Performance of Semi-dwarf Apple Rootstocks in Two-dimensional Training Systems

Abstract

In 2014, an intensive multileader apple rootstock orchard trial was established in Trento province, Northern Italy, using dwarf (‘M.9-T337’) and semidwarf rootstocks (‘G.935’, ‘G.969’, and ‘M.116’) and ‘Gala’, ‘Golden Delicious’, and ‘Fuji’ as the scion cultivars. Trees were trained to Biaxis (‘M.9-T337’) and Triaxis systems (‘G.935’, ‘G.969’, and ‘M.116’) with a tree density of 3175 trees and 2116 trees per hectare, respectively, and with a uniform axis (leader) density of 6348/ha. Comparisons across all training systems by cultivar system showed that after 6 years (2019), trees of ‘Fuji’ and ‘Golden Delicious’ on ‘M.116’ were the largest trees followed by ‘G.969’, ‘G.935’, and ‘M.9-T337’. With ‘Gala’, trees on ‘G.969’ were of similar size as trees on ‘M.116’ and ‘G.935’. Trees of ‘Fuji’ on ‘G.935’ produced the highest yield followed by ‘G.969’, ‘M.116’, and ‘M.9-T337’. For ‘Gala’, trees on ‘M.116’ produced similarly as the ‘M.9-T337’, whereas with ‘Golden Delicious’, ‘G.969’ and ‘G.935’ had higher yields than ‘M.9-T337’. When comparing production per ground surface area (hectare) ‘G935’ had higher yield than ‘M.9-T337’ for all the cultivars in this trial. In addition, yield efficiency of ‘Fuji’ trees on ‘G.935’ was similar or even higher than trees on ‘M.9-T337’. Rootstock did not affect fruit size with ‘Fuji’. For Gala, fruit from ‘G.969’ were significantly larger than those on ‘M.116’. ‘Golden Delicious’ on ‘G.969’ produced smaller fruit compared with those on ‘G.935’. Fruit from trees on ‘M.9-T337’ had the lowest percentage of red color with ‘Fuji’ and the highest with ‘Gala’. When yield and quality data were combined to produce marketable yield, rootstock had a dramatic effect on the cumulative gross crop value per hectare based on local farm gate values for each scion cultivar.

Rootstock effects on leaf function and isotope composition in apple occurred on both scion grafted and ungrafted rootstocks under hydroponic conditions

“…However, M.9 was significantly smaller than the other rootstocks. These results aligned with other studies that reported similar patterns when grafted with ‘Goldspur Delicious’, ‘Redspur Delicious’ progeny ( Tworkoski and Miller, 2007 ), ‘Golden Delicious’, ‘Honeycrisp’, and ‘Fuji’ cultivars ( Dallabetta et al, 2021 ). Slow growth has been reported for M.9 under greenhouse conditions ( Valverdi et al., 2019 ).…”

The Influence of Rootstock on Fruit Ethylene, Respiration, Index of Absorbance Difference, Fruit Quality, and Production of ‘Aztec Fuji’ Apple under a Full-crop Condition

“…Nevertheless, in our study, 'Aztec Fuji' on G.935N and M.9T337 has similar yields. These contradictions could be because of different groups of rootstocks were used in our study and those of Dallabetta et al (2021) and Auvil et al (2011).…”

“…However, in our study, trees on only G.41N had higher yield than those on M.9Pajam2 (Table 1). Also, Dallabetta et al (2021) reported that 'Golden Delicious', 'Gala', and 'Fuji' apples on G.969 and G.935N had more yield than M.9T337. Nevertheless, in our study, 'Aztec Fuji' on G.935N and M.9T337 has similar yields.…”

Assessing Fruit Maturity and Quality of ‘Buckeye Gala’ Grown on a Diverse Panel of Apple (Malus domestica Borkh.) Rootstocks in Western Maryland

“…Several studies have reported that rootstock genotype can influence key aspects of fruit quality such as fruit size/weight, flesh firmness, soluble solids contents (SSC), color, starch contents, as well as fruit maturity by affecting respiration rate and IEC in different apple cultivars [6,15,[25][26][27][28][29][30][31][32]. For example, 'Pacific Gala' fruit on B.9 and G.30 rootstocks had the highest SSC and starch degradation patterns compared to other rootstocks [33], while 'Delicious' apples were reported to develop yellow background color earlier when grown on M.26 than on M.7 [29], and fruit from trees on M9.T337 had the lowest percentage of red color with 'Fuji' and the highest with 'Gala' when compared with other rootstocks [34]. Furthermore, the fruit of 'Starkspur Golden Delicious' was shown to have higher IEC when grafted on M.26 rootstock [26].…”

“…Rootstocks also play a crucial role in controlling tree size and yield. The size of the tree, and consequently tree vigor, is generally expressed as trunk cross-sectional area (TCA) [37,38], and there have been several studies reporting how TCA and yield can be influenced by rootstock genotype [4,10,11,[32][33][34]39,40]. The use of dwarfing rootstocks in apple orchards significantly reduces tree size and yield, allowing for an increased planting density, production efficiency, reduction in input costs and improved apple fruit quality [41,42].…”