Resumo

SANCHEZ F., Luis E.; PARRA, Dercy; GAMBOA, Erbert  e  RINCON, José. Effect of NPK fertilization on yield of a commercial plantation of cocoa at the southeast of Táchira State, Venezuela . Bioagro [online]. 2005, vol.17, n.2, pp.119-122. ISSN 1316-3361.

The low yields in cocoa in Venezuela are associated with lack of fertilization. Two experiments were performed in a commercial plantation in the southeast of Táchira State to determine the response to several doses of fertilization. The treatments were established based on laboratory dose (LD) of NPK estimated from soil analysis. The first trial was run for one year and the following five doses were evaluated (100 % LD, 50 % LD, 200 % LD, 400 % LD and a control without fertilization). The second trial lasted three years and three doses were evaluated (100 % LD, 200 % LD, and a non fertilized control). A complete randomized block design, with six replications and six-tree plots, was used in each experiment. Only one out of the four evaluations showed effect of the fertilizer on the crop yield. It is concluded that several factors, among which the high tree variability that usually exists within cocoa plantations in the country, along with the presence of a seasonal shallow water table, probably affected the tree response to the NPK fertilizer.

Palavras-chave : Theobroma cacao; nitrogen; phosphorus; potassium.