THE INFLUENCE OF PHOSPHORUS FERTILIZER WITH CALCIUM ON THE YIELD AND FRUIT QUALITY OF THE APPLE (Malus domestica Borkh.) CULTIVAR \u27GALA\u27

Jablana (Malus domestica Borkh.) je na našem območju najbolj razširjena sadna vrsta, katere plodovi so že v zgodovini veljali za ene najbolj zanimivih, do danes pa je ta sadna vrsta postala glavna v Sloveniji. V zadnjih letih je skorajšnja prenasičenost trga povzročila željo in zahteve kupcev po najkakovostnejših plodovih 1. razreda. Z namenom doseganja čim boljše kakovosti plodov smo v sadovnjaku na Bizeljskem preizkusili in analizirali delovanje pripravka Phostrade Ca, ki vsebuje fosfor, dušik in kalcij. Poskus smo izvedli v devet let starem nasadu jablan sorte \u27Gala\u27, kjer smo pred obiranjem trikrat foliarno nanesli pripravek Phostrade Ca. Ob obiranju smo plodove z 20 poskusnih in 20 kontrolnih dreves razvrstili v 1. in 2. kakovostni razred. Plodovom smo izmerili dimenzije ploda, parametre osnovne in krovne barve, vsebnost topne suhe snovi, titracijskih kislin in trdoto mesa. Ugotovili smo, da je foliarno gnojilo Phostrade Ca vplivalo na večji pridelek na drevo (17,0 kg/drevo, kar je 2,5 kg/drevo več kot pri kontroli) in na površino (za 8 t/ha več kot pri kontroli), prav tako je bil pri obravnavanju Phostrade Ca večji delež plodov 1. kakovostnega razreda. Vsebnost topne suhe snovi in titracijskih kislin je bila večja pri obravnavanju Phostrade Ca, trdota mesa pa je bila manjša. Plodovi obravnavanja Phostrade Ca so bili obarvani bolj temno rdeče v primerjavi s kontrolnimi plodovi.Apple (Malus domestica Borkh.) is the most widespread fruit species in our area, whose fruits have been considered one of the most interesting throughout history, and until today this species become the most important in Slovenia. In recent years, the almost complete oversaturation of the market has led to the desire and demand of buyers for the highest quality fruit of the first class. In order to achieve the best possible fruit quality, we tested and analysed the performance of the foliar fertiliser Phostrade Ca, which contains phosphorus, nitrogen and calcium, in the orchard in Bizeljsko. The trial was conducted in a 9-year-old orchard with apple trees of the \u27Gala\u27 cultivar, where Phostrade Ca was applied as a foliar fertiliser three times before harvest. At harvest, fruit from 20 experimental and 20 control trees were classified into 1st and 2nd quality classes. We measured fruit dimensions, ground and cover colour parameters, soluble solids content, titratable acids, and flesh firmness. It was found that the foliar fertiliser Phostrade Ca resulted in a higher yield per tree (17.0 kg/tree, which is 2.5 kg/tree more than the control) and per hectare (8 t/ha more than the control), and that the percentage of fruit of the first quality class was higher when the trees were treated with Phostrade Ca. Soluble solids and titratable acid contents were higher and flesh firmness was lower when treated with Phostrade Ca. The fruits of the Phostrade Ca treatment were dark red in colour compared to the control fruits