Aim of the study:
The physiological impact of drought on the crop is reflected into the dendrological changes of the tree or plant body. In this study, we installed automatic dendrometers and we investigated the effect of irrigation dose at different intervals on the growth of sunflower and maize in laboratory conditions.

Material and methods:
For our research was chosen a sunflower (Helianthus annus L.) and maize (Zea Mays L.) seeded in a laboratory equipped with LED lights Mars Hydro 400 as a substitute source of natural sunlight for 12 hours. Both crops were divided into containers A (irrigation dose of 5 mm was applied each day) and B (the same irrigation dose was applied at 3-day interval). In every container was measured volumetric soil water content with sensors 10HS (Decagon Devices) and dendrometric measurements of plants diameter with sensors DD-S (Ecomatik).

Results and conclusions:
A comparison of sunflower and maize irrigated at different intervals showed an increase in the diameters of stems at 1-day irrigation compared to 3-day by 0.8 mm (sunflower) and 12.0 mm (maize). The growth of plant mass was continuous at 1-day irrigation with minor fluctuations during the alternation of the dark and light phases. During the 3-day irrigation, greater shrinkage of the stems occurred, indicating the onset of water stress for the crops. The results of the work can be the basic basis for determining the appropriate application of irrigation bag in conditions of changing climate.