THE PERFORMANCE OF 'JONAGOLD' AND 'EMPIRE' APPLE IN AN NC-140 ROOTSTOCK AND ORCHARD SYSTEMS TRIAL IN MICHIGAN

Ronald L. Perry
A rootstock and orchard systems trial was established in 1990 at the Clarksville Horticultural Experiment Station in Michigan, USA. The experiment was established in a split plot randomized design with 4 replications and multiple plant plots for each of three orchard training systems and rootstock treatment. Orchard system treatments were separated by trees of the scion variety 'Gala' and established and evaluated on 8 rootstocks. The orchard system treatments consisted of the scions 'Jonagold' and 'Empire' planted and trained to the central leader (CL) (1100 trees/ha) and tested on the rootstocks M.26 EMLA and Mark; the vertical axe (VA) (1502 trees/ha) and tested on the rootstocks M.26 EMLA, Mark, P.1, M.9 EMLA, and Ottawa 3; and the slender spindle (SS) (2461 trees/ha) and tested on the rootstocks Mark, Bud.9, and M.9 EMLA. M.9 EMLA was a common stock for only the VA and SS systems. The most productive system for both cultivars on M.9 EMLA rootstock has been the VA. In the CL system, 'Empire' has been most productive on M.26, while 'Jonagold' has been best on Mark. In the SS, Bud.9 has made both varieties most productive. M.26, M.9 EMLA and Mark are the most productive and efficient rootstocks for 'Empire' in the VA. 'Jonagold' has performed best on M.9 EMLA in the VA. The highest cumulative yields in this trial in the first 6 years are 'Empire' on Bud.9 in the SS at 180 tons/hectare. Trees on M.9 are well balanced and productive in the taller-canopied VA system. Trees on Mark are less vigorous but suit the shorter, more intensive spacing of the SS system. The VA is the most yield efficient system for both varieties. Even though the SS system possesses 950 more trees per hectare, cumulative yields of 'Jonagold' and 'Empire' are generally equivalent to or higher in the VA. The production of fruit on the 'Gala' guard trees in the first 6 seasons has been highest on Bud.9 and Mark. However, fruit on Mark have been small over the last 3 years as influenced by high yield. Trees on P.1 are too vigorous and those on M.27 are too weak.
Perry, Ronald L. (1997). THE PERFORMANCE OF 'JONAGOLD' AND 'EMPIRE' APPLE IN AN NC-140 ROOTSTOCK AND ORCHARD SYSTEMS TRIAL IN MICHIGAN. Acta Hortic. 451, 453-458
DOI: 10.17660/ActaHortic.1997.451.51
https://doi.org/10.17660/ActaHortic.1997.451.51

Acta Horticulturae