Applications in sustainable production

Abstract

Capsicum plants were grown under controlled conditions and submitted to individual fertilization with varying rates of NK. N was applied as NH₄NO₃ (N₁: 6 g m^‐2, N₂: 12 g m^‐2, N₃: 18 g m^‐2and N₄: 24 g m^‐2) and K as K₂SO₄ (K₁: 4 g m^‐2, K₂: 8 g m^‐2and K₃: 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 ion was the main N form assimilated by the plant. The products resulting from 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 forms, while inorganic P was unaffected. The acid phosphatase activity proved 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 were maximum at the N₄K₃ rate.