Production Blog

References You Can Count On

Pamela Smith
By  Pamela Smith , Crops Technology Editor
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Bean leaf beetles can do a lot of damage, but it is easy to overestimate the damage. A new free tool helps assess injury. (DTN photo by Pamela Smith)

DECATUR, Ill. (DTN) -- Every farmer knows there's no substitute for having the right tool for the job. While a 9/16th inch box end or a pair of pliers can do a lot, reference tools are just as important when you need them.

All Googling aside, there are a couple of crop information tools that I always keep close at hand or at least near my fingertips.

More than once I've made the comment that every corn farmer using a product containing genetic traits should have The Handy Bt Trait Table as a tattoo. While the statement might be a bit extreme, that's how important and useful that table is for negotiating the maze of Bt field corn traits.

The free, online reference lists all trait trade names, Bt events, protein(s) expressed, targeted insects and herbicide traits. It's updated each year and still has some tweaks coming for 2021, but find the landing page for the chart here:….

The publication highlights insect and Bt combinations with documented field failures, confirmed resistance or cross-resistance. The statements are based on published lab assays and/or field research to alert farmers and consultants to potential management problems, help with seed selection and encourage field scouting.

What's important to remember is the table is a national publication and resistance may be widespread, regional or limited to a few fields. Local seed representatives and extension personnel can help sort what resistance pressures are present in your area.

A version for U.S. sweet corn found at:….

Canadian field corn farmers can find a trait table at:….


The real estate on the surface of seed has been a popular place to put protections against a range of pests -- that includes seedling diseases, insects and nematodes. Seed treatments are even promoted for improving plant health.

The University of Wisconsin has a great chart to take some confusion out of determining what is on seed. Granted, it is for products registered in Wisconsin, but it's the most complete seed treatment chart I've come across.

The seed treatment chart covers corn, soybean, small grain and alfalfa seed. It groups the treatments by the active ingredient group number (1-6), treatment type (fungicide, insecticide, nematicide or plant growth regulator) and alphabetically by product name.

Find the seed treatment guide here:….


Take Action began as a farmer-focused campaign to fight back against herbicide-resistant weeds. It's since broadened beyond weeds to include educational tools to help fight fungicides and insecticide resistance.

The goal is to encourage farmers to adopt good management practices, but the beauty of the site is the many resources it brings together.

Including multiple and diverse sites of action (SOA) to manage fields to combat or prevent herbicide resistant weeds can be complicated, though, especially as new products come along that incorporate many of the same SOA.

Find an app to sort through popular herbicide brands and their actives here:….

Find the herbicide lookup tool to search here:….

A herbicide chart that lists all the many options is here:….

Take similar steps to tackle fungicide resistance with a fungicide look-up tool:….

Find a fungicide classification chart here:….

Insects are smart too. This link will help determine by zip code what Bt refuge requirements you face with various products:….

An insecticide classification chart can be found here:….


Overestimating leaf disease severity and insect defoliation is as easy as overfilling your plate at a potluck. Crop scouts now have a new tool to put estimates on a realistic diet.

This free, interactive activity lets you judge how much of a leaf is covered by lesions or munched on by bugs. With practice, scouts become more accurate in diagnosing need for treatments for a variety of corn and soybean problems.

The Disease Severity and Defoliation Training tool was developed by the Crop Protection Network (CPN), a multistate and international collaboration of university and provincial extension specialists, and public and private professionals. Get your training here before heading to the field:….


Struggling to identify VE from V-3? Need a refresher in growing degree day math? CPN also has a new, free web book called Crop Scouting Basics for Corn and Soybean.

Written and reviewed by Extension pest management specialists from across the country, it is specific to corn and soybean production. The guide covers how to scout and identify problematic weeds, diseases, insect pests and other field issues.

The CPN website houses webinars, videos and other valuable agronomic information, as well. Go to….

Do you have go-to resource guides?

Pamela Smith can be reached at

Follow her at @PamSmithDTN


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