| Chemical composition of potato stem, petiole and leaflet were evaluated in response to the application of K fertilizer. Potassium was applied at six different rates (0, 60, 120, 240, 480 and 960 kg ha-1 of K2O), as K2SO4 and was placed in the furrow during planting. Two plants per plot were sampled 48 days after plant emergence to evaluate N, P, K, Ca, Mg, S, Cu, Mn and Zn concentrations in stems, petioles and leaflets of the youngest fully expanded leaf. It is recommended using potato petioles to evaluate the N, P, K, Ca, Mg and Cu status and using potato leaflet to evaluate the S, Mn and Zn status. The stem was not a good indicator of S nutritional status. Petiole N, P and Cu concentrations associated with the maximum tuber yield (30.5 t ha-1, with 353.4... |
