2016 management yield potentialcropphysiology.cropsci.illinois.edu/documents/2016... · conversely,...

2016 Management Yield Potential Adriano T. Mastrodomenico and Fred E. Below

Crop Physiology Laboratory – Department of Crop Sciences Univeristy of Illinois at Urbana-Champaign

Table of contents

Introduction ................................................................................................................................... 2

Materials and Methods ................................................................................................................. 3

Yield Results - Champaign, IL .................................................................................................... 7

Yield Data - Yorkville, IL ........................................................................................................... 15

Yield Data - Harrisburg, IL ....................................................................................................... 23

Characterization of ‘Workhorse’ and ‘Racehorse’ Hybrids .................................................. 31

Summary of Hybrids Agronomic Characteristics ................................................................... 36

References .................................................................................................................................... 48

2

Introduction Maize yield increases since the 1930s have been due to genetic improvement and better crop

management practices (Duvick, 2005). Because maize genotypes interact with crop management in producing yield, understanding the dynamics between plant genetics and agronomic management will provide the opportunity to obtain the maximum yield potential of the hybrid using a corresponding recommended agricultural management. In addition, continued increases in corn yield will depend on a hybrid’s ability to utilize resources more efficiently when grown under greater planting densities (Tollenaar and Lee, 2002) and under favorable agronomic conditions (Boomsma et al., 2009). Nonetheless, increased plant density needs to be in synergy with other intensified management factors, such as better soil fertility, in order to minimize the current maize yield gap that exists in the U.S. Corn Belt (Ruffo et al., 2015).

Current commercial breeding programs select and develop elite hybrids using a high N fertilizer rate (280 lbs N acre-1) and a standard plant density (32,000 plants acre-1), only evaluating a hybrid’s yield responses to different crop management practices at the pre-commercial stage. Therefore, there are limited reports of genetic variability of elite hybrids for different N-use traits (Bertin and Gallais, 2000). The genetic improvement in yield response to N fertilizer in maize hybrids is well documented (Ding et al., 2005; Coque and Gallais, 2007; Haegele et al., 2013). However, these previous studies used a small representation of elite maize hybrids across limited number of environments, which may have underestimated the genetic diversity of current maize hybrid yields in response to N fertilizer supplementation.

In addition to the genetic improvements in nitrogen use efficiency, tolerance to increased plant density is one of the most valuable agronomic advances since the development of the maize hybrid (Duvick, 1977). The most recent maize yield record in the U.S. (532 bu acre-1) was achieved with a plant density (50,000 plants acre-1) much greater than common agronomic practices (National Corn Growers Association, 2015). The maize world yield record grown under high plant density indicates that the genetic gain of maize is still far from a plateau and that current maize hybrids exhibit greater crowding stress tolerance when compared to their predecessors (Tollenaar and Wu, 1999).

Increased plant density reduces the yield from individual plants, but increases light interception, and to a lesser extent, seed number per ground area, therefore increasing the source-sink ratio (Borras et al., 2003). One of the possible reasons for the success of increasing plant density to increase maize yield is due to the lack of the ear size to have correspondingly increased with yield in hybrids, causing a reproductive-sink limitation (Egli, 2015). The reproductive-sink limitation hypothesis supports the fact that the yield potential of individual plants have not increased over time, rather maize hybrids have increased their stress tolerance, including the ability to tolerate higher plant densities (Tollenaar and Lee, 2002; Duvick, 2005).

One of the future challenges of maize breeding will be selecting genotypes with greater yields in response to increased plant density with concurrent yield stability across environments (Tokatlidis and Koutroubas, 2004). Breeding programs targeting for maize hybrids with improved tolerance to high plant density and N fertilizer response need a comprehensive

3

evaluation using a representative number of commercial maize hybrids at different N rates and plant densities evaluated in multiple environments.

The objective of the Management Yield Potential (MYP) trial is to identify ‘Racehorse’ hybrids, or hybrids with adaptability to high yield environments (i.e. responsive to crop management), and ‘Workhorse’ hybrids, or hybrids with acceptable yields in a low fertility environment (i.e. tolerant to N loss). In our approach, ‘Racehorse’ hybrids are the genotypes that have greater yield increases in the following categories: (i) N fertilizer (RTN, yield change between 0 and 280 lb N acre-1 at 32,000 plants acre-1), (ii) an intermediate plant population (IntRTP, yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), (iii) maximum plant population (MaxRTP, yield change between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and (iv) narrower row spacing (RTR, yield change between 30 and 20 inches row spacing at 44,000 plants acre-1 and 280 lb N acre-1). Conversely, hybrids with high Check Plot yield (at 0 lb N acre-1) and a high initial yield increase with N (InitN, yield change between 0 and 60 lb N acre-1 at 32,000 plants acre-1) were considered ‘Workhorse’ hybrids.

Materials and Methods

For 2016, the trial was planted using a precision plot planter with variable seeding rate capability (SeedPro 360, ALMACO, Nevada, IA) at Champaign, IL (24 April), Yorkville, IL (20 May), and Harrisburg, IL (26 April). 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 Lumax EZ (3.25 qt/A) 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 Champaign, IL (24 May), Yorkville, IL (20 June), and Harrisburg, IL (01 June). Forty seven hybrids represented by seven different seed brands, with relative maturities ranging from 102-120 days were evaluated (Tables 1a and 1b). 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. Treatment (vi) at Champaign was planted at 64,000 plants acre-1 in the 20-inch row space and instead of the desired 44,000 plants acre-1 due to a problem in the configuration of the planter’s software. 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.

The treatments were arranged in a split block experimental design with four replications. Data were analyzed using analysis of variance with the PROC MIXED procedure of SAS (SAS V8 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. Hybrids were ranked from 1 to 10 using the PROC RANK procedure of SAS to generate scores for Check Plot, initial N response (InitN), maximum response to N (RTN), intermediate yield response to population (IntRTP), maximum yield response to plant population (MaxRTP),

4

and yield response to row space (RTR). 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) ranged 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 average ranking a 5.

‘Racehorse’ and ‘Workhorse’ indices were estimated using a multiple regression approach with the Smith-Hazel index (Smith, 1936; Hazel, 1943). The data for yield response to narrower row spacing at Champaign was not included in the ‘Racehorse’ index analysis. 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).

𝑏𝑛 = 𝑃−1𝐺𝑎 [1]

′𝑅𝑎𝑐𝑒ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥′ = 𝑏1𝐼𝑛𝑡𝑅𝑇𝑃 + 𝑏2𝑀𝑎𝑥𝑅𝑇𝑃 + 𝑏3𝑅𝑇𝑁 + 𝑏4𝑅𝑇𝑅 [2] ′𝑊𝑜𝑟𝑘ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥′ = 𝑏5𝐶ℎ𝑒𝑐𝑘 + 𝑏6𝐼𝑛𝑖𝑡𝑁 [3]

Where b is the vector of the weights of the indices, 𝑃−1 is the inverse matrix of the phenotypic variance-covariance, G is the matrix of the genetic variance-covariance, and 𝑎 is the initial weight.

Yield Results - Champaign, IL

The following three sections correspond to the yield results for each treatment and hybrid, and the yield responses to different agronomic management factors. The next six tables (e.g. Tables 2 to 7) 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 described in a summary table (e.g. Table 8). Yield response to different agronomic managements (e. g. Figure 1) is described for each location.

5

Table 1a. A list of 47 hybrids evaluated in the Management Yield Potential trial in 2016 grown at Champaign, Yorkville and Harrisburg, IL. Hybrids are sorted by relative maturity ranging from 102 to 120 days.

Hybrid Brand Company CRM Harrisburg Champaign Yorkville G02W74-3000GT Golden Harvest Syngenta 102 x G03H42-3000GT Golden Harvest Syngenta 103 x

G06N80-3111 Golden Harvest Syngenta 106 x 4644DGVT2P Croplan Winfield 106 x x x

G07B39-3122A-EZ0 Golden Harvest Syngenta 107 x x x G07F23-3111 Golden Harvest Syngenta 107 x x x

208-23STXRIB Channel Monsanto 108 x x x 4895SS/RIB Croplan Winfield 108 x x x 5887VT2P Croplan Winfield 108 x x x

DKC59-50SS DEKALB Monsanto 109 x x x G09E98-3122-EZ0 Golden Harvest Syngenta 109 x x x

DKC60-87SS DEKALB Monsanto 110 x x x 6068RIB Stone Monsanto 110 x x x

G10S30-3220-EZ0 Golden Harvest Syngenta 110 x x x G10T63-3000GT Golden Harvest Syngenta 110 x x x

6110SS/RIB Croplan Winfield 110 x x x P1197AMXT Pioneer Pioneer 111 x x x

G11F16-3111A Golden Harvest Syngenta 111 x x x 6065SS/RIB Croplan Winfield 111 x x x

