Nematode Problem Has No Easy Solution

- Palle Pedersen

Nematodes are a serious issue for farmers, especially in the United States and Brazil. These invisible, microscopic creatures — also called roundworms — live in soil and attack a plant’s roots. It is estimated they destroy over 10 per cent of global crop production every year.

One of the most damaging nematodes in the United States is the soybean cyst nematode (SCN). It was discovered in North Carolina in the 1950s and moved quickly throughout the country’s soybean growing regions.

Over the years, new soybean varieties have been developed with resistance to SCN; however, they were developed from a source of resistance that’s more than 25 years old, so the SCN is now fighting back. The number of nematodes has been dramatically building in fields, because they have adapted to our efforts to fight them.

In Brazil, the nematode problem is even more ominous. A different kind of nematode is present there that thrives on corn, soybean and cotton. Farmers grow multiple crops in a season (making proper crop rotations difficult), and growers are seeing a rapid buildup of nematodes as a result, with no clear solution in sight.

Breeders have difficulty finding new sources of resistance to SCN that have the ideal agronomic characteristics farmers want. They have found new sources that work, but they don’t yield well or are susceptible to other diseases.

Various products have been developed to battle these nematodes, including seed treatments.

Growers in both regions, but especially the United States, must step up to the plate in the fight against the nematode problem. In America, proper crop rotation and regular monitoring of SCN levels in fields are crucial to combating it. In Brazil, the solution isn’t as obvious, but in both regions, we must raise awareness among farmers.

Farmers tend to think the problem is an easy one to solve. Consider that in the United States, SCN-resistant soybean varieties don’t cost more than susceptible varieties. You have a technology that is cheap, and they will keep using it to a point where it stops working, as humans often do.

The effort to raise awareness of this problem is beginning to see some success, with initiatives like a recent partnership between the North Central Soybean Research Program and several universities to launch an awareness campaign.

With the help of growers, we can hopefully one day begin to reverse the continued threat posed by nematodes in the United States and Brazil. As of right now, though, we have a long way to go to secure profitable soybean production in the future.