Influence of pH and urea on the efficacy of the 2-chloroethylphosphonic acid as floral inductant of pineapple

Abstract

This experiment was conducted at the Centro Nacional de Pesquisa de Mandioca e Fruticultura EMBRAPA, in Cruz das Almas, Bahia, Brazil, in order to determine the effects of urea (2%) and pH (raised to ten with Ca (OH)₂) on the efficiency of ethephon to induce flowering in pineapple. Randomized blocks were used with eleven treatments and four replicates, comparing ethephon concentrations of 100 and 50 ppm, applied alone or in mixture with urea and/or Ca(OH)₂, with ethephon alone at 500 ppm and calcium carbide at 4.500 ppm. The results did not show differences among treatments, which means that ethephon above 50 ppm did not respond to the addition of urea nor to the elevation of pH. Keeping the efficacy of ethephon at low concentrations presents great importance, due to the reduction in the costs of its application.