D52VC91RIB Dyna-Gro CPS 112 x x x G12J11-3111A Golden Harvest Syngenta 112 x x x

G12W66-3000GT Golden Harvest Syngenta 112 x x x 6265SS/RIB Croplan Winfield 112 x x x

5290DGVT2P Croplan Winfield 112 x x x P1257AMXT Pioneer Pioneer 112 x x x P1311AMXT Pioneer Pioneer 113 x x x DKC63-71SS DEKALB Monsanto 113 x x x

213-19STXRIB Channel Monsanto 113 x x x 6594SS/RIB Croplan Winfield 113 x x x 6640VT3P Croplan Winfield 113 x x x

D54DC94RIB Dyna-Gro CPS 114 x x x DKC64-34SS DEKALB Monsanto 114 x x x

6458RIB Stone Monsanto 114 x x x P1479AM Pioneer Pioneer 114 x x x

G14R38-3122GT Golden Harvest Syngenta 114 x x x 7087VT2P/RIB Croplan Winfield 114 x x x D55VC77RIB Dyna-Gro CPS 115 x x x DKC63-60SS DEKALB Monsanto 115 x x x G15Z99-3111 Golden Harvest Syngenta 115 x x D56VC46RIB Dyna-Gro CPS 116 x x x DKC66-74SS DEKALB Monsanto 116 x x x

216-36STXRIB Channel Monsanto 116 x x x G16K01-3122 Golden Harvest Syngenta 116 x x

6718RIB Stone Monsanto 117 x x x 7927VT3P/RIB Croplan Winfield 117 x x x 8621VT2P/RIB Croplan Winfield 117 x x x

G18D87-3000GT Golden Harvest Syngenta 118 x x

6

Table 1b. A list of 47 hybrids evaluated in the Management Yield Potential trial in 2016 grown at Champaign, Yorkville and Harrisburg, IL. Hybrids are sorted by company and brand names.

Hybrid Brand Company CRM Harrisburg Champaign Yorkville D52VC91RIB Dyna-Gro CPS 112 x x x D54DC94RIB Dyna-Gro CPS 114 x x x D55VC77RIB Dyna-Gro CPS 115 x x x D56VC46RIB Dyna-Gro CPS 116 x x x

208-23STXRIB Channel Monsanto 108 x x x 213-19STXRIB Channel Monsanto 113 x x x 216-36STXRIB Channel Monsanto 116 x x x DKC59-50SS DEKALB Monsanto 109 x x x DKC60-87SS DEKALB Monsanto 110 x x x DKC63-71SS DEKALB Monsanto 113 x x x DKC64-34SS DEKALB Monsanto 114 x x x DKC63-60SS DEKALB Monsanto 115 x x x DKC66-74SS DEKALB Monsanto 116 x x x

6068RIB Stone Monsanto 110 x x x 6458RIB Stone Monsanto 114 x x x 6718RIB Stone Monsanto 117 x x x

P1197AMXT Pioneer Pioneer 111 x x x P1257AMXT Pioneer Pioneer 112 x x x P1311AMXT Pioneer Pioneer 113 x x x

P1479AM Pioneer Pioneer 114 x x x G02W74-3000GT Golden Harvest Syngenta 102 x G03H42-3000GT Golden Harvest Syngenta 103 x

G06N80-3111 Golden Harvest Syngenta 106 x G07B39-3122A-EZ0 Golden Harvest Syngenta 107 x x x

G07F23-3111 Golden Harvest Syngenta 107 x x x G09E98-3122-EZ0 Golden Harvest Syngenta 109 x x x G10S30-3220-EZ0 Golden Harvest Syngenta 110 x x x G10T63-3000GT Golden Harvest Syngenta 110 x x x G11F16-3111A Golden Harvest Syngenta 111 x x x G12J11-3111A Golden Harvest Syngenta 112 x x x

G12W66-3000GT Golden Harvest Syngenta 112 x x x G14R38-3122GT Golden Harvest Syngenta 114 x x x

G15Z99-3111 Golden Harvest Syngenta 115 x x G16K01-3122 Golden Harvest Syngenta 116 x x

G18D87-3000GT Golden Harvest Syngenta 118 x x 4644DGVT2P Croplan Winfield 106 x x x 4895SS/RIB Croplan Winfield 108 x x x 5887VT2P Croplan Winfield 108 x x x

6110SS/RIB Croplan Winfield 110 x x x 6065SS/RIB Croplan Winfield 111 x x x 6265SS/RIB Croplan Winfield 112 x x x

5290DGVT2P Croplan Winfield 112 x x x 6594SS/RIB Croplan Winfield 113 x x x 6640VT3P Croplan Winfield 113 x x x

7087VT2P/RIB Croplan Winfield 114 x x x 7927VT3P/RIB Croplan Winfield 117 x x x 8621VT2P/RIB Croplan Winfield 117 x x x

7

Yield Results - Champaign, IL Table 2. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 208-23STXRIB 173.7 23 6640VT3P 135.9 2 DKC64-34SS 168.5 24 6065SS/RIB 135.4 3 G11F16-3111A 156.9 25 8621VT2P/RIB 135.0 4 D54DC94RIB 155.9 26 G12J11-3111A 134.2 5 6458RIB 155.4 27 DKC63-71SS 133.2 6 G16K01-3122 154.1 28 5290DGVT2P 131.5 7 G14R38-3122GT 153.6 29 6718RIB 131.3 8 DKC59-50SS 148.4 30 D55VC77RIB 125.6 9 G12W66-3000GT 147.3 31 G07F23-3111 124.5

10 DKC66-74SS 145.1 32 P1479AM 123.7 11 216-36STXRIB 144.6 33 P1197AMXT 121.6 12 DKC60-87SS 144.3 34 G07B39-3122A-EZ0 121.0 13 6110SS/RIB 144.1 35 P1311AMXT 120.0 14 4644DGVT2P 143.6 36 P1257AMXT 118.4 15 G10S30-3220-EZ0 143.1 37 6068RIB 117.5 16 7087VT2P/RIB 142.7 38 6594SS/RIB 116.8 17 4895SS/RIB 142.2 39 D52VC91RIB 113.7 18 DKC63-60SS 139.6 40 6265SS/RIB 111.1 19 5887VT2P 138.0 41 G18D87-3000GT 110.6 20 D56VC46RIB 137.5 42 G15Z99-3111 109.4 21 213-19STXRIB 137.4 43 7927VT3P/RIB 108.9 22 G10T63-3000GT 135.9 44 G09E98-3122-EZ0 107.0

Mean 134.7

LSD (P ≤ 0.10) 25.5

8

Table 3. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 DKC60-87SS 245.7 23 D56VC46RIB 214.1 2 5290DGVT2P 238.4 24 213-19STXRIB 213.7 3 8621VT2P/RIB 237.1 25 4644DGVT2P 213.6 4 DKC64-34SS 235.8 26 DKC63-71SS 213.5 5 DKC66-74SS 235.6 27 6718RIB 213.5 6 6640VT3P 234.8 28 D54DC94RIB 213.3 7 G14R38-3122GT 234.3 29 216-36STXRIB 212.8 8 G10T63-3000GT 234.1 30 G10S30-3220-EZ0 211.7 9 208-23STXRIB 232.0 31 G07B39-3122A-EZ0 211.2

10 6458RIB 227.8 32 5887VT2P 209.6 11 7087VT2P/RIB 227.4 33 6110SS/RIB 209.0 12 DKC59-50SS 226.3 34 P1197AMXT 208.2 13 P1311AMXT 226.1 35 6594SS/RIB 206.0 14 P1257AMXT 225.1 36 G09E98-3122-EZ0 203.5 15 4895SS/RIB 222.4 37 7927VT3P/RIB 203.3 16 G12J11-3111A 221.8 38 G18D87-3000GT 203.1 17 G16K01-3122 220.9 39 6265SS/RIB 202.4 18 DKC63-60SS 220.1 40 6068RIB 201.7 19 P1479AM 219.1 41 G11F16-3111A 200.5 20 D55VC77RIB 219.0 42 D52VC91RIB 199.2 21 G12W66-3000GT 217.8 43 G15Z99-3111 196.6 22 6065SS/RIB 217.8 44 G07F23-3111 188.4

Mean 217.5

LSD (P ≤ 0.10) 25.0

9

Table 4. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 8621VT2P/RIB 278.7 23 P1479AM 249.5 2 P1311AMXT 276.7 24 6640VT3P 249.4 3 P1197AMXT 276.1 25 G16K01-3122 249.3 4 DKC64-34SS 274.7 26 G07B39-3122A-EZ0 247.8 5 DKC60-87SS 272.3 27 G15Z99-3111 245.5 6 G10T63-3000GT 271.6 28 6068RIB 245.4 7 213-19STXRIB 266.5 29 4644DGVT2P 243.9 8 7087VT2P/RIB 266.3 30 D55VC77RIB 243.2 9 P1257AMXT 266.3 31 G14R38-3122GT 241.6

