Biometric Indexes in the Early Selection of Potassium Use Efficient Sugarcane Genotypes

Brazil is the world’s largest producer of sugarcane (Saccharum officinarum). In this context, in addition to the already extensive areas occupied with sugarcane crops, new areas, characterized as having low natural soil fertility, have been incorporated into the production system, showing that the new sugarcane genotypes that are efficient in the use of mineral nutrients in the soil they must be selected for use in these areas. Thus, the objective with this work was to evaluate the feasibility of using biometric indexes in the early selection of potassium (K) use efficient sugarcane genotypes. For this, four sugarcane genotypes were submitted to five doses of K, evaluating the possibility of selection during the initial phases of the crop (at 5, 8 and 14 months of age). The RB92579 genotype was the most efficient in the use of K for stem dry matter, showing that it is possible to select efficient genotypes in the use of K using the stem dry mass or efficiency in the use of K as indexes already at 8 months after planting in sugarcane, but provided that they are tested under conditions of low K availability in the soil, that is, without adding fertilizers to the soil.