Influence of increased iron concentration on the quality of strawberry fruit

Abstract

Jagoda je značajno sezonsko voće, bogato nutrijentima i bioaktivnim tvarima zbog čega često slovi kao super voće. U pogledu agrotehničke zahtjevnosti spada u vrlo zahtjevne, intenzivne kulture te je jedna od najosjetljivijih voćnih vrsta kod koje gnojidba kao i kod ostalih poljoprivrednih kultura ima velik značaj. Značajan mikroelement u ishrani jagode je željezo. Jagoda je osjetljiva na njegov nedostatak pri čemu osjetljivost varira između sorata. Željezo je neophodno za sintezu proteina, redukciju sulfata i nitrata, transport elektrona te je konstituent citokroma, katalaze, feredoksina, kofaktor je približno 140 enzima, ima značajnu ulogu u osnovnim biološkim procesima poput fotosinteze i fiksacije dušika te je sastavni dio svih redoks sustava u biljci. Tri različita tretmana, Fe/Zn obavijeni alginatom, Fe/Zn obavijeni alginatom i kitozanom te folijarna primjena željeza (Fe-EDDHA) primijenjeni su na jagode sorte Clery i Joly s ciljem utvrđivanja utjecaja tih tretmana na urod te na različita svojstva plodova jagode. Pokus je postavljen 2019. godine u 4 repeticije po slučajnom blok rasporedu u mjestu Botinec. Tretmani nisu značajno pridonijeli povećanju količine topljive suhe tvari te su tek neznatno povećali urod i broj plodova. Tri različita tretmana imala su učinak na ukupne kiseline, tvrdoću te boju plodova pri čemu nije bilo ujednačenog djelovanja pojedinog tretmana na ta svojstva ovisno o berbi te sorti jagode. Tretman Fe/Zn koji su obavijeni alginatom je jedini imao značajan pozitivan utjecaj na količinu bioaktivnih tvari i antioksidacijsku aktivnost plodova kod sorte Joly.Strawberry is a significant seasonal fruit, rich in nutrients and bioactive substances, which is why it is often called a super fruit. In terms of agro-technical complexity, it is very demanding, intensive crop and is one of the most sensitive fruit species in which fertilization has great significance, like all other agricultural cultures. A significant trace element in strawberry fertilization is iron. Strawberry is sensitive to its deficiency whereby sensitivity varies between varieties. Iron is essential for protein synthesis, sulfate and nitrate reduction, electron transport, it is constituent of cytochrome, catalase, ferredoxin, it is cofactor of approximately 140 enzymes, plays a significant role in basic biological processes such as photosynthesis and nitrogen fixation, and is integral part of all plant redox systems. Three different treatments, Fe/Zn coated with alginate, Fe/Zn coated with alginate and chitosan, and foliar iron application /Fe-EDDHA) were applied to Clery and Joly strawberries to determine the effect of this on yield and on the different properties of strawberry fruits. The experiment was set in 2019. in 4 repetitions per random block schedule in Botinec. The treatments did not significantly increase the amount of total soluble solids, and only slightly increased the yield and number of fruits. Three different treatments had an effect on total acidity, firmness and color of the fruit, with no uniform effect of each treatment on these properties depending on the harvest and strawberry variety. Fe/Zn coated with alginate is the only treatment that had a significant positive effect on the amount of bioactive substances and antioxidant activity of fruits in the Joly variety