Water relation features of prunus laurocerasus l. under progressive soil drought stress of soutern coast of the Crimea

Study the Ecophysiological reaction Prunus laurocerasus L. effect of progressive soil drought determined optimum thresholds and zones of soil moisture, temperature and light, photosynthesis and transpiration limiting Prunus laurocerasus L. in summer active vegetation on southern coast. Start of development of the plant water stress and inhibition of photosynthesis - the soil moisture reduction to 30% of FC.; Temperature optimum photosynthesis whose exceeding leads to inhibition of the enzyme activity and reduce the rate of photosynthesis - metal temperature 35 °C; Growth inhibition, reduction turgor apical young leaves - soil moisture content decrease to 25-20% FC. and Reduced soil moisture to 18% FC and below results in a sharp decrease transpiration rate - 92.3%, visible photosynthesis rate at 95.1% and stomatal conductance by 94.7%. The proportion of the total dark respiration grossphotosynthetic under strong water stress - 78%, in the absence of stress factors - 25-30%; The beginning of the recovery after watering turgor - 1.5-2 hours, the full restoration of the intensity of photosynthetic gas exchange after watering - after 24 hours. Under strong water stress visually noticeable loss of chlorophyll in leaf: Central vein acquired a yellow-green color to leaf- brownish stains. The culture conditions, this leads to loss of decorative qualities of plants. Disclosure mechanisms of functioning of leaves, depending on the environmental impact, provides the basis for the environmental assessment of the physiology of the evergreen species and the possibility of agricultural technology of choice.