2017 corn management yield potential final …cropphysiology.cropsci.illinois.edu/documents/2017...

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2017 Corn Management Yield Potential Eric Winans, Alison Vogel, and Fred E. Below Crop Physiology Laboratory – Department of Crop Sciences

University of Illinois at Urbana-Champaign

Table of Contents

Research Approach ....................................................................................................................... 2

Yield Results .................................................................................................................................. 7

Yorkville, IL ............................................................................................................................... 9

Champaign, IL ......................................................................................................................... 18

Harrisburg, IL ......................................................................................................................... 27

Characterization of ‘Workhorse’ and ‘Racehorse’ Hybrids .................................................. 36

Summary of Hybrid Agronomic Characteristics ..................................................................... 39

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Research Approach Corn producers have become increasingly aware of the importance of combining

management factors like hybrid, nitrogen, and population to drive increased yields and profitability. Choosing the right hybrid is especially important because not all hybrids are created equally in their ability to use nitrogen or tolerate increased population and narrower row spacing. Despite the need to tailor the hybrid to the overall management system, there is not much information available publicly to make this decision. Therefore, the objective of the Corn Management Yield Potential (MYP) trial is to identify ‘Racehorse’ hybrids, or hybrids that have greater than average yield increases with high-yield crop management, and ‘Workhorse’ hybrids, or hybrids with acceptable yields in a low fertility environment [i.e. tolerant to nitrogen (N) loss].

In our approach, ‘Racehorse’ hybrids are the genotypes that have greater yield increases in the following categories:

(i) N fertilizer (yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1), (ii) an intermediate plant population (yield response between 32,000 and 38,000 plants

acre-1 at 280 lb N acre-1), (iii) high plant population (yield change between 38,000 and 44,000 plants acre-1 at 280 lb

N acre-1), and (iv) narrower row spacing (yield change between 30 and 20 inches row spacing at 44,000

plants acre-1 and 280 lb N acre-1).

On the contrary, ‘Workhorse’ hybrids were those with:

a) high Check Plot yield (at 0 lb N acre-1) and b) a large yield increase with low N (yield change between 0 and 60 lb N acre-1 at

32,000 plants acre-1).

For 2017, the trial was planted using a precision plot planter with variable seeding rate capability (SeedPro 360, ALMACO, Nevada, IA) at Yorkville, IL (16 May), Champaign, IL (19 April), and Harrisburg, IL (9 May). Plots were 17.5 feet in length with 30 or 20-inch row spacing and two rows in width. Force 3G insecticide was applied at planting and Bicep II Magnum (2.5 qt/acre-1) was applied prior to planting as a pre-emergence herbicide. Nitrogen treatments were broadcast applied with urea at 0, 60, and 280 lb N acre-1 between the V4-V6 developmental stages at Yorkville, IL (6 June), Champaign, IL (22 May), and Harrisburg, IL (1 June). Forty-eight hybrids represented by seven different seed brands, with comparative relative maturities (CRMs) ranging from 104-118 days were evaluated (Table 1). Treatments included: (i) 32,000 plants acre-1 at 30-inch row space and 0 lb N acre-1, (ii) 32,000 plants acre-1 at 30-inch row space and 60 lb N acre-1, (iii) 32,000 plants acre-1 at 30-inch row space and 280 lb N acre-1, (iv) 38,000 plants acre-1 at 30-inch row space and 280 lb N acre-1, (v) 44,000 plants acre-1 at 30-inch row space and 280 lb N acre -1, and (vi) 44,000 plants acre-1 at 20-inch row space and 280 lb N acre -1. At maturity, plots were harvested with a two-row plot combine and grain yield is reported as bushels acre-1 at 15.5% moisture concentration. Data also collected and considered were soil test values (Table 2) and weather (Table 3).

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Table 1a. The distribution of 48 hybrids evaluated in the Management Yield Potential trial in 2017 grown at Yorkville, Champaign, and Harrisburg, IL. Hybrids are sorted by company, brand, and comparative relative maturity (CRM). Company Brand CRM Hybrid Yorkville Champaign Harrisburg

CPS Dyna-Gro 111 D51SS54 X X X CPS Dyna-Gro 112 D52SS91 X X X CPS Dyna-Gro 112 D52SS63 X X X CPS Dyna-Gro 114 D54VC52 X X X CPS Dyna-Gro 114 D54DC94 X X X CPS Dyna-Gro 115 D55VC45 X X CPS Dyna-Gro 116 D56VC46 X X X CPS Dyna-Gro 117 D57VC51 X X X CPS Dyna-Gro 118 D58VC65 X X X

Monsanto Channel 110 210-26STXRIB X X X Monsanto Channel 112 212-20STXRIB X X X Monsanto Channel 115 215-75STXRIB X X X Monsanto DeKalb 110 DKC60-87 X X X Monsanto DeKalb 112 DKC62-52 X X X Monsanto DeKalb 113 DKC63-21 X X X Monsanto DeKalb 114 DKC64-34 X X X Monsanto DeKalb 115 DKC65-94 X X Monsanto DeKalb 116 DKC66-74 X X X Monsanto Stone 108 5848SSRIB X X X Monsanto Stone 111 6188SSRIB X X X Monsanto Stone 115 6538SSRIB X X X Pioneer Pioneer 111 P1197AMXT X X X Pioneer Pioneer 113 P1311AMXT X X X

Syngenta Golden Harvest 105 G05B91-3010 X X Syngenta Golden Harvest 105 SL5536ZL-3010 X X Syngenta Golden Harvest 106 G06Z97-3120 X X Syngenta Golden Harvest 107 G07F23-3111 X X X Syngenta Golden Harvest 109 G09A86-3111 X X X Syngenta Golden Harvest 109 G09Y24-3220 X X X Syngenta Golden Harvest 110 SK6405-3220 X X X Syngenta Golden Harvest 110 G10T63-3122 X X X Syngenta Golden Harvest 111 G11X64-3010 X X Syngenta Golden Harvest 112 G12W66-3000GT X X X Syngenta Golden Harvest 114 G14R38-3122 X X X Syngenta Golden Harvest 114 G14V04-3000GT X X Syngenta Golden Harvest 115 G15L32-3111 X X X Syngenta Golden Harvest 116 SL8675-3110 X X WinField Croplan 104 4488SS X WinField Croplan 108 4895SS/RIB X X X WinField Croplan 108 5887VT2P X X WinField Croplan 110 6110SS/RIB X X X WinField Croplan 112 5290DGVT2P X X X WinField Croplan 113 6594SS/RIB X X X WinField Croplan 113 6640VT3P X X X WinField Croplan 116 5678VT2P X X X WinField Croplan 117 7927VT3P/RIB X X X WinField Croplan 117 8621VT2P/RIB X X X

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Table 1b. The distribution of 48 hybrids evaluated in the Management Yield Potential trial in 2017 grown at Yorkville, Champaign, and Harrisburg, IL. Hybrids are sorted by comparative relative maturity (CRM) ranging from 104 to 118 days. CRM Hybrid Brand Company Yorkville Champaign Harrisburg 104 4488SS Croplan WinField X

105 G05B91-3010 Golden Harvest Syngenta X X 105 SL5536ZL-3010 Golden Harvest Syngenta X X

106 G06Z97-3120 Golden Harvest Syngenta X X 107 G07F23-3111 Golden Harvest Syngenta X X X

108 5848SSRIB Stone Monsanto X X X 108 4895SS/RIB Croplan WinField X X X 108 5887VT2P Croplan WinField X X 109 G09A86-3111 Golden Harvest Syngenta X X X 109 G09Y24-3220 Golden Harvest Syngenta X X X 110 SK6405-3220 Golden Harvest Syngenta X X X 110 G10T63-3122 Golden Harvest Syngenta X X X 110 DKC60-87 DeKalb Monsanto X X X 110 210-26STXRIB Channel Monsanto X X X 110 6110SS/RIB Croplan WinField X X X 111 G11X64-3010 Golden Harvest Syngenta

X X

111 6188SSRIB Stone Monsanto X X X 111 D51SS54 Dyna-Gro CPS X X X 111 P1197AMXT Pioneer Pioneer X X X 112 G12W66-3000GT Golden Harvest Syngenta X X X 112 DKC62-52 DeKalb Monsanto X X X 112 212-20STXRIB Channel Monsanto X X X 112 D52SS91 Dyna-Gro CPS X X X 112 D52SS63 Dyna-Gro CPS X X X 112 5290DGVT2P Croplan WinField X X X 113 DKC63-21 DeKalb Monsanto X X X 113 6594SS/RIB Croplan WinField X X X 113 6640VT3P Croplan WinField X X X 113 P1311AMXT Pioneer Pioneer X X X 114 G14R38-3122 Golden Harvest Syngenta X X X 114 G14V04-3000GT Golden Harvest Syngenta

X X

114 DKC64-34 DeKalb Monsanto X X X 114 D54VC52 Dyna-Gro CPS X X X 114 D54DC94 Dyna-Gro CPS X X X 115 G15L32-3111 Golden Harvest Syngenta X X X 115 6538SSRIB Stone Monsanto X X X 115 DKC65-94 DeKalb Monsanto X X 115 215-75STXRIB Channel Monsanto X X X 115 D55VC45 Dyna-Gro CPS X X 116 SL8675-3110 Golden Harvest Syngenta

X X

116 DKC66-74 DeKalb Monsanto X X X 116 D56VC46 Dyna-Gro CPS X X X 116 5678VT2P Croplan WinField X X X 117 D57VC51 Dyna-Gro CPS X X X 117 7927VT3P/RIB Croplan WinField X X X 117 8621VT2P/RIB Croplan WinField X X X 118 G18D87-3111 Golden Harvest Syngenta

X X

118 D58VC65 Dyna-Gro CPS X X X

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Table 2. Soil test values for the Yorkville, Champaign, and Harrisburg, IL field sites sampled prior to planting at a depth of 1 to 6 inches and extracted using Mehlich III.

