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Reakcija tla jedan je od najznačajnijih čimbenika koji utječu na topljivost i pristupačnost hraniva biljci. Provedeno istraživanje imalo je za cilj utvrditi u kojoj mjeri reakcija tla utječe na K/(Ca+Mg) u lišću vinove loze (Vitis vinifera L.), sorta Sauvignon bijeli (podloga SO4) na području Plešivičkog vinogorja (sjeverozapadna Hrvatska). Istraživanja su provedena u razdoblju 2009.-2011. godine na području Plešivičkog vinogorja na tlima jako kisele do kisele reakcije (lokacija Rečki gaj: pHKCl 3,54-5,01) i na tlu alkalne reakcije (lokacija Borička: pHKCl 7,01-7,41). Uzorci lišća za praćenje dinamike kalija, kalcija i magnezija te njihovog međusobnog odnosa uzimani su tri puta tijekom vegetacije (fenofaza cvatnja, šara i berba) u sve tri godine istraživanja. U sve tri godine istraživanja značajan utjecaj na K/(Ca+Mg) odnos u lišću vinove loze imala je reakcija tla te fenofaza rasta i razvoja. Širi odnos K/(Ca+Mg) u lišću vinove loze, u svim godinama istraživanja utvrđen je na tlu kisele reakcije (0,29, 0,58, 0,59) u odnosu na alkalno tlo (0,20, 0,40, 0,38). Najširi kationski odnos utvrđen je u fenofazi cvatnje (0,31-1,02), a najuži u fenofazi berbe (0,15- 0,34) u svim godinama istraživanja neovisno o reakciji tla., Soil reaction is one of the most important factors that affects solubility and availability of nutrients to plants. The aim of the present research was to determine the effect of soil reaction on the K/(Ca+Mg) ratio in the grapevine (Vitis vinifera L.) leaves of the cultivar Sauvignon Blanc (rootstock SO4) in the Plešivica wine growing region (Northwest Croatia). The research was conducted in the period 2009-2011 in the Plešivica wine growing region on very acid to acid soil (location Rečki gaj: pHKCl 3,54-5,01) and on alkaline soil (location Borička: pHKCl 7,01-7,41). Leaves samples for monitoring the dynamics of potassium, calcium and magnesium and their mutual relationship, have been taken each year three times during vegetation (in the following phenological stages: flowering, veraison and harvest). A significant effect on the K/(Ca+Mg) ratio in the grapevine leaves was determined in respect to soil reaction and the phenological stage in all three years of research. The wider ratio of K/(Ca+Mg) in the leaves in all three years was determined on the acidic soil (0.29, 0.58, 0.59) in respect to alkaline soil (0.20, 0.40, 0.38). The widest cation ratio was determined in the stage of flowering (0.31-1.02) while the most limited ratio was determined in the stage of harvest (0.15-0.34) in all research years regardless soil reaction.

Višnja maraska (Prunus cerasus var. Marasca) jedna je od najznačajnijih voćnih vrsta Dalmacije, još od 16 stoljeća od kada datira i proizvodnja poznatog likera Maraschino. Areal rasprostranjenosti maraske ograničen je uglavnom na dio područja sjeverne i srednje Dalmacije od Zadra do Makarske, gdje klima i tlo omogućuju postizanje visoke kvalitete ploda i specifične arome. Provedena istraživanja imala su za cilj utvrditi fizikalno-kemijske parametre (ukupnu suhu tvar, vodotopivu suhu tvar, ukupnu kiselost, udio mesa i koštica), ukupne polifenole i antocijane te antioksidativni kapacitet u plodu višnje maraske u dvije klimatski različite godine (2012 i 2013), na plantaži „Vlačine“ (Zadar). Značajno veće vrijednosti ukupne suhe tvari, ukupnih polifenola i antioksidativnog kapaciteta utvrđene su u 2012., dok su veće vrijednosti ukupnih kiselina i antocijana utvrđene u 2013. godini, što se može dovesti u svezu s većim količinama oborina i nižim temperaturama u fazi zriobe plodova u 2013. godini. Značajno niže vrijednosti antocijana u 2012. u odnosu na 2013. godinu mogu se objasniti ekstremno visokim temperaturama u fazi zriobe u 2012. godini, koje prema literaturnim navodima mogu smanjiti količinu antocijana i do 90 %. U obje godine istraživanja utvrđena je pozitivna korelacija između ukupnih polifenola i antocijana, što potvrđuje činjenicu da su antocijani dominantni polifenolni spojevi u plodu maraske., Sour cherry cv. Marasca (Prunus cerasus cv. Marasca) is one of the most important fruit species of Dalmatia ever since 16th century. Production of the famous liqueur Maraschino began at that time. The areal of the prevalence of marasca