Plum tree water consumption determined in lysimeters as compared to other methods

Investigations done during 1971-1989 within the Fruit Research Institute in Pitesti-Maracineni showed that the real evapotranspiration of the Vinete Romanesti plum tree variety established in non-weighing, percolation-type lysimeter calculated on the April 1 - October 31 period was 622 mm. Mean daily values per month of real evapotranspiration ranged from 1.69 mm on April to 424 mm in July. The average daily values per month of the plum tree transpiration was 0.5 mm/day during October and 1.51 mm/day in July, respectively, while the soil evaporation from bare-soil lysimeters varied from a minimum of 1.07 mm/day in April to a maximum of 2.81 mm/day in July. From all the 15 methods used to evaluate the potential evapotranspiration, the Thornthwaite method produced very closed values to those obtained in lysimeters (97%) and presented the highest similarities to the distribution curves for the mean daily and monthly values.