Location OM† pH CEC P K Ca Mg % units meq 100g-1 -------------------- ppm --------------------

Yorkville 4.1 7.0 21.2 34 171 2939 711 Champaign 3.8 6.0 22.3 78 222 2846 470 Harrisburg 2.3 6.2 13.8 31 114 1945 165

† OM, Organic Matter; CEC, Cation Exchange Capacity Table 3. Precipitation and temperature during the production season at Yorkville, Champaign, and Harrisburg, IL in 2017 compared to the 30-year average. Values were obtained from the Illinois State Water Survey.

Precipitation (in) Temperature (°F)

Month 2017 30-Year Average 2017 30-Year

Average Yorkville, IL

April 6.9 4.0 54 50 May 4.7 4.3 58 61 June 1.8 4.3 72 70 July 7.0 4.7 74 74

August 2.8 4.1 70 72 September 0.1 3.1 68 65

Champaign, IL April 5.8 3.7 57 52 May 5.9 4.9 61 63 June 2.1 4.3 73 72 July 2.8 4.7 76 75


Harrisburg, IL April 14.1 4.4 61 56 May 4.8 5.1 66 66 June 2.3 4.5 74 75 July 1.2 3.8 79 78


The treatments were arranged in a split block experimental design with four replications.

Data were assessed 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. Normality for residuals and outlier observations were evaluated using PROC UNIVARIATE in SAS. Row space, hybrid, N fertilizer rate, and plant population were considered fixed effects, while block and interactions with blocks were considered random effects. Hybrid yields were ranked from 1 to 10 using the PROC RANK

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procedure of SAS to generate decile scores for the: unfertilized check plot yield (yield at 0 lb N acre-1 and 32,000 plants acre-1), yield response to low N (RTLowN; yield change between 0 and 60 lb N acre-1 at 32,000 plants acre-1), yield response to high N (RTN; yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1), yield response to intermediate population (RTIntPop; yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), yield response to high plant population (RTHiPop; yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and yield response to row space (RTS; yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1). This assessment provides scores for each parameter and hybrid within each location, and combined across all locations using the overall yield for the hybrid. Scores for each parameter (and the indices) were ranked from 0 to 10, with 0 being the least yield increase compared to the overall average, and 10 being the greatest yield increase compared to the overall average, with an average ranking a 5.

‘Racehorse’ and ‘Workhorse’ indices were estimated using a multiple regression approach with the Smith-Hazel index (Smith, 1936; Hazel, 1943). Moreover, the genotypic and phenotypic variance-covariance matrices among all the parameters were estimated using restricted maximum likelihood in PROC MIXED of SAS (Holland, 2006). Index weights (vector) for each parameter were estimated by multiplying the phenotypic covariance matrix, the genotypic covariance matrix, and a vector of weight 1 (Eq. 1). ‘Racehorse’ and ‘Workhorse’ indices were calculated using the relative weights to each parameter multiplied by the scores (Eq. 2 and 3).

𝑏! = 𝑃!!𝐺𝑎 [1] ′𝑅𝑎𝑐𝑒ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥! = 𝑏!𝑅𝑇𝐼𝑛𝑡𝑃𝑜𝑝 + 𝑏!𝑅𝑇𝐻𝑖𝑃𝑜𝑝 + 𝑏!𝑅𝑇𝑁 + 𝑏!𝑅𝑇𝑆 [2] ′𝑊𝑜𝑟𝑘ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥! = 𝑏!𝐶ℎ𝑒𝑐𝑘 + 𝑏!𝑅𝑇𝐿𝑜𝑤𝑁 [3]

Where b is the vector of the weights of the indices, 𝑃!! is the inverse matrix of the

phenotypic variance-covariance, G is the matrix of the genetic variance-covariance, and 𝑎 is the initial weight.

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Yield Results Environmental conditions in 2017 created relatively consistent hybrid performances across

the three locations of the trial (Table 3). April started the season warm but very wet, especially at Harrisburg, which led to relatively late planting there. Summer was drier, except for heavy rains in July at Yorkville. Most notably, at all sites, August was much cooler than normal, promoting good grain fill and yield, while September was warmer than normal, with no early frost.

The following three sections correspond to the corn yield results at Yorkville, Champaign, and Harrisburg, IL for each treatment and hybrid, and the yield responses to different agronomic management factors. The next six tables (e.g. Tables 4 to 9) describe the yield rank of the hybrids under different N conditions across different row space and planting population arrangements. Yield values for all treatment combinations are then described in a summary table (e.g. Table 10). Yield response to different agronomic managements (e.g. Figure 1a and 1b) is described for each location.

Overall average check plot yields (0 lb N acre-1) were 225, 211, and 232 bu acre-1 at Yorkville, Champaign, and Harrisburg, IL, respectively. Higher check plot yields at Yorkville and Champaign were associated with high residual N, mineralized from soil organic matter, leading to less yield response to N fertilizer than previous years. An exceptionally high check plot yield also in Harrisburg can be credited to timely rains and a cooler than average August. Overall average yield increases over the check plots using low N were 38, 44, and 46 bu acre-1, and high N increased corn yields by 60, 55, and 54 bu acre-1 over the check plot yields at Yorkville, Champaign, and Harrisburg, IL, respectively.

Overall yield increases due to increasing plant population to the moderate level were 10, 7, and 15 bu acre-1, while the highest plant population increased yield by an additional 0, 4, and 5 bu acre-1 for Yorkville, Champaign, and Harrisburg, respectively. Optimal growing conditions across all locations allowed a majority of the hybrids tested to tolerate higher plant populations. Many hybrids demonstrated yield potentials exceeding 300 bu acre-1, which can be attributed to planting higher populations. The overall average yield response to narrower row spacing was 16, 6, and 8 bu acre-1 at Yorkville, Champaign, and Harrisburg, respectively. Consistent across all locations, narrower row spacing decreased inter-plant competition under higher plant densities and increased individual plant and overall yields.

At Yorkville, IL, hybrids yielded similarly between the intermediate and the high plant populations, but demonstrated a large yield increase to the narrower row spacing. As a result, a new Crop Physiology Lab yield record of 379 bu acre-1 was achieved with Croplan 7927VT3P/RIB when placed in a narrower row arrangement and high N (Table 4). Other hybrids achieving exceptional yields when placed in narrower rows at Yorkville were DeKalb DKC65-94, Channel 215-75STXRIB, Pioneer P1311AMXT, and Dyna-Gro D55VC45. The range in yield responses to both narrower row spacing and increased plant population at Champaign, IL was a good reminder that not all hybrids are created equal (Table 17). When switching from 30 to 20 inch rows, Golden Harvest G18D87-3111 increased in yield by over 50 bu acre-1, yet

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Croplan 6640VT3P decreased in yield by more than 50 bu acre-1. An example of a hybrid showing a positive yield response to both intermediate and high plant population is Golden Harvest G12W66-3000GT. In contrast, an example of a hybrid that did not tolerate increased plant population and showed a decrease in yield at Champaign was Pioneer P1311AMXT. The site providing the highest yields on average across the three locations in 2017 was Harrisburg, IL (Table 24). High check plot yields and large yield increases from fertilization even with 60 lb N acre-1 fertilizer were the main reasons for such a high trial average yield of 286 bu acre-1. Examples of hybrids with a high check plot yield and above average yield response to 60 lb N acre-1 at Harrisburg are Golden Harvest G14V04-3000GT and Dyna-Gro D54DC94.

