In limed cotton crops (Gossypium hirsutum), B deficiency is likely to appear. In Brazil, there are B fertilization recommendations based on results obtained with the cultivar 'IAC 20', which is not in use anymore. This experiment was conducted to study the response of the cotton cultivars 'IAC 22' and 'CNPA-ITA 90' (Deltapine) to B as compared to 'IAC 20', grown in nutrient solutions ranging from 0 to 28 mmol L-1 of B. The plants grown in solution without B were discarded, because there was no growth at all. Dry matter yield and B uptake were analyzed. All the three cultivars had a similar response to B levels in nutrient solution as regarding to dry matter yield, number of reproductive structures and B content in the tissues. The level of 21 mmol L-1 of B in the nutrient solution lead to the highest cotton yield, corresponding to 16 mg kg-1 of B in the 3rd and 4th leaves of the plant during blossom.
Gossypium hirsutum; cotton; boron; micronutrient
