Biofortificação agronômica do milho verde com ferro e zinco.

Abstract

Hidden hunger is a serious nutritional security problem in the world, with an estimated five billion people with Fe deficiency and about 1.5 billion Zn. Among many alternatives to mitigate the effects of micronutrient deficiency on food, the biofortification of food is highlighted through the soil enrichment practices with higher nutritional contents. Green maize grains (Zea mays L.) stand out as a source of food in poorer regions, however, shows low concentration of Fe and Zn, which does not contribute to minimize the picture of disability in humans. The objective of the study was to increase, by means of agronomic biofortification, the contents of Fe and Zn in the grain of green corn from the management of soil fertility. Two parallel experiments were conducted under irrigated field conditions, in Luvissolo chromic of the city of Vieirópolis – PB, between March and June 2018. The experimental design was that of casualized blocks, with five treatments and four repetitions, in each experiment. In Experiment I, we studied the application of five doses of fertilizer with the Fe micronutrient and Experiment II, the application of five doses of Zn, being applied entirely via the soil foundation fertilization, having both Experiments developed in the following doses: 0; 2.5; 5.0; 7.5 e 10.0 kg ha-1. The foliar and grain contents and accumulations were evaluated for the Fe and Zn nutrients, in addition to the characteristics of fresh and dry phyto mass in the plant components. The levels of Fe and Zn in soil were also quantified at the end of the experiments. Fe doses influenced the fresh and dry phytomic matter of the clouds and grains, as well as the contents and accumulations in the leaf, grains and soil contents. There was no significant effect of the doses of Zn on the soil under the dry and fresh phyto-mass characteristics of plant components. The different doses of Zn affected the content and accumulation of this in the leaves and the content in the soil. For the present study, the agronomic biofortification of green corn with iron, in the doses studied, proved inefficient in increasing the content of this nutrient in the grains of green corn. The agronomic biofortification of green corn with zinc, in doses up to 10 kg ha-1, did not present a significant response in the increase of the levels of this micronutrient in the grains. For both micronutrients, the practice had a significant positive effect on the content and accumulation of iron and zinc in the leaves of green corn, hybrid AG 1051, with a better performance observed as a function of the highest dose employed.