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Yorkville, IL Table 4. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 0 lb N acre-1, and 30-inch row spacing at Yorkville, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 6110SS/RIB 262.6 23 G07F23-3111 223.0 2 8621VT2P/RIB 255.5 24 6188SSRIB 222.2 3 D54VC52 249.3 25 P1197AMXT 221.5 4 G10T63-3122 247.7 26 6640VT3P 221.1 5 5290DGVT2P 245.9 27 5887VT2P 220.4 6 P1311AMXT 245.6 28 4488SS 219.3 7 D56VC46 243.4 29 G09Y24-3220A 218.5 8 D52SS91 242.8 30 G06Z97-3120 218.0 9 G09A86-3111 240.0 31 DKC62-52 217.7 10 D58VC65 239.6 32 5678VT2P 215.9 11 DKC65-94 238.8 33 DKC60-87 211.5 12 210-26STXRIB 237.7 34 5848SSRIB 209.9 13 DKC66-74 235.4 35 6594SS/RIB 209.6 14 7927VT3P/RIB 235.0 36 212-20STXRIB 208.3 15 D52SS63 234.0 37 G14R38-3122 207.5 16 SK6405-3220 233.6 38 G12W66-3000GT 206.3 17 G15L32-3111 233.3 39 4895SS/RIB 206.1 18 D55VC45 232.8 40 G05B91-3010 204.7 19 215-75STXRIB 228.3 41 DKC63-21 201.8 20 D57VC51 226.7 42 D51SS54 201.0 21 6538SSRIB 224.8 43 D54DC94 200.3 22 DKC64-34 223.8 44 SL5536ZL 190.7

Mean 225.3 LSD (P ≤ 0.10) 29.9

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Table 5. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 60 lb N acre-1, and 30-inch row spacing at Yorkville, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 5290DGVT2P 326.8 23 4488SS 260.7 2 P1311AMXT 308.0 24 G06Z97-3120 260.4 3 8621VT2P/RIB 299.5 25 G07F23-3111 260.0 4 7927VT3P/RIB 284.6 26 6640VT3P 258.6 5 SK6405-3220 282.8 27 DKC63-21 254.4 6 G10T63-3122 281.8 28 5848SSRIB 254.1 7 G15L32-3111 278.8 29 5678VT2P 253.7 8 G14R38-3122 278.5 30 215-75STXRIB 253.2 9 P1197AMXT 275.8 31 DKC64-34 252.8 10 D56VC46 274.9 32 5887VT2P 251.6 11 G12W66-3000GT 274.1 33 G05B91-3010 251.0 12 DKC66-74 274.0 34 G09Y24-3220A 250.5 13 6110SS/RIB 272.7 35 6538SSRIB 250.1 14 D55VC45 270.0 36 D57VC51 247.9 15 4895SS/RIB 268.0 37 DKC60-87 247.2 16 D58VC65 267.3 38 D51SS54 246.3 17 G09A86-3111 266.5 39 D52SS91 245.3 18 210-26STXRIB 266.3 40 D54DC94 243.8 19 DKC65-94 265.0 41 6188SSRIB 241.5 20 6594SS/RIB 263.9 42 D52SS63 241.0 21 D54VC52 263.1 43 212-20STXRIB 235.1 22 DKC62-52 262.6 44 SL5536ZL 197.7

Mean 262.8 LSD (P ≤ 0.10) 29.9

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Table 6. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 280 lb N acre-1, and 30-inch row spacing at Yorkville, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 7927VT3P/RIB 333.1 23 D57VC51 280.8 2 P1311AMXT 330.5 24 DKC63-21 279.5 3 G10T63-3122 322.5 25 6188SSRIB 279.5 4 5290DGVT2P 319.0 26 6640VT3P 277.8 5 8621VT2P/RIB 317.7 27 D52SS91 277.4 6 P1197AMXT 314.3 28 G06Z97-3120 277.2 7 DKC66-74 306.6 29 5678VT2P 277.1 8 D56VC46 303.5 30 4488SS 276.7 9 SK6405-3220 302.4 31 G09Y24-3220A 275.2 10 D54VC52 298.6 32 212-20STXRIB 274.4 11 6594SS/RIB 298.4 33 5887VT2P 274.0 12 DKC65-94 294.6 34 DKC64-34 272.9 13 G12W66-3000GT 293.8 35 215-75STXRIB 272.8 14 D55VC45 292.9 36 4895SS/RIB 272.3 15 DKC62-52 292.1 37 5848SSRIB 271.7 16 G09A86-3111 287.7 38 D52SS63 271.6 17 G15L32-3111 287.5 39 D51SS54 271.2 18 6110SS/RIB 287.1 40 210-26STXRIB 268.3 19 D58VC65 284.9 41 G14R38-3122 264.3 20 G07F23-3111 284.3 42 DKC60-87 262.7 21 6538SSRIB 282.2 43 G05B91-3010 259.9 22 D54DC94 281.9 44 SL5536ZL 211.5

Mean 285.6 LSD (P ≤ 0.10) 29.8

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Table 7. Grain yield of the 44 hybrid entries grown under agronomic conditions of 38,000 plants acre-1 at 280 lb N acre-1 and 30-inch row spacing at Yorkville, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 7927VT3P/RIB 356.3 23 6538SSRIB 292.8 2 G10T63-3122 348.4 24 5678VT2P 292.3 3 P1311AMXT 340.6 25 DKC63-21 290.7 4 5290DGVT2P 337.4 26 4488SS 289.5 5 P1197AMXT 331.1 27 6594SS/RIB 286.5 6 D56VC46 327.7 28 5887VT2P 284.9 7 8621VT2P/RIB 322.6 29 215-75STXRIB 283.2 8 D55VC45 322.2 30 6640VT3P 281.5 9 DKC65-94 320.2 31 210-26STXRIB 280.2 10 DKC64-34 319.9 32 G09A86-3111 279.8 11 DKC66-74 318.8 33 D54DC94 279.3 12 DKC62-52 314.2 34 6188SSRIB 274.5 13 D52SS63 307.5 35 G14R38-3122 273.7 14 D54VC52 306.0 36 DKC60-87 273.5 15 G15L32-3111 302.1 37 D57VC51 273.3 16 G09Y24-3220A 299.6 38 G06Z97-3120 273.0 17 SK6405-3220 297.0 39 D51SS54 272.4 18 G07F23-3111 295.7 40 212-20STXRIB 267.4 19 D52SS91 295.3 41 5848SSRIB 264.8 20 D58VC65 295.0 42 G05B91-3010 252.6 21 6110SS/RIB 293.6 43 4895SS/RIB 250.2 22 G12W66-3000GT 293.3 44 SL5536ZL 221.8

Mean 295.0 LSD (P ≤ 0.10) 30.3

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bu acre-1 bu acre-1 1 5290DGVT2P 336.2 23 6538SSRIB 293.0 2 8621VT2P/RIB 327.9 24 212-20STXRIB 292.0 3 G10T63-3122 327.4 25 G12W66-3000GT 291.8 4 DKC65-94 327.4 26 210-26STXRIB 291.1 5 P1311AMXT 327.3 27 DKC64-34 289.4 6 7927VT3P/RIB 326.5 28 6188SSRIB 288.0 7 D56VC46 319.6 29 G07F23-3111 287.4 8 DKC66-74 314.4 30 5848SSRIB 287.0 9 P1197AMXT 312.3 31 6110SS/RIB 286.7 10 D52SS63 311.7 32 G06Z97-3120 285.7 11 D55VC45 311.5 33 D54DC94 285.1 12 DKC62-52 310.3 34 DKC63-21 279.6 13 D54VC52 305.2 35 D57VC51 279.1 14 SK6405-3220 305.0 36 215-75STXRIB 278.5 15 G09A86-3111 302.0 37 G14R38-3122 276.8 16 D58VC65 300.4 38 G09Y24-3220A 275.4 17 D52SS91 299.4 39 G05B91-3010 272.7 18 6594SS/RIB 298.5 40 D51SS54 272.4 19 G15L32-3111 298.0 41 6640VT3P 272.4 20 5887VT2P 295.8 42 4895SS/RIB 271.6 21 5678VT2P 295.2 43 DKC60-87 261.3 22 4488SS 294.7 44 SL5536ZL 225.0

Mean 295.2 LSD (P ≤ 0.10) 30.2

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bu acre-1 bu acre-1 1 7927VT3P/RIB 379.2 23 D58VC65 310.7 2 DKC65-94 359.6 24 5848SSRIB 309.9 3 215-75STXRIB 356.2 25 G12W66-3000GT 309.7 4 P1311AMXT 355.6 26 D54DC94 309.6 5 D55VC45 352.2 27 D52SS63 309.0 6 DKC66-74 337.7 28 D51SS54 306.7 7 SK6405-3220 335.7 29 G14R38-3122 300.6 8 G10T63-3122 333.8 30 6594SS/RIB 298.3 9 8621VT2P/RIB 333.5 31 DKC63-21 295.8 10 5290DGVT2P 333.0 32 4895SS/RIB 295.5 11 6188SSRIB 330.6 33 DKC60-87 294.3 12 D57VC51 329.2 34 G09Y24-3220A 291.2 13 5678VT2P 325.7 35 5887VT2P 288.8 14 6538SSRIB 325.2 36 6110SS/RIB 286.1 15 DKC64-34 323.4 37 6640VT3P 285.4 16 DKC62-52 320.5 38 210-26STXRIB 283.3 17 D56VC46 319.1 39 G15L32-3111 280.1 18 G07F23-3111 318.3 40 G05B91-3010 279.5 19 G09A86-3111 317.2 41 4488SS 278.8 20 P1197AMXT 316.6 42 D52SS91 265.0 21 D54VC52 316.0 43 G06Z97-3120 261.9 22 212-20STXRIB 313.5 44 SL5536ZL 228.9

Mean 311.4 LSD (P ≤ 0.10) 36.2

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Table 10. Individual yield values of all hybrid entries (n = 44) grown under two levels of row spacing (30 and 20 inches), three levels of plant population (32,000, 38,000, and 44,000 plants acre-1) and three levels of N supply (0, 60, and 280 lb N acre-1) at Yorkville, IL in 2017. Trial means and hybrid yield ranges are shown for comparison. Hybrids are sorted by relative maturity within each brand. Each value is the average of four replications.

