Quality of onion depending on forms of fertilizer

Abstract

On alluvial meadow soil was investigated after-effect of organic, mineral and organo-mineral fertilization on some of the indicators of quality onion. In standard production between 25890 and 27560 kg.ha-1 for fertilization variants and 19830 kg.ha-1 from not-fertilized plants, low yields from control variant with after-effect of organic fertilization compensatde with most large bulbs 1st and 2nd quality. Dry matter in leaves (11.53 and 13.38%) of green onions in variant with after-effect of organic and organic-mineral fertilization was almost equally higher than dry matter in the leaves of plants with mineral fertilization. In the bulbs dry matter content was greater than in the leaves and at fertilization variants was between 13.55 and 16.21% and high levels were measured in bulbs with organic fertilization. The highest content of total sugars in the leaves of onion (6%) was recorded in plants grown with after-effect of organic fertilization. The bulbs of fertilization variants were almost identical contents of two sugars approximately 9.0%. Measured contents of nitrate in leaves of onions were below the permissible limits. It was proven high positive correlation between the contents of mineral nitrogen in the soil and nitrate and between the contents of total nitrogen and nitrates in the leaves and bulbs of onion.