It’s a major new technology similar to the impact of cold storage and CA storage. That’s how Phil Schwallier described the storage treatment 1-methyl-cyclopropen (1-MCP) to an apple industry group gathered at a pre-harvest clinic in Alpine Township, Mich. in August.
“I think this (1-MCP) is a major breakthrough in new technology for the industry. It will extend the storage life and shelf life of apples and other commodities and deliver hard, crisp, tasty apples to the consumer,” Schwallier, Michigan State University (MSU) district horticultural agent, said.
1-MCP, marketed as SmartFresh from AgroFresh, is packaged as a powder. When water is added, the sugar dissolves and MCP is released as a gas into the surrounding environment. It must be released in an airtight room.
MCP was first labeled for use in the United States last year and was used in a modest number of CA rooms across the country. In Michigan, demonstrations were done last year mostly on the Ridge in West Michigan, at the MSU postharvest laboratory and the Clarksville Horticulture Experiment Station.
Schwallier said that MCP will work well on all varieties, although some varieties – including Jonathon and Jonagold – are more sensitive to 1-MCP because they get a better response and condition and overall quality are much improved. He said varieties such as McIntosh and Cortland tend to have a more erratic or variable response, so additional work needs to be done for those varieties.
“1-MCP is not as effective on McIntosh as other varieties. We’re not sure why,” Dr. Randy Beaudry said. Beaudry is an MSU professor of horticulture and one of the primary Midwest researchers on MCP. He said that the physiology of McIntosh may make a difference. He spoke to growers about the application of 1-MCP and ReTain on McIntosh and the influence of 1-MCP on aroma of apple fruit.
“ReTain has been useful in delaying harvest and reducing fruit drop in Michigan,” Beaudry said.
He said ReTain along with MCP shuts down ethylene – helping to keep the ethylene low in McIntosh and improve the efficacy of MCP.
Beaudry told growers that even after seven months storage in CA, apples still responded to 1-MCP, which indicates the need for ethylene action to complete the ripening process. He said fruit firmness was substantially higher with 1-MCP on every variety tested, and aroma production is reduced or delayed with the product.
When apples treated with 1-MCP are marketed too soon there may be flavor problems, Beaudry said.
“They may be relatively tasteless if consumed too soon after treatment due to the impact of 1-MCP on aroma compounds,” he said.
Fruit must have the right maturity when 1-MCP is applied for the fruit to be responsive, Beaudry said. The more ripe, the less responsive to 1-MCP, he said.
When using 1-MCP growers have to strike a balance between storability and marketability of their apples, Beaudry said. For example, McIntosh apples harvested early can be green in appearance yet very receptive to MCP; however, very green apples are not marketable. Beaudry said that when 1-MCP was applied late on two rooms of apples 1-MCP had no effect on them.
“That tells me that maturity at treatment (of 1-MCP) is the most important factor,” Beaudry said.
Dr. Nate Reed, formerly with Penn State University and now with AgroFresh, said the guidelines on when to apply SmartFresh (1-MCP) are internal ethylene content (IEC), fruit firmness and starch content. Since sophisticated equipment is required to measure IEC, growers must rely on starch content and fruit firmness to guide them in the decision process, Reed said.
AgroFresh has published a booklet “Apple use Recommendations 2003,” which lists specific recommendations for 16 apple varieties and general recommendations for all varieties.
“SmartFresh needs to be applied quite quickly after apples are harvested – within probably seven days,” Schwallier said.
Airtight rooms will be needed for 1-MCP application; this requirement will not pose problems for CA rooms although it might be a problem for application in cold storage rooms, he said. This year AgroFresh plans to make all the applications of SmartFresh themselves.
The impact of SmartFresh will probably be greater with cold storage apples, compared with CA apples, Schwallier said. Apples in cold storage for three months get fairly soft while CA apples stored for six months still have fairly good quality, Schwallier said.
Jim Swindeman, from Applewood Orchards in Deerfield, Mich., told growers he treated three rooms with SmartFresh. He said he had very good luck with SmartFresh in a room with the Fuji variety. Those Fuji apples were marketed after three months, which garnered a tremendous response from buyers. Galas from a room treated with SmartFresh were marketed rather quickly so it was not a good sampling.
Swindeman told growers that this year he plans on using SmartFresh on Fujis and probably a room of Galas and one other room of mixed varieties.
“There was a pretty pronounced increase of packout on treated fruit,” Swindeman said. He told growers he can justify the cost of using SmartFresh, which is estimated at 35 cents per bushel.
Pat Chase, from Jack Brown Produce in Sparta, Mich., said his company treated one 1,000-bin room with SmartFresh. The room was treated with SmartFresh on Oct. 17, 2002, and the room opened on Jan. 23, 2003 with samples tested on Jan. 27, 2003. “I was real impressed with the response that we saw,” Chase said. He noted that last year’s growing conditions were less than ideal.
“The Jonathons were phenomenal,” Chase said. He said that using SmartFresh did not negatively affect the treated varieties.
Schwallier said that one of the main advantages to using 1-MCP will be a more orderly marketing of apples throughout the whole process. Growers interested in using Smart Fresh should first plan to move their apples after harvest into storage in a timely fashion, he said.
SmartFresh is registered for seven crops, and last year seven states had commercial applications. Red Delicious, Golden Delicious, Granny Smith and Gala make up 85% of the apples treated nationwide, Reed said. MCP was used on 10% of fresh market apples in Pennsylvania and on 18% of fresh apples in Washington state, Reed said.
With all the advantages of SmartFresh, Schwallier cautioned that once third world countries start using the product, the U.S. apple industry will be more vulnerable to these nations as they have lower production costs.
For more information visit www.smartfresh.com or call toll-free (866) 206-1001.
