Project Details:

Title:
Six Secrets - Identifying Best Management Practice for "Offensive/Racehorse" and "Defensive/Workhorse" Varieties

Parent Project: Six secrets of soybean success
Checkoff Organization:Illinois Soybean Association
Categories:Crop management systems, Communication
Organization Project Code:
Project Year:2018
Lead Principal Investigator:Fred Below (University of Illinois at Urbana-Champaign)
Co-Principal Investigators:
Keywords:

Contributing Organizations

Funding Institutions

Information and Results

Comprehensive project details are posted online for three-years only, and final reports indefinitely. For more information on this project please contact this state soybean organization.

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Final Project Results

Updated March 25, 2019:
RESEARCH APPROACH:
Understanding soybean yield responses to foliar protection and increased fertility may help producers
better position soybean varieties. The objective of this study is to identify ‘Offensive’ soybean varieties,
or varieties with adaptability to high yield environments (i.e., responsive to crop management), and
‘Defensive’ soybean varieties, or varieties with acceptable yields in low yield environments (i.e.,
resilience to pests and diseases, and tolerance to nutrient deficiency). In our approach, ‘Offensive’
varieties are the genotypes that combine above-average yield increases from: (i) foliar protection [PROT,
foliar protection (insecticide and fungicide) versus no-foliar protection], (ii) fertility [FERT, yield change
between 0 and 187 lbs/acre of MicroEssentials S10 (N, P, & S)], and (iii) yield performance under the
combination of both treatments (BOTH, yield with additional fertility and foliar protection). Conversely,
varieties with high yield performance under no additional fertilizer or foliar protection (Control) and low
yield response to foliar protection (low PROT) were considered ‘Defensive’ varieties.
The 2018 trial evaluated 61 soybean varieties from six different brands, and maturity groups ranging
from 2.1 to 4.8 (Table 1). Thirty-six varieties were evaluated at Yorkville, Champaign, and Harrisburg.
The trial was planted using a precision plot planter (SeedPro 360, ALMACO, Nevada, IA) at Harrisburg,
IL (2 May 2018), Champaign, IL (16 May 2018), and Yorkville, IL (19 May 2018). Plots were 16 feet in
length with 30-inch row spacing and two rows in width to achieve a final population of approximately
160,000 plants acre-1. The foliar protection treatment was applied using a tractor mounted sprayer and
consisted of an insecticide (Endigo® ZC; Lambda-cyhalothrin + Thiamethoxam) and fungicide
(Trivapro™; Benzovindiflupyr + Azoxystrobin + Propiconazole) application at the R3 stage at a rate of
3.8 and 13.7 oz per acre, respectively. Application dates for foliar protection were 2 July 2018
(Harrisburg), 17 July 2018 (Champaign), and 25 July 2018 (Yorkville). The fertility treatment consisted
of a premium MAP-based phosphorus fertilizer that also contained S, MicroEssentials S10 (MES10, 12-
40-0-10S; The Mosaic Company, Plymouth, MN), applied at 187 lbs acre-1 in a subsurface band 4 to 6
inches deep immediately prior to planting using a research-scale fertilizer toolbar to provide 22 lbs N, 75
lbs P2O5, and 18 lbs S per acre.
Plots were arranged in a split-plot RCB design with four replications. The main plot was fertility (n=2)
and the split-plot was foliar protection (n= 2) and variety (n=36) randomly assigned within each treatment
block. Data were analyzed using analysis of variance with the PROC MIXED procedure of SAS (Version
8, SAS Institute, Cary, NC) and means were separated using Fisher’s protected LSD test at the 0.10 level
of significance. Variety, fertility, and foliar protection were considered fixed effects, while block and
interactions with blocks were considered random effects. At maturity, yield (bu acre-1) was measured with
a plot combine and adjusted to constant moisture (i.e., 13% grain moisture concentration).

