Diagnosis of foliar potassium in saccharine sorghum: identification of the best plant organs and growth stage for sampling

Abstract

This experiment was carried out in field conditions during the agricultural year of 1982/83 at the Unidade de Execução de Pesquisa de Ambito Estadual of EMBRAPA, in Pelotas, RS, in a Pelotas soil unit, for the purpose of identifying the best parts and growth for sampling saccharine sorghum cv. BR-501, in order to make potassium diagnosis. The experimental design was a complete randomized block design with split plots, and three replications, with levels of potassium (0, 50,100 and 150 kg/ha) in the plots, and sampling times (boot stage, half-bloom, and between soft-dought and hard-dought) in the split plots. The plants were dissected into individual leaves, inflorescences, internodes and rests. The evaluations indicated that the best samples were leaves 5, 6, 7, 8, 9, 10, 11 and 12, and internodes 3, 8, 9, 10, 11 and 12 both when harvested at booting stage.