When retail grocers complain about defects in their fresh potatoes and you’re known worldwide for growing famous potatoes, it’s something you as an industry take a proprietary interest in correcting.

What began in 2017 as an effort to remedy a quality issue of Idaho’s fresh-market potatoes eventually developed into an offensive to limit defects in both the fresh and processed potato market sectors.

During the past four years, two University of Idaho potato researchers — Mike Thornton and Nora Olsen — have followed the journey of Idaho potatoes from harvest to storage and then from out of storage in transit to distribution centers to find the sources of potato defects, with the ultimate goal of improving the quality of Idaho’s potatoes.

Thornton, a professor of plant sciences working primarily on potatoes and onions at the Parma Research & Extension Center, said impact bruising contributes to an array of other potato defects.

“If you take the things that are directly related to a bruise — so shatter bruise, black spot — and then the things that we know are secondarily related to bruise — the rots, wet rot and dry rot — that come in through a shatter bruise ... if you do that it’s like 70 percent of all the rejection notices are tied to those things that are related to impacts that happen at harvest or while we’re handling them or shipping them,” Thornton said.

Olsen, a professor specializing in potato storage at the Kimberly Research & Extension Center, said the many factors that create quality control issues include potato variety susceptibility to bruising, ideal temperatures for harvesting, storage, transportation and late-season soil moisture.

“There’s just so many layers to bruise, we just need to keep peeling it back and figure out what are the bigger targets,” Olsen said.

Both Thornton and Olsen have spent countless hours over the past four years observing potato harvest practices, measuring the drop heights of harvest equipment, the speed of the rollers and the amount of padding and quality of conveyor belts moving the potatoes into storage as well as moving the potatoes out of storage and to distributions centers around the country.

At the same time, they have overseen production of a series of instructional videos on best management practices to avoid potato bruising. The videos come in both English and Spanish narration.

The videos illustrate proper techniques to minimize drop heights in the field operations of windrowers, potato harvesters, stingers, conveyors and pilers when transferring potatoes from trucks to the storage cellars. The video also covers the correct operation of the potato scooper and the drop height of the conveyor into the trailer when moving potatoes out of storage.

An important partner throughout their quality control research was Walmart.

“They have this massive data set from all the distribution centers,” Thornton said of Walmart. “They have the best data set that they could share with us where we could see what’s going on in real time. They sent us those every week.”

Olsen said that Walmart provided a lot of in-kind information and a lot of details that provided insight into the data they were collecting.

“You can collect any data but if you don’t have the context behind it then it’s hard to put it into action,” Olsen said. “Walmart did a nice job of doing that and then, also, a lot of our packers were great. Our fresh packers were so welcoming and helpful, trying different things and being very open with us, as well. I think that was key.”

One of the Idaho shippers working with Thornton and Olsen was Wada Farms out of Pingree. Wada Farms is one of the major suppliers of Idaho potatoes to Walmart.

Eric Beck, director of marketing for Wada Farms, said Walmart was the driving factor behind the project. According to Beck, Walmart wanted to identify not only ways to promote potato health at harvest but specifically for potatoes coming out of storage.

“It was pretty cool to see a retailer say, 'We want to be part of the process,'” Beck said. “'Let’s utilize our resources and let’s work together to find a good result not just for Walmart’s customers but for the industry in general.'”

Beck said that Thornton and Olsen “did tremendous amounts of sampling on the product that was coming inbound that day in the storages getting data from that aspect of it so we could see from storage to final destination what were the core factors that were affecting potato health at that time.”

After sampling potatoes coming out of storage Beck, Thornton and Olsen would meet the trucks at their final destination — Walmart distribution centers in Utah, North Carolina, South Carolina, Arkansas and New York.

“We met them when they opened up the doors,” Olsen said, referring to meeting the trailers when they arrived at the distribution centers.

“We were able to go into all the Walmart facilities and work with their (quality control) teams,” Beck said. “We were able to observe their quality control and inspection processes in order to see if there’s any anomalies and then identify the consistencies that we’re seeing across the board.”

Beck, Thornton and Olsen all were complimentary in their appraisal of Walmart’s quality control teams.

“We saw those people — they’re really dedicated, trying to do a good job of detecting the actual quality so actual problem lots get tagged,” Thornton said. “They’re not trying to tag lots as an issue that aren’t an issue. They’re trying to do a really good job.”

Beck said that there were several items they identified during the process that improved their understanding of how to improve the quality of potatoes from the field to the consumer’s table.

“I think every little bit kind of helps overall to the bigger picture,” he said.

One factor that seemed to stand out was some trailers were not always kept at a temperature range of between 40 and 45 degrees.

Thornton said that when checking the tractor-trailer logs they would find some trailer temperatures never dropped below 50 to 55 degrees.

“They’re not meeting the conditions in the trucks that they think they’re getting and that’s contributing to some of this loss in quality,” he said.

Travis Blacker, director of industry relations for the Idaho Potato Commission, said that the IPC contributed about $250,000 for the project.

“This project easily paid for itself,” Blacker said. “This wasn’t just for shippers; this was for all growers — better practices and helping with harvest and handling and storage and packing. This is not just fresh pack growers but processed growers as well. Really, it affects the bottom line of returns going directly back to the growers.”

Thornton said that the success of the program could be seen in the reduction of rejected shipments at the distribution centers.

“The rejection notice data speaks for itself,” Thornton said. “We’ve seen a steady drop every year in the number of rejections. That’s telling us we’ve got less shipments that got a problem when they show up at the distribution center.”

Thornton said that Walmart has taken notice of the program’s success and has started applying some of the lessons learned to other lines of fresh produce.

Thornton believes their work has helped to unify the fresh potato industry behind the goal of trying to improve quality controls.

“I think the best thing about this project was it brought the whole fresh industry’s attention to, ‘Hey, we got to work hard to make sure we have quality potatoes 12 months of the year because one of our biggest customers is asking us to do that,” he said. “I think all Nora and I did was give them some tools, give them some information, but they did all the work. The fact that rejections have gone down is because shippers have started paying more attention to the quality assurance process.”