HarvestWatch DCA-CF with granny smith apples

Feb 8, 2021
Reducing postharvest storage disorders, extending apple storage life with HarvestWatch DCA-CF

{Sponsored} Apple storage issues are numerous, from reduction in flavor and crunchy texture to disorders that form during storage such as superficial scald and flesh browning. Scientists have known for a long time that controlling the oxygen level is key. However, knowing exactly what oxygen levels are optimal for each variety was traditionally up to guesswork. Oxygen that is too low may cause fermentation and fruit damage.

The HarvestWatch technology was developed by Dr. Robert Prange in 2000 in order to identify the optimal low oxygen level for fruit storage. This storage technology uses chlorophyll fluorescence (CF) to identify the Low Oxygen Level (LOL) of each variety — the level to store just above to optimize storage without allowing fermentation to start.

The bio-sensor based DCA technology is easily added to enhance existing CA stores making them smarter, according to Prange. “The result is improved storage quality and the elimination of some postharvest disorders. All this is achieved without adding additional chemicals to the stored fruit,” Prange said.

Storing at optimal low oxygen levels with DCA-CF provides significant benefits compared to conventional CA storage allowing producers to extend the marketing window and still having those apples be crunchy and delicious. Work at Cornell University has shown that DCA can also slow down development of internal browning disorders such as flesh browning of Gala apples.

HarvestWatch DCA-CF is exclusively marketed in the U.S. by Gas At Site. The HarvestWatch technology is used in more than 2300 rooms globally. Vega Brink, the marketing manager for Gas At Site confirms that Gas At Site has supplied more than 350 DCA rooms with HarvestWatch across Washington, Oregon and New York.

Rocky Surace, account manager at Sun Orchard Fruit Company, a packing warehouse in New York state, saw first-hand the issues with traditional CA at Sun Orchard: browning, superficial scald, internal carbon dioxide damage and questionable apple health throughout the duration of storage. His facility recently implemented HarvestWatch DCA-CF. They’re now able to market apples for a full year without any issues they had prior to adding the technology to their storage facilities.

“We are essentially trying to put the apple to sleep, so to speak, by minimizing respiration and halting maturation. We do this by controlling the gas levels in each room, reducing the chance they will go over ripe and start to break down,” Surace said. The software used to control the HarvestWatch DCA-CF sensors gives Surace an hour-by-hour glimpse into what is happening within each room.

Since the rooms must remain sealed until the apples are ready to go to market, this means that Surace always knows what is happening inside each room. This also allows Surace to choose which room to open next by comparing conditions inside each room to one another. By using HarvestWatch DCA-CF, Sun Orchard was able to reduce the oxygen within their storage rooms from 3% to 4% safely down to 0.5% to 1%, which enabled their DCA stored apples to stay fresh months longer than before adding the technology to their CA facilities.

Similarly, Allan Brothers Inc., an operation with growing and packing facilities in Naches, Washington, has seen large improvements in storage since adopting HarvestWatch DCA-CF six years ago. The scald issues have virtually disappeared and Eric Orozco, the facility manager, is able to have his teams monitor storage by checking 24 hours’ worth of data every morning. They were able to implement the system within a year, starting with a few rooms. Now Allan Brothers have the capabilities to store up to 10 rooms full of apples.

“One of our growers loves HarvestWatch because he sees that we can manage and reduce the scald on his fruit and he can achieve really good pack-outs. We can also store the fruit longer and let it go to market when it is in-demand, as opposed to not having a choice and opening a room because it is starting to go. HarvestWatch gives us the ability to prolong storage and keep fruit at really good quality,” Orozco said.

For more information about HarvestWatch DCA-CF, visit www.HarvestWatch.net.