Row Spacing

30 inches 20 inches

Plant Population (plants/acre)

32,000 38,000 44,000 44,000 Seed Brand Nitrogen Level (lbs/acre)

Hybrid 0 60 280 280 280

------------------------------------------ bushels/acre ----------------------------------------- Golden Harvest SL5536ZL 191 198 212 222 225 229

G05B91-3010 205 251 260 253 273 280 G06Z97-3120 218 260 277 273 286 262 G07F23-3111 223 260 284 296 287 318

G09Y24-3220A 218 251 275 300 275 291 G09A86-3111 240 266 288 280 302 317 SK6405-3220 234 283 302 297 305 336 G10T63-3122 248 282 323 348 327 334

G12W66-3000GT 206 274 294 293 292 310 G14R38-3122 208 278 264 274 277 301 G15L32-3111 233 279 288 302 298 280

Channel 210-26STXRIB 238 266 268 280 291 283 212-20STXRIB 208 235 274 267 292 313 215-75STXRIB 228 253 273 283 279 356

DeKalb DKC60-87 212 247 263 274 261 294 DKC62-52 218 263 292 314 310 321 DKC63-21 202 254 280 291 280 296 DKC64-34 224 253 273 320 289 323 DKC65-94 239 265 295 320 327 360 DKC66-74 235 274 307 319 314 338

Stone 5848SSRIB 210 254 272 265 287 310 6188SSRIB 222 241 280 274 288 331 6538SSRIB 225 250 282 293 293 325 Dyna-Gro D51SS54 201 246 271 272 272 307 D52SS63 243 245 277 295 299 265 D52SS91 234 241 272 308 312 309 D54DC94 200 244 282 279 285 310 D54VC52 249 263 299 306 305 316 D55VC45 233 270 293 322 312 352 D56VC46 243 275 303 328 320 319 D57VC51 227 248 281 273 279 329 D58VC65 240 267 285 295 300 311 Croplan 4488SS 219 261 277 290 295 279

4895SS/RIB 206 268 272 250 272 296 5887VT2P 220 252 274 285 296 289

6110SS/RIB 263 273 287 294 287 286 5290DGVT2P 246 327 319 337 336 333

6640VT3P 221 259 278 281 272 285 6594SS/RIB 210 264 298 287 299 298 5678VT2P 216 254 277 292 295 326

7927VT3P/RIB 235 285 333 356 327 379 8621VT2P/RIB 256 299 318 323 328 334

Pioneer P1197AMXT 221 276 314 331 312 317 P1311AMXT 246 308 331 341 327 356

LSD (P ≤ 0.10) 30 30 30 30 30 36 Mean 225 263 286 295 295 311 Range 191-263 198-327 212-333 222-356 225-336 229-379

16

Figure 1a. Yield change due to low nitrogen supply (i.e., yield increase between 0 and 60 lbs N acre-1 at 32,000 plants acre-1), and the yield response to high nitrogen (i.e., yield increase between 0 and 280 lbs N acre-1) at Yorkville, IL in 2017.

17

Figure 1b. Yield response to intermediate population (yield change between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), yield response to high plant population (yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1) at Yorkville, IL in 2017.

18

Champaign, IL Table 11. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 0 lb N acre-1, and 30-inch row spacing at Champaign, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 G18D87-3111 250.2 23 4895SS/RIB 208.7 2 5290DGVT2P 236.2 24 G11X64-3010 208.1 3 8621VT2P/RIB 233.2 25 6538SSRIB 208.1 4 5678VT2P 233.1 26 DKC64-34 207.8 5 D57VC51 230.3 27 DKC60-87 207.7 6 G09A86-3111 227.6 28 212-20STXRIB 207.0 7 SK6405-3220 227.5 29 D52SS91 204.9 8 G15L32-3111 227.0 30 P1311AMXT 204.7 9 D58VC65 226.5 31 G09Y24-3220A 204.6 10 G07F23-3111 223.3 32 P1197AMXT 203.5 11 215-75STXRIB 222.2 33 G14R38-3122 202.6 12 DKC66-74 221.1 34 D54VC52 201.1 13 SL8675-3110 220.1 35 D56VC46 200.9 14 210-26STXRIB 219.1 36 5848SSRIB 197.8 15 D51SS54 219.0 37 G14V04-3000GT 197.4 16 D54DC94 218.3 38 G10T63-3122 190.2 17 D52SS63 218.2 39 DKC62-52 187.5 18 6110SS/RIB 216.4 40 G12W66-3000GT 185.1 19 G06Z97-3120 216.4 41 6594SS/RIB 184.9 20 6640VT3P 214.8 42 DKC63-21 184.3 21 6188SSRIB 212.9 43 G05B91-3010 181.9 22 7927VT3P/RIB 209.8 44 SL5536ZL 170.1

Mean 210.7 LSD (P ≤ 0.10) 31.5

19

Table 12. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 60 lb N acre-1, and 30-inch row spacing at Champaign, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 SL8675-3110 286.3 23 DKC62-52 254.3 2 5290DGVT2P 280.4 24 P1197AMXT 251.4 3 G07F23-3111 280.0 25 D51SS54 250.8 4 G09Y24-3220A 279.9 26 D52SS63 250.8 5 5678VT2P 279.0 27 DKC60-87 248.9 6 D58VC65 275.8 28 6538SSRIB 248.9 7 8621VT2P/RIB 274.9 29 G06Z97-3120 248.7 8 212-20STXRIB 271.7 30 G15L32-3111 248.5 9 D57VC51 271.0 31 G11X64-3010 245.1 10 D56VC46 269.3 32 DKC64-34 244.8 11 G18D87-3111 269.1 33 P1311AMXT 244.6 12 D54VC52 263.8 34 7927VT3P/RIB 241.9 13 G09A86-3111 263.3 35 DKC63-21 241.7 14 6640VT3P 262.9 36 G12W66-3000GT 240.0 15 6110SS/RIB 261.9 37 G14R38-3122 239.7 16 6188SSRIB 261.4 38 4895SS/RIB 239.2 17 D54DC94 261.1 39 5848SSRIB 238.7 18 SK6405-3220 260.7 40 G14V04-3000GT 236.1 19 G10T63-3122 260.2 41 DKC66-74 235.7 20 D52SS91 259.5 42 6594SS/RIB 229.7 21 215-75STXRIB 257.3 43 G05B91-3010 217.0 22 210-26STXRIB 255.0 44 SL5536ZL 206.7

Mean 254.7 LSD (P ≤ 0.10) 31.2

20

Table 13. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 280 lb N acre-1 and 30-inch row spacing at Champaign, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 8621VT2P/RIB 314.2 23 210-26STXRIB 265.2 2 5678VT2P 302.6 24 G09A86-3111 264.3 3 SL8675-3110 296.1 25 DKC66-74 263.5 4 5290DGVT2P 291.7 26 DKC64-34 262.2 5 P1311AMXT 290.5 27 G14R38-3122 261.7 6 G18D87-3111 285.6 28 D56VC46 261.5 7 D54DC94 284.6 29 G06Z97-3120 259.9 8 D58VC65 284.2 30 D52SS63 259.7 9 G09Y24-3220A 284.2 31 6538SSRIB 259.1 10 G10T63-3122 283.4 32 212-20STXRIB 259.1 11 G07F23-3111 282.5 33 P1197AMXT 258.7 12 DKC62-52 279.5 34 6110SS/RIB 258.2 13 DKC60-87 272.9 35 G11X64-3010 252.9 14 D54VC52 272.8 36 7927VT3P/RIB 250.6 15 SK6405-3220 270.7 37 D51SS54 244.4 16 6640VT3P 270.6 38 DKC63-21 243.2 17 215-75STXRIB 270.5 39 D52SS91 241.2 18 D57VC51 269.9 40 4895SS/RIB 238.1 19 5848SSRIB 269.7 41 G05B91-3010 236.2 20 G15L32-3111 267.6 42 6594SS/RIB 228.2 21 G14V04-3000GT 265.7 43 G12W66-3000GT 226.6 22 6188SSRIB 265.3 44 SL5536ZL 218.7

