The No. 1 robber of soybean yields in the U.S. may surprise you. Soybean Cyst Nematode (SCN), microscopic worms that live in the soil, infect soybean roots and lead to stunting and yellowing. However, a low infestation can be hard to spot, meaning many farmers may be unaware they have SCN. Greg Tylka, Iowa State University professor and leader of the Soybean Cyst Nematode Coalition, says fields can experience up to 30% yield loss with virtually no visible symptoms. That loss on 70-bushel beans at $14/bushel prices equates to a loss of $294 per acre.

SCN has been ranked as the most damaging soybean pathogen in all of North America for the last 20 years, with losses estimating $1.5 billion annually. How can farmers stay on guard against the silent yield robber? A simple dig with a spade to access soybean roots can help the naked eye spot the pest.

Read more on soybean cyst nematode here.