Application of zinc formulations with microalgae in blueberry cultivation

Američka borovnica (Vaccinium corymbosum L.) je višegodišnja voćna vrsta i sve popularnija namirnica zbog dobrih nutritivnih svojstava. Tijekom uzgoja potrebno je voditi računa o kvalitetnoj prihrani, zaštiti i agrotehničkim mjerama. Cilj uzgoja je maksimalno plodonošenje i dobra kvaliteta ploda s većom količinom sekundarnih biljnih metabolita. To se može postići primjenom novih tipova agroekoloških biopolimernih formulacija. U svrhu ovog diplomskog rada pripravljene su biopolimerne formulacije ispunjene mikroalgom i kemijskim reagensom; cinkovim sulfatom ZnSO4 x 7H2O te su folijarno primijenjene na borovnicu. Pokus je postavljen u nasadu borovnice tvrtke Fragaria d.o.o. u mjestu Velika Ludina, 2021. godine, prema metodi SBR u četiri ponavljanja. Tretirane su dvije sorte borovnica 'Duke' i 'Aurora'. Primijenjena su četiri tretmana: 1. kontrola – destilirana voda; 2. 10 %-tna otopina mikroalgi; 3. biopolimerne formulacije otopine cinkovog sulfata; 4. biopolimerne formulacije otopine mikroalgi. Dospjeli plodovi su podvrgnuti fizikalnim i kemijskim analizama (masa, pH vrijednost, topiva suha tvar, ukupne kiseline polifenoli, antocijani i flavonoidi). Kod plodova sorte 'Aurora' tretiranih biopolimernim formulacijama mikrokapsula s cinkom i biopolimernim formulacijama mikrokapsula s mikroalgama primijećene su povećane količine polifenola, flavonoida i antocijana (mikrokapsule s cinkom: polifenoli 299,20 mg/100 g, flavonoidi 218,75 mg/100 g, antocijani 88,15 mg/100 g i mikrokapsule s algama: polifenoli 315,91 mg/100 g, flavonoidi 225,75 mg/100 g, antocijani 93,52 mg/100 g).American blueberry (Vaccinium corymbosum L.) is a perennial fruit specie with good nutritional properties. During cultivation, it is necessary to take care of good quality fertilization, protection and agrotechnical measures. Main purpose of fruit production is to achieve maximum fruiting with high amount of secondary plant metabolites. It may be achieved by applying new types of agroecological biopolymer formulations. For this thesis were prepared biopolymer formulations filled with microalgae and a chemical reagent; zinc sulfate ZnSO4 x 7H2O. Biopolymer formulations were foliarly applied on blueberry plants. Experiment was conducted with blueberry (varieties Duke and Aurora) on field of Fragaria company near town Velika Ludina, in 2021. The experiment was set up according to the RCBD in four replications. Top-dressing was applied in four different variants: 1. control – distilled water; 2. 10% microalgae solution; 3. Biopolymer formulations of zinc sulfate solution; 4. biopolymer formulations solution of microalgae. Ripe fruits were studied of pomological and chemical properties (fruit weight, pH value, soluble solids and total acids content polyphenols, flavonoids and anthocyanins). Increased amounts of polyphenols, flavonoids and anthocyanins were observed in the fruits of the cultivar 'Aurora' treated with biopolymer formulations of microcapsules with zinc and biopolymer formulations of microcapsules with microalgae (microcapsules with zinc: polyphenols 299.20 mg/100 g, flavonoids 218.75 mg/100 g, anthocyanins 88.15 mg/100 g and microcapsules with algae: polyphenols 315.91 mg/100 g, flavonoids 225.75 mg/100 g, anthocyanins 93.52 mg/100 g)