Varying Density with Constant Rectangularity: II. Effects on Apple Tree Yield, Fruit Size, and Fruit Color Development in Three Training Systems over Ten Years

Abstract

<jats:p>The effect of increasing planting density at constant rectangularity on the fruit yield, fruit size, and fruit color of apple [<jats:italic>Malus</jats:italic> ×<jats:italic>sylvestris</jats:italic> (L) var. <jats:italic>domestica</jats:italic> (Borkh.) Mansf.] in three training systems (slender spindle, tall spindle, and Geneva Y trellis) was assessed for 10 years. Five tree densities (from 1125 to 3226 trees/ha) and two cultivars (Royal Gala and Summerland McIntosh) were tested in a fully guarded split-split plot design. Density was the most influential factor. As tree density increased, per-tree yield decreased, but yield per unit area increased. The relation between cumulative yield per ha and tree density was linear at the outset of the trial, but soon became curvilinear, as incremental yield diminished with increasing tree density. The chief advantage of high density planting was a large increase in early fruit yield. In later years, reductions in cumulative yield efficiency, and in fruit color for `Summerland McIntosh', began to appear at the highest density. Training system had no influence on productivity for the first 5 years. During the second half of the trial, fruit yield per tree was greater for the Y trellis than for either spindle form at lower densities but not at higher densities. The slender and tall spindles were similar in nearly all aspects of performance, including yield. `Summerland McIntosh' yielded almost 40% less than `Royal Gala' and seemed more sensitive to the adverse effects of high tree density on fruit color.</jats:p>

Field Evaluation of 64 Apple Rootstocks for Orchard Performance and Fire Blight Resistance

“…Based on the relationship between canopy size and production potential, it was not unexpected that the most dwarfing rootstocks had the highest yield efficiency. These results support previous research in which smaller canopy volume coupled with higher tree density increased cumulative yield potential of an orchard site (Hampson et al, 2002(Hampson et al, , 2004a(Hampson et al, , 2004b. However, there were notable exceptions to the rule that dwarfing rootstocks are the most yield-efficient.…”

“…Dwarfing rootstocks significantly reduce tree size, facilitating an increase in planting density (Ferree et al, 1993;Hampson et al, 2002Hampson et al, , 2004aHampson et al, , 2004b. Contemporary high-density orchards have tree densities of 1200 to 7000 trees/ha.…”

“…Contemporary high-density orchards have tree densities of 1200 to 7000 trees/ha. Planting densities of this magnitude reduce yield on a per-tree basis but significantly increase the yield per unit area (Hampson et al, 2002(Hampson et al, , 2004a(Hampson et al, , 2004b as a result of enhanced annual and lifetime light interception and maximized light partitioning within the canopy (Ferree et al, 1993;Webster et al, 2000).…”

Light interception and partitioning between shoots in apple cultivars influenced by training

“…We studied trees in a low-density orchard (714 trees ha -1 ) to ensure optimal architectural development of each tree according to training system. However, as previously shown by Hampson et al (2004), there are complex interactions between tree density and training system in determining yield and individual fruit quality (especially fruit mass and color). Because there is a predominant effect of tree density on yield in the early years, whereas there is no significant effect of training system before the sixth year in the orchard, we did not conduct a yield analysis.…”

Tree Growth Yield and Fruit Quality of Different Apple Cultivars Trained as Super Spindle

“…However, low unit area yields and lack of cultivars with strong competitive power in foreign markets negatively affect the exports (Özkan et al, 2009). Apple production in Turkey has systems allowing better branch angles provide better light distribution and efficiency (Hampson et al, 2002a;Hampson et al, 2004). Indeed, several researchers emphasized that tall trees collected more light than short trees and that they were more efficient (Hampson et al, 2002b).…”