Effect of organic fertilization on the quality and yield of two radish cultivars in greenhouse organic cultivation

The greenhouse study was conducted in 2013-2014 at the Research Institute of Horticulture in Skierniewice. The area certified for organic production is 200 m² in separated block in Venlo type greenhouse. This greenhouse is designated for vegetable cultivation with crop rotation and cultivation according to the requirements for organic farming. The cultivars used in experiments were recommended for organic production in Poland. Radish was cultivated in early spring. The results of the two-year experiment showed that fertilizers had a significant impact on the yield of radish. The higher total and marketable yields of radish were obtained at the rate of 50 and 100 kg N ha^-1 of organic fertilizer Fertilan L. The highest dose 150 kg N ha^-1 did not bring the expected results because the yield was lower compared to the yield obtained at the lower doses. At the dose of 150 kg N ha^-1 the marketable yield was higher in relation to the yield obtained from control plots and fertilized with eco-compost 30 t ha^-1. It was also found that the means for yield were significantly different regardless of the type and dose of fertilizer compared to control. Each cultivar was also evaluated for its suitability for organic farming. The two-year study did not give a clear answer which one is better. 'Rudolf's roots were a little bit more susceptible to cracking than roots of 'Opolanka', but 'Opolanka' accumulated more nitrates in roots than 'Rudolf' at the same doses of fertilizers.