Soybean Yield Response to DuPont™ Aproach® Prima Fungicide (Southern U.S.)

Objective

Evaluate soybean yield response to DuPont™ Aproach® Prima fungicide applied at the R3 growth stage on Pioneer® brand soybean varieties.

Study Description

Plot Layout:		On-farm strip trials
Locations:		9 (Miss., Ky., Ala, Tenn.)
Years:		2014-2015

Fungicide Treatment¹:

Aproach Prima fungicide (6.8 fl oz/acre at R3 stage)
Non-treated control


Pioneer brand soybean varieties:
Variety/Brand²:	P47T36R P48T53R	P50T64R 94Y82(R)

Data Collected: Soybean yield (bu/acre)

¹ Make no more than 2 applications of a picoxystrobin containing product before switching to a fungicide with a different mode of action. The minimum retreatment interval in soybeans for Aproach Prima fungicide is 14 days. Do not exceed 13.6 fluid ounces of Aproach Prima fungicide per acre per crop.

² All Pioneer products are varieties unless designated with LL, in which case some are brands.

Results

Leaves from Pioneer® variety P54T94R treated with Aproach Prima and leaves from a non-treated plant from a trial near Leland, Miss. in 2015.

Application made July 15; photo taken August 24. FELS score for P54T94R = 4 using a 1-9 scale where 1=highly susceptible and 9=resistant.

Pioneer variety P54T94R non-treated (left) and treated with Aproach Prima (right) near Leland, Miss., in 2015.

Application made July 15; photo taken August 31. FELS score for P54T94R = 4 using a 1-9 scale where 1=highly susceptible and 9=resistant.

**Figure 1.** Average yield of soybeans treated with Aproach Prima fungicide compared to a non-treated control.

Data averaged over 9 locations and 19 individual observations from Ala., Ky., Miss., and Tenn. in 2014-2015.

**Figure 2.** Soybean yield response to Aproach Prima fungicide by location and variety.

Data collected from 9 locations and 19 paired comparisons from Ala., Ky., Miss., and Tenn. in 2014-2015. Red dashed line: breakeven price = 2.5 bu/acre assuming $8.75/bu soybean price.

**Figure 3.** Soybean yield response to Aproach Prima fungicide treatment by variety.

Data collected from 7 locations and 17 paired comparison from Ala., Ky., Miss, and Tenn. in 2015. Red dashed line: breakeven price = 2.5 bu/acre assuming $8.75/bu soybean price.

Summary

Averaged over 19 locations, soybean plots treated with Aproach Prima fungicide yielded an average of 3.7 bu/acre more than non-treated plots (Figure 1).
Economical yield responses occurred with 13 of 19 paired comparisons, or 68% of the time (Figure 2).
Soybean yield responses to Aproach Prima fungicide applied at the R3 growth stage ranged from 2.7 bu/acre with Pioneer variety P47T36R to 3.9 bu/acre with 94Y82 (Figure 3).
Yield response to Aproach Prima fungicide for varieties with a frogeye leaf spot score of 5 were not greater than responses observed with more tolerant varieties (Figure 4).
These data indicate that economical yield responses can be achieved with Aproach Prima fungicide applied to soybean at the R3 growth stage and that these responses may not necessarily be correlated with disease susceptibility scores.

Authors: Darrin Malone and Dan Poston

The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. 2014-2015 data are based on average of all comparisons made in 9 locations through Nov. 11, 2015. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary. Pioneer® brand products are sold subject to the terms and conditions of sale which are part of the labeling and purchase documents.

Related Content

Back to Trials

R - Contains the Glyphosate Tolerant trait. Always follow grain marketing, stewardship practices and pesticide label directions. Varieties with the Glyphosate Tolerant trait (including those designated by the letter “R” in the product number) contain genes that confer tolerance to glyphosate herbicides. Glyphosate herbicides will kill crops that are not tolerant to glyphosate.