The effect of crown shape on vegetative potential of peach cultivars

Abstract

The crown shape of peach is determined by distribution of scaffold branches The crown shape affects the interception and distribution of light in crown the use of machinery and possibility of performing most operations on fruits from the ground, without the use of platforms and ladders. The following four crown shapes of peach have been evaluated in the paper: Veronese vase Veronese spindle, pal spindle and open vase. The studied shapes were formed on trees of three peach types: Redhaven, Cresthaven and Summerset. The planting distance was 5m between the rows and 4 m in the row for all cultivars and crown shapes. The changes in parameters of vegetative potential as affected by different crown shapes were assessed over 1999-2000. The annual growth increment of the trunk cross-sectional area and the total length of scaffold branches, irrespective of the cultivars, was the greatest in trees with open vase and the lowest in trees trained to pal spindle shape. The greatest growth increment of the cross-sectional area and the total length of scaffold branches were recorded in cv Redhaven. As opposed to shapes with central leader (Veronese spindle and pal spindle) open vase has a problem with retaining vegetative activity at the crown base. Veronese vase is distinguished by evenly distributed fruiting branches in all crown parts. Cv Redhaven is well garnished with fruiting branches in all crown parts, whereas cv Summerset has an extremely low number of mixed branches in the lower crown half. In open training systems without the central leader (open vase and Veronese vase) due to massive emergence of succory a greater wood removal occurs by winter pruning as compared to the central leader.

Četiri oblika krane: veronska vaza, veronsko vreteno, pal Spindel i kotlasta kruna obrazovani su na stablima tri sorte breskve: Redheven, Krestheven i Samerset. Razmak sadnje je 5x4 m za sve sorte i oblike krune (500 st/ha). U dvogodišnjem periodu ispitivana je promena vegetativnog potencijala pod dejstvom oblika krune. Godišnji prirast površine poprečnog preseka debla i ukupna dužina skeletnih grana, nezavisno od sorte, najveći je kod stabala sa kotlastom krunom, a najmanji kod stabala sa oblikom pal Spindel. Sorta Redheven imala je najveći prirast površine poprečnog preseka debla i ukupnu dužinu skeletnih grana. Kotlasta kruna, za razliku od oblika sa centralnom vodicom (veronsko vreteno i pal Spindel) ima problem zadržavanja vegetativnog poteneijala u osnovi krune. Veronska vaza odlikuje se ravnomernom zatupljenošću rodnih grančica u svim delovima krune. Sorta Redheven je dobro obezbeđena rodnim grančicama u svim delovima krune, a sorta Samerset u donjoj polovini krune ima veoma malo mešovitih rodnih grančica. Otvoreni uzgojni oblici bez centralne vodice (kotlasta kruna i veronska vaza) zbog masovnije pojave vodopija imaju veće odbacivanje drveta zimskom rezidbom od oblika sa centralnom vođicom.