10 DKC66-74SS 264.8 32 4895SS/RIB 241.3 11 5290DGVT2P 264.2 33 DKC63-71SS 240.2 12 G12W66-3000GT 263.0 34 G11F16-3111A 238.5 13 7927VT3P/RIB 262.0 35 G07F23-3111 238.5 14 D54DC94RIB 258.1 36 5887VT2P 235.0 15 6718RIB 256.6 37 D52VC91RIB 234.9 16 DKC63-60SS 255.7 38 6065SS/RIB 234.7 17 6458RIB 254.5 39 DKC59-50SS 232.9 18 6110SS/RIB 253.6 40 6594SS/RIB 232.2 19 216-36STXRIB 252.8 41 G09E98-3122-EZ0 231.6 20 G18D87-3000GT 252.1 42 D56VC46RIB 227.4 21 G12J11-3111A 251.2 43 6265SS/RIB 226.9 22 G10S30-3220-EZ0 249.9 44 208-23STXRIB 208.1

Mean 250.6

LSD (P ≤ 0.10) 15.9

10

Table 5. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 G10T63-3000GT 283.4 23 DKC63-60SS 261.2 2 DKC64-34SS 282.7 24 P1479AM 258.8 3 P1197AMXT 280.5 25 7927VT3P/RIB 258.8 4 DKC60-87SS 278.4 26 DKC59-50SS 258.3 5 DKC66-74SS 275.6 27 G07F23-3111 257.0 6 P1257AMXT 275.5 28 G14R38-3122GT 256.2 7 D54DC94RIB 275.4 29 208-23STXRIB 255.6 8 G12W66-3000GT 274.8 30 6065SS/RIB 254.8 9 G18D87-3000GT 273.1 31 4895SS/RIB 251.7

10 G10S30-3220-EZ0 273.0 32 G11F16-3111A 250.3 11 7087VT2P/RIB 272.5 33 G15Z99-3111 249.5 12 5290DGVT2P 270.3 34 6068RIB 249.5 13 6458RIB 269.2 35 6265SS/RIB 246.7 14 P1311AMXT 268.8 36 G09E98-3122-EZ0 246.4 15 6110SS/RIB 268.2 37 DKC63-71SS 246.1 16 6718RIB 268.1 38 G07B39-3122A-EZ0 245.8 17 G16K01-3122 268.0 39 D55VC77RIB 243.0 18 216-36STXRIB 266.7 40 5887VT2P 241.7 19 4644DGVT2P 265.9 41 6594SS/RIB 239.7 20 8621VT2P/RIB 265.9 42 D56VC46RIB 232.1 21 6640VT3P 265.0 43 D52VC91RIB 228.7 22 G12J11-3111A 263.6 44 213-19STXRIB 217.3

Mean 259.9

LSD (P ≤ 0.10) 18.3

11


Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 G10T63-3000GT 291.9 23 216-36STXRIB 259.6 2 P1197AMXT 287.7 24 6640VT3P 258.8 3 DKC64-34SS 286.5 25 4895SS/RIB 258.0 4 8621VT2P/RIB 283.0 26 6068RIB 256.9 5 G12W66-3000GT 281.5 27 G12J11-3111A 256.8 6 DKC60-87SS 278.6 28 G15Z99-3111 255.0 7 213-19STXRIB 278.2 29 G14R38-3122GT 253.7 8 P1311AMXT 275.4 30 G07B39-3122A-EZ0 252.9 9 P1257AMXT 273.2 31 6065SS/RIB 251.0

10 G16K01-3122 271.7 32 G10S30-3220-EZ0 250.7 11 G18D87-3000GT 270.4 33 DKC59-50SS 250.0 12 DKC66-74SS 269.4 34 G07F23-3111 249.9 13 D54DC94RIB 269.3 35 5887VT2P 249.7 14 5290DGVT2P 268.8 36 7927VT3P/RIB 245.4 15 7087VT2P/RIB 268.5 37 DKC63-71SS 244.1 16 P1479AM 266.5 38 D55VC77RIB 243.3 17 6718RIB 265.6 39 G11F16-3111A 242.4 18 DKC63-60SS 265.3 40 G09E98-3122-EZ0 241.1 19 208-23STXRIB 264.1 41 6594SS/RIB 239.2 20 4644DGVT2P 263.2 42 D56VC46RIB 234.0 21 6110SS/RIB 262.8 43 6265SS/RIB 232.1 22 6458RIB 260.1 44 D52VC91RIB 231.4

Mean 260.3

LSD (P ≤ 0.10) 18.7

12


Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 G10T63-3000GT 302.2 23 6265SS/RIB 247.4 2 5290DGVT2P 294.6 24 6110SS/RIB 246.1 3 DKC64-34SS 289.4 25 G10S30-3220-EZ0 245.3 4 G12W66-3000GT 288.1 26 DKC59-50SS 245.2 5 DKC60-87SS 282.0 27 DKC63-71SS 244.7 6 6458RIB 276.7 28 G07B39-3122A-EZ0 244.3 7 P1479AM 276.6 29 6068RIB 243.5 8 DKC66-74SS 275.9 30 4895SS/RIB 242.6 9 P1197AMXT 275.7 31 G16K01-3122 240.1

10 213-19STXRIB 270.3 32 6594SS/RIB 236.8 11 DKC63-60SS 269.3 33 G14R38-3122GT 234.3 12 G18D87-3000GT 264.3 34 P1257AMXT 234.1 13 4644DGVT2P 263.6 35 D56VC46RIB 231.6 14 8621VT2P/RIB 261.1 36 D54DC94RIB 230.7 15 6718RIB 259.3 37 G15Z99-3111 225.1 16 216-36STXRIB 257.5 38 6640VT3P 223.6 17 G11F16-3111A 254.4 39 208-23STXRIB 222.1 18 6065SS/RIB 253.9 40 D55VC77RIB 216.6 19 7927VT3P/RIB 253.1 41 D52VC91RIB 212.1 20 G07F23-3111 252.8 42 P1311AMXT 200.7 21 7087VT2P/RIB 250.4 43 5887VT2P 198.8 22 G12J11-3111A 248.3 44 G09E98-3122-EZ0 190.7

Mean 249.5

LSD (P ≤ 0.10) 29.1

13

Table 8. Individual yield values of all hybrid entries (n = 44) grown under two levels of row spacing (30 and 20 inches), four levels of plant population (32,000, 38,000, 44,000, and 64,000 plants acre-1) and three levels of N supply (0, 60, and 280 lb N acre-1) at Champaign, IL in 2016. Trial means and phenotypic ranges (smallest and largest hybrid means) shown for comparison. Hybrids are sorted by company.

20 in38,000 plts a-1 44,000 plts a-1 64,000 plts a-1

0 lb N 60 lb N 280 lb N 280 lb N--- bu acre-1 ---

DynagroD52VC91RIB 113.7 199.2 234.9 228.7 231.4 212.1D54DC94RIB 155.9 213.3 258.1 275.4 269.3 230.7D55VC77RIB 125.6 219.0 243.2 243.0 243.3 216.6D56VC46RIB 137.5 214.1 227.4 232.1 234.0 231.6

Monsanto208-23STXRIB 173.7 232.0 208.1 255.6 264.1 222.1213-19STXRIB 137.4 213.7 266.5 217.3 278.2 270.3216-36STXRIB 144.6 212.8 252.8 266.7 259.6 257.5

6068RIB 117.5 201.7 245.4 249.5 256.9 243.56458RIB 155.4 227.8 254.5 269.2 260.1 276.76718RIB 131.3 213.5 256.6 268.1 265.6 259.3

DKC59-50SS 148.4 226.3 232.9 258.3 250.0 245.2DKC60-87SS 144.3 245.7 272.3 278.4 278.6 282.0DKC63-60SS 139.6 220.1 255.7 261.2 265.3 269.3DKC63-71SS 133.2 213.5 240.2 246.1 244.1 244.7DKC64-34SS 168.5 235.8 274.7 282.7 286.5 289.4DKC66-74SS 145.1 235.6 264.8 275.6 269.4 275.9

PioneerP1197AMXT 121.6 208.2 276.1 280.5 287.7 275.7P1257AMXT 118.4 225.1 266.3 275.5 273.2 234.1P1311AMXT 120.0 226.1 276.7 268.8 275.4 200.7

P1479AM 123.7 219.1 249.5 258.8 266.5 276.6Syngenta

G07B39-3122A-EZ0 121.0 211.2 247.8 245.8 252.9 244.3G07F23-3111 124.5 188.4 238.5 257.0 249.9 252.8

G09E98-3122-EZ0 107.0 203.5 231.6 246.4 241.1 190.7G10S30-3220-EZ0 143.1 211.7 249.9 273.0 250.7 245.3G10T63-3000GT 135.9 234.1 271.6 283.4 291.9 302.2G11F16-3111A 156.9 200.5 238.5 250.3 242.4 254.4G12J11-3111A 134.2 221.8 251.2 263.6 256.8 248.3

