Summary:

A field experiment was carried out from 2007-2009 at the University of Natural Sciences and Humanities greenhouse complex in Siedlce. The trial was set up as randomized blocks with three replications. In the experiment was investigated the effect of method of AgroHydroGel application (control, AgroHydroGel applied under seedlings, AgroHydroGel applied under plants in the field, half of the AgroHydroGel rate applied under seedlings, the other half under plants in the field) and cultivar (‘Gabi', ‘Delikates Biała', ‘Wiedeńska Biała') on the yield level and quality of kohlrabi grown in the field under the weather conditions of central-eastern Poland. Kohlrabi seedlings were grown in a non-heated greenhouse. The seeds each cultivars were sown in late March to seedling containers with peat substrate amended with AgroHydroGel or peat substrate only. The kohlrabi was harvested two times at 7-10 days intervals, at a minimum bulb diameter of 3 cm. The beginning of harvest was after 50-51 days from the planting of seedlings. There was found that weather conditions in the study years had significant influence on the yield level, average weight and bulb diameter as well as on the nutrient contents in the kohlrabi bulb. The most favourable on the increase of yield of the investigated kohlrabi cultivars affected AgroHydroGel applied in the whole rate under plant in the field. Among the examined cultivars ‘Gabi' and ‘Wiedeńska Biała' were characterized higher yield, average weight and bulb diameter in comparison with ‘Delikates Biała'. It was found that the method of AgroHydroGel application had no influence on the nutrient content in the kohlrabi bulb.