Comportamento de genótipos de trigo em relação a fósforo no solo

An experiment was carried out in pots, using samples collected from a dark red dystrophic latosol at 0-20 cm depths. The objective was to verify differences among three wheat genotypes in relation to applied phosphorus. Three wheat genotypes were assessed (Toropi, IAC 5-Maringa, and BH 1146) at six levels of P 2 O 5 (0, 30, 60, 120, 240, and 480 mg kg -1 ) and at two levels of liming (0 and 1 SMP for pH 6.0). The fixed parameters of above-ground plant parts were more closely related with both levels and contents of phosphorus in the soil, as compared to dry matter production and root length. Among the parameters of above-ground plant parts, green matter production (WV) and dry matter production (MS) showed the highest correlation indexes with root parameters. MV and MS were adequate to assess the behavior of wheat genotypes, as related to phosphorus content in the soil. In spite of the fact that the genotypes studied are considered tolerant to soil acidity, lime application was essential and provided an increase of close to four times in the efficiency of phosphorus fertilization for MS parameters. The effect of phosphorus fertilization was more intense on the above-ground plant parts than on the root system. This also occurred for liming, although to a lesser extent. The cultivar Toropi showed higher rates of take-up and use of phosphorus for the production of dry matter of above-ground plant parts, as compared to cultivars IAC 5-Maringa and BH 1146.