Improvement of the growth, grain yield, and nitrogen, phosphorus, and potassium nutrition of grain corn through weed control

Abstract

In the course of an experiment in Arganda del Rey (Autonomous Community of Madrid), a herbicide was tested in a grain corn field heavily infested with weeds. The herbicide, a mixture of metolachlor and atrazine, was applied when the corn had developed eight leaves. There was a great variety of weed species and their distribution in the plots depending on the climatic conditions. The control achieved with the herbicide was high, 100% in 1992 and 90.5% in 1993. Weed control improved the growth, grain yield, number of grains per ear, 1,000 grain weight, ? grain content, total uptake of nitrogen (N), phosphorus (P), and potassium (K) by the plant, and ?, ? and ? translocation efficiency to the corn grain. Per 100 g/m² of additional weed dry weight, there was a grain yield decrease of 98.2 kg/ha as well as a decrease of the total uptake of N, P, and ? of 14.6, 2.7 and 9.5 kg/ha, respectively, by the corn plant.