Micronutrients do not improve agronomic efficiency under field conditions without nutritional stress to maize plants

Os micronutrientes não melhoram a eficiência agronômica em condições de campo sem stress nutricional para as plantas de milho

Abstract

Maize plants (Zea mays L.) are a cultivated crop of significant importance in global food security, because they have a high nutritional value and are used in the composition of chicken, pig, cattle, and goat feed. However, the physiological potential of maize plants has not been fully explored. Micronutrients are mineral elements required by enzyme activators in the processes of obtaining energy and in the accumulation of dry matter. We examined the hypothesis that maize plants treated with a micronutrient mixture (MNM), via foliar application, will not improve plant growth and, consequently, agronomic efficiency, under field conditions without nutritional stress. The experiment was carried out using the commercial hybrid 3646YHR (Pioneer®) with the application of boron (B), zinc (Zn), copper (Cu) and molybdenum (Mo) available in the ‘Mover’ commercial product (Stoller-do-Brasil®) to the leaves of either 0.0 L.ha-1, 1.25 L.ha-1, 2.5 L.ha-1, 5.0 L.ha-1, and 7.5 L.ha-1 distributed in a randomized block experimental design. We measured plant growth parameters and also calculated physiological indexes and agronomic efficiency. The data were subjected to an analysis of variance (ANOVA) and their means were compared using Tukey’s test at 5% significance (α=0.05). In summary, our findings did not show improvements in plant growth and agronomic efficiency data. Therefore, we accepted our original hypothesis (‘H0’), which suggests that mineral elements did not enhance the biological productivity and agronomic efficiency performance of our maize plants when they were not under nutritional stress. Investigation on maize leaf micronutrient mixture application is limited and so an excellent opportunity for future study