The influence of crop load and the amount of applied nitrogen on the parameters of ripeness and quality of ´Fuji´apples (Malus domestica B.)

Leta 2005 smo na posestvu Fakultete za kmetijstvo in biosistemske vede (UKC Pohorski dvor) ugotavljali vpliv interakcije gnojenja z različnimi odmerki dušika (60 kg N/ha, 75 kg N /ha, 90 kg N/ha) in različnimi oveski (nizek – 25 do 35 plodov, srednji – 55 do 65 plodov ter visok – 90 in več plodov na drevo) na parametre zrelosti in kakovosti pridelka jablan sorte´Fuji´. Devet obravnavanj je predstavljalo kombinacije različnih odmerkov dušika in oveskov. Rezultati raziskave vpliva posameznega dejavnika so pokazali signifikanten vpliv gnojenja na trdoto mesa plodov (TMP) ter oveska na vsebnost skupnih titracijskih kislin (TK) in topne suhe snovi (TSS). Večanje odmerka dušika se je odrazilo v zmanjšani trdoti mesa plodov, večanje oveska pa v zmanjšanju skupnih titracijskih kislin. Interakcija testiranih dejavnikov je pokazala izrazit vpliv na proučevane parametre zrelosti in kakovosti (TMP, TSS, TK, sočnost), razen na povprečno maso plodov. Kot najuspešnejša glede kakovosti pridelka se je pokazala kombinacija srednjega oveska z nizkim in srednjim odmerkom dušika.In 2005 at the Faculty of Agriculture and Life Sciences (UMC Pohorski dvor), the influence of interaction of fertilisation and the amount of applied nitrogen (60kg N/ha, 75kg N/ha, 90kg N/ha) and various crop loads (low - 25 to 35 fruits, medium - 55 to 65 fruits, high – 90 fruits per tree and more) on the parameters of ripeness and quality harvest of ´Fuji´ apples was determined. Nine treatments had presumed a combination of different doses of nitrogen and crop load. The results of studying the influence of a particular factor showed significant impact of fertilisation on the fruit flesh firmness (TMP) and crop load on the content of total titration acids (TK) and soluble dry substance (TSS). Increased amounts of nitrogen reflected in reduced fruit flesh firmness, however increase of crop load resulted with decrease of TK content. The interaction of tested factors revealed a distinct impact on the studied parameters of ripeness and quality (TMP, TSS, TK, juiciness), except on the fruit average mass. As the most successful in quality of harvest proved combination of medium crop load with low and medium amount of applied nitrogen