Desenvolvimento inicial e respostas fisiológicas do pinhão manso (Jatropha curcas L.) a diferentes lâminas de irrigação e doses de nitrogênio

Well-managed irrigation and fertilization are fundamental for sustainable cultivation of jatropha (Jatropha curcas L.) in the semi-arid portion of northeastern Brazil. Thus, the objective this work was to evaluate biometric and physiological parameters on jatropha initial developmental stage under different levels of water availability in the soil and nitrogen doses in the semi-arid region of northeastern Brazil. The experimental design was randomized block with four nitrogen doses (0, 120, 240, and 360 kg ha-1), three levels of available soil water (100, 66 and 33%) and three replications. We evaluated biometric features (height, stem diameter and leaf area); leaf, stem and root biomass; and physiological parameters (photosynthesis, transpiration, stomatal conductance and leaf temperature). Biometric features height and leaf area; leaf, stem and root biomass; and the physiological parameters, had interaction with water and nitrogen availability in the soil. There was a significant increase with increasing water and nitrogen levels, with slight variations among them.