Gaining more and more relevance within the regional scenario, the wheat crop has been standing out due to its high profitability in recent harvests. This factor makes producers who, many times, did not consider some important crop managements as relevant, end up rethinking such cultivation in more detail. In this sense, they seek to improve cultural management and the production scenario, in order to obtain higher yields in this crop, which has a growing participation in profitability and maintenance of the positive financial balance within the property, especially in years of drought in the soybean crop. .
Among the managements related to nutrition, there are all precautions related to NPK, however, there are also other nutrients that are essential for the crop, such as, for example, zinc (Zn), iron (Fe), manganese (Mn), boron ( B) and molybdenum (Mo). All these have in common the fact that they are considered micronutrients. Because they are “micro”, it does not mean that they are less important than the “macro” (N, P, K, Ca, S and Mg), but that the wheat crop needs them in smaller amounts per hectare. Both macronutrients and micronutrients are essential elements for the plant to complete its cycle in the same degree of importance, the only difference is that the plant needs the macronutrients in the proportion of kilograms and the micronutrients in the proportion of grams.
Among these micronutrients, Zn is one that has the greatest influence on the development of wheat plants, especially in the early stages of the crop. This is due to its role in the synthesis of tryptophan, the precursor amino acid of auxin, a hormone that is directly related to plant growth and development.
A successful crop starts with a good establishment, and it is during the emergence and initial development of the wheat crop that we seek to ensure a quick and uniform start-up of the seedlings, greater rooting, more vigorous plants and a greater number of tillers. This will result in plants that are more prepared for possible adversities that may arise throughout the season.
In this scenario, the practice of seed treatment with Zn-based products can help for an excellent establishment of the crop, since proven results are known in terms of better rooting, initial start-up and uniformity, vigor and stress tolerance, reserve of stem and potential for grain filling in plants treated with Zn-based products.
Even with sufficient levels indicated in the soil analysis, some factors may influence, reducing the availability of this nutrient in the soil, such as, for example, high pH due to a high dose of limestone, antagonistic effect with phosphorus (P) when in high doses . Furthermore, the treatment of seeds with Zn promotes a stimulus with a physiological effect on the plants, stimulating their initial development, when they still have an underdeveloped root system.
In order to have good results with the management of nutrition, we need to have a good diagnosis of our area and have knowledge about the real demand of the crop for the productivity we expect, and, then, we are acting in the relationship between these two factors, supplying in an adequate way nutrients with the right source, dose, place and time. With regard to Zn, providing between 100g and 150g of this nutrient per hectare in seed treatment tends to be sufficient to meet the demand for most of the genetic material cultivated in the south of the country. With this management, better rooting, greater initial growth and an average increment of 2.8 bags per hectare were observed in demonstrative plantations conducted by farmers with monitoring by Yara Brasil.
