Issue link: https://read.dmtmag.com/i/67288
More predictability with MCP needed Packers say they need to learn how to treat pears with SmartFresh and have the fruit reach consumers in good eating condition. by Geraldine Warner "But a pear is not like an apple. On a pear, we want to delay maturity long enough so we can store it and then turn it back on somehow." —Jake Gutzwiler F ruit packers in Washington State say they'd like to feel more confident about using SmartFresh (1-methylcyclopropene) on pears to reduce problems with storage scald and enhance storability, but results are not yet predictable. What they need is a formula that will tell them how to treat a given lot of pears with SmartFresh so they can get the results they want. Use of SmartFresh on pears involves a lot more management than using it on apples, Welcome Sauer, president of AgroFresh, which manufactures and sells the product, said during a discussion at the Washington State Horticultural Association's annual meeting last winter. Research is going on around the world—in AgroFresh's labs, research labs, and many fruit packing houses—on how Jake Gutzwiler said pear packers need to be able to use MCP accurately, effectively, and efficiently. to successfully treat pears with SmartFresh, Sauer said. AgroFresh has seven researchers working in laboratories in Washington State, California, and Chile, who are analyzing over a million fruit samples a year. For many packers, however, it's been a case of trial and error so far, with some shipments ripening too slowly and others too fast. An incident where SmartFresh-treated pears were mixed in bins with untreated pears and diverted for processing was a learning experi- ence both for the producer and the processor that received them, as the pears ripened at different times, Sauer said. Dr. Jim Mattheis, postharvest physiologist with the U.S. Department of Payments as Low as $ Lease per month oac 313 Agriculture in Wenatchee, Washington, said SmartFresh has proven effective for slowing ripening, controlling scald, and warding off disorders that are related to senescence in pears, but many factors can influence how well it works. These include: maturity of the fruit at harvest, the interval between harvest and treatment, the SmartFresh concentration, temperature of the fruit when treated, storage conditions, storage duration, and poststorage conditions. Not like an apple Jake Gutzwiler, quality control supervisor at Stemilt Growers, Inc., in Wenatchee, Washington, said SmartFresh does exactly what it's supposed to do: delay maturity of climacteric fruit. "From that aspect, it's a complete success," he said. "But a pear is not like an apple. On an apple, we want to delay maturity and keep the apple crunchy. On a pear, we want to delay maturity long enough so we can store it, and then turn it back on somehow." In small, controlled trials in a lab setting, the company has been able to Lease a new T4000 Series Tractor for as low as $313.00 per month o.a.c. Call for details. •T4000V and T4000F Series Tractors (62 to 82 PTO hp) •TNV-A Series Tractors (60 to 80 PTO hp) treat pears and have them ripen perfectly, Gutzwiler said. But with commer- cial fruit, there's been great variability. One lot of fruit might have a two-day delay in ripening, while in another lot, ripening might be delayed by five or six days. "But, then, we also know we have a wide range of maturity at harvest and as we pull the fruit out of storage. What we don't know is what's the formula to make it stop ripening and then start ripening again and get it to the customer in perfect condition and then to the consumer in an edible state," he said. Gutzwiler said it's obvious that a packer can't just put five different grower lots into a room and treat them, and expect the same results. Packers will need a lot of information about each lot of fruit to determine how to treat it to get the best results. Stemilt is using SmartFresh on pears, but believes it is rolling the dice in terms of the ultimate condition of the pears, he said. "How do we get to the point of using it accurately, effectively, and efficiently?" Bob Gix at Blue Star Growers, Cashmere, Washington, said the biggest chal- lenge, in his experience, is getting the fruit to uniformly ripen and fitting the treatment into the commercial system. If a way could be found to treat pears and have them ripen predictably, SmartFresh would be particularly useful for fruit shipped to export markets that don't have good cold storage, he said. It also has great potential as an alternative to the antioxidant ethoxyquin for scald control. 36 JUNE 2012 GOOD FRUIT GROWER www.goodfruit.com