G12W66-3000GT 147.3 217.8 263.0 274.8 281.5 288.1G14R38-3122GT 153.6 234.3 241.6 256.2 253.7 234.3

G15Z99-3111 109.4 196.6 245.5 249.5 255.0 225.1G16K01-3122 154.1 220.9 249.3 268.0 271.7 240.1

G18D87-3000GT 110.6 203.1 252.1 273.1 270.4 264.3Winfield

4644DGVT2P 143.6 213.6 243.9 265.9 263.2 263.64895SS/RIB 142.2 222.4 241.3 251.7 258.0 242.6

5290DGVT2P 131.5 238.4 264.2 270.3 268.8 294.65887VT2P 138.0 209.6 235.0 241.7 249.7 198.8

6065SS/RIB 135.4 217.8 234.7 254.8 251.0 253.96110SS/RIB 144.1 209.0 253.6 268.2 262.8 246.16265SS/RIB 111.1 202.4 226.9 246.7 232.1 247.46594SS/RIB 116.8 206.0 232.2 239.7 239.2 236.86640VT3P 135.9 234.8 249.4 265.0 258.8 223.6

7087VT2P/RIB 142.7 227.4 266.3 272.5 268.5 250.47927VT3P/RIB 108.9 203.3 262.0 258.8 245.4 253.18621VT2P/RIB 135.0 237.1 278.7 265.9 283.0 261.1LSD (P ≤ 0.10) 25.5 25.0 15.9 18.3 18.7 29.1

Mean 134.8 217.5 250.9 260.1 260.7 249.6Range 107-174 188-246 208-279 217-283 231-292 191-302

30 in32,000 plts a-1

280 lb N---------- bu acre-1 -------------------- bu acre-1 ----------

14

Table 9. Yield values averaged within seed companies under two levels of row spacing (30 and 20 inches), four levels of plant population (32,000, 38,000, 44,000 and 64,000 plants acre-1) and three levels of N supply (0, 60, and 280 lb N acre-1) at Champaign, IL in 2016.

30 in 20 in 32,000 plts a-1 38,000 plts a-1 44,000 plts a-1 64,000 plts a-1 0 lb N 60 lb N 280 lb N 280 lb N 280 lb N

---------- bu acre-1 ---------- ---------- bu acre-1 ---------- --- bu acre-1 ---- Dyna-Gro 133.1 211.4 240.9 244.8 244.5 222.8 Channel 151.9 219.5 242.4 246.6 267.3 250.0

Stone 134.7 214.3 252.2 262.2 260.9 259.8 DeKalb 146.5 229.5 256.8 267.1 265.7 267.8 Pioneer 120.9 219.6 267.2 270.9 275.7 246.8

Syngenta 133.1 212.0 248.4 261.8 259.8 249.2 Winfield 132.1 218.5 249.0 258.4 256.7 247.7

Figure 1. Yield response to different agronomic management practices for intermediate yield response to population (IntRTP, yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), maximum yield response to plant population (MaxRTP, yield response between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (RTR, yield response between 30 inches at 44,000 plants acre-1 and 20 inches at 64,000 plants acre-1 at 280 lb N acre-1) at Champaign, IL

15

Yield Data - Yorkville, IL Table 10. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 6458RIB 256.0 23 DKC60-87SS 213.4 2 6718RIB 251.9 24 G10S30-3220-EZ0 213.1 3 G12W66-3000GT 249.2 25 G09E98-3122-EZ0 211.7 4 DKC64-34SS 243.0 26 6110SS/RIB 211.7 5 G10T63-3000GT 242.7 27 6068RIB 211.2 6 213-19STXRIB 240.2 28 DKC59-50SS 211.2 7 DKC63-60SS 233.8 29 G12J11-3111A 210.0 8 G14R38-3122GT 230.6 30 P1257AMXT 209.5 9 216-36STXRIB 230.1 31 G07F23-3111 208.8

10 DKC66-74SS 228.3 32 P1311AMXT 208.5 11 P1479AM 227.4 33 5290DGVT2P 206.4 12 D54DC94RIB 226.7 34 7927VT3P/RIB 206.0 13 P1197AMXT 224.2 35 D56VC46RIB 206.0 14 8621VT2P/RIB 220.6 36 G03H42-3000GT 204.5 15 6594SS/RIB 219.9 37 G11F16-3111A 202.8 16 D52VC91RIB 219.9 38 6640VT3P 199.1 17 DKC63-71SS 219.7 39 G07B39-3122A-EZ0 197.5 18 7087VT2P/RIB 218.9 40 4644DGVT2P 195.6 19 5887VT2P 217.3 41 G06N80-3111 194.7 20 D55VC77RIB 215.7 42 G02W74-3000GT 181.3 21 208-23STXRIB 214.9 43 4895SS/RIB 181.0 22 6065SS/RIB 214.5 44 6265SS/RIB 179.5

Mean 216.1

LSD (P ≤ 0.10) 25.7

16

Table 11. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 G10T63-3000GT 269.5 23 5290DGVT2P 235.3 2 8621VT2P/RIB 268.5 24 6594SS/RIB 235.3 3 6458RIB 263.9 25 D52VC91RIB 234.8 4 6718RIB 263.9 26 G07F23-3111 234.4 5 DKC64-34SS 261.8 27 DKC63-71SS 233.5 6 P1197AMXT 259.6 28 G10S30-3220-EZ0 233.5 7 G12W66-3000GT 256.0 29 G14R38-3122GT 232.1 8 7927VT3P/RIB 253.7 30 7087VT2P/RIB 230.8 9 216-36STXRIB 251.7 31 208-23STXRIB 227.0

10 D54DC94RIB 251.1 32 D55VC77RIB 226.1 11 213-19STXRIB 249.1 33 6068RIB 225.1 12 DKC66-74SS 246.8 34 6065SS/RIB 223.8 13 DKC63-60SS 246.2 35 5887VT2P 222.2 14 G09E98-3122-EZ0 244.7 36 G06N80-3111 220.9 15 6640VT3P 242.3 37 DKC60-87SS 220.5 16 G12J11-3111A 240.1 38 G07B39-3122A-EZ0 217.8 17 6110SS/RIB 239.7 39 DKC59-50SS 216.8 18 P1479AM 238.0 40 P1257AMXT 216.5 19 4644DGVT2P 238.0 41 4895SS/RIB 215.7 20 G11F16-3111A 236.9 42 G03H42-3000GT 214.5 21 P1311AMXT 236.7 43 6265SS/RIB 208.3 22 D56VC46RIB 235.9 44 G02W74-3000GT 200.9

Mean 236.8

LSD (P ≤ 0.10) 20.4

17

Table 12. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 8621VT2P/RIB 294.5 23 G09E98-3122-EZ0 241.0 2 G10T63-3000GT 275.7 24 7087VT2P/RIB 240.8 3 P1197AMXT 274.7 25 D54DC94RIB 240.0 4 DKC64-34SS 272.8 26 DKC63-71SS 238.4 5 7927VT3P/RIB 272.3 27 6065SS/RIB 237.4 6 6718RIB 267.9 28 G14R38-3122GT 236.6 7 G12W66-3000GT 265.3 29 D56VC46RIB 235.9 8 DKC66-74SS 263.5 30 6068RIB 234.8 9 6458RIB 262.3 31 G11F16-3111A 234.8

10 213-19STXRIB 261.3 32 4644DGVT2P 232.3 11 G12J11-3111A 259.2 33 DKC59-50SS 232.2 12 DKC63-60SS 256.0 34 P1311AMXT 231.8 13 216-36STXRIB 256.0 35 G10S30-3220-EZ0 228.3 14 5290DGVT2P 253.7 36 208-23STXRIB 223.8 15 D55VC77RIB 250.8 37 5887VT2P 222.4 16 6594SS/RIB 248.7 38 6640VT3P 222.2 17 P1257AMXT 247.7 39 G07B39-3122A-EZ0 221.8 18 D52VC91RIB 247.5 40 G03H42-3000GT 221.4 19 DKC60-87SS 246.2 41 4895SS/RIB 219.5 20 6110SS/RIB 243.7 42 G06N80-3111 213.7 21 P1479AM 242.7 43 6265SS/RIB 206.6 22 G07F23-3111 241.2 44 G02W74-3000GT 199.0

Mean 243.6

LSD (P ≤ 0.10) 21.2

18

Table 13. 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 8621VT2P/RIB 289.0 23 6065SS/RIB 242.3 2 P1197AMXT 281.0 24 D52VC91RIB 241.4 3 G10T63-3000GT 279.0 25 6068RIB 239.3 4 7927VT3P/RIB 278.6 26 4644DGVT2P 239.1 5 G12W66-3000GT 276.9 27 G11F16-3111A 235.5 6 DKC64-34SS 276.1 28 G14R38-3122GT 234.9 7 213-19STXRIB 270.6 29 DKC59-50SS 234.9 8 6718RIB 263.6 30 DKC63-71SS 233.3 9 216-36STXRIB 260.8 31 G03H42-3000GT 231.9

