The impact of tehnological measures on the quality of corn salad (Valerianella locusta (L.) Betcke), rocket (Eruca sativa Mill.) and spinach (Spinacia oleracea L.)

V diplomskem delu so predstavljeni učinki, ki jih imajo tehnološki ukrepi pridelave na količino in kakovost pridelka treh listnatih zelenjadnic: motovilca (Valerianella locusta L. Betcke), rukvice (Eruca sativa Mill.) in špinače (Spinacia oleracea L.). Zasnova posevka, termin pridelave, tehnike gojenja, namakanje, gnojenje in dosvetljevanje v času pridelave pomembno vplivajo na kakovostne parametre pridelanih vrtnin. Jesenski termin pridelave vpliva na večjo vsebnost sladkorjev in fenolnih spojin v pridelku motovilca glede na pomladansko setev. Zasnova posevka pri rukvici vpliva predvsem na količino pridelka, ki je bil v pomladanskem času pridelave večji pri presajanju sadik, v poletnem času pa pri neposredni setvi. Pri špinači je vsebnost nitrata eden od pomembnih kakovostnih parametrov pridelka. Ugotovljeno je, da je pri jesenskem terminu pridelave vsebnost nitrata v pridelku večja, glede na spomladanski termin pridelave, kar je posledica predvsem slabših svetlobnih razmer v jesenskem času, glede na pomladansko obdobje. Pomemben vpliv na kakovost listnate zelenjave ima tudi izbor sistema pridelave. Ugotovljeno je, da lahko pri hidroponskem sistemu pridelave z uravnavanjem vsebnosti nitratnega iona v hranilni raztopini pomembno zmanjšamo vsebnost nitrata v pridelku listnate zelenjave. Z gnojenjem in namakanjem lahko prav tako pomembno vplivamo na prehransko kakovost listnate zelenjave. Pri divji rukvici je bilo ugotovljeno, da z namakanjem in gnojenjem z dušikom povečamo pridelek, poveča pa se tudi vsebnost nitrata. Zmanjšanje obroka vode ob namakanju in dodanega dušika pa je vplivalo na večjo vsebnost fenolnih spojin, karotenoidov in večji antioksidativni potencial. Na prehransko vsebnost listnate zelenjave vpliva tudi izbor gnojila. Špinača, gnojena z mineralnim in organskim gnojilom je vsebovala več vitamina C in manj nitrita in oksalata. Motovilec, gnojen z mineralnim in organskim gnojilom pa je vseboval manjšo vsebnost sladkorjev in več klorofila in kartenoidov glede na negnojene rastline. Prehranska kakovost listnate zelenjave se uravnava tudi z dosvetljevanjem rastlin v času rasti, s katerim povečamo fotosintetsko aktivnost rastlin in s tem izboljšamo pogoje za asimilacijo nitrata v organske molekule, kar je posledično povezano z manjšo vsebnostjo nitrata v pridelku.The diploma thesis will present the effects of technological production measures on the quantity and quality of the yield of three leafy vegetables: corn salad (Valerianella locusta L. Betcke), rocket (Eruca sativa Mill.) and spinach (Spinacia oleracea L.). Crop design, production date, cultivation techniques, irrigation, fertilization and additional lighting during production have a significant impact on the quality parameters of harvested vegetables. The autumn production period affects the higher content of sugars and phenolic compounds in the crop of cornsalad compared to spring sowing. The design mainly affects the amount of yield at rocket, which was higher in the spring during the seedling transplantation, and in the summer during direct sowing. In the case of spinach, the nitrate content is one of the most important quality parameters of the crop, as spinach is a distinctly nitriphilic plant. It was found that the nitrate content in the crop is higher during the autumn production period, compared to the spring production period, which is mainly due to poorer lighting conditions in the autumn, compared to the spring period. The choice of production system also has a significant impact on the quality of leafy vegetables. It has been found that in a hydroponic production system, the nitrate content in the leafy vegetable crop can be significantly reduced by regulating the nitrate ion content in the nutrient solution. Fertilization and irrigation can also have a significant impact on the nutritional quality of leafy vegetables. In wild rocket, it has been found that watering and fertilizing with nitrogen increases the yield, but also the nitrate content. The reduction in irrigation water intake and added nitrogen, however, resulted in higher content of phenolic compounds, carotenoids, and antioxidant potential. The nutritional content of leafy vegetables is also influenced by the choice of fertilizer. Spinach fertilized with mineral and organic fertilizers contained a higher content of vitamin C and a lower content of nitrite and oxalate. Cornsalad, fertilized with mineral and organic fertilizers, contained a lower content of sugars and a higher content of chlorophyll and carotenoids compared to non-fertilized plants. The nutritional quality of leafy vegetables is also regulated by supplemental lightening the plants during growth, which increases the photosynthetic activity of plants and thus better conditions for the assimilation of nitrate into organic molecules and consequently lower nitrate content in the crop