year old 'Germersdorfi FL 45' sweet cherry trees. The following treatments were applied: 6-BA 0.06% treat- ment 3 times, and 6-BA 0.06% 3 times with two addi-.
Gartenbauwissenschaft, 64 (2). S. 75–78, 1999, ISSN 0016–478X. © Verlag Eugen Ulmer GmbH & Co., Stuttgart
Improved Feathering on One-Year-Old ‘Germersdorfi FL 45’ Sweet Cherry Trees in the Nursery Förderung der Bildung vorzeitiger Triebe bei einjährigen ‘Germersdorfi FL 45’-Süßkirschen in der Baumschule K. Hrotkó, L. Magyar, and B. Öri (Faculty of Horticulture Department of Fruit Growing, UHF Budapest, Hungary)
Summary 6-BA (6-benzyladenine, in water soluble formulation, Paturyl 10 WSC) and GA4+7 were separately applied in a nursery trial to stimulate the lateral branching of oneyear old ‘Germersdorfi FL 45’ sweet cherry trees. The following treatments were applied: 6-BA 0.06% treatment 3 times, and 6-BA 0.06% 3 times with two additional GA4+7 0.04% applications. Growth, as well as the number and lenght of laterals were measured at the end of the growing season. 6-Benzyladenine treatments significantly increased the total number of laterals in comparison to the untreated control. Additional GA4+7 treatments did not affect the total number of laterals, but increased the lenght of lateral shoots. Zusammenfassung Einjährige Süßkirschbäume mit vorzeitigen Trieben werden für die Pflanzung von Anlagen mit Spindelbäumen bevorzugt. Mit dem Ziel der Förderung der vorzeitigen Triebe an „Germersdorfi FL 45“-Süßkirschbäumen wurden Versuche mit 6-BA (6-benzyladenine, in wasserlöslicher Formulierung, Paturyl 10 WSC) und Gibberellinsäure GA4+7 durchgeführt. Die Bioregulatoren wurden in den folgenden Behandlungen getrennt angewendet: 6-BA 0.06% dreimal gespritzt und 6-BA 0.06% dreimal und zweimal zusätzlich GA4+7 0.4% gespritzt. Die Anzahl der vorzeitigen Triebe wurde gezählt und Trieblänge, Baumhöhe und Stammdurchmesser vor dem Roden gemessen. Die 6-BA-Behandlungen förderten deutlich die Bildung der vorzeitigen Triebe, die Anzahl der Triebe war signifikant größer im Vergleich zu unbehandelten Kontrollbäumen. In der kombinierten Behandlung, in der nach der zweiten Spritzung mit 6-BA die Behandlung durch GA4+7 ergänzt wurde, ist die Anzahl der vorzeitigen Triebe durch GA4+7 nicht beeinflußt, aber im Durchschnitt waren die Triebe bedeutend länger. Introduction Growers require well-branched maiden trees for planting intensive orchards as feathered trees with wide angled secondary laterals provide earlier and higher yields. Advanced training systems for sweet cherry trees (e.g. the Cherry-spindle developed by ZAHN 1990, 1996) are based on such planting material, thus Gartenbauwissenschaft 2/99
improving the lateral shoot formation in nurseries is going to be more and more important. Formation of lateral shoots differs among cherry cultivars and is determined by the apical dominance of the cultivar. Cherry cultivars with weak apical dominance (such as ‘Van’) generally form lateral shoots easily in the nursery, while others with strong apical dominance (e.g. ‘Bigarreau Burlat’, ‘Germersdorfi óriás’) form few laterals even with special treatments. Pinching the terminal shoot on cultivars of strong apical dominance results in few laterals and these secondary shoots are narrow angled. Certain plant bioregulators are able to break the dormant state of summer buds. 6-Benzyladenine (BA) is one of these bioregulators used as a branching agent in nurseries and in young orchards (BASAK and SOCZEK 1986, BASAK et al. 1993, 1994, CODY et al. 1985, JACYNA et al. 1989, LOONEY 1996, MILLER 1983, POPENOE and BARRITT 1988, WERTHEIM and ESTABROOKS, 1994, HROTKÓ et al. 1996 a, b, 1997). MILLER (1983) and JACYNA et al. (1989) applied Promalin (6-BA + GA4+7) to young sweet cherry trees in orchard conditions, while CODY et al. (1985) achieved good feathering on 1-year-old nursery trees with 500–2000 ppm Promalin treatments. However, the results of POPENOE and BARRITT (1988) indicate that the separated application of the two plant bioregulators (first 6-BA and later GA4+7) can be more succesful on apple trees. Feathering of apple nursery stock by repeated application of Paturyl 10 WSC containing 10% 6-BA was succesfully improved (HROTKÓ et al. 1996, 1997). As most of the available reports, concerning the improved formation of lateral shoots by Paturyl 10 WSC (10% 6-BA), were in connection with apple cultivars, and there were no appropriate data available for sweet cherry, experiments were started in 1993 on the effect of BA applications on one-year-old cherry trees. Our main aim was to improve the lateral shoot formation of hardly branching cultivars and we also wished to develop a practical method for nurserymen. First we used 0.02% of 6-benzyladenine (6-BA) which proved to be low. Although the results of the first trial in 1993 did not show significant difference between control trees and the ones treated with 6-BA regarding the longer (>10cm) laterals, there was a clear difference between them concerning the number of short (0–10 cm) lateral shoots (Hrotkó et al. 1995). Due to the importance of this topic we decided to continue the
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Hrotkó K. et al.: Vorzeitige Triebbildung bei Süßkirschen
Table 1. Effect of treatments on lateral shoot formation of ‘Germersdorfi FL 45’ cherry nursery trees. Einfluß der Behandlungen auf die Bildung von vorzeitigen Trieben bei „Germersdorfi FL 45“-Süßkirschen in der Baumschule. Treatment
1. Untreated control 2. 6-BA 0.06% x3 3. 6-BA 0.06% x3 + GA4+7 x2
Total number Number of of laterals short laterals per tree (10cm) per tree 1.14 a 1.98 a 3.59 b
1. Untreated control 2. 6-BA 0.06% x3 3. 6-BA 0.06% x3 + GA4–7 x2
Average length of all laterals (cm) 17.55 ab 11.14 a 24.56 b
Average length of short (10 cm) laterals (cm) 17.55 a 11.61 a 27.89 b
Note: Means followed by different letters differ significantly at P=0.05 compared by t-test
Note: Means followed by different letters differ significantly at P=0.05 compared by t-test
Table 2. Effect of treatments on growth of laterals of ‘Germersdorfi FL 45’ cherry nursery trees. Einfluß der Behandlungen auf das Wachstum der vorzeitigen Triebe der „Germersdorfi FL 45“-Süßkirsche.
3. 0.06% 6-BA sprayed 3 times, on June 19., 26., and July 3. + GA4+7 0,04% sprayed 2 times, on June 26. and July 3.
Treatment
1. Untreated control 2. 6-BA 0.06% x3 3. 6-BA 0.06% x3 + GA4+7 x2
Total length of laterals (cm/tree)
Total length of long laterals (>10 cm) (cm/tree)
Total length of short laterals (
