2014 Frogeye Leaf Spot and Cercospora Blight Foliar Fungicide Trials: Trial Data

Soybean variety and locations

In all trials, Armor DK 4744, a frogeye leaf spot susceptible soybean variety was used.  Fungicide trials were conducted in Starkville (n=2) and Stoneville (n=6) in field situations where continuous soybean had been planted.  The Starkville location was non-irrigated while the Stoneville location was irrigated.  Starkville was conducted in plots that were 40 feet in length on 38 inch centers while Stoneville plots varied in length as either 20 (1 trial) or 30 (5 trials) in length, but all Stoneville plots were on 40 inch centers.

Fungicide application and application timings

Fungicides were applied in 15 gallons of water/acre with a non-ionic surfactant at 0.25% v/v.  Several different fungicide timings were considered during 2014.  Fungicide applications were made as early as V7 in one instance (2014 Stoneville Bayer).  Additional timed applications were made at R2, R3, R4, R5, and R6 depending on the specifics of each trial.  Some sequential timings were also included, such as V7 fb R4 and R2 fb R4.

Ratings

Disease ratings (Cercospora blight and frogeye leaf spot) were conducted on a scale of 0-9 whereby 0=no foliar disease present and 9=extreme foliar disease present indicative of approximately 90% of the leaf surface area covered by disease.  In all cases, disease was rated either immediately before the fungicide application or a few days following the application to provide a baseline observation of disease present.  Phytotoxicity present following fungicide application was observationally rated on a scale of 0-100% by observing the level of tissue within the center two rows of each plot to contain plant tissue affected.  Green stem was rated immediately prior to harvest by counting plants affected in three replicated 3 foot areas within each plot.  Green stem is presented as a percentage (0-100%) for the nontreated as well as the treated trials conducted in Stoneville.  Green stem ratings were not recorded for the Starkville location.

Fungicide product cross reference guide

To see a specific product, product rate, or application timing, please refer to the table and the associated trial as outlined below by letter (A, B, E, F, I, S, Y, Z).  Starkville trials are presented as Y and Z, while the trials conducted in Stoneville are presented as A, B, E, F, I, and S.  In all, 34 different products or product combinations were assessed during 2014.

QoI = quinone outside inhibitor or strobilurin

DMI = demethylation inhibitor or triazole

SDHI = succinate dehydrogenase inhibitor or carboximide

MBC = methyl benzimidazole carbamate

Trial data

2014 Starkville test Y

2014 Starkville test Z

2014 Stoneville BASF-2 test B

2014 Stoneville BASF test S

2014 Stoneville Bayer test A

2014 Stoneville Cheminova II test I

2014 Stoneville Marrone test E

2014 Stoneville Viva, Inc. test F