Pests & Diseases

Over the past four years, Iowa State University has conducted 14 site-years of foliar fungicide research trials with alfalfa at the ISU Northeast Research and Demonstration Farm near Nashua, Iowa.

When it comes to voles, pocket gophers and field mice, forage growers will do just about anything to get them off their property – or at least under control.

We have some effective pesticides, but when do you need to apply them? The answer for many of us procrastinators is 10 days to two weeks ago. Rather than adding to a problem of selection for pesticide-resistant insects, maybe a better plan is to just cut the forage early and then monitor for continued problems.

As their name implies, sugarcane aphids have been a significant pest in sugarcane for decades. These small yellow, gray or tan aphids (Photo 1) feed on the underside of the plant leaf. The host range of these aphids was thought to only include sugarcane, but that changed in 2013.

Although many vertebrate pests cause problems in alfalfa, the most frequent offenders are often pocket gophers (geomyidae) and meadow voles (also known as meadow mice; Microtus spp.). Pocket gophers are short, stout burrowing rodents, usually 6 to 8 inches in length.

Some of the more panicked calls I receive during summer months are from silage corn growers who have suddenly discovered they have a spider mite infestation in their fields. In many cases, it seems the mites that weren’t there yesterday have multiplied an hundredfold overnight.