EFFECT OF ROOT-ZONE WARMING ON STRAWBERRY PLANTS GROWN WITH NUTRIENT FILM TECHNIQUE (NFT)

Strawberry plants were grown under unheated glasshouse conditions during a six-month period, (from November until May), using the Nutrient Film Technique (NFT). The aim of the experiment was to investigate whether solution heating could compensate for low air temperature.
Rooted runners, cv. «Osso Grande» were grown under different minimum nutrient solution temperature regimes: control plants (no heating), 20^oC and 25^oC (minimum temperatures). Flower trusses were removed weekly for two months (January and February), and runners throughout the growing period.
Harvesting started at the beginning of March, with plants from the heated solutions (20^oC and 25^oC) giving 38% and 37% of the total marketable yield during the first month of picking, respectively.
The higher minimum nutrient solution temperature (25^oC) significantly increased plant growth, giving the highest values for shoot fresh weight, shoot dry weight, root dry weight mean leaf petiole length and average trifoliate leaf number among the temperature regimes.
The shoot/root ratio was the highest for this treatment, too.
Yield and earliness were significantly improved by nutrient solution warming, the highest yield/plant (325g) was obtained from the higher (25^oC) solution temperature regime while the lowest (145g) was from the control plants.
Average fruit weight was not influenced by the nutrient solution temperature, but the number of harvested fruits per plant increased with increasing solution temperature.
The percentage of malformed fruits increased significantly with nutrient solution warming, while the percentage of albino fruits decreased.

International Symposium on Growing Media and Hydroponics

C.D. Economakois, L. Krulji

strawberry, root temperature, soilless cultivation, NFT

https://doi.org/10.17660/ActaHortic.2001.548.20