Root growth and mineral nutrition of cotton cultivars as affected by liming

Abstract

Cotton root growth is under genetic control but can be decreased by soil factors as Al toxicity and low Ca levels. Lime was applied to a Dark-Red Latosol (sandy loam) with 10% of base saturation, to raise base saturation to 30, 50 and 70%, in order to study the effects of liming on root growth and mineral nutrition of cotton (Gossypium hirsutum L., v. latifolium Hutch), cv. IAC 20, IAC 22 e CNPA-ITA 90 cultivares. The experiment was conducted in pots with 4 L of soil, under greenhouse conditions, up to 37 days after plant emergence in a 3 x 4 factorial design with four replications in randomized blocks. Liming was necessary in order to get a good cotton root growth. The IAC 22 cv. showed roots more tolerant to low soil base saturation than cv. IAC 20 and cv. CNPA-ITA 90. Maximum root growth was observed when the soil base saturation was around 50%. CNPA-ITA 90 showed a higher K absorption and was more tolerant to high Mn levels, showing a decrease in dry matter production at the highest soil base saturation.