Nível crítico de fósforo em cultivares de algod？o I: crescimento em fun？？o dos níveis externos de fósforo

in order to establish the critical level of phosphorus in annual varieties of iac-17, lac-19, iac-20, cnpa 78/sme-4 and in perennial varieties cnpa 2m and cnpa 3m, young cotton plants were grown in nutrient solutions containing the following phosphorus concentrations: 0.38ppm, 1.14ppm, 3.42ppm, 10.26ppm and 30.78ppm. plants were harvested when 75 days old. plant height and dry weight of roots, stem and leaves were determined. the authors concluded that available p for all varieties is in the range between 19.20 and 21.9ppm.