Mean 265.6 LSD (P ≤ 0.10) 31.8

21

Table 14. Grain yield of the 44 hybrid entries grown under agronomic conditions of 38,000 plants acre-1 at 280 lb N acre-1 and 30-inch row spacing at Champaign, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 SL8675-3110 312.5 23 P1311AMXT 273.7 2 P1197AMXT 309.3 24 D52SS91 273.7 3 8621VT2P/RIB 301.8 25 212-20STXRIB 272.8 4 D57VC51 301.6 26 G07F23-3111 272.6 5 7927VT3P/RIB 300.3 27 D51SS54 272.0 6 G10T63-3122 297.1 28 DKC60-87 271.1 7 G09A86-3111 296.0 29 G15L32-3111 268.5 8 G18D87-3111 293.2 30 G14V04-3000GT 267.7 9 G09Y24-3220A 290.2 31 215-75STXRIB 267.4 10 SK6405-3220 283.8 32 D52SS63 264.7 11 210-26STXRIB 283.2 33 5678VT2P 261.6 12 D54DC94 282.1 34 DKC62-52 261.6 13 5848SSRIB 281.0 35 4895SS/RIB 257.5 14 G11X64-3010 280.0 36 G12W66-3000GT 257.2 15 G14R38-3122 279.3 37 G06Z97-3120 254.8 16 6640VT3P 279.3 38 6188SSRIB 252.8 17 D56VC46 279.0 39 6110SS/RIB 245.1 18 D54VC52 277.0 40 6594SS/RIB 240.3 19 DKC64-34 277.0 41 DKC63-21 240.2 20 D58VC65 276.7 42 6538SSRIB 231.4 21 5290DGVT2P 276.2 43 G05B91-3010 230.0 22 DKC66-74 273.9 44 SL5536ZL 222.0

Mean 272.5 LSD (P ≤ 0.10) 35.5

22


bu acre-1 bu acre-1 1 SL8675-3110 320.6 23 D51SS54 276.7 2 G09Y24-3220A 310.5 24 6188SSRIB 275.2 3 D58VC65 297.5 25 6538SSRIB 274.4 4 G09A86-3111 297.1 26 5678VT2P 274.3 5 D56VC46 297.0 27 G11X64-3010 273.2 6 G07F23-3111 296.9 28 DKC66-74 271.9 7 P1197AMXT 296.4 29 DKC60-87 271.0 8 212-20STXRIB 294.7 30 DKC64-34 270.7 9 5290DGVT2P 291.7 31 DKC62-52 270.3 10 G10T63-3122 290.7 32 G14R38-3122 270.0 11 8621VT2P/RIB 288.6 33 6110SS/RIB 266.7 12 D54VC52 287.5 34 D52SS63 265.7 13 210-26STXRIB 285.9 35 G14V04-3000GT 264.6 14 6640VT3P 284.8 36 G18D87-3111 262.4 15 D54DC94 284.7 37 DKC63-21 261.2 16 7927VT3P/RIB 284.3 38 G06Z97-3120 257.9 17 D52SS91 281.8 39 P1311AMXT 253.3 18 D57VC51 281.7 40 6594SS/RIB 250.9 19 SK6405-3220 280.9 41 4895SS/RIB 249.2 20 5848SSRIB 280.9 42 G15L32-3111 248.0 21 215-75STXRIB 280.7 43 SL5536ZL 232.1 22 G12W66-3000GT 278.6 44 G05B91-3010 229.5

Mean 276.4 LSD (P ≤ 0.10) 32.8

23


bu acre-1 bu acre-1 1 DKC64-34 328.4 23 G09A86-3111 282.1 2 G18D87-3111 320.6 24 5678VT2P 282.0 3 SL8675-3110 318.3 25 D57VC51 282.0 4 5848SSRIB 310.1 26 G11X64-3010 281.7 5 6188SSRIB 306.5 27 DKC63-21 280.9 6 G10T63-3122 303.7 28 D56VC46 279.7 7 P1197AMXT 303.2 29 G09Y24-3220A 278.7 8 DKC62-52 302.6 30 210-26STXRIB 275.9 9 G14V04-3000GT 301.4 31 215-75STXRIB 275.4 10 SK6405-3220 301.3 32 G14R38-3122 274.9 11 DKC60-87 299.8 33 G12W66-3000GT 273.4 12 5290DGVT2P 299.8 34 D54DC94 272.3 13 D58VC65 298.7 35 D52SS63 272.1 14 8621VT2P/RIB 297.8 36 G07F23-3111 265.2 15 D54VC52 296.2 37 6594SS/RIB 261.0 16 212-20STXRIB 291.2 38 D52SS91 259.8 17 G15L32-3111 290.9 39 G06Z97-3120 256.2 18 7927VT3P/RIB 290.4 40 6110SS/RIB 249.5 19 4895SS/RIB 289.3 41 6538SSRIB 248.8 20 D51SS54 286.4 42 G05B91-3010 233.0 21 P1311AMXT 285.7 43 6640VT3P 230.8 22 DKC66-74 285.3 44 SL5536ZL 198.3

Mean 282.3 LSD (P ≤ 0.10) 38.6

24

Table 17. Individual yield values of all hybrid entries (n = 44) grown under two levels of row spacing (30 and 20 inches), three levels of plant population (32,000, 38,000, and 44,000 plants acre-1) and three levels of N supply (0, 60, and 280 lb N acre-1) at Champaign, IL in 2017. Trial means and hybrid yield ranges are shown for comparison. Hybrids are sorted by relative maturity within each brand. Each value is the average of four replications.

Row Spacing

30 inches 20 inches



Hybrid 0 60 280 280 280

--------------------------------------------- bushels/acre --------------------------------------------- Golden Harvest G05B91-3010 182 217 236 230 229 233

SL5536ZL 170 207 219 222 232 198 G06Z97-3120 216 249 260 255 258 256 G07F23-3111 223 280 282 273 297 265 G09A86-3111 228 263 264 296 297 282

G09Y24-3220A 205 280 284 290 311 279 SK6405-3220 227 261 271 284 281 301 G10T63-3122 190 260 283 297 291 304 G11X64-3010 208 245 253 280 273 282

G12W66-3000GT 185 240 227 257 279 273 G14R38-3122 203 240 262 279 270 275

G14V04-3000GT 197 236 266 268 265 301 G15L32-3111 227 249 268 268 248 291 SL8675-3110 220 286 296 312 321 318 G18D87-3111 250 269 286 293 262 321


DeKalb DKC60-87 208 249 273 271 271 300 DKC62-52 187 254 279 262 270 303 DKC63-21 184 242 243 240 261 281 DKC64-34 208 245 262 277 271 328 DKC66-74 221 236 264 274 272 285

Stone 5848SSRIB 198 239 270 281 281 310 6188SSRIB 213 261 265 253 275 306 6538SSRIB 208 249 259 231 274 249 Dyna-Gro D51SS54 219 251 244 272 277 286 D52SS63 218 251 260 265 266 272 D52SS91 205 260 241 274 282 260 D54DC94 218 261 285 282 285 272 D54VC52 201 264 273 277 288 296 D56VC46 201 269 261 279 297 280 D57VC51 230 271 270 302 282 282 D58VC65 226 276 284 277 298 299 Croplan 4895SS/RIB 209 239 238 258 249 289

6110SS/RIB 216 262 258 245 267 250 5290DGVT2P 236 280 292 276 292 300 6594SS/RIB 185 230 228 240 251 261 6640VT3P 215 263 271 279 285 231 5678VT2P 233 279 303 262 274 282

7927VT3P/RIB 210 242 251 300 284 290 8621VT2P/RIB 233 275 314 302 289 298


LSD (P ≤ 0.10) 32 31 32 36 33 39 Mean 211 255 266 272 276 282 Range 170-250 207-286 219-314 222-313 230-321 198-328

25

Figure 2a. Yield change due to low nitrogen supply (i.e., yield increase between 0 and 60 lbs N acre-1 at 32,000 plants acre-1), and the yield response to high nitrogen (i.e., yield increase between 0 and 280 lbs N acre-1) at Champaign, IL in 2017.

26

Figure 2b. Yield response to intermediate population (yield change between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), yield response to high plant population (yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1) at Champaign, IL in 2017.

27

Harrisburg, IL Table 18. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 0 lb N acre-1, and 30-inch row spacing at Harrisburg, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 5678VT2P 265.6 23 DKC60-87 231.0 2 G18D87-3111 258.9 24 6538SSRIB 229.5 3 5290DGVT2P 257.5 25 D56VC46 229.3 4 8621VT2P/RIB 256.1 26 6640VT3P 228.5 5 D57VC51 253.2 27 DKC62-52 227.2 6 G14V04-3000GT 249.7 28 P1197AMXT 225.0 7 DKC63-21 247.4 29 G07F23-3111 224.4 8 SL8675-3110 246.8 30 D51SS54 223.7 9 D54DC94 242.9 31 G09Y24-3220A 223.6 10 DKC64-34 241.5 32 4895SS/RIB 223.2 11 215-75STXRIB 240.6 33 6594SS/RIB 223.0 12 DKC66-74 240.5 34 G09A86-3111 222.4 13 DKC65-94 239.8 35 5887VT2P 220.6 14 D54VC52 238.8 36 212-20STXRIB 220.6 15 G15L32-3111 237.7 37 G12W66-3000GT 218.8 16 D58VC65 237.1 38 G10T63-3122 217.5 17 6188SSRIB 235.7 39 P1311AMXT 217.0 18 7927VT3P/RIB 234.9 40 D55VC45 216.7 19 D52SS63 232.7 41 210-26STXRIB 216.1 20 SK6405-3220 231.5 42 D52SS91 214.0 21 6110SS/RIB 231.2 43 G14R38-3122 212.9 22 5848SSRIB 231.1 44 G11X64-3010 211.2

