The Yield and Winter Hardiness of Selected Welsh Onion (Allium fistolosum L.) Cultivars Grown in Soil Fertilized with Polimag® S

Welsh onion (Allium fistulosum L.) is grown in Olsztyn (NE Poland) on an area of 4.0 ha. The habitat conditions in the Warmia region are conducive to growing new Welsh onion varieties as annual crops for selective harvesting. A two-factorial field experiment was conducted in a randomized block design with there replications in the Experimental Garden of the University of Warmia and Mazury in Olsztyn in 2009 - 2012. Seeds of three Welsh onion cultivars, Long White Ishikura, Parade and Performer were used. The effects of the following experimental factors were determined- Welsh onion cultivars Long White Ishikura, Parade and Performer grown from seedlings; the application of a mixed fertilizer, Polimag® S, at two rates of 0.72 t ha-2and 1.44 t ha-2, referred to as 50% and 100% rates. The studied Welsh onion cultivars did not differ significantly with respect to yield, although an increase was noted in the total yield of Welsh onion leaves cv. Performer. Polimag® S applied at a 50% and 100% rate significantly increased the total yield of Welsh onion leaves. However, fertilization rate should not be increased above the 50% level since Welsh onion bulb yields were comparable at 50% and 100% rates of Polimag® S. During three consecutive growing seasons, Welsh onion plants cv. Long White Ishikura were characterized by the highest winter hardiness.