REZIDBA KROŠNJE NE SMANJUJE ALTERNATIVNU RODNOST JABUKE SORTE “ELSTAR”

Four alternative pruning strategies (A– 25 generative buds, B– 50 generative buds, C– 75 generative buds and D–100 generative buds per tree) for Elstar apple cultivar and their possible impact on improvement in productivity were examined in 1999 and 2000. Year was significant factor for all traits, except yield. The pruning strategy is significant for number of fruits per flower cluster and fruit mass. Interaction year and pruning strategy is significant only for number of fruits per flower cluster. Fruit mass was larger for pruning strategy A compared to the pruning strategies C and D. Yield efficiency and biennial bearing index were not affected by pruning strategies. The biennial bearing index variance was the lowest for the pruning strategy B. Trunk cross sectional area (TCSA) had negative impact on fruit mass in pruning strategy C. Correlation between the flower and crop density was positive in pruning strategy A. Flower density was in positive correlation with yield in pruning strategy C. The research shows that tree pruning alone will not result in adequate yield regulation in ‘Elstar’ apple.Istraživane su četiri različite varijante reza jabuke sorte Elstar u 1999. i 2000. godini te njihov mogući utjecaj na poboljšanje produktivnosti te sorte (rez A– opterećenje od 25 generativnih pupova /stablu, B– 50 generativnih pupova /stablu, C– 75 generativnih pupova /stablu i D–100 generativnih pupova /stablu). Godina je imala signifikantan utjecaj na sve tretmane, osim priroda. Načini rezidbe bili su signifikantni za broj plodova po gronji i za masu plodova. Interakcija godina*rez je signifikantna samo za broj plodova po gronji. Rez A dao je veću masu plodova u odnosu na rezove C i D. Efikasnost rodnosti i indeks alternacije nisu pokazali opravdane razlike izmeñu načina reza. Varijanca indeksa alternativnosti bila je najniža za rez B. Poprečna površina presjeka debla (TCSA) imala je negativan utjecaj na masu plodova kod reza C. Korelacija izmeñu broja gronja/TCSA i broja plodova /TCSA bila je pozitivna u rezu A. Broj gronja/TCSA u pozitivnoj je korelaciji s prirodom u rezu C. Zaključeno je da rezidba nadzemnog dijela ne može dati odgovarajuću regulaciju rodnosti jabuke sorte Elstar