CarbonWorks Restore Doubles Sweet Potato Root Mass in 5 Weeks

Product Performance
February 1, 2018

CarbonWorks Restore welcomes use on it's newest crop! On a 1000+ acre field trial, results from the first 5 weeks are in!

CarbonWorks recently partnered with a California sweet potato grower to test our CarbonWorks Restore starter. It was the first time we’ve used CarbonWorks Restore on sweet potatoes, so we were anxious to get them in the ground and see what difference CarbonWorks Restore would make.

As you’ve probably guessed from the title of this post, CarbonWorks Restore delivered! Let’s survey the progress after the plants were in the ground for five weeks . . . 

harvested sweet potato sprouts ready to plant
The sprouts are then harvested and prepared for planting.
sweet potato sprouts growing
Sweet potatoes are first established under low greenhouses early in the year.

But first, do you know how California growers produce their delicious sweet potatoes? The state’s abundant sunshine and warm nights combine to create the perfect conditions to grow these tubers. Most grow in three counties—Merced, Stanislaus, and Kern—where legacy farmers have been producing sweet potatoes for generations, thanks to the ideal sandy loam soil and weather conditions.

The sweet potato season starts in late winter when growers lay seed potatoes under plastic covers, which create long mini greenhouses. The potatoes sprout, and growers allow them to grow under the plastic until the sprouts are about 12 inches tall. At this point, growers harvest the sprouts from the seed potatoes and prepare them for planting.

Growers and their farm hands then plant all the sprouts by hand! The next time you enjoy sweet potatoes at Thanksgiving (or any time of year) think about the hard work and dedication that goes into each and every one.

It’s at this point where CarbonWorks Restore enters the picture. During sprout planting, we separated the trial crop into three groups:

  • One group with no CarbonWorks Restore applied.
  • One group with half the recommended rate (2.5 gallons per acre) of CarbonWorks Restore applied.
  • One group with the full rate (5 gallons per acre) of CarbonWorks Restore applied.

We did this so we could observe how CarbonWorks Restore affected the sweet potato plants’ root development. We wanted to see if CarbonWorks Restore would work as it does on many other crops: Would it increase root mass? By how much? As you can probably guess, a larger root mass—with a greater number of stolons, or runners—has the power to increase yields. Why? Bigger roots can deliver more nutrients to the plant.


sweet potato root development
1 week after planting: Left: 2.5 gal/A CarbonWorks Restore; Middle: Untreated; Right: 5 gal/A CarbonWorks Restore

At one week after planting, we see that a plant from the group that received the full rate of CarbonWorks Restore is leading in root development. 


sweet potato root development
3 weeks after planting: Left: Untreated; Middle: 2.5 gal/A CarbonWorks Restore; Right: 5 gal/A CarbonWorks Restore

Here we see the same story at the three-week mark. The full rate of CarbonWorks Restore is dominating the other two with a root mass three times larger than the plant that received no CarbonWorks Restore. Which looks like the healthier, more productive plant to you? 


sweet potato root development
5 weeks after planting: Left: Untreated; Right: 5 gal/A Restore

At five weeks into the growing season, a plant that received the full recommended rate of CarbonWorks Restore is showing double the root mass of a plant that received no CarbonWorks Restore. (We actually severed numerous roots attempting to dig it out of the ground.) Look at the picture one last time: If you grew sweet potatoes, which plants would you want populating your fields?


Although sweet potatoes are CarbonWorks’ newest crop, CarbonWorks Restore’s results are exactly what we would expect. After all, CarbonWorks Restore is already proven to deliver robust emergence and massive roots. As the sweet potatoes seek nutrients and water in the soil, the larger root mass will bring back more for the plant to use. And in the end, this will boost the total yield come harvest time.

George Sims