SEASONAL CROP COEFFICIENT OF GERBERA SOILLESS CULTURE

Seasonal crop coefficients, for gerbera soilless culture grown in perlite, sand, zeolite and rockwool substrates in plastic greenhouses, were estimated during the growing season, summer 1991 – summer 1993.

The crop coefficients were calculated on a monthly basis as the ratio of the actual evapotranspiration ETa, measured using the water balance formula, to the potential evapotranspiration ETp, as it is given by the solar radiation method.

The monthly values of the crop coefficient showed that they can be grouped into four categories, one for each growing period.

The first growing period is summer, soon after the transplantation, where the mean value of crop coefficient for sand – zeolite was found 0.47 and for perlite – rockwool 0.53.

The second period is the flowering one (autumn – spring) with a mean value of 0.54 for sand – zeolite and 0.71 for rockwool perlite.

The third one is summer, where the flowering is ceased for commercial reasons, with a mean value of 0.35 for sand and zeolite and 0.52 for rockwool and perlite.

The fourth period is the flowering one of the second year with a mean value of 0.51 for sand and zeolite and 0.72 for rockwool and perlite.

International Seminar on Soilless Culture Technology Protected Crops Mild Winter Climates

A. Papadopoulos, E. Maloupa, F. Papadopoulos

evapotranspiration, crop coefficient, substrate, soilless culture, greenhouse, gerbera

https://doi.org/10.17660/ActaHortic.1995.408.8