10 DKC66-74SS 259.9 32 208-23STXRIB 231.5 11 P1257AMXT 259.2 33 7087VT2P/RIB 231.2 12 G12J11-3111A 258.2 34 G07F23-3111 226.5 13 6594SS/RIB 256.4 35 D56VC46RIB 225.8 14 6110SS/RIB 255.9 36 6640VT3P 223.5 15 D54DC94RIB 254.1 37 G10S30-3220-EZ0 222.4 16 P1479AM 250.1 38 4895SS/RIB 219.9 17 6458RIB 249.9 39 6265SS/RIB 219.5 18 DKC63-60SS 247.9 40 P1311AMXT 216.1 19 DKC60-87SS 247.3 41 G06N80-3111 215.4 20 G09E98-3122-EZ0 246.5 42 G07B39-3122A-EZ0 215.3 21 D55VC77RIB 244.6 43 5887VT2P 215.3 22 5290DGVT2P 244.1 44 G02W74-3000GT 210.2

Mean 244.4

LSD (P ≤ 0.10) 24.8

19


Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 P1197AMXT 301.9 23 6594SS/RIB 236.7 2 8621VT2P/RIB 283.3 24 G11F16-3111A 235.3 3 6718RIB 276.8 25 DKC59-50SS 234.0 4 DKC66-74SS 276.1 26 6065SS/RIB 233.0 5 213-19STXRIB 270.5 27 5290DGVT2P 230.0 6 216-36STXRIB 266.9 28 G09E98-3122-EZ0 229.8 7 DKC64-34SS 264.0 29 208-23STXRIB 229.7 8 G10T63-3000GT 263.1 30 G14R38-3122GT 229.4 9 G12W66-3000GT 262.1 31 G03H42-3000GT 226.8

10 6458RIB 254.5 32 D54DC94RIB 226.2 11 6110SS/RIB 252.7 33 5887VT2P 225.2 12 7927VT3P/RIB 250.1 34 4895SS/RIB 225.2 13 DKC63-60SS 246.8 35 7087VT2P/RIB 223.4 14 P1257AMXT 246.3 36 6265SS/RIB 221.8 15 G12J11-3111A 245.7 37 G06N80-3111 221.5 16 6068RIB 242.5 38 DKC63-71SS 215.8 17 D55VC77RIB 242.2 39 G07B39-3122A-EZ0 215.2 18 G07F23-3111 240.4 40 P1311AMXT 204.2 19 DKC60-87SS 239.5 41 G10S30-3220-EZ0 203.4 20 D52VC91RIB 239.1 42 G02W74-3000GT 200.3 21 4644DGVT2P 238.3 43 6640VT3P 198.9 22 P1479AM 237.0 44 D56VC46RIB 196.2

Mean 238.7

LSD (P ≤ 0.10) 36.9

20


Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 G10T63-3000GT 326.9 23 G11F16-3111A 255.4 2 7927VT3P/RIB 313.2 24 6458RIB 255.2 3 P1197AMXT 307.1 25 6065SS/RIB 255.1 4 D54DC94RIB 304.0 26 6068RIB 252.0 5 DKC66-74SS 302.6 27 4644DGVT2P 251.1 6 8621VT2P/RIB 300.6 28 DKC60-87SS 250.5 7 DKC63-60SS 293.1 29 D52VC91RIB 249.0 8 DKC64-34SS 287.9 30 216-36STXRIB 246.3 9 213-19STXRIB 285.2 31 6594SS/RIB 245.9

10 5290DGVT2P 284.7 32 D56VC46RIB 241.0 11 G12W66-3000GT 283.6 33 G14R38-3122GT 227.5 12 G09E98-3122-EZ0 282.3 34 G07B39-3122A-EZ0 223.9 13 6718RIB 279.6 35 4895SS/RIB 222.8 14 G12J11-3111A 273.8 36 6265SS/RIB 221.6 15 7087VT2P/RIB 271.1 37 6640VT3P 214.3 16 P1311AMXT 264.6 38 D55VC77RIB 213.9 17 DKC63-71SS 263.8 39 G03H42-3000GT 213.4 18 DKC59-50SS 261.3 40 208-23STXRIB 208.4 19 6110SS/RIB 261.1 41 G10S30-3220-EZ0 207.2 20 P1479AM 259.8 42 G06N80-3111 206.7 21 G07F23-3111 259.4 43 5887VT2P 200.1 22 P1257AMXT 256.1 44 G02W74-3000GT 183.9

Mean 256.1

LSD (P ≤ 0.10) 32.8

21

Table 16. 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 2016. Trial means and phenotypic ranges (smallest and largest hybrid means) shown for comparison. Hybrids are sorted by company.


0 lb N 60 lb N 280 lb N 280 lb N--- bu acre-1 ----



6068RIB 211.2 225.1 234.8 239.3 242.5 252.06458RIB 256.0 263.9 262.3 249.9 254.5 255.26718RIB 251.9 263.9 267.9 263.6 276.8 279.6



P1479AM 227.4 238.0 242.7 250.1 237.0 259.8Syngenta

G02W74-3000GT 181.3 200.9 199.0 210.2 200.3 183.9G03H42-3000GT 204.5 214.5 221.4 231.9 226.8 213.4

G06N80-3111 194.7 220.9 213.7 215.4 221.5 206.7G07B39-3122A-EZ0 197.5 217.8 221.8 215.3 215.2 223.9

G07F23-3111 208.8 234.4 241.2 226.5 240.4 259.4G09E98-3122-EZ0 211.7 244.7 241.0 246.5 229.8 282.3G10S30-3220-EZ0 213.1 233.5 228.3 222.4 203.4 207.2G10T63-3000GT 242.7 269.5 275.7 279.0 263.1 326.9G11F16-3111A 202.8 236.9 234.8 235.5 235.3 255.4G12J11-3111A 210.0 240.1 259.2 258.2 245.7 273.8

G12W66-3000GT 249.2 256.0 265.3 276.9 262.1 283.6G14R38-3122GT 230.6 232.1 236.6 234.9 229.4 227.5

Winfield4644DGVT2P 195.6 238.0 232.3 239.1 238.3 251.14895SS/RIB 181.0 215.7 219.5 219.9 225.2 222.8

5290DGVT2P 206.4 235.3 253.7 244.1 230.0 284.75887VT2P 217.3 222.2 222.4 215.3 225.2 200.1



Mean 216.1 236.8 243.7 244.5 238.9 256.3Range 179-256 201-270 199-294 210-289 196-302 184-327

30 in32,000 plts a-1


22

Table 17. Yield values averaged within seed companies 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 2016.

32,000 plts a-1 38,000 plts a-1 44,000 plts a-1 44,000 plts a-1 0 lb N 60 lb N 280 lb N 280 lb N 280 lb N




Figure 2. Yield response to different agronomic management practices for intermediate yield response to population (IntRTP, yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), maximum yield response to plant population (MaxRTP, yield response between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (RTR, yield response between 30 and 20 inches row spacing at 44,000 plants acre-1 and 280 lb N acre-1) at Yorkville, IL.

23

Yield Data - 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 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 208-23STXRIB 112.9 23 5887VT2P 89.9 2 DKC60-87SS 106.9 24 G14R38-3122GT 89.8 3 213-19STXRIB 103.2 25 D52VC91RIB 89.7 4 G07F23-3111 103.0 26 DKC59-50SS 89.3 5 G10T63-3000GT 101.2 27 G09E98-3122-EZ0 87.5 6 G12W66-3000GT 98.9 28 6265SS/RIB 87.5 7 D54DC94RIB 98.1 29 P1479AM 86.9 8 4644DGVT2P 97.9 30 6718RIB 86.1 9 7087VT2P/RIB 97.1 31 6065SS/RIB 86.0

10 DKC63-60SS 96.3 32 7927VT3P/RIB 85.6 11 DKC64-34SS 96.1 33 G15Z99-3111 85.4 12 6458RIB 96.0 34 G12J11-3111A 84.4 13 D55VC77RIB 95.6 35 216-36STXRIB 84.4 14 8621VT2P/RIB 94.3 36 6640VT3P 83.5 15 G10S30-3220-EZ0 94.2 37 G18D87-3000GT 82.9 16 5290DGVT2P 94.1 38 P1197AMXT 81.0 17 DKC66-74SS 93.6 39 4895SS/RIB 79.9 18 G11F16-3111A 93.5 40 G16K01-3122 79.2 19 6068RIB 93.5 41 P1257AMXT 79.0 20 D56VC46RIB 93.2 42 P1311AMXT 78.2 21 6594SS/RIB 90.4 43 6110SS/RIB 77.6 22 DKC63-71SS 90.3 44 G07B39-3122A-EZ0 74.4