Mean 232.4 LSD (P ≤ 0.10) 19.7

28

Table 19. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, 60 lb N acre-1, and 30-inch row spacing at Harrisburg, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 5678VT2P 310.08 23 DKC65-94 276.8 2 G18D87-3111 303.78 24 6538SSRIB 276.4 3 SL8675-3110 299.97 25 D54VC52 275.7 4 D54DC94 299.96 26 6188SSRIB 275.3 5 P1197AMXT 298.06 27 G09A86-3111 275.1 6 P1311AMXT 298.04 28 212-20STXRIB 274.3 7 D58VC65 296.17 29 DKC60-87 273.9 8 5290DGVT2P 292.35 30 DKC66-74 272.7 9 D57VC51 291.13 31 G15L32-3111 271.1 10 8621VT2P/RIB 288.46 32 G12W66-3000GT 271.0 11 D56VC46 287.79 33 D55VC45 270.1 12 215-75STXRIB 287.47 34 D52SS63 266.0 13 G14V04-3000GT 286.97 35 5848SSRIB 263.5 14 SK6405-3220 285.48 36 6594SS/RIB 263.2 15 6640VT3P 284.6 37 6110SS/RIB 262.3 16 G09Y24-3220A 283.82 38 210-26STXRIB 260.4 17 7927VT3P/RIB 282.94 39 5887VT2P 259.7 18 D52SS91 282.68 40 G07F23-3111 258.1 19 G10T63-3122 282.49 41 DKC63-21 257.7 20 DKC62-52 282.01 42 G14R38-3122 257.7 21 D51SS54 278.58 43 G11X64-3010 253.6 22 DKC64-34 277.85 44 4895SS/RIB 251.2

Mean 278.3 LSD (P ≤ 0.10) 19.5

29

Table 20. Grain yield of the 44 hybrid entries grown under agronomic conditions of 32,000 plants acre-1, and 280 lb N acre-1, and 30-inch row spacing at Harrisburg, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 SL8675-3110 319.4 23 DKC63-21 285.7 2 D57VC51 314.0 24 D51SS54 285.5 3 5678VT2P 311.2 25 D54DC94 284.1 4 G18D87-3111 310.8 26 G09Y24-3220A 281.2 5 D58VC65 310.8 27 6640VT3P 278.9 6 D56VC46 308.0 28 D55VC45 277.1 7 5290DGVT2P 307.9 29 D54VC52 274.8 8 P1311AMXT 307.3 30 G12W66-3000GT 273.0 9 P1197AMXT 302.7 31 6188SSRIB 272.8 10 DKC66-74 300.3 32 6594SS/RIB 272.2 11 SK6405-3220 299.8 33 5887VT2P 272.2 12 8621VT2P/RIB 298.8 34 G09A86-3111 271.9 13 DKC64-34 295.5 35 G11X64-3010 271.7 14 G10T63-3122 292.7 36 D52SS91 270.8 15 DKC60-87 291.6 37 210-26STXRIB 270.6 16 DKC62-52 291.4 38 212-20STXRIB 269.6 17 7927VT3P/RIB 291.1 39 6110SS/RIB 266.5 18 G15L32-3111 287.8 40 6538SSRIB 264.9 19 215-75STXRIB 287.1 41 G14R38-3122 263.6 20 G14V04-3000GT 286.7 42 5848SSRIB 263.5 21 DKC65-94 286.1 43 G07F23-3111 263.3 22 4895SS/RIB 285.7 44 D52SS63 259.3

Mean 285.9 LSD (P ≤ 0.10) 19.7

30

Table 21. Grain yield of the 44 hybrid entries grown under agronomic conditions of 38,000 plants acre-1 at 280 lb N acre-1 and 30-inch row spacing at Harrisburg, IL in 2017. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 SL8675-3110 331.9 23 DKC66-74 300.7 2 5678VT2P 325.0 24 DKC62-52 298.2 3 G18D87-3111 324.3 25 G09Y24-3220A 298.1 4 D58VC65 324.2 26 D52SS63 293.1 5 D57VC51 323.6 27 DKC65-94 292.6 6 G14V04-3000GT 320.5 28 D55VC45 292.5 7 D56VC46 319.9 29 D51SS54 292.5 8 P1197AMXT 319.9 30 6538SSRIB 292.0 9 SK6405-3220 319.5 31 D52SS91 289.7 10 5290DGVT2P 319.3 32 5887VT2P 289.5 11 8621VT2P/RIB 317.9 33 6640VT3P 287.8 12 7927VT3P/RIB 317.2 34 G12W66-3000GT 287.7 13 P1311AMXT 315.0 35 G09A86-3111 286.7 14 G10T63-3122 309.4 36 5848SSRIB 286.2 15 6188SSRIB 308.9 37 6594SS/RIB 283.8 16 215-75STXRIB 308.9 38 G15L32-3111 281.1 17 D54DC94 307.8 39 G14R38-3122 280.1 18 DKC63-21 303.0 40 210-26STXRIB 280.0 19 DKC60-87 302.9 41 G07F23-3111 275.5 20 DKC64-34 302.7 42 6110SS/RIB 273.7 21 D54VC52 301.4 43 4895SS/RIB 272.8 22 212-20STXRIB 301.0 44 G11X64-3010 270.7

Mean 300.7 LSD (P ≤ 0.10) 18.4

31


bu acre-1 bu acre-1 1 SL8675-3110 342.7 23 D52SS63 301.9 2 P1197AMXT 338.4 24 6640VT3P 299.8 3 SK6405-3220 336.9 25 DKC65-94 298.9 4 G14V04-3000GT 333.8 26 G09A86-3111 298.8 5 7927VT3P/RIB 328.4 27 G12W66-3000GT 298.8 6 G18D87-3111 328.3 28 DKC60-87 298.4 7 D57VC51 327.6 29 5848SSRIB 298.3 8 8621VT2P/RIB 324.2 30 DKC66-74 297.8 9 5290DGVT2P 323.9 31 6594SS/RIB 297.1 10 5678VT2P 323.1 32 212-20STXRIB 295.3 11 DKC64-34 320.7 33 D55VC45 294.5 12 D56VC46 320.3 34 4895SS/RIB 294.0 13 P1311AMXT 317.9 35 6538SSRIB 290.1 14 D58VC65 316.7 36 D52SS91 289.8 15 D54DC94 313.4 37 210-26STXRIB 289.0 16 215-75STXRIB 312.0 38 G11X64-3010 287.3 17 DKC63-21 310.9 39 G07F23-3111 283.7 18 G10T63-3122 309.5 40 D51SS54 283.6 19 D54VC52 306.2 41 6110SS/RIB 283.2 20 G09Y24-3220A 304.1 42 G14R38-3122 279.9 21 6188SSRIB 303.3 43 G15L32-3111 278.8 22 DKC62-52 303.3 44 5887VT2P 278.5

Mean 306.0 LSD (P ≤ 0.10) 16.8

32


bu acre-1 bu acre-1 1 SL8675-3110 370.4 23 D52SS91 310.8 2 G18D87-3111 362.0 24 G09A86-3111 308.3 3 P1197AMXT 353.1 25 215-75STXRIB 308.0 4 D56VC46 343.8 26 G15L32-3111 304.9 5 7927VT3P/RIB 342.0 27 D52SS63 303.7 6 D57VC51 340.7 28 DKC62-52 302.0 7 8621VT2P/RIB 340.3 29 D51SS54 301.8 8 DKC64-34 339.8 30 G09Y24-3220A 300.7 9 G10T63-3122 337.8 31 6640VT3P 299.3 10 D54DC94 332.5 32 DKC65-94 296.7 11 5678VT2P 331.5 33 6594SS/RIB 296.5 12 5290DGVT2P 329.1 34 212-20STXRIB 295.9 13 P1311AMXT 328.9 35 DKC63-21 295.6 14 G12W66-3000GT 326.2 36 G07F23-3111 293.5 15 G14V04-3000GT 324.5 37 5848SSRIB 290.9 16 D54VC52 323.1 38 G11X64-3010 288.4 17 D58VC65 322.4 39 4895SS/RIB 282.9 18 6188SSRIB 321.2 40 6538SSRIB 282.0 19 SK6405-3220 316.8 41 210-26STXRIB 280.9 20 DKC60-87 315.9 42 G14R38-3122 277.6 21 DKC66-74 315.3 43 5887VT2P 275.7 22 D55VC45 312.0 44 6110SS/RIB 274.7

Mean 313.6 LSD (P ≤ 0.10) 18.7

33

Table 24. Individual yield values of all hybrid entries (n = 44) grown under two levels of row spacing (30 and 20 inches), three levels of plant population (32,000, 38,000, and 44,000 plants acre-1) and three levels of N supply (0, 60, and 280 lb N acre-1) at Harrisburg, IL in 2017. Trial means and hybrid yield ranges are shown for comparison. Hybrids are sorted by relative maturity within each brand. Each value is the average of four replications.

