Chlorophyll fluorescence in castor bean fertilized with castor cake and nickel

Abstract

The objective of this work was to evaluate the chlorophyll fluorescence of castor bean in response to fertilization with castor bean and nickel. The experiment was carried out in a protected environment at the Empresa Brasileira de Pesquisa Agropecuária, in the city of Campina Grande, Brazil. The experimental design was completely randomized, in factorial 4x4, with four doses of castor cake: 0; 1.0; 2.0 and 3.0 t ha-1 and four concentrations of Nickel: 0; 4.0; 8.0 and 12.0 mg L-1, with four replicates. At 60 and 85 days of cultivation was evaluated the chlorophyll fluorescence of the castor bean plants cv. BRS Energia. The Fv/Fm, Fv/Fo and Fo/Fm ratios were influenced by castor cake doses at 60 and 85 days. While foliar application of nickel at 60 days influenced only Fv/Fo, and at 80 days only Fo was not affected. Increasing castor cake doses reduces the photosynthetic efficiency of the castor bean plants, but does not damage the integrity of PSII. Foliar applications of nickel up to 12 mg L-1 increase the photosynthetic capacity of the castor bean at 85 days of cultivation.

Keywords

• organic fertilization, photosynthetic efficiency, ricinus communis (l.).