impact of nutrition on the quality and quantity of cauliflower florets

Abstract

Cauliflower (Brassica oleracea var botrytis) as a member of the family Brassicaceae belongs to worldwide popular vegetable with using in all kinds of cuisine. The aim of the work was to find out the effects of nutrition and fertilization (in dependence on the amount of nitrogen) on the yield of florets as well as on selected qualitative characteristics - vitamin C, nitrate and sulforaphane content. Analyses were done by the help of liquid chromatograph (HPLC) with UV detector for separation. The trial was led in Nitra, Slovakia, in 2014 - 2015. Cauliflower variety CHARLOT F1 was selected for testing. Four variants have been examined in the trial: control (without application of fertilizers), N₁₅₀S₈₀ (application of nitrogen and sulphur at the supply level N: S = 150:80 kg.ha^-1), N₂₀₀S₈₀ and N₂₅₀S₈₀. Application of nitrogen led to significant increasing of the yields of primary cauliflower florets in case of the dose 200 and 250 kg N.ha^-1 (increasing about 87% and 134% compared to control). Applied nitrogen nutrition caused significant nitrates increasing in monitored cauliflower florets in order of the variants: 1 (control) <2 (N = 150 kg.ha^-1) <3 (N = 200 kg.ha^-1) <4 (N = 250 kg.ha^-1), but the highest dosage of nitrates is still under the permissible standard according to Food codex of Slovak republic (700 mg.kg^-1 of FM). The influence of differentiated nutrition on sulforaphane content was statistically confirmed in case of the 4^th variant in comparison to control, where the decrease about 40% was noticed. Influence of nitrogen fertilizing according to used methodology on vitamin C (AA) content was not statistically confirmed. The nutrient concentration in the curds and stalks of cauliflower varied insignificantly with levels of nitrogen applied.