Row Spacing

30 inches 20 inches



Hybrid 0 60 280 280 280

--------------------------------------------- bushels/acre --------------------------------------------- Golden Harvest G07F23-3111 224 258 263 276 284 293 G09A86-3111 222 275 272 287 299 308

G09Y24-3220A 224 284 281 298 304 301 SK6405-3220 231 285 300 320 337 317 G10T63-3122 218 282 293 309 309 338 G11X64-3010 211 254 272 271 287 288

G12W66-3000GT 219 271 273 288 299 326 G14R38-3122 213 258 264 280 280 278

G14V04-3000GT 250 287 287 321 334 324 G15L32-3111 238 271 288 281 279 305 SL8675-3110 247 300 319 332 343 370 G18D87-3111 259 304 311 324 328 362


DeKalb DKC60-87 231 274 292 303 298 316 DKC62-52 227 282 291 298 303 302 DKC63-21 247 258 286 303 311 296 DKC64-34 242 278 296 303 321 340 DKC65-94 240 277 286 293 299 297 DKC66-74 240 273 300 301 298 315

Stone 5848SSRIB 231 263 263 286 298 291 6188SSRIB 236 275 273 309 303 321 6538SSRIB 229 276 265 292 290 282 Dyna-Gro D51SS54 224 279 285 292 284 302 D52SS63 233 266 259 293 302 304 D52SS91 214 283 271 290 290 311 D54DC94 243 300 284 308 313 333 D54VC52 239 276 275 301 306 323 D55VC45 217 270 277 293 295 312 D56VC46 229 288 308 320 320 344 D57VC51 253 291 314 324 328 341 D58VC65 237 296 311 324 317 322 Croplan 4895SS/RIB 223 251 286 273 294 283

5887VT2P 221 260 272 289 278 276 6110SS/RIB 231 262 266 274 283 275

5290DGVT2P 258 292 308 319 324 329 6594SS/RIB 223 263 272 284 297 297 6640VT3P 228 285 279 288 300 299 5678VT2P 266 310 311 325 323 332

7927VT3P/RIB 235 283 291 317 328 342 8621VT2P/RIB 256 288 299 318 324 340


LSD (P ≤ 0.10) 20 20 20 18 17 19 Mean 232 278 286 301 306 314 Range 211-266 251-310 259-319 271-332 279-343 275-370

34

Figure 3a. Yield change due to low nitrogen supply (i.e., yield increase between 0 and 60 lbs N acre-1 at 32,000 plants acre-1), and the yield response to high nitrogen (i.e., yield increase between 0 and 280 lbs N acre-1) at Harrisburg, IL in 2017.

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Figure 3b. Yield response to intermediate population (yield change between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), yield response to high plant population (yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1) at Harrisburg, IL 2017.

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Characterization of ‘Workhorse’ and ‘Racehorse’ Hybrids Similar to previous years, there was large genetic variation of corn hybrids for yield in

response to different agronomic conditions (Figures 1-3). The objective of the MYP trial is to identify the impact of the most important agronomic factors on grain yield for different corn genotypes and develop parameters that allow agronomists and farmers to better position their products. ‘Racehorse’ and ‘Workhorse’ indices support agronomic decisions in order to express a hybrid’s maximum yield potential using the recommended crop management system.

The ‘Racehorse’ index is composed of the yield responses to: high N (RTN; yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1), intermediate population (RTIntPop; yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), high plant population (RTHiPop; yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and row spacing (RTS; yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1) evaluations. The ‘Workhorse’ index is based on the check plot yield (yield at 0 lb N acre-1 and 32,000 plants acre-1) and the yield response to low N (RTLowN; yield change between 0 and 60 lb N acre-1 at 32,000 plants acre-1). ‘Racehorse’ and ‘Workhorse’ indices consider the variation and relationship of each parameter across environments and their contributions to observed yield increases. Using multivariate analysis, the relative weights for RTIntPop, RTHiPop, RTN, RTS, Check, and RTLowN were generated. The objective of this trial is to develop indices that will be consistent to the genetic characteristic of each hybrid regardless of the year and location tested. Therefore, the relative weights of each parameter were generated using the 2015, 2016 and 2017 data in the same analysis to better estimate the value of each parameter. Using the combined data, the relative weights for Check, RTLowN, RTN, RTIntPop, RTHiPop, and RTS parameters were 0.938, 0.062, 0.502, 0.120, 0.034, and 0.343 respectively (Eqs. 4 and 5). Parameter scores for each hybrid across locations are represented in Table 25. The calculation of a hybrid score for each location enables the understanding of the genetic by environment interaction for a specific parameter and hybrid. ′𝑅𝑎𝑐𝑒ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥! = 0.50 𝑅𝑇𝑁 + 0.12 𝑅𝑇𝐼𝑛𝑡𝑃𝑜𝑝 + 0.03 𝑅𝑇𝐻𝑖𝑃𝑜𝑝 + 0.34 𝑅𝑇𝑆 [4] ′𝑊𝑜𝑟𝑘ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥! = 0.94 𝐶ℎ𝑒𝑐𝑘 + 0.06 𝑅𝑇𝐿𝑜𝑤𝑁 [5]

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Table 25. Scores for the check plot yield (Check), yield response to low N (RTLowN), yield response to high N (RTN), yield response to intermediate plant population (RTIntPop), yield response to high plant population (RTHiPop), and yield response to narrower row spacing (RTS), for corn hybrids grown at Yorkville, Champaign, and Harrisburg, IL for 2017. Scores for each parameter are ranked from 0 to 10, with 0 being the least yield increase compared to the overall average, and 10 being the greatest yield increase compared to the overall average, with and average ranking of 5.

Brand Yorkville Champaign Harrisburg Hybrid Check† RTLowN RTN RTIntPop RTHiPop RTS Check RTLowN RTN RTIntPop RTHiPop RTS Check RTLowN RTN RTIntPop RTHiPop RTS

Golden Harvest G05B91-3010 1 8 3 1 9 4 1 2 5 3 4 4 - - - - - - SL5536ZL-3010 1 1 1 5 6 3 1 3 4 4 7 1 - - - - - -

G06Z97-3120 3 6 5 2 9 1 6 2 3 3 5 4 - - - - - - G07F23-3111 5 5 6 6 3 8 8 8 7 2 10 1 4 2 2 4 6 5 G09A86-3111 8 3 2 1 10 5 9 3 1 9 4 2 3 7 4 5 8 5 G09Y24-3220 4 4 4 9 1 5 3 10 9 5 8 1 3 9 7 6 5 2 SK6405-3220 7 8 7 2 8 8 9 2 3 6 3 8 6 8 9 8 10 1 G10T63-3122 10 4 9 10 1 3 2 10 10 7 3 7 2 10 10 6 3 10 G11X64-3010 - - - - - - 5 4 4 9 2 6 1 4 7 1 9 4

G12W66-3000GT 2 10 10 3 4 5 1 8 2 9 9 3 2 6 6 5 8 10 G14R38-3122 2 10 4 4 5 6 3 4 7 8 2 4 1 5 5 6 3 3

G14V04-3000GT - - - - - - 2 4 8 4 3 9 9 3 2 10 9 1 G15L32-3111 6 8 3 7 4 1 9 1 2 4 1 10 7 2 4 1 2 9 SL8675-3110 - - - - - - 7 9 9 7 6 3 9 7 9 4 7 10 G18D87-3111 - - - - - - 10 1 1 5 1 10 10 5 5 5 4 10

Channel 210-26STXRIB 8 3 1 6 8 1 7 3 4 8 5 3 1 5 6 3 7 2 212-20STXRIB 2 3 7 2 10 6 4 9 5 7 10 3 2 7 3 10 1 4 215-75STXRIB 6 2 2 5 3 10 8 3 4 3 8 3 8 6 3 8 4 2

DeKalb DKC60-87 3 4 3 5 2 9 4 5 8 4 4 8 5 4 8 3 2 7 DKC62-52 3 7 8 8 4 4 2 10 10 1 6 9 4 8 9 2 5 3 DKC63-21 1 9 9 6 2 5 1 9 7 3 9 8 9 1 2 7 6 1 DKC64-34 5 3 2 10 1 9 4 3 5 7 3 10 8 3 5 2 10 8 DKC65-94 8 2 4 9 8 8 - - - - - - 7 3 3 1 6 3 DKC66-74 7 6 8 7 3 6 8 1 3 6 3 7 8 1 7 1 2 8

Stone 5848SSRIB 3 7 6 2 10 6 2 5 9 6 4 8 5 1 1 8 9 2 6188SSRIB 5 2 4 2 9 10 5 7 5 2 10 9 6 4 2 10 1 8 6538SSRIB 5 2 5 5 5 8 4 5 4 1 10 1 5 6 1 9 2 2

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Table 25. (con’t.) Brand Yorkville Champaign Harrisburg Hybrid Check† RTLowN RTN RTIntPop RTHiPop RTS Check RTLowN RTN RTIntPop RTHiPop RTS Check RTLowN RTN RTIntPop RTHiPop RTS

Dyna-Gro D51SS54 1 7 8 3 5 9 7 1 1 9 5 7 3 8 8 2 1 8 D52SS63 7 1 1 10 6 2 6 2 2 5 4 5 6 2 1 10 7 4 D52SS91 9 1 1 8 6 1 4 8 1 10 6 2 1 10 6 7 3 9

