Location: Plant Genetic Resources ResearchTitle: Geneva apple rootstock performance in New York state and progress in commercialization Author
Submitted to: Compact Fruit Tree
Publication Type: Trade Journal
Publication Acceptance Date: 4/15/2011
Publication Date: 7/15/2011
Citation: Robinson, T., Fazio, G., Hoying, S., Miranda, M., Iungerman, K. 2011. Geneva apple rootstock performance in New York state and progress in commercialization. Compact Fruit Tree. 44:22-28. Interpretive Summary:
Technical Abstract: A number of new apple rootstocks from the Cornell/USDA apple rootstock breeding project, located at Geneva NY which are resistant to the bacterial disease fire blight (Erwinia amylovora) are rapidly becoming available. Some named rootstock genotypes from this program have previously been tested in second and third level trials within NY state, Washington state, national trials in the US, Canada and Mexico, France, Poland, Switzerland and New Zealand with ‘McIntosh’, ‘Gala’, ‘Golden Delicious’, ‘Fuji’, ‘Jonagold’ ‘Liberty’ and ‘Empire’. In this paper, we report on the field performance of elite Geneva rootstocks from 4 replicated trials in New York State with ‘Golden Delicious’ as the scion cultivar or the weak-growing scion cultivar ‘Honeycrisp’. Our data shows that over a broad range of climates, 2 Geneva stocks, G.11 and G.41 are very similar in dwarfing to M.9 and offer substantial benefits to US growers. The ‘Golden Delicious’ trial planted in 2001 again showed that G.11 is slightly more dwarfing than G.41 and that both stocks are very yield efficient. Due to the outstanding performance of CG.4214, CG.6969 and CG.5890 in this and later trials these three stocks were released in 2010. The duplicate rootstock trials planted at Geneva (Western, NY) and Peru (Northern, NY) revealed a significant difference in performance of each rootstock genotype between Geneva and Peru. The results of fruit size indicate that G.41 and G.11 produce similar fruit size to M.9 even when fruit size is calculated independent of crop load. However, our results show that G.935 produces slightly smaller fruit size than M.9 with fruit size similar to M.26. Our results also show that four Geneva rootstocks (G.65, G.16, CG.3007 and 4013) produce significantly smaller fruit size than M.9. Our data have shown that over a broad range of climates and soils, that 3 dwarfing Geneva stocks, G.11, G.41 and G.214 have performed better than M.9 while G.935, which is similar in vigor to M.26, has also performed better than M.9. Their significant fire blight resistance is an advantage over M.9 and offers substantial benefits to North American apple growers. Other studies have shown that G.41 and G.214 also have significant resistance to replant disease. We have also identified several new elite rootstocks (G.969 and G.890), which may have potential for moderate density processing where a free standing tree is required. These stocks are semi-dwarfing fire blight resistant stocks with high yield efficiency and good precocity.