Influence of the photoperiod on the utilization of macronutrients as observed in tomatoes and spinach

Abstract

Investigations on the influence of the photoperiod on the utilization of mineral nutrients by tomatoes, 'Karzełek Chodowski' cv. and spinach 'Matador' cv. were performed in a phytotron. The biomass of experimental plants increased with the length of the photoperiod, for tomatoes and spinach from 9 to 16 and from 9 to 14 hours depending on the concentration of nutrient solution. The percentage of macronutrients in the biomass of both plants increased, the higher the salt concentration of the solution, only during the appropriate lenght of the day. The utilization of mineral nutrients regardless of their concentration reached a maximum for tomatoes and spinach in the conditions of 16 and 11 hour day respectively.