Minnesota Crop News

 Jared Goplen and Dave Nicolai, Extension educators-crops Part I in a three-part series Photo 1. Mow fence lines now to minimize deposits to the weed seed bank. Photo: Jared Goplen. Harvest will soon be in full swing. Take the time now to mow fence line weeds or field edges to prevent or minimize seed production. Field edges are often where weed infestations start. By eliminating fence line weeds, we prevent combine harvesters from picking up weed seeds from the field edges and pulling them into the field where they can be further spread by harvesting and tillage equipment. Most weeds common to corn and soybean fields are in the flowering and seed development stages of their life cycle. This means that there is still time to control some weeds before they can produce viable seed. Viable seeds may have already been produced by early-maturing broadleaf weeds like lambsquarters, kochia, and redroot pigweed. Later-maturing weeds, like giant and common ragweed, are still pollinating in...

Anthony Hanson, Ian MacRae, Bruce Potter, and Robert Koch Grasshopper populations have become more noticeable this year, especially along field edges, pastures, and CRP acres. Due to the hot dry conditions, population densities earlier in the year were similar to what we’d typically see in August in some areas, which has led to sustained or even higher populations as we now move towards the end of the growing season. Earlier this summer, some parts of the state, such as northwestern Minnesota, did have treatable levels of grasshoppers in small grains. While grasshoppers are making their presence known this year, presence alone does not necessarily mean they are causing economically significant damage in soybeans or forages (Fig. 1). Insecticide options may also be limited as harvest season approaches. Figure 1. Red-legged grasshopper on soybean. Photo: Anthony Hanson There are multiple species of grasshoppers in Minnesota that can commonly be found in field cro...

Robert Koch (UMN), Theresa Cira (MDA), Raj Mann (MDA), Bruce Potter (UMN), Anthony Hanson (UMN) In a pre-publication of a final rule released on August 18, 2021, the EPA announced   that the agency is revoking all tolerances for chlorpyrifos. A “tolerance” represents the maximum level of pesticide residue legally allowed in or on raw agricultural commodities and processed foods. Revoking of tolerances will stop the use of chlorpyrifos on all food and feed, taking effect six months after the final rule is published. See 40 CFR Part 180 for a list of chlorpyrifos tolerances on food commodities. The pre-publication announcement from EPA indicates that growers can still use chlorpyrifos through the end of the 2021 growing season.   Non-agricultural uses are unaffected by the final tolerance rule.  Background and Decision Chlorpyrifos is an active ingredient in many commonly used insecticides such as Chlorpyrifos, Govern, Hatchet, Lorsban, Lorsban Advanced, Vulcan, War...