Resumo

RAMIREZ, Ricardo. Eficiencia del uso del fósforo de la roca fosfórica por cultivares de maíz. INCI [online]. 2006, vol.31, n.1, pp.45-49. ISSN 0378-1844.

Acidic soils in Venezuela are characterized by low fertility, requiring the application of P, N and lime to produce acceptable crops. This study was conducted to evaluate the efficiency of two corn varieties, Sikuani (Sk) and Agua Blanca (AB) and one hybrid (PB8) in using P from phosphate rock (PR). A pot experiment was set up using a soil low in P and pH of 4.4. Triple super phosphate (TSP) and PR were the P sources, at rates of 0, 40 and 100mg P·kg^-1 of soil. Aluminum tolerant Sk resulted more efficient in dry matter production, P uptake, root length (RL) and PR dissolution in the soil than AB and PB8 cultivars, which are not tolerant to Al. The good response of Sk to PR indicates that Al tolerant corn cultivars are more efficient in using P from PR. RL appears to be a good estimator of corn P efficiency.

Palavras-chave : Fósforo Absorbido ; Longitud Radica ; Zea mays L.