Potassium deficiency affects the carbon-nitrogen balance in cotton leaves.

Potassium (K) plays important roles in the metabolism of carbon (C) and nitrogen (N), but studies of K deficiency affecting C-N balance are lacking. This study explored the influence of K deficiency on C-N interaction in cotton leaves by conducting a field experiment with cotton cultivar DP0912 under two K rates (K0: 0 kg KO ha and K67: 67 kg KO ha) and a controlled environment experiment with K-deficient solution (K1: 0 mM K) and K-sufficient solution (K2: 6 mM K). The results showed that leaf K content, leaf number, leaf area, boll number, reproductive dry weight and total dry weight were significant lower under K deficiency (K0 or K1).