Inter-annual Trend of Fruit Yield and Quality of Apple Trees with Marubakaido Rootstock Trained with Flat Trellis System

• Published in: Horticultural Research (Japan) Vol. 17; no. 2; pp. 191 - 197
• Main Author: Ito, Daiyu
• Format: Journal Article
• Language: Japanese
• Published: THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 2018
• Subjects: flower bud; fruit weight; H-shaped training; high yielding in the first years; soluble solids content
• ISSN: 1347-2658; 1880-3571
• DOI: 10.2503/hrj.17.191

To develop a low-tree-height apple cultivation technique using a flat trellis system, large-sized nursery stocks of the apple cultivars ‘Fuji’, ‘Tsugaru’, and ‘Koukou’ with Marubakaido rootstock were planted under a 1.8- m- high flat trellis in 2004, at a density of 400 plants ha–1. They were then grown and trained following an H-shaped pattern for 9 years, with fruit yield and quality evaluated annually. It was found that apple trees under the flat trellis system were high yielding in the first years compared with those under the conventional open center training system, because the fruit yield of the three varieties exceeded local average productivity (22 t・ha–1) in the fifth or sixth years after planting, and two of them met local target productivity (35 t・ha–1) in the ninth year. However, the average yield of each variety from the seventh to ninth years was 71–81% of the target productivity, which was lower than that of the adult trees under the open center training system. The fruit weight and soluble solids content of each variety increased annually, and fruits grown under the trellis system became larger than those grown under the open center training system, with soluble solids contents greater than 13° or 14° at the end of the study. A high number of water sprouts, however, emerged on trees under the flat trellis system, which led to a lower number of flower buds, particularly on the lateral shoots near the main stem, despite pinching and summer pruning being conducted. The decreased number of flower buds further resulted in a reduced fruit yield in the following years, therefore, the cultivation system used in this study should be improved to reduce water sprout emergence.