Deploying a Pathogen Quantification Assay to Improve Fungicide Use Efficiency for Sustainable Sod Production in the Northeast

Commodities

• Agronomic: grass (turfgrass, sod)

Practices

• Crop Production: application rate management
• Education and Training: decision support system, on-farm/ranch research
• Pest Management: chemical control, field monitoring/scouting

This project aims to develop a decision support tool to guide precision fungicide application against brown patch, gray leaf spot, dollar spot and anthracnose for sod producers in New Jersey and the Northeast. New Jersey sod farms covered 3,359 hectares with an estimated economic impact of $94.7 million in the 2019 census. A survey conducted through the Rutgers University Plant Diagnostic Laboratory revealed that, over the past 18 years, 75% of the diseased samples were foliar, and the four diseases the project plans to address accounted for over 70% of them. Through in-person, email and phone interviews, sod growers in New Jersey expressed that the most common way to control disease is through calendar-based fungicide applications, mainly due to lack of decision support tool that can be easily integrated into the current production system. A calendar-based program is imprecise: it often results in over-applications and, at other times, is susceptible to disease breakthrough due to missed critical timing for disease development. This proposal aims to develop a disease control decision support tool for sod growers to promote informed decision-making and to facilitate environmentally and financially sustainable sod production.

A multiplexed digital PCR (dPCR) pathogen quantification assay was recently developed by our team, and it is capable of quantifying causal agents for the abovementioned turfgrass diseases using turfgrass mowing clippings. Since mowing is part of the day-to-day practice in sod production, using mowing clippings to measure the disease pressure allows seamless integration of this decision support tool into the current operation. This assay was developed using clippings collected from the research farm at Rutgers University. Ground-truthing the assay to relate the dPCR data and observed disease pressure is required to ensure practical utility. Therefore, this proposed project will collaborate with New Jersey sod growers who will work with us to validate the assay and establish practical disease risk thresholds to complete development of this decision support tool.

The collaborative farmers will establish research plots on their farms, monitor the disease development on the control plots, collect mowing clippings and submit the sample weekly for pathogen load monitoring. Once the preliminary disease risk thresholds are established, the collaborators will plan their disease management according to the measured disease risks. We also plan to provide a trial of the prototype decision support tool in the third year of the study so that more sod farmers can be exposed to this tool and potentially take advantage of the service once fully developed. We will also be able to collect grower’s feedback to optimize this tool. The developed service is anticipated to be publicly available through the Rutgers University Plant Diagnostic Laboratory to benefit sod growers in the Northeast and beyond.

A recently developed pathogen quantification assay will be field validated in collaboration with sod producers to evaluate its practical utility, aiming to develop a decision-support tool which informs disease risks for sod growers. This collaborative study will generate pathogen load data, which will be coupled with weather data, field observations and end-user feedback to make the data relevant to real-world scenario and help us optimize assay efficiency and practicality. This proposed decision-support tool will help sod growers in the Northeast better evaluate the disease risks so they can apply fungicides precisely for a more environmentally and financially sustainable sod production.