2023 MSU Corn Hybrid Trial Disease Evaluations – Non-irrigated Locations

During 2023, 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=5) and non-irrigated (n=5; however, the plots at Verona were unable to be evaluated due to lack of disease/drought) were evaluated at approximately dent (R5) during the 2023 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.  In some cases a limited amount of southern rust was observed.  In addition, several locations were observed for what we are presently calling an abiotic disorder.

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 53 hybrids while the non-irrigated locations contained 44 hybrids.

Non-irrigated MSU Corn OHT locations:

Aberdeen 2023 Corn OHT non irrigated Aberdeen

Brooksville 2023 Corn OHT non irrigated Brooksville

Horn Lake 2023 Corn OHT non irrigated Horn Lake

Raymond 2023 Corn OHT non irrigated Raymond

Stoneville (loam) 2023 Corn OHT non irrigated Stoneville Loam