Resumo

CASIERRA-POSADA, Fánor  e  CARDENAS-HERNANDEZ, Julián. GROWTH OF MAIZE SEEDLINGS (Zea mays L. var. Porva) IN NUTRIENT SOLUTION WITH LOW (Ca+Mg+K)/Al ratio. rev.udcaactual.divulg.cient. [online]. 2009, vol.12, n.2, pp.91-100. ISSN 0123-4226.

Aluminium injury or toxicity is frequently related to field crops grown in acid soils with high Al³⁺ availability. Often, pH values below 5.0 have a toxic effect on the growth of agriculturally important plant species, because of the Al³⁺ solubility. An experiment was carried out in Tunja/Colombia to determine the toxic effect of aluminium on the growth of maize seedlings (Zea mays L. var. Porva). Seedlings were grown in aerated nutrient solution (macro and micronutrients) containing 1, 0.75 or 0.5 (Ca+Mg+K)/Al ratios by addition of Al₂(SO₄)3.18H₂O in relation to the bases (Ca, Mg and K) content in the solution. To the growth solution of the control plantlets no Al was added. The pH was adjusted to 5.5 in all treatments. Seedlings were harvested when the Al-toxicity symptoms were evident. The total root length, the dry matter production and the leaf area were measured; additionally, the root/shoot ratio was calculated. The leaf area, the total dry matter production and the total root length showed no statistical differences between treatments with 1 to 0.5 (Ca+Mg+K)/Al ratios, but all treatments containing Al were statistically different to the control. The value of the root/shoot ratio showed an inversely proportional tendency to the (Ca+Mg+K)/Al ratio. These results suggest that the maize variety Porva is very Al-sensitive, independently of a low or in balance bases/Al ratio.

Palavras-chave : Toxicity; stress; aluminum; acid soils.

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