Whether they’re grown for drinking or for decorating, hops are a valuable specialty crop. Per USDA-NASS, the value of the crop was $446 million in 2024, so making sure as many hops get to market as possible is incredibly beneficial.

The total cultivated area for hops was 61,177 acres in 2022 (at the release of the last Ag Census). In all those acres, the hop cyst nematode (HCN) is one of the most impactful nematode pests. Infested hop plants can see a reduction of as much as 68% in root length. And HCN-infested hops produced 38% fewer dry cones per bine compared with hops not infested with HCN (in a 2023 study).

Undertaking at a field evaluation of organic composts and nematicides that could fight against HCN in hops recently were Muhammad Usman, Elisabeth Darling and Marisol Quintanilla-Tornel, all of the Department of Entomology at Michigan State University.

Their hop survey revealed that HCN is already established in the hopyards of Michigan, which is concerning. Michigan-grown hops tend to sell for between $12 and $14 per pound, nearly double the national average.

Unfortunately, there are no management strategies available to manage HCN in hops, the research team reported. So, the goal of their study was to determine the efficacy of organic compost and nematicide applications against HCN in hops.

Their field trial was conducted at the Michigan Hop Alliance in Northport, MI, in 2023 and 2024. Two rows of the popular cultivar ‘Cascade’ were highly infested with HCN. Seven different treatments were applied: an untreated control; a layer ash blend at 0.5 tons/acre; poultry manure at 1 ton/acre; urea at 300 lbs./acre; Majestene® at 8 gallons/acre; Velum® Prime (half rate) at 3.42 fl. oz./acre; Velum Prime (full rate) at 6.84 fl. oz./acre. Six plants were chosen for each treatment application.

To see how effective each treatment was, soil samples were collected at three different times. There was a pre-treatment application (June 7, 2023 and May 6, 2024); a mid-season application (40 days after application); and an end of season application (80 days after application).

For treatment comparisons, they counted the total number of HCN cysts and juveniles from each of the soil samples.

What they found varied in each growing season. In 2023, HCN juvenile abundance was significantly different among the different treatments at mid-season sampling. Performing adequately, poultry manure, urea (both rich in nitrogen) and Majestene all had about 100 HCN juveniles per 100 cubic centimeters (cc) of soil. Performing even better were the Velum Prime treatments, especially at the half-rate at midseason.

That same season, HCN cyst abundance was not very different among all the different treatments at all sampling intervals. The researchers found between 30 and 50 cysts per 100 cc of soil.

However, 2024 was a different year. The survey found that all the treatments significantly reduced the abundance of HCN juveniles compared with the untreated plants at mid- and end of season sampling.

That same season, a significantly lower abundance of HCN cysts were observed in all treatments compared with the control at mid- and end of season sampling as well.

Ultimately, it seems like some good news resulted from the research. The MSU team concluded that organic composts (like the layer ash blend and poultry manure) and certain nematicides (like Majestene and Velum Prime) could have the potential to manage HCN in hops.

That’s comforting news for the nearly 70 farms growing more than 670 acres of hops in the Wolverine State.