YIELD RESULTS:
Soil pH, organic matter, and fertility levels were relatively adequate, allowing for growing
conditions generally conducive to favorable grain yields (Table 2). The 2018 crop growing season
experienced excessive rainfall in June across the state (Table 3). During the remainder of the growing
season rainfall was similar to the 30-year average. Throughout the growing season temperatures were
fairly consistent with the 30-year average, with the exception of May being relatively hot across locations
and September in Champaign.
4
Location significantly affected grain yields (Table 4), with average yields of 90.6, 86.8, and 79.0
bu acre-1 for Yorkville, Champaign, and Harrisburg, respectively (Tables 5 to 19). Foliar protection
increased soybean yield at Champaign and Harrisburg, but did not increase yield at Yorkville due to dry
conditions during July and August, and low disease and insect pressure. Unlike foliar protection,
additional fertility increased grain yield in Yorkville. On average, foliar protection increased yield by
+0.7, +6.9 and +3.5 bu acre-1 at Yorkville, Champaign, and Harrisburg, respectively, while fertility
additions altered yield by +1.6, -0.8, and +0.2 bu acre-1 at these same sites (Figures 1 to 3). Additional
fertility in combination with foliar protection generated the largest yield responses at Yorkville (+2.3 bu
acre-1) and Harrisburg (+3.7 bu acre-1) compared to fertility or foliar protection alone. At Champaign,
foliar protection alone resulted in the largest response at +6.9 bu acre-1.
Across all three locations, varieties had significantly different grain yields. With standard
management (no fertility additions or foliar protection) there was a yield range of 25, 28, and 20 bu acre-1
from highest to lowest yielding varieties at Yorkville, Champaign, and Harrisburg, respectively. The
greatest range in yield response among from varieties was from foliar protection at Harrisburg (36 bu
acre-1).
The highest yields recorded were 107.8, 103.4, and 91.7 bu acre-1 at Yorkville, Champaign, and
Harrisburg, respectively (varieties AG36X6, S41XS98, and AG42X6 and P46A93X, respectively). In
Yorkville, the top five yields were from the following varieties (without repeating a variety): AG36X6
(107.8 bu acre-1), RX3896 (104.9 bu acre-1), AG32X8 (101.9 bu acre-1), S34XT69 (101.9 bu acre-1),
AG37X9 (101.3 bu acre-1), RX3337 (101.3 bu acre-1), and S37XT28 (100.2 bu acre-1). Moving down the
state of Illinois, the top five yields at Champaign were achieved by the following varieties: S41XS98
(103.4 bu acre-1), S39XT68 (100.5 bu acre-1), AG37X9 (100.4 bu acre-1), AG36X6 (100.4 bu acre-1),
GH3546X (99.7 bu acre-1), AG32X8 (98.6 bu acre-1), AG36X6 (98.6 bu acre-1), and S36XT09 (97.7 bu
acre-1). Harrisburg had the highest overall yields achieved by: AG42X6 (91.7 bu acre-1), P46A93X (91.7
bu acre-1), AG42X6 (91.4 bu acre-1), AG41X8 (90.7 bu acre-1), S39XT68 (88.4 bu acre-1), S44XS68 (88.4
bu acre-1), and S37XS89 (88.0 bu acre-1).
Yield responses to additional fertility among individual varieties compared to the untreated control
at all locations ranged from -11.8 to +11.7 bu acre-1 indicating different genetic sensitivity to soil nutrient
availability. Foliar protection application yield-responses ranged from -12.5 to +19.7 bu acre-1 and when
applied in combination with additional fertility the yield changes ranged from -13.9 to +14.3 bu acre-1.
The differences observed in yield performance among varieties and their interaction with
agronomic management across environments highlights the importance of soybean genetic
characterization in response to different agronomic management factors. These characterizations are
summarized in the second half of this report.


CHARACTERIZATION OF VARIETIES IN RESPONSE TO MANAGEMENT:
The differences observed in yield performance among varieties and their interaction with
agronomic management across environments highlights the opportunity of soybean genetic
characterization in response to different agronomic management factors.
The objective of the Soybean MYP trial is to characterize elite soybean cultivars for their
yield response to different agronomic management conditions. Variety decile ranks for yield
performance under low agronomic management input (Yield Control), yield response to increased
fertility (FERT), yield response to foliar protection (PROT), yield response to foliar protection
combined with increased fertility compared to the control (PROT + FERT), and yield performance
ranking compared to other varieties resulting from the combination of both treatments (Yield
BOTH) across locations are presented in Table 20. Agronomists and farmers may use the score
from each parameter to better position their soybean variety based on the agronomic performance
and response to agronomic management at different locations. ‘Defensive’ varieties can be
considered as ones having a high ranking for Yield Control and a low ranking for yield response
to foliar protection (low PROT), while ‘Offensive’ varieties can be considered ones having a high
ranking for Yield Both and high rankings for yield response to foliar protection (high PROT) and
increased fertility (high FERT).

