2021 MSU Corn Hybrid Trial Disease Evaluations – Non-irrigated Locations

During 2021, corn hybrid trials 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 this project.

The foliar diseases present within each of the OHT locations (irrigated (n=5) and non-irrigated (n=5 total locations; however, the plots at Crystal Springs was unable to be evaluated)) were evaluated at approximately dent (R5) during the 2021 season. The diseases present at each location were observed based on natural occurrence. Curvularia leaf spot and southern rust were the two most prevalent diseases.  In addition, southern corn leaf blight (SCLB), which is predominantly a lower canopy disease, and northern corn leaf blight (NCLB) were evaluated at several of the locations since I have had numerous questions regarding the increased incidence of this particular disease recently.

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).  Curvularia leaf spot and NCLB were evaluated based on their presence on the ear leaf and above.  SCLB was observed from the ear leaf and below.  Southern rust was evaluated from the ear leaf and above; however, southern rust evaluations varied widely across the state simply due to the severity of the disease during 2021.  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.

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 73 hybrids while the non-irrigated locations contained 58 hybrids.  Both sets, whether irrigated or non-irrigated contained five experimental hybrids as indicated in the tables by an asterisk.

Non-irrigated MSU Corn OHT locations:

Aberdeen 2021 Aberdeen Non-irr

Brooksville 2021 Brooksville Non-irr

Olive Branch 2021 Olive Branch Non-irr

Stoneville (loam) 2021 Stoneville loam Non-irr

Verona 2021 Verona Non-irr

To see the response of hybrids at the irrigated MS locations visit: https://www.mississippi-crops.com/2021/11/21/2021-msu-corn-hybrid-trial-disease-evaluations-irrigated-locations/