New apple rootstocks’ influence on mineral composition of leaves and fruit

New apple rootstocks’ influence on mineral composition of leaves and fruit

Summary

This project is looking at the leaf and fruit nutrient content of two apple cultivars, Buckeye Gala and Aztec Fuji, on four dwarfing rootstocks, G.935, G.41, G.11 and M.9 NAKB T-337. The trees were planted in 2014 and produced their first commercial crop in 2016. The study is being conducted in the orchards of Hollabaugh Brothers Inc. located in Biglerville, PA in the largest fruit producing region of Pennsylvania. Leaf samples and fruit peel samples were collected and analyzed by the Penn State University Agricultural Analytical Services Lab. Six replicated samples of both leaves and cortical peels were collected from each of the rootstocks. At the same time four replicated leaf samples consisting of leaves from current season’s growth were collected for plant sap analysis by Crop Health Labs. The study is being conducted for two years in 2016 and 2017. Bruce Hollabaugh is the grower-cooperator. He is the Production & Personnel Manager for the business. He is responsible for the horticultural operations in the orchard including supervising pruning, fertilizing, weed control and harvesting the study block.

Objectives/Performance Targets

• Collected replicated foliar analysis samples of Gala and Fuji on the four rootstocks in early August
• Collected fruit samples for storage and apple peel analysis for Gala in early August approximately 3 weeks before harvest
• Collected fruit samples for storage and apple peel analysis in late September approximately 3 weeks before harvest.
• Sap analysis samples for both cultivars were collected approximately 3 weeks before harvest
• Storage samples were evaluated for bitter pit after 2 months of storage
• Sap analysis has been completed and analyzed
• Leaf and peel samples have been submitted to the Penn State Ag. Analytical Services Laboratory for nutrient level determination.
• We received the results December 8 and will analyze later this month.

Accomplishments/Milestones

May 5, 2016 – Visited Bruce Hollabaugh to lay out locations of trees in the study and had extended discussion about the project

August 3 – 4 Traveled to Hollabaugh Orchard and collected leaf samples for foliar analysis for Gala and Fuji. Collected leaves for sap analysis for Gala ~ 3 weeks before harvest. Collected Gala fruit for peel nutrient analysis. Collected fruit for evaluation after 2 months of storage

August 5 Placed leaf samples into forced air dryer. Prepared peel samples and placed into dryer. Prepared and shipped leaves for sap analysis to NovaCrop

August 15 Sap analysis of Gala completed and results received

September 21 – 22 Traveled to Hollabaugh Orchard and collected leaf samples leaves for sap analysis for Fuji ~ 3 weeks before harvest. Collected Fuji fruit for peel nutrient analysis. Collected fruit for evaluation after 2 months of storage

September 23 Placed leaf samples into forced air dryer. Prepared peel samples and placed into dryer. Prepared and shipped leaves for sap analysis to NovaCrop.

October 3 Sap analysis of Fuji completed and results received

October 10 Evaluated Gala apples in storage for symptoms of bitter pit. None found.

November 8 Statistical analysis of Sap results for both Gala and Fuji completed.

November 18 Communicated with Bruce on pre-season fertilizer applications and season long calcium foliar sprays.

November 28 Evaluated Fuji apples in storage for symptoms of bitter pit. Some showed bitter pit. Data will be analyzed this winter.

Impacts and Contributions/Outcomes

Since only the sap analysis data has been analyzed and it is just a single season it is too early to draw any significant long term conclusions. Statistical analysis of the results of the sap analysis did show significant cultivar x rootstock interactions in 2016 season.

The following are comments from Bruce Hollabaugh on the 2016 growing season. Fuji — Besides sunburn and a bit of BMSB damage, fruit quality was excellent. The 935s seemed like they cracked worse than the other stocks. That was interesting to me because they had much more fruit on than the other trees. The ground is weaker (and drier this season) up where the 935s are — so perhaps the trees were drier/weaker as well. (Note that the planting has the same soil type throughout – Arendtsveille gravelly loam).

Gala — Quality was excellent however they were very small. Fruit size was inversely proportionate to the amount of fruit on the trees. The M9s set and carried the least fruit — and therefore had the nicest, largest fruit at harvest. The 935s were thinned “normally” for 3rd leaf gala trees and carried an appropriate crop load however the fruit was nearly unmarketable due to small size. Certainly a result of our drought.

Collaborators: