Respostas de lâminas de irrigação e tipos de adubação no crescimento e produção do pinhão-manso em condições de campo.

Abstract

The Jatropha curcas is a oil producer plant now considered as an alternative for biodiesel production. This research aimed to evaluate the effects of the application of different leveis of replacement of the evapotranspiration, through the irrigation with saline water, and effects of the organic and chemical manuring in the cultivation of the Jatropha curcas under field conditions. The experiment was developed in the Farm Barra, in the municipal district of Santa Luzia, in the Paraíba semi-arid. The used statistical design was in randomized blocks, in an scheme of subdivided plots, with four replications. Five leveis of replacement of water (25; 50; 75; 100 and 125% of the reference evapotranspiration) and three manuring types (organic, mineral and natural fertility of the soil, that is, without fertilizer application) were studied. The appraised variables were: plants height; stem diameter, number of leaves, the seeds, fruits and peei weight, and at the end of the experiment a leave analysis was accomplished, aiming to observe the accumulation of nutrients in the leaves. The irrigation water depths and the manuring type exercised, in a certain evaluation period or in ali of them, significant effects on the growth parameters and on the number of leaves. The irrigation water depths didn't affect the weight of the seeds, of the fruits and of the peei, while the manuring caused effect highly significant. The irrigation water depths promoted significant effect on the content of nutrients of the leaves by the end of the experiment, just in the elements sodium and nitrogen, while the effect of the manurings was not significant in none of the elements. The differences in the content of nutrients of the leaves among the water depths of 25% and 75% of ETo were significant just for the elements N and Na; already in the mean of the treatments of the organic and chemical manurings and without manuring, didn't happen statistical differences.