Shelf-life and Marketing Window Extension in Sweet Cherries in NY

Shelf-life and Marketing Window Extension in Sweet Cherries in NY

Summary

Six sweet cherry growers participated in the study, and stored a total of 1,375 pounds of fruit in modified atmosphere packaging bags (MAPs) and corresponding un-bagged controls. The varieties tested, based on previous years’ promising results included Sam, Hudson, Emperor Francis, and Hardy Giant. Growers and the PL rated texture and flavor on cherries coming out of MAPs at 4, 5, and 6 weeks (if necessary), along with corresponding controls. Overall ratings were given based on these 2 main factors, and growers were asked if they would market the fruit. Results are still being analyzed, but overall, most of the varieties in the MAPs were rated by the growers as of acceptable quality at 4 weeks, with some extending to 5 and 6 weeks, with nearly all controls rated as unacceptable or fair even at 4 weeks. Stem color, loss, and hold were also rated and considered as additional key factors to marketability. Three of the six growers in this study indicated they would extend the season on sweet cherries by storing part of their crop in MAPs and marketing them at a later date. A presentation on the project, given by the PL, will take place at the Lake Ontario Fruit Program’s Winter Fruit Schools in Wallington and Albion, NY on January 18 & 19, 2011.

Objectives/Performance Targets

Six sweet cherry growers named as cooperators on this project ended up choosing 1-4 varieties that have shown promise with previous MAP testing or that have not been tested before. For five of the growers, each used their standard pre-harvest practices followed by their usual method of harvest, cooling (statically- overnight). Each variety was placed in the MAP liners and sealed, alongside un-bagged controls. CO2 and O2 concentrations inside the liners were all checked at 12-15 days. Evaluations were done at roughly 4 weeks after packing, and also at approximately 5 and 6 weeks if the quality was acceptable from previous evaluations. Evaluations were performed that consisted of a grower and project leader ratings on appearance, stem data, flavor, and texture, as outlined in the methods section and in the addendum. The remaining 3 growers did as above, except they compared static cooling with hydro-cooling, on 1 of their varieties.

Accomplishments/Milestones

Nearly all accomplishments/milestones outlined in the proposal were met to date with few exceptions. The MAP liners and fungicide/disinfecting chemicals were ordered/received in April and May. Initial grower consultations/farm visits were in late May or June. The proposal stated that 6 of the 8 sweet cherry growers who initially agreed to be cooperators would end up participating. This turned out exactly correct -2 of the 8 partners were not able to participate in the study. One grower could not participate because the two varieties we had lined up to test received heavy rain cracking prior to harvest and could not be harvested. Another grower could not participate due to a family emergency that rendered the farm short-handed. The proposal stated that each farm would choose 1-3 varieties to test that have shown promise with previous MAP testing or that have not been tested before. This was true, but one grower tried four varieties. Evaluations were to be done at 4 weeks, and also at approximately 5 and 6 weeks after packing if the quality was acceptable from previous observations. The 4, 5, and 6 week observations did not vary more than 3 days on either side, due to scheduling/logistics for the PL. The proposal stated the evaluations would be +/- 2 days. Harvest, sorting/grading, cooling, and packing occurred from late June though early July, depending on the varieties tested and the optimal harvest date based on local growing conditions. Harvest and sorting/grading was performed by grower personnel. Cooling and packing was performed by the PL in nearly all cases (1 variety on 1 farm was packed by a grower, under the PL’s direction). A technician from the Department of Food Science measured CO2 and O2 concentrations in the MAPs 12-15 days after the packing of cherries in liners. All atmospheres were within recommended levels. The PL, growers, technician, and key personnel (when growers were unavailable) performed assessments from late July though late August.

While all basic accomplishments/milestones were met, there were some interesting things learned. Budbreak, full bloom, and harvest dates were nearly record-early, and harvest ended up being 1-2 weeks ahead of normal. The growing season was characterized by timely rains, and development of near record degree-growing days due to the earliness of budbreak. However, there was no real period of extreme heat, drought, rainy, or severe weather. With a few exceptions, most tree fruit growers in Western NY agreed that 2010 was one of the best growing seasons on record. Untimely rains just prior to anticipated harvest did cause some significant rain cracking in a few cases. Fruit size and quality of sweet cherries at harvest were good to excellent. Fruit for this study were harvested at proper maturity, were free from brown rot, and properly cooled prior to harvest, with one exception, which is noted in the detailed data. Thus, it could be argued that this year represents a “best case scenario” for sweet cherry quality-wise, as they were packed into MAPs. Nearly all of the varieties tested compared closely in storage life, taste, texture, and stem color, hold, and loss across the different farms. There were a few exceptions. As predicted, sweet cherry quality and marketability were better in hydro-cooled fruit as compared to statically cooled fruit in most cases. Three varieties (19, Summit, and Honey) that were not previously tested were included in the study. 19 showed excellent promise, and storage up to 5 weeks. Summit had some temperature issues at harvest and packing that could have caused an unacceptable number of rots. Honey bruised too easily and lost too many stems, even though the flavor was still good.

• ‘Emperor Francis’, over 5 weeks after harvest. Green stems, and firm fruit with few blemishes.
• ‘Hudson’ 5 weeks after harvest. Note green stems and firm fruit.

Impacts and Contributions/Outcomes

Presentations of this research by the PL will be at a regional fruit meeting, the Lake Ontario Fruit Program’s Winter Fruit Schools in Wallington and Albion, NY on January 18 & 19, 2011, in which over 200 growers and other industry personnel usually attend this 2 day event. Plans to write a follow –up article in the New York Fruit Quality will disseminate the results to a larger audience. With positive growers’ experiences and feedback, along with other industry people (extension, postharvest and storage personnel) promoting the use of MAP, it is my hope that in a few years time, a significant percentage of growers state-wide will use MAP in a portion of their crop to increase availability of local produce, and to give consumers who want to “buy local”, an extended season to do so.

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