View uploaded report PDF file

RESEARCH APPROACH:
Understanding soybean yield responses to foliar protection and increased fertility may help producers
better position soybean varieties. The objective of this study is to identify ‘Offensive’ soybean varieties,
or varieties with adaptability to high yield environments (i.e., responsive to crop management), and
‘Defensive’ soybean varieties, or varieties with acceptable yields in low yield environments (i.e.,
resilience to pests and diseases, and tolerance to nutrient deficiency). In our approach, ‘Offensive’
varieties are the genotypes that combine above-average yield increases from: (i) foliar protection [PROT,
foliar protection (insecticide and fungicide) versus no-foliar protection], (ii) fertility [FERT, yield change
between 0 and 187 lbs/acre of MicroEssentials S10 (N, P, & S)], and (iii) yield performance under the
combination of both treatments (BOTH, yield with additional fertility and foliar protection). Conversely,
varieties with high yield performance under no additional fertilizer or foliar protection (Control) and low
yield response to foliar protection (low PROT) were considered ‘Defensive’ varieties.
The 2018 trial evaluated 61 soybean varieties from six different brands, and maturity groups ranging
from 2.1 to 4.8 (Table 1). Thirty-six varieties were evaluated at Yorkville, Champaign, and Harrisburg.
The trial was planted using a precision plot planter (SeedPro 360, ALMACO, Nevada, IA) at Harrisburg,
IL (2 May 2018), Champaign, IL (16 May 2018), and Yorkville, IL (19 May 2018). Plots were 16 feet in
length with 30-inch row spacing and two rows in width to achieve a final population of approximately
160,000 plants acre-1. The foliar protection treatment was applied using a tractor mounted sprayer and
consisted of an insecticide (Endigo® ZC; Lambda-cyhalothrin + Thiamethoxam) and fungicide
(Trivapro™; Benzovindiflupyr + Azoxystrobin + Propiconazole) application at the R3 stage at a rate of
3.8 and 13.7 oz per acre, respectively. Application dates for foliar protection were 2 July 2018
(Harrisburg), 17 July 2018 (Champaign), and 25 July 2018 (Yorkville). The fertility treatment consisted
of a premium MAP-based phosphorus fertilizer that also contained S, MicroEssentials S10 (MES10, 12-
40-0-10S; The Mosaic Company, Plymouth, MN), applied at 187 lbs acre-1 in a subsurface band 4 to 6
inches deep immediately prior to planting using a research-scale fertilizer toolbar to provide 22 lbs N, 75
lbs P2O5, and 18 lbs S per acre.
Plots were arranged in a split-plot RCB design with four replications. The main plot was fertility (n=2)
and the split-plot was foliar protection (n= 2) and variety (n=36) randomly assigned within each treatment
block. Data were analyzed using analysis of variance with the PROC MIXED procedure of SAS (Version
8, SAS Institute, Cary, NC) and means were separated using Fisher’s protected LSD test at the 0.10 level
of significance. Variety, fertility, and foliar protection were considered fixed effects, while block and
interactions with blocks were considered random effects. At maturity, yield (bu acre-1) was measured with
a plot combine and adjusted to constant moisture (i.e., 13% grain moisture concentration).

