1, MSFMa between 107 and 220 kg.ha-1, MSCBa between 1,950 and 705 kg. ha-1 and PB between 13 and 17%. The 25% residue allowed a higher forage harvest with greater participation of leaf blades. When the largest residue was maintained (50%) There was a lower forage harvest, but there was no limitation on PB harvesting. The highest frequency between defoils (2F) and residues equivalent to 50% favor the structure of the pasture, especially at the end of the cycle.