Organomineral fertilization in growth, physiology and phytomass production of castor oil plant BRS energia

This work aims to study the effect of castor oil plant cake doses (0.0; 1,100; 2,200 and 3,300 Kg ha-1) associated with P doses (0.0 and 90 Kg ha-1) and K doses (0.0 and 60 Kg ha-1) on initial growth period of castor oil plant BRS Energia. The experiment was conducted under greenhouse's conditions at the Embrapa Algodao, located in Brazil. The experimental design of randomized blocks was used in a 4x2x2 factorial arrangement, with 4 replications, totaling 64 experimental units. The castor oil plant cake application influenced the pH, phosphorus (P), potassium (K), magnesium (Mg) and organic matter (M.O.) values in the soil. The variables of growth, height, stem diameter, number of leaves and leaf area increased linearly with the application of castor oil plant doses, as well as for the variables of phytomass production from root, aerial part and total. The doses of castor oil plant cake influenced the nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) contents. The relative chlorophyll content and transpiration increased in a quadratic manner due to the castor oil plant cake application. Key words: Castor oil plant cake, organic waste, phosphorus, potassium.