Development of improved controlled-atmosphere storage techniques for gooseberries and red currants.

Development of improved controlled-atmosphere storage techniques for gooseberries and red currants.

Summary

The importance of controlled atmosphere (CA) storage for Ribes has become very apparent over the past two 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. So far the self-regulating plastic bags used for CA storage without gas have not proven successful for currants, but it is hoped that with some more careful pre-harvest control of fungus, they might work.

Objectives/Performance Targets

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.

Accomplishments/Milestones

1. Cost data has being 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. It is proposed to try growing a rep of red currants under plastic covers, and another rep with fungicide to see if the stored fruit will have a longer storage life in CA.

5. A report on CA storage of gooseberries was written.

Impacts and Contributions/Outcomes

1. With the data about identifying the green mature stage of gooseberries, we will be able to set up a better trial this year and avoid ethylene contamination which ripens fruit prematurely. We will also experiment with MCP to be able to hold the gooseberries for a longer period of time.

2. 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. FAID funding from the Grow New York program was not awarded for further research, but another source has been identified.

3. 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.
4. The post harvest handling techniques and CA storage techniques used successfully in Holland are now available in the US.