Tillage effects on the development of several cotton cultivars in Southwest of Bahia, Brazil

Cotton (Gossypium hirsutum L.r. latifolium Hutch) is very sensitive to soil conditions. The Iuiu Valley, located in the Southwest of Bahia State in Brazil, was an important area for cotton production but an inadequate soil management for years and consequent soil quality degradation lead to the decline of the crop in the region. In an effort to reestablish cotton, this study was carried out to identify a sustainable soil management system for cotton production in the region. The experiment was carried out in Palmas de Monte Alto (Bahia, Brazil) on an Eutrichrept soil, and consisted of eight treatments (two tillage systems and four cotton cultivars). The field lay-out was a split-plot with tillage systems as main plots and cultivars as subplots. The tillage systems consisted of conventional and reduced tillage and cotton cultivars used were ‘BRS Aroeira’, ‘BRS 201’, ‘Delta Opal’ and ‘BRS Cedro’. No signif icant differences were observed between the two tillage systems for plant height, stem diameter, boll weight, yield, f iber percentage, and fiber length. Conventional tillage promoted higher fiber length and uniformity for BRS 201 as well as higher fiber resistance for the other three cultivars. On the other hand, reduced tillage promoted higher micronaire index values for Delta Opal. The BRS Cedro cultivar showed a greater plant height independently from the tillage system. In conclusion, reduced tillage allowed a sustainable soil management without compromising cotton yields and quality. Additional key words: fiber quality, Gossypium hirsutum, micronaire index, soil compaction, soil tillage.