is limited mainly to the part of the north and central Dalmatia, from Zadar to Makarska, where the climate and soil allow the achievement of high fruit quality and specific aroma. The investigations were aimed to determine the physico-chemical parameters (total dry matter, water soluble dry matter, total acids and percentage of flesh and endocarp in fruit) and biologically active compounds (total polyphenols, anthocyanins and antioxidant capacity) of the marasca cherry fruit in the climatic two different years (2012 and 2013) on the „Vlačine” (Zadar) plantation. Significantly higher values of total dry matter, total polyphenols and antioxidant capacity were determined in 2012, while in 2013 higher values of total acids and anthocyanins were determined. That can be brought into connection with significantly higher amount of precipitation and lower temperatures in the phase of fruit ripening in 2013. In both years of investigation a positive correlation between the total polyphenols and anthocyanins was determine which confirms the fact that the anthocyanins are dominant polyphenolic compounds in the marasca fruit. Significantly lower values of anthocyanins in 2012. compared to 2013. can be explained by the extremely high temperatures in the stage of maturity in 2012. which, according to the literature, can reduce the amount of anthocyanins up to 90%

Cilj ovog istraživanja bio je utvrditi utjecaj folijarnih gnojiva na sadržaj suhe tvari i koncentraciju mineralnih elemenata u gomolju krumpira. Pokusi s tri tretmana folijarne gnojidbe (Epso Salt, Drin i Megagreen) te kontrolom (bez primjene folijarnih gnojiva) provedeni su u tri ponavljanja po shemi slučajno-bloknog rasporeda u plasteniku Agronomskog fakulteta tijekom vegetacijskih sezona 2006. i 2007. Folijarna gnojidba provedena je pet puta tijekom vegetacijskih sezona, u intervalima od deset dana, u razdoblju od faze inicijacije gomolja do faze fiziološke zrelosti. Sadržaj suhe tvari značajno se razlikovao pod utjecajem folijarnih tretmana u pojedinim vegetacijskim sezonama. U vegetacijskoj sezoni 2007. značajno veći sadržaj suhe tvari u gomolju ostvaren je kod tretmana Megagreen u odnosu na kontrolu. U 2006. sadržaj suhe tvari u gomolju krumpira nije bio pod utjecajem folijarnih tretmana. Najveća koncentracija dušika u gomolju utvrđena je kod tretmana Epso Salt u odnosu na kontrolu. Utjecaj folijarnih tretmana na koncentraciju fosfora, kalija i magnezija u gomolju nije bio značajan. Koncentracija kalcija u gomolju značajno je varirala pod utjecajem folijarnih tretmana u vegetacijskim sezonama. U 2006. najveću koncentraciju kalcija u gomolju ostvarila je kontrola, dok je u 2007. najveća koncentracija kalcija u gomolju utvrđena kod tretmana Epso Salt., The aim of this study was to determine the effect of foliar fertilizers on dry matter content and concentration of mineral elements in potato tubers. The experiments with three foliar fertilization treatments (Epso Salt, Drin and Megagreen) and control (without application of foliar fertilizers) were carried out in three replications and arranged in a randomized complete block design. The experiments were conducted in the greenhouse of Faculty of Agriculture during the vegetation seasons 2006 and 2007. Foliar fertilization was carried out five times during the vegetation seasons in ten-day intervals, in the period from the beginning of tuber formation to the stage of full tuberization. Dry matter content differed significantly under the influence of foliar treatments in different vegetation seasons. Significantly higher dry matter content in potato tubers was achieved in 2007 by Megagreen treatment compared to control. In 2006, dry matter content in potato tubers was not affected by foliar treatments. Significantly the highest concentration of nitrogen in tubers was found in Epso Salt treatment compared to control. The effect of foliar treatments on concentration of phosphorus, potassium and magnesium in tubers was not significant. The concentration of calcium in tubers significantly varied under the influence of foliar treatments in vegetation seasons. In 2006 the highest concentration of calcium in tubers achieved control, while in 2007 the highest concentration of calcium in tubers was determined in Epso Salt treatment.

