Nitrogen and phosphorus metabolism and yield of capsicum plant (Capsicum annuum L. cv. Lamuyo) in response to increases in NK fertilization

Capsicum plants were grown under controlled conditions and submitted to ind ividual fertilization with varying rates of NK. N was applied as NH4NO3 (N- 1: 6 g m(-2), N-2: 12 g m(-2), N-3: 18 g m(-2) and N-4: 24 g m(-2)) and K a s K2SO4 (K-1: 4 g m(-2), K-2: 8 g m(-2) and K-3: 12 g m(-2)), resulting in 12 treatments of the corresponding crosses between the different rates of N and K. Applying high rates of N and K led to an increase in the absorption and translocation of NO to the shoot, however, the trend of the NR in the two assays studied (NRc and NRi) and that of NH indicate that this latter i on was the main N form assimilated by the plant. The products resulting fro m this process, mainly proteins, increased with higher N and K rates, which also gave rise to the maximum leaf concentrations of organic and total P f orms, while inorganic P was unaffected. The acid phosphatase activity prove d to be a good indicator of the nutritional status of P. Finally, yield in Kg plant(-1) was maximum at N3K1, whereas the greatest number of fruits wer e maximum at the N4K3 rate.