D54DC94 1 6 9 3 7 7 7 6 8 3 5 2 8 9 2 9 5 9 D54VC52 10 1 2 4 4 4 3 9 9 4 7 6 7 3 1 9 5 7 D55VC45 6 5 6 10 2 9 - - - - - - 1 7 7 6 3 7 D56VC46 9 4 5 9 3 2 2 10 7 8 8 2 4 9 10 4 3 9 D57VC51 6 2 3 1 7 10 9 4 2 10 1 4 9 3 8 3 4 6 D58VC65 8 3 2 4 7 4 8 8 6 2 9 4 7 9 9 4 1 5 Croplan 4488SS 4 6 5 7 6 1 - - - - - - - - - - - -

4895SS/RIB 2 9 7 1 10 7 5 1 1 8 2 10 3 1 8 1 10 1 5887VT2P 4 4 3 6 8 2 - - - - - - 2 4 5 7 1 3

6110SS/RIB 10 1 1 4 3 2 6 6 3 2 9 2 5 1 1 2 7 1 5290DGVT2P 9 10 8 8 4 2 10 6 6 1 8 6 10 2 4 3 4 4 6594SS/RIB 2 9 10 1 9 3 1 6 3 6 7 7 3 4 4 4 9 3 6640VT3P 4 5 4 3 2 4 6 7 6 5 6 1 4 8 4 3 8 4 5678VT2P 3 5 6 7 5 7 10 7 8 1 7 5 10 5 3 5 2 5

7927VT3P/RIB 7 8 10 9 1 10 5 2 2 10 1 5 6 6 6 9 8 6 8621VT2P/RIB 10 7 7 3 7 3 10 5 10 2 2 6 10 2 3 8 6 7

Pioneer P1197AMXT 4 9 10 8 1 3 3 7 6 10 2 5 4 10 10 7 10 6 P1311AMXT 9 10 9 4 2 7 3 4 10 1 1 9 2 10 10 2 4 6

† Check, unfertilized check plot yield (yield at 0 lb N acre-1 and 32,000 plants acre-1); RTLowN, yield response to low N (yield change between 0 and 60 lb N acre-1 at 32,000 plants acre-1); RTN, yield response to high N (yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1); RTIntPop, yield response to intermediate population (yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1); RTHiPop, yield response to high plant population (yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1); RTS, yield response to row space (yield change between 30 and 20 inch row spacing at 44,000 plants acre-1 and 280 lb N acre-1).

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Summary of Hybrid Agronomic Characteristics This section presents a brief summary of the yield responses to different managements for

each corn hybrid in 2017. Scores for check plot yield, yield response to low N, yield response to high N, yield response to intermediate pop., yield response to high pop., yield response to row spacing, ‘Workhorse’ index, and ‘Racehorse’ index were generated for each hybrid (bar graphs) using the combined data from all locations. CHANNEL:

210-26STXRIB

Above average check plot yield with little response to Nitrogen. Responsive at the moderate planting rate and shows inconstancy at the higher rate. Did not improve with narrow rows.

212-20STXRIB

Poor check plot yields across environments. Shows greatest response to low N. Responds to increasing plant population but does not show added value in narrow rows.

215-75STXRIB

Good check plot yields across all environments with highest yield potential among Channel hybrids. Showed below average response to N and inconsistent responses in population and row spacing. Although, a 77.7 bu acre-1 response to row spacing was observed at Yorkville.

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CROPLAN:

4488SS:

This short season hybrid was only planted at our Yorkville location. It showed above average responses to nitrogen and increased population. Did not improve with narrow rows.

4895SS/RIB:

Below average check plot yield. Shows great yield potential with moderate to high populations and in narrow rows.

5887VT2P:

Below average yields across environments. Did not improve with narrow rows.

6110SS/RIB:

Strong workhorse hybrid. Above average yields in low N environments. Plant at a moderate to high plant population.

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5290DGVT2P:

High yielding workhorse hybrid that demonstrated stability across all environments and growing conditions.

6640VT3P/RIB:

Average and stable hybrid across environments with good response to low N. Below average yield increases with increasing plant population.

6594SS/RIB:

Yields well when nitrogen is adequately managed. High yield potential at high plant densities. did not gain from narrow row spacing.

5678VT2P:

Above average performance across all locations and levels of N availability. Higher pops are better managed in narrow rows with this hybrid.

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DEKALB:

7927VT3P/RIB:

High yielding hybrid that requires N management. Best planted at moderate to high plant populations. Highest yield potential in narrow rows. Achieved highest yield of trial when planted in 20 inch rows at the Yorkville location.

8621VT2P/RIB:

Highest yielding Croplan hybrid averaged across treatments and locations. High yielding in all plant densities and shows some response to narrow rows. Demonstrated high yields in low N conditions and response to N fertilizer.

DKC60-87SS

Responds well to N fertilization. Plant at moderate populations. Takes advantage of narrow row spacing.

DKC62-52SS

Must manage nitrogen. Low check plot yields and demonstrated a high response to N.

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DKC63-21SS

Responsive to nitrogen and showed inconsistent yield responses to increased plant population.

DKC64-34SS

Consistent hybrid across environments and growing conditions. Notably high yields at 44,000 plants acre-1 in 20 inch row spacing.

DKC65-94SS

High yields in low N environments. Responded well to population and narrow row spacing at our northern site in Yorkville.

DKC66-74SS

High check plot yield and responsive to nitrogen fertilization. Benefits from narrow rows.

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DYNA-GRO:

D51SS54:

Tends to be responsive to Nitrogen. Plant at a low to moderate plant population. Very responsive to narrow rows.

D52SS63:

Above average performance in low N environments with minimal response to N fertilization. Responsive to increased planting population.

D52SS91:

Will yield well in N loss situations. Position in a medium to medium-high plant population.

D54VC52:

Strong check plot yield and stable performance across all environments and growing conditions.

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D54DC94:

Good yield response to N fertilizer. Responsive to higher planting densities and narrow rows at the southern location.

D55VC45:

‘Racehorse’ hybrid with high yield potential. Responds to N and increased plant population. Better to manage high pops with narrower rows with this hybrid.

D56VC46RIB:

Performs across all environments and growing conditions. Shows above average response to N and plant density. Highest yield potential is at medium to high populations.

D57VC51:

Exceptional check plot yields with limited response to N fertilization. Plant at a low to medium population. Responds well to narrow rows.

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GOLDEN HARVEST:

D58VC65:

‘Workhorse’ hybrid with exceptional performance in all yield environments. Expresses stability across locations and managements. Responds to higher populations with little response to row spacing.

G05B91-3010:

Low yielding hybrid across all N environments. Shows inconsistency in response to management.

SL5536ZL:

Short statured hybrid that had consistently lower-than-average yields across environments. Shows response to increased populations.

G06Z97-3120:

Average check plot yield with below average response to increased nitrogen. Responds to higher planting densities.

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G07F23-3111:

Good performance across all yield environments. Responsive to increased population. Underperformed at the southern location.

G09A86-3111:

Performs well in low yielding environments. Position in a high plant density.

G09Y24-3220A:

Must adequately manage nitrogen. Performs best at a moderate to high population.

SK6405-3220:

This hybrid combines strong ‘workhorse’ and ‘racehorse’ characteristics. High yielding across all yield environments. Tolerates high plant densities with highest yield potential in narrow rows.

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G10T63-3122:

Yields exceptionally well with adequate N. Best planted at an intermediate population. High yield potential at higher populations in narrow rows.

G11X64-3010:

Responsive to nitrogen management. Top performance in higher populations or narrow rows.

G12W66-3000GT:

‘Racehorse’ hybrid with consistently low check plot yield and high response to nitrogen across all locations. Shows great response to higher plant densities and 20 inch rows.

G14R38-3122:

Combines low check plot score and an above average response to low nitrogen. Best planted at an intermediate plant population (38,000 plants acre-1).

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G14V04-3000GT:

High check plot yield in Harrisburg, yet a lower check plot yield in Champaign resulting in a response to N. Population increases helped yields in Harrisburg. A large response to narrow rows was observed in Champaign.

G15L32-3111:

Stress tolerant ‘workhorse’ hybrid. Demonstrates an above average check plot yield with minimal response to N fertilization. Good hybrid in a narrow row arrangement.

SL8675-3110:

High yielding ‘workhorse’ and ‘racehorse’ hybrid. Performs well in all N environments. Place in a high plant density for best yield potential. Also responds well to narrow rows.

G18D87-3111:

High ‘workhorse’ index with excellent check plot yields observed in 2017. Performs exceptionally well in 20 inch rows.

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PIONEER:

STONE:

P1197AMXT:

Highest yielding hybrid for Pioneer brand in the trial. Best suited for high yielding environments. Performs best in intermediate plant densities. High ‘Racehorse’ index.

P1311AMXT:

Demonstrates more N loss tolerance than P1197AMXT while still showing a large yield response to N fertilization. Highest yield potential is in a narrow row spacing.

5848SSRIB:

Below average check plot yield and response to N across all locations. Responds well to high plant populations and narrow rows.

6188SSRIB:

Stable yields across all locations and environments. Increase yield potential with high pops or narrow rows.

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6538SSRIB:

Average check plot yield with little response to N fertilization. Plant at a high density for top performance.

2017 corn management yield potential final …cropphysiology.cropsci.illinois.edu/documents/2017...

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