GROWTH AND WATER REQUIREMENTS OF CARNATION CULTIVATED IN RAISED BENCHES

An experiment aimed at the acquisition of basic information on water requirements of carnation cultivated in raised benches was carried out by water - balance lysimeters. The water losses for evaporation and for evapotranspiration were determined during the whole cultural cycle. The transpiration was calculated by the difference between evapotranspiration and evaporation. The growth of the plant was monitored too. At the beginning of the cultural cycle the water requirement for evaporation is much higher than the water requirement for transpiration. Later on the transpiration prevails over the evaporation. The extent of transpiration depends on a great number of factors like the microclimate and the cultivation parameters. It is related to plant growth parameters too. The results of this experiment suggest that the transpiration level is related both to dry matter production and to peculiar developmental stages, particularly the bud differentiation and the flower growth. As regards the choice of a control system for irrigation, the use of a "crop coefficient" should be proposable but it should be difficult to introduce into the practice depending on its great variability during the cultural cycle. So a rational system for the management of irrigation into the practice can base itself on data regarding the plant water status or the substrate water status.