Determining the level of disease infection or defoliation by insects is an important aspect of determining if treatment is needed or not for several plant disease and insect pests. It can also be a challenge to be able to do so accurately. Accurately assessing disease and insect damage is also important from an economic standpoint. Applying pesticides when the pest is far below economic thresholds will not likely result in a positive return on investment.
To help farmers and crop scouts improve accuracy in determining levels of infection or defoliation the Crop Protection Network has a new online Disease Severity and Defoliation tool that was developed at Iowa State University that can be used to help calibrate ones eye or used to compare samples with either in the field using a smart phone or tablet or bringing plants back to a computer. This tool is a great resource to help improve assessment accuracy. It can be found at this link: https://severity.cropprotectionnetwork.org/
The Crop Protection Network is a consortium of Land Grant Universities and Provincial Agencies.
Please feel free to contact Carolyn Ihde, Extension Richland County Ag Agent, at email: email@example.com