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dissected whorl of waist-high corn plant shows tassel, at knife tip, already developing Tom J. Bechman
IDENTIFY PLANT PARTS: Dissecting the whorl of this waist-high corn plant reveals the tassel, at the knife tip, already developing.

Purdue crop guide helps determine growth stages

This pocket guide and its related apps bring information about crops, weeds, insects and diseases to the field.

The 2020 edition of the Purdue University Extension Corn & Soybean Field Guide is now available. It’s produced each year by the Crop Diagnostic Training and Research Center, headed by Corey Gerber, a Purdue agronomist.

The guide features colored pictures that help determine critical growth stages for both corn and soybeans. For example, if you want to know the difference between the dough stage and dent stage for corn, the pocket guide offers an exact definition, complete with pictures.

It also provides detailed information and pictures regarding growth stages in soybeans. If insects threaten late in the season, you need to know growth stage to know whether treatment might still pay.

The pocket guide is also filled with pictures of diseases and insects for both corn and soybeans, plus descriptions of each key pest and economic thresholds for determining whether the problem justifies treatment or not. There are also sections on key weeds, complete with pictures.

For ordering information, visit App versions of the guide, called Corn Field Scout and Soybean Field Scout, are available at minimal cost from the App Store. Both apps contain calculators that allow you to run numbers and make “treat or no treat” decisions in the field.

Purdue’s Education Store also offers separate wheat, cover crop and forage guides. Each one is printed in color.

Due to the COVID-19 pandemic, the Crop Diagnostic Training and Research Center opted not to hold training sessions this year. “We’re building our library and developing resources, and will return next season,” Gerber says.

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