YIELD RESULTS:
Soil pH, organic matter, and fertility levels were relatively adequate, allowing for growing
conditions generally conducive to favorable grain yields (Table 2). The 2018 crop growing season
experienced excessive rainfall in June across the state (Table 3). During the remainder of the growing
season rainfall was similar to the 30-year average. Throughout the growing season temperatures were
fairly consistent with the 30-year average, with the exception of May being relatively hot across locations
and September in Champaign.
4
Location significantly affected grain yields (Table 4), with average yields of 90.6, 86.8, and 79.0
bu acre-1 for Yorkville, Champaign, and Harrisburg, respectively (Tables 5 to 19). Foliar protection
increased soybean yield at Champaign and Harrisburg, but did not increase yield at Yorkville due to dry
conditions during July and August, and low disease and insect pressure. Unlike foliar protection,
additional fertility increased grain yield in Yorkville. On average, foliar protection increased yield by
+0.7, +6.9 and +3.5 bu acre-1 at Yorkville, Champaign, and Harrisburg, respectively, while fertility
additions altered yield by +1.6, -0.8, and +0.2 bu acre-1 at these same sites (Figures 1 to 3). Additional
fertility in combination with foliar protection generated the largest yield responses at Yorkville (+2.3 bu
acre-1) and Harrisburg (+3.7 bu acre-1) compared to fertility or foliar protection alone. At Champaign,
foliar protection alone resulted in the largest response at +6.9 bu acre-1.
Across all three locations, varieties had significantly different grain yields. With standard
management (no fertility additions or foliar protection) there was a yield range of 25, 28, and 20 bu acre-1
from highest to lowest yielding varieties at Yorkville, Champaign, and Harrisburg, respectively. The
greatest range in yield response among from varieties was from foliar protection at Harrisburg (36 bu
acre-1).
The highest yields recorded were 107.8, 103.4, and 91.7 bu acre-1 at Yorkville, Champaign, and
Harrisburg, respectively (varieties AG36X6, S41XS98, and AG42X6 and P46A93X, respectively). In
Yorkville, the top five yields were from the following varieties (without repeating a variety): AG36X6
(107.8 bu acre-1), RX3896 (104.9 bu acre-1), AG32X8 (101.9 bu acre-1), S34XT69 (101.9 bu acre-1),
AG37X9 (101.3 bu acre-1), RX3337 (101.3 bu acre-1), and S37XT28 (100.2 bu acre-1). Moving down the
state of Illinois, the top five yields at Champaign were achieved by the following varieties: S41XS98
(103.4 bu acre-1), S39XT68 (100.5 bu acre-1), AG37X9 (100.4 bu acre-1), AG36X6 (100.4 bu acre-1),
GH3546X (99.7 bu acre-1), AG32X8 (98.6 bu acre-1), AG36X6 (98.6 bu acre-1), and S36XT09 (97.7 bu
acre-1). Harrisburg had the highest overall yields achieved by: AG42X6 (91.7 bu acre-1), P46A93X (91.7
bu acre-1), AG42X6 (91.4 bu acre-1), AG41X8 (90.7 bu acre-1), S39XT68 (88.4 bu acre-1), S44XS68 (88.4
bu acre-1), and S37XS89 (88.0 bu acre-1).
Yield responses to additional fertility among individual varieties compared to the untreated control
at all locations ranged from -11.8 to +11.7 bu acre-1 indicating different genetic sensitivity to soil nutrient
availability. Foliar protection application yield-responses ranged from -12.5 to +19.7 bu acre-1 and when
applied in combination with additional fertility the yield changes ranged from -13.9 to +14.3 bu acre-1.
The differences observed in yield performance among varieties and their interaction with
agronomic management across environments highlights the importance of soybean genetic
characterization in response to different agronomic management factors. These characterizations are
summarized in the second half of this report.


CHARACTERIZATION OF VARIETIES IN RESPONSE TO MANAGEMENT:
The differences observed in yield performance among varieties and their interaction with
agronomic management across environments highlights the opportunity of soybean genetic
characterization in response to different agronomic management factors.
The objective of the Soybean MYP trial is to characterize elite soybean cultivars for their
yield response to different agronomic management conditions. Variety decile ranks for yield
performance under low agronomic management input (Yield Control), yield response to increased
fertility (FERT), yield response to foliar protection (PROT), yield response to foliar protection
combined with increased fertility compared to the control (PROT + FERT), and yield performance
ranking compared to other varieties resulting from the combination of both treatments (Yield
BOTH) across locations are presented in Table 20. Agronomists and farmers may use the score
from each parameter to better position their soybean variety based on the agronomic performance
and response to agronomic management at different locations. ‘Defensive’ varieties can be
considered as ones having a high ranking for Yield Control and a low ranking for yield response
to foliar protection (low PROT), while ‘Offensive’ varieties can be considered ones having a high
ranking for Yield Both and high rankings for yield response to foliar protection (high PROT) and
increased fertility (high FERT).

Project Years