PHYSIOLOGICAL CHANGES CAUSED BY THE SEPTORIA DUBIA Sacc. et Syd FUNGUS AT QUERCUS ROBUR LEAVES

The researches carried out in this survey aimed at establishing the effect that Septoria dubia fungus has on the physiological processes at the sprout oak trees. In case of plants that have been damaged by the Septoria dubia fungus, there was noticed a drastic drop of the leaves photosynthesis. By analyzing the influence of the Septoria dubia fungus on the intensity of net assimilation, there was noticed a difference, in comparison with the value of healthy plants. The damaged tissue has a higher value of the intensity of respiration process, in comparison with the healthy tissue and the intensity of transpiration had lower values. The pathologic changes of nitrogen, calcium and magnesium circulation established on damaged plants are caused by the influence of extra cell ferments of the parasite.