Leaf assimilation area was measured with the automat measurer (WinDias). Dry
matter were established gravimetrically, after drying at the temperature of 105 ± 2 °C
up to the unchangeable mass (Manuals, 1986). Crop assimilation area was calculated
by multiplying plant leaf assimilation area and crop density. Net photosynthesis
productivity was calculated according to the formula 1