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Inoculation Method Impacts Symptom Development Associated with Diaporthe

Soybean (Glycine max) is one of the most important crops in the United States. One production constraint includes the five diseases caused by species of Diaporthe, which can greatly affect yields. During 2014, approximately 1 million metric tons were lost in the U.S. and Canada from Diaporthe-associated diseases.

A research study used many inoculation techniques over five decades to study more than 150 Diaporthe isolates, that can be further separated into five types, from symptomatic soybean stem samples from Iowa and around the region. The researchers’ goal was to examine aggressiveness, disease severity, pathogen recovery and relative treatment effects of each of the five types of isolates to find the more effective ways to research the diseases, and ultimately combat them. Their study suggests different inoculation methods can have a significant impact on the study of symptom development in soybeans, with the toothpick and stem-wound inoculation methods being the most effective techniques on three of the five types to yield research data.

This study was published in 2019. To view the whole study, click here.

Project Type: 
Duration: 
03/04/2019
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Effect of Tillage and Cultivar on Plant Population, Sudden Death Syndrome, and Yield of Soybean in Iowa

Sudden death syndrome (SDS) affects soybeans around the world and accounts for millions of tons of yield loss in the United States and Canada, ranking it as one of the top 10 yield-reducing diseases of soybean for 16 years. Managing SDS has been difficult with the lack of effective foliar fungicides and completely resistant cultivars, environmental influences and inconsistent management practices.

The researchers in the study aimed to determine the impact conservation tillage had in relation to SDS. Conservation tillage practices have become common practice to preserve soil moisture and prevent erosion, and has shown results in reducing soybean cyst nematode (SCN) populations in the field. Both SCN and SDS have a linked severity, but SDS also has a positive correlation with the soil moisture content.

The field experiments took place in Iowa in a field with a history of SDS and were evaluated for five consecutive years. Data showed there were differences in root rot severity and foliar disease symptoms across the years among different cultivars, but this was not due to tillage. Although yields were different across the years, researchers write that this was not due to tillage and can be explained by seeding rates and sufficient rainfall. The study confirms using resistant cultivars is the best practice to fight SDS, and that seed treatment, SCN management and diversification in cropping systems can aid in disease resistance. In all, incidences of SDS were not dependent on tillage method, as the incidence of disease was consistent throughout the study. SDS resistant cultivars would make the most impact.  

This study was published in 2019. To view the whole study, click here.

Project Type: 
Duration: 
03/04/2019
Category: 

Yard and Garden: Lawn Mowing Tips

April 30, 2014

AMES, Iowa — Proper mowing practices play a vital role in helping to maintain a healthy, sustainable home lawn. Horticulturists with Iowa State University Extension and Outreach answer questions about lawns and lawn mowing. Homeowners and gardeners with lawn questions should contact horticulturists at Hortline by emailing hortline@iastate.edu or calling 515-294-3108.

What is the proper mowing height for a lawn? 

2014 Crop Scouting Competition Open to High School Students

April 28, 2014

AMES, Iowa — The Integrated Pest Management program at Iowa State University is hosting its fourth crop scouting competition on Aug. 5 for teams of Iowa high school students. Organizers announced the 2014 theme, Crop Scouting Innovations, this week along with extending an invitation to participate to teams of high school students (those completing grades 9-12).

Emerald Ash Borer Confirmed in Jasper County

March 28, 2014

DES MOINES – Emerald Ash Borer has been positively identified in a residential tree in Newton in Jasper County from a larva sample collected on March 20, 2014. EAB kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America.
 

Emerald ash borer confirmed in Keokuk County

January 30, 2015

Iowa map of emerald ash borer confirmations

DES MOINES – Emerald Ash Borer (EAB) has been positively identified in the Iowa community of Hedrick in Keokuk County. EAB kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America.

Emerald ash borer confirmed in Montgomery Co, IA

August 18, 2015

DES MOINES – The emerald ash borer (EAB), a destructive and invasive insect of ash trees has been discovered in central rural Montgomery County. Iowa’s growing number of counties with confirmed detections has now reached twenty-seven. Native to Asia, EAB has spread to 25 states since first being identified in Michigan back in 2002. This exotic pest is responsible for the death of tens of millions of ash trees.  Click for current map of infestations.

 

Bundle Deals at the ISU Extension Store!

February 28, 2017

The new crop season is right around the corner, and we want you to be prepared!

Two publications have new bundle discounts—the Weed Identification Field Guide, 2nd Edition, and the new Corn and Soybean Field Guide, recently published in fall 2016.corn and soybean field guide

Deals

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