Plant Disease Management for Agricultural Crops

Information in this section was developed by the Extension Plant Pathology Team in the University of Nebraska–Lincoln Department of Plant Pathology. It's designed to help crop producers, agricultural consultants, extension educators, and other agricultural professionals in Nebraska identify and manage plant diseases, a major yield limiting factor for many Nebraska crops. The most critical issue for profitable management of plant diseases is obtaining a correct diagnosis. In any given year, the question is not whether diseases will occur in Nebraska but rather which diseases will occur and at what incidence and severity.

Many factors influence disease development in plants including hybrid/variety genetics, age of the plant at the time of infection, environment (e.g., soil, climate), weather (e.g., temperature, rain, wind, hail, etc.), single versus mixed infections, and genetics of the pathogen populations. Due to variation inherent in these factors, diagnosis of plant diseases can be difficult at the early stages of disease on individual plants as well as at the early stages of an epidemic. However, for many diseases symptoms do become diagnostic at some stage of disease development and a reasonable level of confidence can be placed in diagnoses based on these symptoms.

Contact the University of Nebraska-Lincoln Plant and Pest Diagnostic Clinic in Lincoln and the Panhandle Plant Disease Diagnostic Lab in Scottsbluff for assistance with diagnosis or confirmation. For many diseases, symptoms become diagnostic and a reasonable level of confidence can be placed in diagnosis based on symptoms.

Information on the pathogen, symptoms, favorable environmental conditions, management, and related links for each disease are listed by crop:

Plant Diagnostic Clinics

UNL offers two Plant Diagnostic Clinics — one in Lincoln and one in Scottsbluff. For all samples please submit a Sample Submission Form.

Lincoln Plant and Pest Diagnostic Clinic

Located in the Department of Plant Pathology, this facility provides diagnostic services in plant pathology, entomology, horticulture and weed science. In addition to accurate diagnosis of your pest problems, you will be provided with current information about the disease and management recommendations. Learn more about services and how to submit a sample.

Scottsbluff Panhandle Plant Disease Diagnostic Lab

Located at the Panhandle Research and Extension Center at Scottsbluff, this lab focuses only on plant disease identification. Most of its samples are of sugar beets or soil samples from sugar beet fields; however, diagnostic services are provided for any diseases encountered in the Panhandle. Learn more.

Plant Disease Video Library

Thirty videos on identification and management of corn and soybean diseases are available at UNL CropWatch on YouTube. Go to the field with UNL Plant Pathologists Tamra Jackson-Ziems and Loren Giesler as they show you what to watch for to correctly identify and manage Nebraska crop diseases.

Related Articles

Examples of good and bad samples received at the Plant and Pest Diagnostic Clinic
Figure 1. How you package your plant sample can significantly affect the quality of the diagnoses you receive. Above are several samples received recently by the university's Plant and Pest Diagnostic Clinic. Samples that are too wet (left) or too dry (middle) obscure symtom expression and make disease diagnosis difficult. The sample on the right was packaged well and shipped early in the week. (Photos by Kyle Broderick)

Quality Samples Lead to Better Diagnoses May 31, 2018

Correct identification of insects and other pests and diagnoses of diseases starts by submitting quality samples. This outlines how best to submit plant samples to the university's Plant and Pest Diagnostic Clinic.

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Violet root rot, a rhizoctonia crocorum fungus, in soil

The First Identified Root Pathogen: Rhizoctonia April 12, 2018

This is the second article in a series on distinct sugar beet root rot diseases caused by the genus Rhizoctonia. This week Rhizoctonia solani and Rhizoctonia solani are featured.

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Nebraska map of PPDC reporting districts

Crop Diseases Confirmed by PPDC Sept. 27-Oct. 5 October 6, 2017

Anthracnose in corn and soybeans was among the diseases diagnosed by the university's Plant and Pest Diagnostic Clinic in the last two weeks. See their report for soybean, corn, hops, and alfalfa. Clinic services will be reduced Oct. 12-19.

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New Extension Crop Publications August 17, 2017

Among new releases from Nebraska Extension are two on the use of biologicals to manage crop disease as part of an integrated pest management (IPM) plan.

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Has Ergot Altered Events in World History? August 17, 2017

One of the few plant diseases that can also cause direct damage to humans, ergot, particularly in rye grain, may have been a factor in several world events..

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