S. Fabek, N. Toth, B. Benko, J. Borošić, I. Zutić, B. Novak
In an all year round floating system production, the response of lamb’s lettuce to abiotic factors was observed over three growing periods: summer-autumn (SAGP), autumn-winter (AWGP) and spring (SGP). The effect of sowing density (2000 and 3000 seeds m-2) and cultivar (‘Juwabel’ and ‘Cirilla’) on the lamb’s lettuce yield was evaluated by harvest of rosette with 6 to 8 leaves. During 312 days of research the 13 trials were laid out according to a randomized block scheme with four replications. Temperature, dissolved oxygen concentration (DOC), pH and EC value of nutrient solution (NS), along with minimum and maximum air temperature and relative humidity (RH) were measured daily. Observed abiotic parameters of the nutrient solution were as follows: temperature, DOC, pH and EC value 9.5 to 27.2°C, 4.2 to 9.3 mg L-1, 5.4 to 6.6 and 1.9 to 3.0 dS m-1, respectively. Minimum and maximum values of air temperature and RH were in the range between 2.9 to 19.7°C and 12.0 to 47.8°C, 10.3 to 99%, respectively. The shortest production cycles (average of 37 days from sowing to harvest) were in SGP with mean air and nutrient solution temperature 23.4 and 18.8°C, RH 56.2% and DOC 6.5 mg L-1. The longest production cycles (average of 80 days) were in AWGP with minimized air and nutrient solution temperature (12.7 and 12.6°C), the highest RH (75.1%) and DOC (8.3 mg L-1). Regardless of the cultivar and sowing density, the highest lamb’s lettuce yield was obtained in AWGP (2,149 kg m-2) and it was 7 and 15% higher than in SGP and SAGP. Almost in all growing cycles the highest lamb’s lettuce yields were obtained with the combination of cultivar ‘Juwabel’ and lower sowing density.
Fabek, S., Toth, N., Benko, B., Borošić, J., Zutić, I. and Novak, B. (2011). LAMB'S LETTUCE GROWING CYCLE AND YIELD AS AFFECTED BY ABIOTIC FACTORS. Acta Hortic. 893, 887-894
DOI: 10.17660/ActaHortic.2011.893.98
dissolved oxygen, floating system, relative humidity, temperature, Valerianella locusta L.

Acta Horticulturae