Posts tagged ‘Stratego’

Foliar Fungicide Application to Corn

Late July through early August used to be a time when things settled down on most farms. The last of the herbicides had been sprayed on soybeans, and wheat has been baled and stored.  During the past couple of years, however, there has been a push to apply foliar fungicides to corn during the critical corn reproductive stage.  Questions remain as to the efficacy of applying fungicides to corn this time of year, and whether or not this practice is warranted.

In this video clip shot July 23, 2009, I am spraying my corn fungicide trial with Stratego @ 10 oz/acre + NIS @ 0.125% v/v. Volume was 15 GPA at 40 PSI with XR11004 on very early VT corn. I noted less than 1% leaf area had rust, no other diseases were present. Thanks to Brent Neate for application and use of the Walker 44.

I am involved with three studies over the past three years looking at this very issue.  I have data to share for 2007 and 2008, and will be releasing the 2009 data following harvest this fall.  Below, I will summarize the results from 2007 and 2008 studies.

The studies from 2007 and 2008 are similar in design.  In both years the study was set up as three treatments with four replications of each treatment in a randomized complete block design. Plot size was 45 feet wide by 1090 feet long. The treatments tested were: 1) Untreated check, 2) Headline at 6.0 ounces per acre + nonionic surfactant (NIS) at 0.25% v/v, and 3) Stratego at 10.0 ounces per acre + nonionic surfactant (NIS) at 0.125% v/v.  Fungicide applications were made with a high clearance ground sprayer in 15 gallons per acre spray volume at 50 psi using TeeJet XR11004 flat fan nozzles.

Due to differences in growing seasons between 2007 and 2008, the application date was different.  In 2007, both the Headline and Stratego foliar fungicide treatments were applied on July 18 with corn at growth stages VT-tassel emergence to R1- silking.  In 2008, both the Headline and Stratego foliar fungicide treatments were applied on August 8 with corn at growth stage R2-blister.

Results of the studies are similar. Data from the trials indicates there were no statistically significant differences between the treatments for corn yield.  Visual inspections during the growing season did not show any significant disease pressures in any of the plots, but the fungicide treated plots did have greener plants later in the season.  Here are the actual yield numbers for 2007: untreated check = 184.6 bushels/acre, Headline = 183.4 bushels/acre, and Stratego = 188.0 bushels/acre.  Here are the actual yield numbers for 2008: untreated check = 118.2 bushels/acre, Headline = 123.9 bushels/acre, and Stratego = 125.5 bushels/acre.  Variability between the yield means is most likely being caused by other outside influences and cannot be attributed to the fungicide treatments based on the statistical analysis.

The complete studies (which include data on hybrid, planting date, fertility, etc.) are available online at: http://farmfocus.osu.edu/corn_foliar_fungicides-07.pdf and http://farmfocus.osu.edu/corn_foliar_fungicide-08.pdf.  For more information on corn diseases and fungicides recommendations for corn, please stay informed with the weekly updates from the OSU Extension Agronomic Crops Team CORN Newsletter at http://corn.osu.edu/.

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July 27, 2009 at 8:00 am

Fungicide Use Evaluated, Summarized in Soybeans

In the recent Iowa State University Integrated Crop Management Newsletter, XB Yang and his associates summarize six years of fungicide research on soybeans. Their research appears to be exhaustive, examining up to 50 treatments replicated four times in a year. Obviously, the summary of data relates directly to Iowa, but I believe there is some applicability in Ohio.

Their study found that some soybean fungicide treatments consistently ranked top in terms of increase in yields in our multiple year tests (except for one season) even when disease pressure was low to moderate. Also, they found that application at R1 or earlier did not pay off, but application at R3 consistently produced highest yields. They summarize their study by stating that fungicide application is best reserved for seasons when foliar diseases are severe. The full Iowa State University article is available here.

In local research, Gary Prill and I have conducted three years of similar research at Farm Focus. Our findings are consistent:

2006: We compared separately Quadris, Headline, and Presto (foliar fertilizer) to an untreated check. Fungicide application was made at soybean growth stage R3. The Headline treatment provided a statistically significant yield increase compared to the Quadris, Presto and untreated check. The application of Headline paid for itself and provided an economic return in 2006. Study available here: http://farmfocus.osu.edu/bean_plant_health-06.pdf

2007: We compared separately Stratego, Headline and Presto (foliar fertilizer) to an untreated check. Fungicide application was made at soybean growth stage R3. The Headline treatment provided a statistically significant yield increase compared to the Stratego and untreated check. The application of Headline paid for itself and provided an economic return in 2007. Study available here: http://farmfocus.osu.edu/bean_plant_health-07.pdf

2008: We compared separately Domark, Headline and Stratego to an untreated check. Fungicide application was made at soybean growth stage R3. None of the treatments provided a statistically significant yield increase when compared to the untreated check even though the Headline and Domark treatment increased yield over the check. (Unpublished at the time or writing this blog post)

It is clear from three years of data that using fungicides on soybeans as a preventative measure may provide a net return in some years. In none of the three study years at Farm Focus was soybean foliar leaf disease present at levels that would have justified a fungicide treatment.

Full podcast available here:

12/18/08 Update:

XB Yang contacted me and provided a link to the full presentation.  He indicates the presentation is available for use, except for the photos (which are copyright protected). Full presentation available in a pdf file here.

December 3, 2008 at 7:00 am 2 comments


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This blog is no longer being maintained. Information on this blog may still be relevant, but for the latest agronomic information and farm management information please visit http://corn.osu.edu and http://ohioagmanager.osu.edu, respectively.

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