Indicadores de efciência do uso da água e de nutrientes de clones de palma forrageira em condições de sequeiro no semiárido Brasileiro

Abstract

The objective was to evaluate the productive efficiency of three cactus pear clones, resistant to Cochineal Carmine, grown in rainfed conditions in the Brazilian semi-arid region. The evaluated clones were IPA-Sertânia (IPA), Miúda (MIU) and Orelha de Elefante Mexicana (OEM). The indicators of water use efficiency were calculated: crop water productivity (CWP), economic water productivity (EWP) and nutrient use efficiency (NUE), all based on rain (Prec.) and the real crop evapotranspiration (ETr). The ETr was quantified by the method of the soil water balance. It was found that the CWP on a dry basis (DB) did not differ from one clone to the others (CWP(Prec.) ~ 8.1 kg DB ha-1 mm-1; CWP (ETr.) ~ 9.1 kg DB ha-1 mm-1), but they differed on a green base (GB). The OEM was the most efficient clone (CWP(Prec.) ~ 104.8 kg GB ha-1 mm-1; PAC(ETr.) ~ 112.1 kg GB ha-1 mm-1), follow by the IPA concerning the ETr (CWP(ETr.) ~ 101.1 kg GB ha-1 mm-1). The MIU was least efficient clone for the Brazilian semi-arid region. There was no difference of PEA (PEA(Prec.) ~ R$ 35.4 ha-1 mm-1; PEA(ETr.) ~ R$ 39.5 ha-1 mm-1) and EUN, with exception of magnesium use efficiency based on the ETr, which was higher for the OEM (EUN(Mg) ~ 111.4 g ha-1 mm-1) and IPA (EUN(Mg) ~ 77.4 g ha-1 mm-1), and of the sodium based on the rain, which was superior for the OEM (EUN (Mg) ~ 4854.3 mg ha-1 mm-1) and MIU (EUN (Mg) ~ 3383.6 mg ha-1 mm-1) clones.