Mean 90.6

LSD (P ≤ 0.10) 9.2

24

Table 19. Grain yield of the 44 hybrid 3 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 2016. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 DKC64-34SS 160.8 23 D55VC77RIB 143.4 2 208-23STXRIB 160.7 24 216-36STXRIB 143.3 3 213-19STXRIB 160.5 25 5887VT2P 141.9 4 5290DGVT2P 160.1 26 G09E98-3122-EZ0 141.7 5 7087VT2P/RIB 158.6 27 DKC59-50SS 140.9 6 DKC60-87SS 158.1 28 DKC63-71SS 140.9 7 G10T63-3000GT 157.3 29 6065SS/RIB 140.8 8 8621VT2P/RIB 155.6 30 G14R38-3122GT 140.3 9 DKC66-74SS 152.2 31 6068RIB 139.4

10 D52VC91RIB 151.8 32 4644DGVT2P 139.3 11 6458RIB 151.6 33 P1197AMXT 130.9 12 7927VT3P/RIB 150.6 34 6265SS/RIB 130.8 13 6718RIB 150.5 35 P1479AM 129.6 14 G12W66-3000GT 149.9 36 P1257AMXT 129.5 15 G12J11-3111A 149.9 37 6594SS/RIB 129.1 16 G07F23-3111 149.6 38 6640VT3P 127.8 17 DKC63-60SS 149.0 39 G15Z99-3111 125.4 18 D56VC46RIB 147.0 40 6110SS/RIB 122.0 19 G11F16-3111A 144.8 41 4895SS/RIB 120.9 20 D54DC94RIB 144.4 42 G16K01-3122 120.1 21 G10S30-3220-EZ0 144.4 43 P1311AMXT 119.8 22 G18D87-3000GT 143.7 44 G07B39-3122A-EZ0 109.4

Mean 142.2

LSD (P ≤ 0.10) 17.4

25

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 2016. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 DKC64-34SS 202.7 23 D52VC91RIB 179.4 2 G10T63-3000GT 201.7 24 D56VC46RIB 178.3 3 DKC60-87SS 200.3 25 D55VC77RIB 177.6 4 213-19STXRIB 197.9 26 G12W66-3000GT 175.3 5 5290DGVT2P 197.2 27 6640VT3P 174.9 6 DKC66-74SS 196.1 28 P1479AM 173.9 7 8621VT2P/RIB 195.5 29 G10S30-3220-EZ0 173.7 8 6458RIB 195.3 30 G09E98-3122-EZ0 173.2 9 208-23STXRIB 194.4 31 G18D87-3000GT 173.0

10 P1197AMXT 192.9 32 4895SS/RIB 172.7 11 7927VT3P/RIB 190.3 33 6065SS/RIB 172.0 12 6718RIB 188.7 34 6594SS/RIB 171.4 13 G07F23-3111 188.4 35 5887VT2P 170.5 14 DKC63-60SS 186.7 36 G14R38-3122GT 170.2 15 P1257AMXT 186.0 37 G11F16-3111A 169.3 16 D54DC94RIB 185.9 38 6110SS/RIB 168.0 17 G12J11-3111A 185.0 39 G16K01-3122 165.5 18 216-36STXRIB 183.5 40 G15Z99-3111 164.6 19 P1311AMXT 182.1 41 DKC59-50SS 163.7 20 7087VT2P/RIB 182.1 42 6265SS/RIB 163.6 21 DKC63-71SS 180.7 43 G07B39-3122A-EZ0 162.7 22 6068RIB 180.7 44 4644DGVT2P 152.9

Mean 180.5

LSD (P ≤ 0.10) 9.6

26

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 2016. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 DKC64-34SS 200.7 23 D55VC77RIB 177.2 2 213-19STXRIB 198.6 24 P1257AMXT 177.0 3 208-23STXRIB 198.5 25 P1311AMXT 176.9 4 G10T63-3000GT 198.5 26 G10S30-3220-EZ0 176.6 5 DKC60-87SS 197.0 27 G11F16-3111A 175.8 6 8621VT2P/RIB 195.8 28 D52VC91RIB 173.2 7 5290DGVT2P 192.6 29 4895SS/RIB 172.9 8 6458RIB 191.6 30 6065SS/RIB 172.9 9 P1197AMXT 191.3 31 5887VT2P 172.1

10 7087VT2P/RIB 189.8 32 6594SS/RIB 171.5 11 6718RIB 187.8 33 G14R38-3122GT 170.5 12 DKC63-71SS 187.2 34 6110SS/RIB 170.2 13 DKC63-60SS 185.2 35 G12W66-3000GT 168.5 14 216-36STXRIB 184.7 36 G09E98-3122-EZ0 168.2 15 DKC66-74SS 184.3 37 4644DGVT2P 166.0 16 D54DC94RIB 183.9 38 G12J11-3111A 165.0 17 6068RIB 182.7 39 DKC59-50SS 163.8 18 D56VC46RIB 182.4 40 G18D87-3000GT 162.4 19 7927VT3P/RIB 182.2 41 G16K01-3122 161.7 20 P1479AM 181.4 42 G07B39-3122A-EZ0 158.5 21 G07F23-3111 179.3 43 6265SS/RIB 158.0 22 6640VT3P 177.5 44 G15Z99-3111 157.7

Mean 178.8

LSD (P ≤ 0.10) 12.1

27

Table 22. Grain yield of the 44 hybrid entries grown under agronomic conditions of 44,000 plants acre-1 at 280 lb N acre-1 and 30-inch row spacing at Harrisburg, IL in 2016.

Rank Hybrid Grain yield Rank Hybrid Grain yield bu acre-1 bu acre-1 1 208-23STXRIB 209.7 23 4895SS/RIB 181.1 2 DKC64-34SS 209.6 24 6068RIB 180.9 3 213-19STXRIB 205.3 25 5887VT2P 179.0 4 DKC60-87SS 204.1 26 P1479AM 178.5 5 G10T63-3000GT 202.8 27 D52VC91RIB 178.1 6 5290DGVT2P 201.2 28 6594SS/RIB 178.1 7 DKC63-60SS 198.1 29 G10S30-3220-EZ0 178.1 8 6458RIB 197.6 30 G11F16-3111A 176.3 9 DKC66-74SS 196.0 31 G12W66-3000GT 176.1

10 6718RIB 193.2 32 6110SS/RIB 174.3 11 D54DC94RIB 188.6 33 G14R38-3122GT 173.5 12 7927VT3P/RIB 187.9 34 P1257AMXT 173.0 13 DKC63-71SS 187.5 35 G09E98-3122-EZ0 171.2 14 216-36STXRIB 187.4 36 G18D87-3000GT 170.5 15 P1197AMXT 186.4 37 DKC59-50SS 169.9 16 D56VC46RIB 186.0 38 P1311AMXT 167.5 17 7087VT2P/RIB 185.7 39 4644DGVT2P 167.2 18 8621VT2P/RIB 185.6 40 G16K01-3122 165.6 19 6640VT3P 185.3 41 G15Z99-3111 162.5 20 6065SS/RIB 184.8 42 G07B39-3122A-EZ0 161.1 21 G07F23-3111 182.8 43 6265SS/RIB 160.3 22 D55VC77RIB 181.9 44 G12J11-3111A 155.2

Mean 182.4

LSD (P ≤ 0.10) 13.4

28

Table 23. Grain yield of the 44 hybrid entries grown under agronomic conditions of 44,000 plants acre-1 at 280 lb N acre-1 and 20-inch row spacing at Harrisburg, IL in 2016. Rank Hybrid Grain yield Rank Hybrid Grain yield

bu acre-1 bu acre-1 1 G10T63-3000GT 245.4 23 G12W66-3000GT 195.7 2 G07F23-3111 223.9 24 6065SS/RIB 191.9 3 DKC63-60SS 222.7 25 4895SS/RIB 191.9 4 DKC66-74SS 219.7 26 7087VT2P/RIB 186.8 5 D54DC94RIB 217.3 27 DKC63-71SS 186.7 6 5290DGVT2P 217.2 28 4644DGVT2P 184.4 7 7927VT3P/RIB 217.0 29 G09E98-3122-EZ0 184.3 8 8621VT2P/RIB 214.4 30 G18D87-3000GT 183.8 9 P1197AMXT 213.0 31 G12J11-3111A 183.5

10 6068RIB 211.4 32 P1311AMXT 182.3 11 P1479AM 210.8 33 6594SS/RIB 182.1 12 216-36STXRIB 209.7 34 DKC59-50SS 181.4 13 213-19STXRIB 208.5 35 G14R38-3122GT 180.5 14 DKC64-34SS 208.3 36 208-23STXRIB 178.4 15 D56VC46RIB 208.1 37 P1257AMXT 172.8 16 6640VT3P 202.4 38 G10S30-3220-EZ0 172.1 17 DKC60-87SS 201.9 39 G15Z99-3111 169.2 18 6458RIB 201.5 40 D52VC91RIB 164.9 19 D55VC77RIB 200.5 41 G16K01-3122 164.4 20 6718RIB 200.0 42 6265SS/RIB 158.9 21 G11F16-3111A 200.0 43 G07B39-3122A-EZ0 157.4 22 6110SS/RIB 199.4 44 5887VT2P 154.8

Mean 194.6

LSD (P ≤ 0.10) 29.7

29

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 2016. Trial means and phenotypic ranges (smallest and largest hybrid means) shown for comparison. Hybrids are sorted by company.


