2022 MSU Corn Hybrid Trial Disease Evaluations – Irrigated Locations

During 2022, corn hybrid trials, planted by the MSU Variety Testing Program and considered to be the Official Hybrid Trials (OHT) were evaluated to determine the response of corn hybrids planted in our production system to the most commonly occurring foliar diseases.  Over the past several years, numerous questions have originated regarding the response of hybrids to foliar diseases such as Curuvularia leaf spot.  At present, little if any information exists regarding the impact of Curvularia leaf spot on yield or even whether or not management options should be considered.  The MS Corn Promotion Board sponsored the evaluations conducted in the associated tables.

The foliar diseases present within each of the OHT locations (irrigated (n=6) and non-irrigated (n=5 total locations; however, the plots at Brooksville were unable to be evaluated due to lack of disease/drought)) were evaluated at approximately dent (R5) during the 2022 season. The diseases present at each location were observed based on natural occurrence. Curvularia leaf spot was the most prevalent disease observed during the season.  However, evaluations on southern corn leaf blight (SCLB), southern rust (two locations), and Physoderma brown spot (from one location) were also captured.

Disease evaluations were based on the presence of each of the diseases within the respective area of the canopy where the disease is most often observed and where the disease could be a concern with regards to yield reduction (ear leaf and above).  All evaluations were conducted using a 0-9 scale where 0=no disease present, 5=a moderate level of disease, and 9=leaves completely covered with the specific disease.  Evaluations should be considered to represent disease severity from within each location.

As some background regarding the irrigated and non-irrigated OHT locations.  Each specific irrigation regime generally contains a different number of hybrids.  All locations were planted as two row plots and replicated four times.  The irrigated OHT contained 62 hybrids while the non-irrigated locations contained 45 hybrids.  The irrigated set contained two experimental hybrids as indicated in the tables by an asterisk.

Irrigated MSU Corn OHT locations:

Lake Cormorant 2022 Lake Cormorant Irr

Macon 2022 Macon Irr

Minter City 2022 Minter City Irr

Rolling Fork 2022 Rolling Fork Irr

Stoneville (clay) 2022 Stoneville (clay) Irr

Stoneville (loam) 2022 Stoneville (loam) Irr

To see the response of hybrids at the non-irrigated MS locations visit: https://www.mississippi-crops.com/2022/11/11/2022-msu-corn-hybrid-trial-disease-evaluations-non-irrigated-locations/