Аннотация:Experiments with lawn grasses and theirs seeds in a greenhouse and climate chamber at the optimum soil wetting allowed to evaluate the effect of temperature on the rate of water transpiration. In field experiment the transpiration values ranged from 3 to 10 mm/day at a temperature range from 22 to 49 ° C in the sun and from 22 to 32 ° C in the shade. Generalized according to field and laboratory observations dependence looked like a function with an extremum (maximum) of transpiration about 6-7 mm/day, falling to the temperature of 40 °C. approximately. The results are interesting for use as a boundary conditions in modern computer models of soil water mass transfer and plant productivity.