Comportamento do pinhão-manso sob adubação orgânica lâminas de irrigação e cobertura do solo.

Abstract

The Jathropa curcas is important because o f its oil, one o f the best raw materials for biodiesel fabrication and others uses on industry. The objective of the present work was to study the performance of the Jathropa curcas to different doses of nitrogen, water regimes with and without mulching. The experiment was conducted from May 2009 to February 2010 on a greenhouse of the CDSA/UFCG at Sume-PB, under an experimental design with three blocks on a factorial scheme with four doses of nitrogen (0, 50,100 and 150 kg ha"1 ) four water regimes (50, 75, 100 and 125% of the evaporation) and four additional treatments with mulching (nitrogen treatments of the soil without mulching and the irrigation regime of the covered soil, based on the crop coefficient}. For this, 60 plastic vases of 100 kg capacity were used to cultivate a plant during 257 days. The reposition levels of water on the soil without mulching were obtained by monitoring daily a Class A pan evaporation, installed inside the greenhouse. Every 30 days were evaluated the plant height, stem diameter and the leaf area, At the end of the experiment were evaluated the total plant phytomass and the root length. The results were submitted to variance analyses, to the Scheffe test for comparison of the contrast means and to regression analyses for the quantitative treatments. The nitrogen doses did not have any significant effect for the evaluated variables. The increase of the soil water and the mulching has significant effect on plant height, stem diameter, phytomass and water use efficiency of the plant.