Abstract
The plants were grown under controlled conditions at 24/24°C and 24/14°C day/night temperatures in growth chambers. It was shown that the cool night conditions which decreased dry matter growth of plants and leaves area, inhibited dark respiration and lowered Ca content in leaves. Under these conditions the specific leaf weight (SLW) and the content of N, P, K, calculated for 1 dm2 of leaves area increased. The intensity of plant leaves photosynthesis from differentiated night temperature was similar.