The influence of sulfur fertilization on glucosinolates in broccoli (Brassica oleracea var. italica L.)

Glukozinolati su složena skupina spojeva tioglukozidne strukture svojstvena biljkama porodice Brassicae u koju ubrajamo i brokulu. Razlika u sadržaju glukozinolata u povrću ovisi o genotipu, klimatskim uvjetima, sezoni uzgoja te agronomskim uvjetima (sastav tla i gnojidba). U radu je ispitan utjecaj različite razine gnojidbe sumporom (0, 25, 50 i 90 kg S ha-1) u tlu na udio ukupnih i pojedinačnih glukozinolata u dvije sorte brokule Parthenon i Ironman. Analizirane sorte brokule različito se ponašaju pri različitom režimu gnojidbe. Kod sorte Ironman statistički značajno povećanje ukupnih glukozinolata utvrđeno je kod razine sumpora od 90 kg S ha-1, dok je pri razinama sumpora u tlu od 25 i 50 kg S ha-1 uočeno statistički značajno smanjenje. Kod sorte Parthenon povećani udio glukozinolata uočen je pri razini gnojidbe od 25 i 50 kg S ha-1. Rezultati ovog rada ukazuju da optimalna količina gnojidbe sa sumporom ovisi o sorti te je potrebno provesti istraživanja režima gnojiva za svaku pojedinu sortu s ciljem dobivanja optimalnih prinosa i udjela glukozinolata.Glucosinolates are a complex group of compounds of thioglucosyde structure that are typical for Brassicae family plants, which include broccoli. The difference in the content of glucosinolates in vegetables depends on the genotype, climate conditions, season of breeding, and agronomic conditions (soil composition and fertilization). This paper researches the impact of different levels of sulfur fertilization (0, 25, 50 and 90 kg S ha-1) in the soil on the proportion of total and individual glucosinolates in two broccoli cultivars Parthenon and Ironman.The analyzed broccoli cultivars behave differently at different fertilization regimes. At the Ironman cultivar a statistically significant increase in total glucosinolates was found at sulfur levels of 90 kg S ha-1, while at levels of sulfur in the soil of 25 and 50 kg S ha-1 a statistically significant reduction in total glucosinolates was noted. At the Parthenon cultivar an increased proportion of glucosinolates was found at the level of fertilization of 25 and 50 kg S ha-1. The results of this paper suggest that the optimal quantity of sulfur fertilizing depends an the cultivar, and that research in fertilizer regime needs to be done for each cultivar in order to obtain optimum yield and glucosinolates share