ATIVIDADE ENZIMÁTICA NA CULTURA DO MILHO EM FUNÇÃO DO MOLIBDÊNIO E DE ÉPOCAS DE ADUBAÇÃO NITROGENADA

Abstract

Molybdenum applications and nitrogen fertilization at different times may interfere with enzymaticactivity in maize (Zea mays L.) plants. The aim of this work was evaluate the effect of nitrogen fertilization andmolybdenum application on the activity of the enzyme nitrate reductase (NR), nitrogen content and grain yield intwo maize cultivars. A randomized blocks experimental design was used, in a 3 x 2 x 2 + 2 factorial scheme withfour replications and 50.000 plants ha-1. The following parameters were evaluated: enzymatic activity depending onthe harvest season, leaf nitrogen content and grain yield. The time of nitrogen application affected enzymatic activityindependent of fertilization with molybdenum. The highest grain yield and increased enzymatic activity were obtainedby applying nitrogen at the four expanded leaves stage. The growing seasons of corn cultivars may affect the enzymeactivity.

Keywords

• Vegetative cycle
• nitrogen
• yeld
• nitrate reductase.