EFEITOS DO SÓDIO NA FISIOLOGIA DO ALGODOEIRO ARBÓREO E HERBÁCEO. I - CRESCIMENTO E TOXIDEZ

Resumo

A greenhouse experiment was conducted according to a completely randomized block design. The treatments used were as follows: five levels of sodium (0, 40, 80, 160 and 320 ppm) added as NaCl and Na2S04, respectively to a HOAGLAND and ARNON complete nutrient solution. These were used individually as nutrient media for two cotton plant cultivars, namely "CNPA 3M" (perennial cotton) and "CNPA 3H" (annual cotton) originated from the National Center of Research on Cotton, in Campina Grande City, Paraíba State, Brazil. The results showed that the growth rate of the perennial cotton was affected by increased levels of NaCl and Na2SO4, respectively, while the growth rate of the annual cotton was affected only by increased levels of NaCl. In both cultivars symptoms of sodium toxicity were observed when the higher levels of this element were added.