From 2012 to 2020, SDS, Fusarium diseases, charcoal rot, and Phytophthora root rot cost Kansas soybean farmers an average of 7.8% of production per year. Through past KSC support, the Row Crops Pathology Lab at KSU has taken a leadership role in soybean root health research with an emphasis on diseases. Our priorities are the discovery of plant resistance, management strategies, and new disease information to help Kansas producers increase their yields and profits over the long-term. The project objectives for this program seek to discover resistance, evaluate management strategies, assess re-emerging root pathogens, and communicate management strategies for soybean root and seedling diseases in Kansas.

1. Discover resistance to Fusarium seedling diseases, sudden death syndrome (SDS), and charcoal rot in germplasm with abiotic stress resistance traits.
2. Evaluate management strategies for soybean seedling and root diseases.
3. Assess the impact of re-emerging root pathogens: Phytophthora sojae in Kansas.
4. Develop and communicate management considerations based on objectives 1, 2, and 3.

In terms of outcomes: (1) Identification of breeding lines, PIs, and commercial varieties with resistance to SDS, Fusarium root rot/seedling disease, and charcoal rot. (2) Determine the effectiveness of management strategies, esp. the use of Brassica juncea cover crops on SDS and Fusarium root and seedling disease control. (3) Develop a SEK Phyotophthora sojae set that can be evaluated. (4) Results obtained during the proposed studies will be published in recognized scholarly journals. (5) Useful information from these studies will be incorporated into future Kansas Research & Extension publications such as new plant pathology fact sheet(s), crop production support guide(s), and Agronomy eUpdates. (6) We will communicate these results to producers and stakeholders at training sessions and field days. (7) Results will also be communicated on a regular basis on the K-State Radio Network program, Agriculture Today.

Update:
1. Discover resistance to Fusarium seedling diseases, sudden death syndrome (SDS), and
charcoal rot in germplasm with abiotic stress resistance traits.
2. Evaluate management strategies for soybean seedling and root diseases.
3. Assess the impact of re-emerging root pathogens: Phytophthora sojae in Kansas.
4. Develop and communicate management considerations based on objectives 1, 2, and 3.
OBJ 1.
The primary activities associated with this objective have been on the pathogen side. We have
screened multiple isolates of root and seedling-associated Fusarium spp. against soybeans
('AG3403') in a rolled-towel pathogenicity assay and obtained germination, root length, and
seedling weight data. See Figure 1 on linked document for more information.
Abiotic stress resistance traits:
In addition, 47 plant introductions (PIs) with heat tolerance, 151 PIs with halotolerance, and 360
PIs with chlorosis scores of '1' have been identified from the GRIN database that may have the
potential for pathogen screening to integrate abiotic stress tolerance with root and seedling
Fusarium disease resistance. Integrating these with charcoal rot resistance, to the extent that it
exists, is also of interest.
OBJ 2.
The primary activities associated with this objective have been testing Fusarium proliferatum
isolates against strobilurin fungicides. An undergraduate, Hutch Turner, is working on this and has
completed a set of 30+ F. proliferatum isolates and their growth on azoxystrobin. This data is still
being analyzed and also EC50 calculations need to be performed. Hutch will also extract DNA and
perform PCR on all isolates using species-specific primers to ensure the proper identification of
these pathogens.
OBJ 3.
Numerous soil and plant samples have been obtained from southeast Kansas at both experiment
station sites and cooperator farmers' fields. These samples have been collected a pre-, mid-, and
post-season time points. Phytophthora-specific primers are being used to amplify whole soil DNA
and seedling/root DNA to detect the presence of P. sojae. In addition, traditional culturing
approaches are being used. Also, other pathogens, such as Diaporthe spp. are quite common in
this production area and co-exist with Macrophomina, Fusarium, and other root pathogens of
interest.
OBJ 4.
Information and updates that come from these studies are communicated by the Row Crops
Extension Pathologist, Rodrigo Onofre, at grower meetings, radio interviews, field days, and other
opportunities for interaction. A potential goal would be to develop a soybean seedling and root
disease extension publication for Kansas in the future

View uploaded report

Updated July 23, 2024:
Summary: This project focuses on several key objectives aimed at enhancing soybean health and productivity through various approaches.

Objective 1 revolves around identifying resistance to Fusarium seedling diseases, sudden death syndrome (SDS), and charcoal rot in soybean germplasm that also exhibits traits for abiotic stress tolerance. We conducted extensive screening of Fusarium spp. isolates from Kansas soybeans using a rolled-towel pathogenicity assay. Fusarium proliferatum and F. reticulatum showed significant negative impacts on seed germination. We are currently analyzing root length data and preparing for publication. Additionally, we identified plant introductions (PIs) from the GRIN database with heat and halotolerance traits, along with resistance to chlorosis, potentially integrating these traits with disease resistance studies.

Objective 2 involves evaluating management strategies for soybean seedling and root diseases, particularly focusing on Fusarium proliferatum's response to strobilurin fungicides. We are assessing sensitivity among isolates and employing species-specific PCR to verify pathogen identity.

Objective 3 assesses the re-emergence of Phytophthora sojae in Kansas. We collected soil and plant samples, detecting P. sojae using specific primers and traditional culturing methods alongside other pathogens like Diaporthe spp.

Objective 4 aims to develop and disseminate management strategies based on the findings from Objectives 1, 2, and 3. Information is communicated through various platforms by the Extension Pathologist, Rodrigo Onofre, to stakeholders such as growers and agricultural professionals. The goal includes producing extension publications tailored for Kansas growers.

The findings highlight the complexity of soybean disease management, emphasizing the integration of pathogen screening with abiotic stress tolerance traits. By understanding pathogen behavior and the efficacy of fungicidal treatments, the team aims to provide practical solutions for enhancing soybean resilience and yield in Kansas's agricultural landscapes.

View uploaded report

BLURB: "Improving soybean health in Kansas by tackling root and seedling diseases."

Spring 2024 Progress:

1. Finding Disease Resistance:
Researchers are testing different soybean varieties to find those that can resist diseases caused by Fusarium fungi, sudden death syndrome (SDS), and charcoal rot. They’re also looking for plants that can handle stress from heat and other factors.

2. Testing Management Strategies:
We're experimenting with different ways to manage Fusarium fungi and testing how well common fungicides work against them. An undergraduate student is leading this work, and they’re analyzing how sensitive the fungi are to specific fungicides.

3. Tracking Re-emerging Pathogens:
We're monitoring the presence of Phytophthora sojae, a root pathogen that is becoming more common. They’re collecting and analyzing soil and plant samples from various locations to detect this and other pathogens.

4. Sharing Findings:
The project team is sharing updates through meetings, radio interviews, and field days. They plan to create a guide for Kansas soybean farmers on managing these diseases based on their research findings.

In essence, the project aims to identify resistant soybean plants, test disease management methods, track troublesome pathogens, and share useful information with farmers to improve soybean health.

(1) SDS, Fusarium, and charcoal rot resistant materials in the breeding pipeline. Traits to be incorporated in future seed available to farmers. LONG-TERM BENEFIT
(2) Communication of management strategies, including cover crops and seed treatments, for improved seedling and root health. SHORT- and MEDIUM-TERM BENEFIT