Trogodišnje istraživanje utjecaja reakcije tla na količinu šećera i ukupnih kiselina u moštu sorte Sauvignon bijeli, na podlozi Berlandieri x Riparia (SO4), provedeno je na području Plešivičkog vinogorja, sjeverozapadna Hrvatska, u razdoblju 2007-2009 godine. Temeljem rezultata preliminarnih istraživanja fizikalnokemijskih svojstava i biljno hranidbenog kapaciteta tla za istraživanje su odabrane dvije lokacije: „Rečki gaj“ s jako kiselom do kiselom reakcijom tla (pHKCl 3,76-4,63) i „Borička“ s alkalnom reakcijom tla (pHKCl 7,24-7,35). Na svakoj lokaciji formirano je 9 pokusnih parcela u pravilnom kvadratnom rasporedu 3 x 3, a svaka od njih uključivala je 2 reda sa po 20 trsova (40 trsova po pokusnoj parceli). Kontrolni uzorci tla uzimani su svake godine na početku vegetacije sa svake parcele, dok su uzorci mošta analizirani svake godine nakon berbe. Rezultati kemijskih analiza prosječnih uzoraka tla, uzetih svake godine na početku vegetacije s pokusnih parcela na svakoj od lokacija, pokazali su da tijekom trajanja istraživanja nije bilo značajnih odstupanja u pH vrijednosti tla, kao ni koncentracijama fosfora, mangana, željeza i cinka u tlu. Također, značajna odstupanja nisu utvrđena ni u koncentracijama mobilnog aluminija u kiselim tlima, kao ni količinama ukupnih karbonata i fiziološki aktivnog vapna u alkalnom tlu. Rezultati analize mošta ukazuju na činjenicu da postoji pozitivna korelacija između reakcije tla i količine šećera te negativna korelacija između reakcije tla i količine ukupnih kiselina. Tijekom svih godina istraživanja veće količine šećera u moštu utvrđene su na karbonatnom u odnosu na kisela tla, dok je kod ukupnih kiselina trend bio suprotan, odnosno veće koncentracije kiselina utvrđene su na kiselim tlima u odnosu na alkalno tlo., Investigation of influence of soil reaction on must total acids and sugar content was conducted in Plešivica wine growing region, northwestern Croatia, during 2007–2009, on variety Sauvignon Blanc, on the Berlandieri x Riparia (SO4) rootstock. Based on the results of preliminary investigations of the physicochemical properties and plant nutrient capacity of the soil, two locations were selected for investigation: “Rečki gaj”, with very acid to acid soil reaction (pHKCl 3.76 to 4.63) and “Borička” with alkaline soil reaction (pHKCl 7.24 to 7.35). At each location, nine experimental plots in a regular square arrangement 3 x 3 were formed, each of the plots included 2 rows with 20 vines (40 vines per experimental plot). Control soil samples from each plot were taken each year early in the season, while must samples were analyzed each year after the harvest. Results of chemical analysis of the control soil samples showed that there were no significant differences in soil pH, phosphorus, manganese, iron and zinc concentrations as well as mobile aluminum in acidic soils and total carbonate and physiologically active lime in alkaline soil. The results of must analysis show that there is a positive correlation between soil reaction and must sugar content and a negative correlation between soil reaction and must total acids. During all the years of research, higher amounts of sugar in the must have been determined on alkaline compared to acidic soils, while for the total acids trend was the opposite, higher concentrations of acids were found in acidic soils compared to alkaline soil.