The importance of controlled atmosphere (CA) storage for Ribes has become very apparent over the past few production seasons. Yields of the ribes berries has increased to the point where it can become difficult to move the fruit at the height of harvest, and storage would be a way to help maintain prices at a decent level for producers. In this project we have defined the green-mature stage for gooseberries and have found that if picked at the proper stage, they can be held for at least a few months. Currants must be kept free of fungus on their striggs, and have vibrant green, healthy striggs in order to be suitable for storage. The use of self-regulating plastic bags used for CA storage without gas have not proven successful for currantsgrown in the Northeast, but it is hoped that with some more careful pre-harvest control of fungus, they might have a possible role for CA storage. Traditional palletized CA storage has proven itself in Europe, and two currant growers in the Northeast will be using the system beginning with the 2006 season.
This project was completed through the cooperative efforts of Cornell Cooperative Extension, New York, DVL Plant in Holland, and cooperating growers in The Northeastern US including Nourse Farme, Golden Harvest Farms, and Mountain Range Farms.
Activities included research which followerd the growth of a gooseberry plant and its berries through ripening. This helped to understand the physiology of the berries for improved CA handling. The gooseberry can be held in a green mature stage for 3-6 months at 0 C, and can be ripened in elevated cold storage or room temperatures. Ethylene is produced during the ripening process.
The successful CA storage methods being used for red currants in Holland were documented and written up so that Northeast farmers can duplicate the procedure. The proper growing of the fruit which allows the quality necessary for extended CA storage was also described. Self regulating CA bags were not successful at this point due to decay and the fact that the respiration pattern of red currants doesn’t seem to allow the bags to function properly.
1. Collect cost data for running a traditional cold storage CA chamber for red currants and gooseberries.
2. Monitor the growth of gooseberry fruit from flower to harvest, recording weather data, plant growth data, and fruit growth data. Photograph gooseberries at the green mature stage. Collect existing similar data for red currants.
3. Place ‘ Achilles’ gooseberries of various ripeness in CA storage and monitor quality during the storage season.
4. Place US-grown red currants in cold storage in self-conditioning poly CA bags, and sample them during the storage season.
5. Develop needed publications describing how to best grow red currants to have the highest quality fruit that will last the longest in cold storage.
Comparative CA Trials, Red Currants
The self-regulating CA bag research was done in New York using Rovada red currants (the industry standard) from the commercial fields of Nourse Farms. The berries were a representative sample harvested when fully ripe and placed in cold storage at 0 C for immediate cooling. The strigs of the fruit were not bright green which was indidative of stress. There was no visible fungus.
Gas samples to monitor CO2, O2, and ethylene were taken outside and inside the bag, and no differences were found.Within two weeks, the samples began to decay, and by five weeks had to be removed and destroyed.
Cooperators in Holland chose not to participate with the work on bags, but did do their traditional palletized storage. Berries were placed in CA storage in August, and held through April. A 5-10 % loss due to decay was noted.
Green Mature Testing
Gooseberries (Achilles) were selected randomly by our Dutch counterpart and placed into CA storage. I had intended to have all green-mature fruit in this trial, but the Dutch researcher disagreed. The mixed fruit was placed into CA storage and removed and photographed during 3 months. Pictures and a full report describing fruit quality is available.
Gooseberry Fruit Development
Instruments to measure environmental conditions and corresponding growth of gooseberry plants and fruits were run for one season. Data was collected, graphed, and analyzed in a written report.
1. Cost data has been collected during the two seasons of production for both red currants and gooseberries. Initial data has been collected.
2. One complete season’s growth data for ‘Achilles’ gooseberry has been collected. Weather data was monitored, and plant growth and condition were monitored, along with fruit growth. This data is available on request in a separate report. The data is available for red currants from previous research.
3. ‘Achilles ‘ gooseberries were harvested at various stages of ripeness during the harvest season. Berries were placed at 1C and held in CA storage through November 2003. The berries were evaluated monthly by photos, and taste test. The Dutch producers complained that the green-mature fruit did not ripen to their standards. I believe that they did not ripen the fruit properly, and we re-evaluated their conclusions in the 2004 run. Green-mature gooseberries stored at refrigerator temperature held for two months with a minimum loss of quality, and ripened fully while in storage.
4. The US- grown currants stored in the self-conditioning bags had severe problems with decay. The experiment was ended in November because all the fruit had decayed to an unmarketable quality. There was a lot of rain this season which predisposed the fruit to decay. The respiration pattern for red currants doesn’t seem to be appropriate for using the bags.
5. A report on CA storage of gooseberries was written. Also a pamphlet on growing ribes for CA storage and the process of CA storage of ribes has been written.
1. With the data about identifying the green mature stage of gooseberries, we are able to avoid ethylene contamination which ripens fruit prematurely. We understand how they ripen in cold storage.
2. Growth and development data for the gooseberries is very complete, and is good basic knowledge to compare to similar data previously collected for red currants. The data is useful for post harvest physiologists in making further recommendations to improve CA storage techniques.
3. The results with the self-conditioning plastic bags has shown the importance of starting with clean fruit. We now know that fungicide treatment or plastic covers will be important cultural practices if we wish to hold red currants for CA storage. The red currants were more delicate than the gooseberries for CA storage in their disposition to pick up fungus infections.
4. The post harvest handling techniques and CA storage techniques used successfully in Holland are now available in the US. Articles and a pamphlet on CA storage of ribes has helped two Northeast farmers install pallet CA. This will help at least 20 local farmers receive more constant prices for their berries, and keep red currant and gooseberry production sustainable.
Education & Outreach Activities and Participation Summary
Pamphlet: Gooseberry Growth and Development and CA Storage Trials of Gooseberry
Pamphlet: CA Storage of Ribes
Magazine Article: New York Quarterly March, 2006, CA Storage of Ribes
Mid Atlantic Horticulture Meeting, Hershey, Feb. 2006
2005, 2006 Hudson Valley Fruit School
2004, 2004 Hudson Valley Ribes School
Onion School, (berry alternatives/ CA storage of Ribes) Middletown, NY
The impact of CA storage of Ribes in the Northeast is that it will help to avoid dips in prices of red currants by extending the season, and releasing the crop as needed. Small CA systems are practical for the small producer, and will run around $10,000 in cost.
Larger systems to hold 75,000 kilos will run about $300,000 to construct. This comes out to about $4.80 per kilo of capacity to construct. (The off season fruit sells for about $24 per kilo.)
The following farmers are installing palletized CA storage systems for the 2006 season:
41 River Road
South Deerfield, MA 01373
Stone Ridge Orchard
Stone Ridge, NY 12484
Each of these farmers plans to serve local currant and gooseberry growers in their area which could total around 20 people. This will help level out the local market.
Areas needing additional study
The research conducted in this project demonstrated that the use of reuseable, self-conditioning bags for CA storage of red currants is not practical. Disease problems , and having fruit in the proper condition for placement in the bags was not achieved with the current cultural techniques. If plastic tunnels or roof structures are employed, and fungicide sprays used regularly, it could be possible to improve the success of storage in bags. Further study of bags could be considered as cultural practices for currants improve over the next few years.
It has been suggested that MCP could be used to hold gooseberries in cold storage for extended periods. Partially ripe gooseberries should be tried first since green mature berries would likely never ripen if MCP is used. Study of the uses of MCP could be beneficial.
More study of the varieties of gooseberry finally chosen for commercial production would be good. More careful definition of green mature characteristics including brix and pressure tests. Expanding on current post harvest data would be helpful.