0 lb N 60 lb N 280 lb N 280 lb N--- bu acre-1 ---



6068RIB 93.5 139.4 180.7 182.7 180.9 211.46458RIB 96.0 151.6 195.3 191.6 197.6 201.56718RIB 86.1 150.5 188.7 187.8 193.2 200.0



P1479AM 86.9 129.6 173.9 181.4 178.5 210.8Syngenta

G07B39-3122A-EZ0 74.4 109.4 162.7 158.5 161.1 157.4G07F23-3111 103.0 149.6 188.4 179.3 182.8 223.9

G09E98-3122-EZ0 87.5 141.7 173.2 168.2 171.2 184.3G10S30-3220-EZ0 94.2 144.4 173.7 176.6 178.1 172.1G10T63-3000GT 101.2 157.3 201.7 198.5 202.8 245.4G11F16-3111A 93.5 144.8 169.3 175.8 176.3 200.0G12J11-3111A 84.4 149.9 185.0 165.0 155.2 183.5

G12W66-3000GT 98.9 149.9 175.3 168.5 176.1 195.7G14R38-3122GT 89.8 140.3 170.2 170.5 173.5 180.5

G15Z99-3111 85.4 125.4 164.6 157.7 162.5 169.2G16K01-3122 79.2 120.1 165.5 161.7 165.6 164.4

G18D87-3000GT 82.9 143.7 173.0 162.4 170.5 183.8Winfield

4644DGVT2P 97.9 139.3 152.9 166.0 167.2 184.44895SS/RIB 79.9 120.9 172.7 172.9 181.1 191.9

5290DGVT2P 94.1 160.1 197.2 192.6 201.2 217.25887VT2P 89.9 141.9 170.5 172.1 179.0 154.8



Mean 90.6 142.2 180.5 178.8 182.4 194.6Range 74-113 109-161 153-203 158-201 155-210 155-245

30 in32,000 plts a-1


30

Table 25. Yield values averaged within seed companies 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 2016.

30 in 20 in 32,000 plts a-1 38,000 plts a-1 44,000 plts a-1 44,000 plts a-1 0 lb N 60 lb N 280 lb N 280 lb N 280 lb N




Figure 3. Yield response to different agronomic management practices for intermediate yield response to population (IntRTP, yield response between 32,000 and 38,000 plants acre-1 at 280 lb N acre-1), maximum yield response to plant population (MaxRTP, yield response between 38,000 and 44,000 plants acre-1 at 280 lb N acre-1), and the yield response to narrower row spacing (RTR, yield response between 30 and 20 inches row spacing at 44,000 plants acre-1 and 280 lb N acre-1) at Harrisburg, IL

31

Characterization of ‘Workhorse’ and ‘Racehorse’ Hybrids Environmental conditions in 2016 created different hybrid performances across the three

locations of the trial. Overall average check plot yield (0 lb N acre-1) was 134.9, 216.1, and 90.6 bu acre-1 at Champaign, Yorkville, and Harrisburg, IL, respectively. High check plot yield at Yorkville was associated with high residual N, mineralized from soil organic matter. Overall average initial yield response to N was 82.5, 20.7, and 51.6 bu acre-1 and maximum yield response to N was 115.6, 27.5, and 89.8 bu acre-1 at Champaign, Yorkville, and Harrisburg, IL, respectively. The low yield response to N at Yorkville was associated with high check plot yield, while low check plot and low yield response to N at Harrisburg was associated with suboptimal yield environmental conditions during the growing season (high temperature and low soil moisture).

Overall average intermediate yield response to plant population was 9.3, 0.8, and -1.7 bu acre-1 and maximum yield response to population was 0.5, -5.7, and 3.6 bu acre-1 for Champaign, Yorkville, and Harrisburg, respectively. Minimal yield response to increased plant population at Harrisburg indicates that under stressed conditions high plant density increases the intra-plant competition and decreases corn yield. On the other hand, overall average yield response to narrower row spacing was 17.4, and 12.2 bu acre-1 at Yorkville and Harrisburg, respectively. Narrower row spacing decreased inter-plant competition and increased individual plant yield under ultra-high plant density conditions in high and low yield environments (Yorkville and Harrisburg, respectively). Yield response to increased plant density and narrower row spacing (yield response between 30 inches row spacing at 44,000 plants acre-1 and 20 inches row spacing at 64,000 plants acre-1) was -10.9 bu acre-1 at Champaign. Notably, approximately 75% of the tested hybrids did not tolerate high plant densities even under narrower row spacing conditions. Nonetheless, the only hybrid (G10T63-3000GT) at Champaign that exceeded 300 bu acre-1 was grown under 20 inches row spacing and 64,000 plants acre-1.

Similarly to previous years, there was large genetic variation of corn hybrids in response to different agronomic conditions. 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. ‘Workhorse’ and ‘Racehorse’ indices will 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 intermediate and maximum yield response to plant population (IntRTP and MaxRTP), maximum yield response to N (RTN), and yield response to narrower row spacing (RTR) evaluations. The ‘Workhorse’ index is constituted by the check plot yield (Check) and the initial yield response to N (InitN). ‘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 IntRTP, MaxRTP, RTN, RTR, Check, and InitN 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 were generated using the 2015 and 2016 data in the same analysis to better estimate the value of each

32

parameter (Table 26). Using the combined data, the relative weights for IntRTP, MaxRTP, RTN, RTR, Check, and InitN parameters were 0.104, 0.039, 0.615, 0.242, 0.735, and 0.260, respectively (Eq. 4 and 5). Parameter scores for each hybrid across locations are represented in Table 27. 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′ = 0.10 𝐼𝑛𝑡𝑅𝑇𝑃 + 0.04 𝑀𝑎𝑥𝑅𝑇𝑃 + 0.62 𝑅𝑇𝑁 + 0.24 𝑅𝑇𝑅 [4] ′𝑊𝑜𝑟𝑘ℎ𝑜𝑟𝑠𝑒 𝑖𝑛𝑑𝑒𝑥′ = 0.74 𝐶ℎ𝑒𝑐𝑘 + 0.26 𝐼𝑛𝑖𝑡𝑁 [5]

Table 26. Relative weights for IntRTP, MaxRTP, RTN, RTR, Check, and InitN generated for hybrids tested in 2015 and 2016. Total of 67 hybrids evaluated at Champaign, DeKalb, and Harrisburg in 2015 and Champaign, Yorkville, and Harrisburg in 2016.

Year used for data analysis IntRTP MaxRTP RTN RTR Check InitN

2015 0.026 0.004 0.485 0.486 0.355 0.645 2016 0.085 0.013 0.616 0.286 0.846 0.154

2015 and 2016 0.104 0.039 0.615 0.242 0.735 0.260

33

Table 27a. Scores for intermediate response to population (IntRTP), maximum response to plant population (MaxRTP), maximum yield response to N (RTN), response to narrower row spacing (RTR), initial response to N (InitN), and Check plot yield (Check) for Dyna-Gro and Monsanto hybrids at Champaign, Yorkville, and Harrisburg IL.

*RTR at Champaign refers to the yield response between 30 inches row spacing at 44,000 plants acre-1 and 20 inches row spacing at 64,000 plants acre-1 and was not included in the ‘Racehorse’ index analysis.

IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitNCPS

D52VC91RIB 1 6 6 3 2 6 3 6 6 4 7 4 2 6 5 1 4 9D54DC94RIB 8 3 3 2 10 1 10 1 1 10 8 6 4 5 5 9 9 3D55VC77RIB 2 6 6 2 3 8 2 6 8 1 6 3 5 5 3 6 7 3D56VC46RIB 3 6 1 6 6 3 1 1 7 8 2 8 9 4 3 7 6 6Monsanto

208-23STXRIB 10 10 1 1 10 1 8 6 1 1 5 3 9 10 3 1 10 4213-19STXRIB 1 10 8 5 5 3 9 8 3 5 9 2 7 7 7 3 10 8216-36STXRIB 7 2 4 6 8 2 7 9 5 1 8 6 7 3 7 7 2 8

6068RIB 2 9 8 4 2 5 6 8 5 4 4 4 8 2 4 10 6 36458RIB 7 1 2 10 9 3 1 8 1 3 10 2 4 7 8 3 8 76718RIB 5 4 7 5 4 5 3 10 2 3 10 3 5 6 9 4 3 9

DKC59-50SS 10 1 1 6 9 4 5 7 3 8 4 1 6 7 1 5 4 6DKC60-87SS 3 6 8 8 8 9 5 4 8 5 5 2 4 8 7 2 10 5DKC63-60SS 3 7 5 8 6 4 2 6 4 8 9 4 5 10 6 8 8 6DKC63-71SS 3 5 3 7 4 4 3 2 3 9 6 4 10 2 6 2 5 5DKC64-34SS 4 7 3 7 10 2 6 3 6 7 10 5 4 9 10 2 8 10DKC66-74SS 5 3 6 8 8 7 4 10 8 7 8 5 1 10 9 8 6 8

Champaign HarrisburgYorkville*

34

Table 27b. Scores for intermediate response to population (IntRTP), maximum response to plant population (MaxRTP), maximum yield response to N (RTN), response to narrower row spacing (RTR), initial response to N (InitN), and Check plot yield (Check) for Pioneer, Syngenta, and Winfield hybrids at Champaign, Yorkville, and Harrisburg IL.


IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitNPioneer

P1197AMXT 2 9 10 4 3 6 7 10 10 3 7 9 5 1 10 8 2 4P1257AMXT 4 5 10 1 2 10 9 3 9 4 3 1 1 2 10 3 1 4P1311AMXT 1 8 10 1 2 10 1 4 4 10 3 7 3 1 9 5 1 2

P1479AM 5 9 7 9 3 8 8 3 2 7 8 3 10 2 4 10 4 2Syngenta

G02W74-3000GT - - - - - - 9 4 3 1 1 5 - - - - - -G03H42-3000GT - - - - - - 9 5 2 2 2 2 - - - - - -

G06N80-3111 5 9 3 2 1 7G07B39-3122A-EZ0 2 8 7 4 3 7 2 7 5 4 2 5 3 3 5 1 1 1

G07F23-3111 8 2 4 7 3 1 1 10 7 6 3 6 1 4 3 10 10 3G09E98-3122-EZ0 8 3 7 1 1 8 7 2 6 9 4 9 3 4 4 5 4 7G10S30-3220-EZ0 10 1 3 5 7 2 3 2 2 3 5 6 9 3 2 1 7 4G10T63-3000GT 6 10 9 9 5 9 6 2 8 10 9 7 4 5 8 10 9 7G11F16-3111A 6 2 1 10 10 1 4 7 7 6 2 9 9 2 1 7 6 5G12J11-3111A 6 2 5 4 4 6 4 3 10 8 4 8 1 1 8 9 3 10

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

G15Z99-3111 2 7 9 2 1 6 - - - - - - 2 6 2 4 3 1G16K01-3122 9 7 2 2 9 2 - - - - - - 3 4 4 2 1 1

G18D87-3000GT 9 4 9 5 1 8 - - - - - - 1 9 5 5 2 8Winfield

4644DGVT2P 10 4 3 7 7 2 8 7 9 5 1 10 10 3 1 6 9 24895SS/RIB 5 8 2 4 6 4 4 9 9 2 1 9 6 9 7 4 2 1

5290DGVT2P 3 5 8 10 4 10 2 3 9 9 3 8 3 9 9 6 7 10

5887VT2P 4 9 2 1 6 3 2 9 1 1 6 1 8 8 2 1 5 66065SS/RIB 9 4 2 8 5 5 6 4 4 7 5 2 7 10 4 4 3 76110SS/RIB 7 3 4 3 7 1 10 5 7 3 4 7 8 5 6 8 1 3

6265SS/RIB 9 1 5 10 1 7 10 8 5 2 1 8 2 3 1 2 4 2

6594SS/RIB 4 5 4 6 2 7 8 1 6 4 7 4 6 7 2 3 5 16640VT3P 8 2 4 2 5 9 5 1 4 5 2 10 8 8 6 6 2 2

7087VT2P/RIB 4 3 6 3 7 5 1 4 4 9 6 3 10 1 3 3 8 97927VT3P/RIB 1 1 10 9 1 10 7 1 10 10 3 10 2 6 10 9 3 108621VT2P/RIB 1 10 9 3 4 9 3 5 10 6 7 10 6 1 8 9 7 9

Champaign Yorkville Harrisburg*

35

Table 28. Average scores across seed brands for intermediate response to population (IntRTP), maximum response to plant population (MaxRTP), maximum yield response to N (RTN), response to narrower row spacing (RTR), initial response to N (InitN), and Check plot yield (Check) at Champaign, Yorkville, and Harrisburg IL.


IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitN IntRTP MaxRTP RTN RTR Check InitN

Dynagro 4 5 4 3 5 5 5 5 4 6 7 5 4 4 6 6 6 5

Channel 6 7 4 4 8 2 8 7 6 4 7 7 8 8 3 2 7 4

DeKalb 5 5 6 6 5 4 6 5 7 6 6 6 3 9 3 3 8 3

Stone 5 5 4 7 8 5 5 8 7 5 7 7 4 5 5 7 7 4

Pioneer 3 8 9 4 3 9 5 2 8 7 2 3 6 5 6 6 5 5

Syngenta 7 5 5 5 5 5 4 4 4 5 5 5 5 5 5 5 4 6

Winfield 5 5 5 6 5 6 6 6 5 5 5 5 6 5 7 5 4 7

Champaign Yorkville Harrisburg

*

36

Summary of Hybrids Agronomic Characteristics This section presents a brief summary for each hybrid. Scores for each hybrid (bar-graph

figures) were generated using the combined data from all locations, which allows us to understand the overall response for each hybrid across different environments in 2016.

CHANNEL:

208-23STXRIB

High yield response to increased plant density at 30 inch row space. High tolerance to N loss, and low yield response to N fertilizer and narrower row spacing.

213-19STXRIB

Highest yielding hybrid from Channel in the trial. High yield potential and stable performance. Combines high Check Plot and high maximum yield response to N fertilizer.

216-36STXRIB

Average and stable performance across environments. Yield responsive to increased plant density.

37

CROPLAN

4644DGVT2P:

Good yield response to increased population and to narrower row spacing.

4895SS/RIB:

High maximum response to population, but low yield response to narrower row spacing.

5290DGVT2P:

High yield and stable performance across environments. Combines high yield response to N fertilizer and narrower row spacing. High ‘Racehorse’ index.

5887VT2P:

High yield response to increased plant population, but poor tolerance to narrower row spacing.

38

6065SS/RIB:

Average and stable performance across environments. Average yield response to increased plant population and to narrower row spacing.

6110SS/RIB:

Low tolerance to N loss conditions. Average response to increased plant population and narrower row spacing.

6265SS/RIB:

Low tolerance to N loss conditions, but above average response to initial N and increased population.

6594SS/RIB:

Below average response to N and to increasing plant population.

39

6640SS/RIB:

High yield response to initial N and intermediate plant population, but below average for other characters.

7087VT2P/RIB:

Above average for tolerance to low N, but low yield response to increased plant population.

7927VT3P/RIB:

Excellent yield response to N fertilizer and narrower row spacing, but low Check Plot score. The highest ‘Racehorse’ index of the trial.

8621VT2P/RIB:

Highest yielding hybrid for Croplan brand across locations. Versatile hybrid with high ‘Racehorse’ and ‘Workhorse’ indices. Good tolerance to low N conditions and good response to N fertilizer.

40

DEKALB

DKC59-50SS

Low yield response to N fertilizer, but above average yield response to increasing plant population and narrower row spacing.

DKC60-87SS

High ‘Workhorse’ index. Combines high yield response to N fertilizer and high Check Plot score.

DKC63-60SS

Consistent high yield performance in narrower row spacing. Average performance under 30 inch row spacing. Tolerant to low N conditions, high yield response to narrower row spacing and high plant density.

DKC63-71SS

Above average response to narrower row spacing and tolerant to low N conditions.

41

DYNA-GRO:

D52VC91RIB:

Good yield response to N fertilizer and increased plant density, but average response to increasing plant population and poor tolerance to narrower row spacing.

D55VC77RIB:

Average response to most characters, but poor tolerance to narrower row spacing.

DKC64-34SS

Highest yielding hybrid for the DeKalb brand across treatments and environments. High yield performance and yield stability. High Check Plot score and ‘Workhorse’ index.

DKC66-74SS

High yielding hybrid and stable performance across locations. Versatile hybrid with high ‘Racehorse’ and ‘Workhorse’ indices.

42

GOLDEN HARVEST

D54DC94RIB:

Highest yielding hybrid for Dyna-Gro brand in the trial. Good yield response to increased plant density and narrower row spacing. High Check score, but below average response to N fertilizer.

D56VC46RIB:

High yield response to narrower row spacing and good tolerance to low N conditions.

G02W74-3000GT:

Hybrid only tested at Yorkville. High yield response to intermediate plant population, but below average for most characters.

G03H42-3000GT:

Hybrid only tested at Yorkville. Poor tolerance to N loss and yield response to N fertilizer. High yield response to plant population.

43

G06N80-3111:

Hybrid only tested at Yorkville. High yield response to initial N and high plant populations. Low Check Plot yield and tolerance to narrower row spacing.

G07B39-3122A-EZ0:

High yield response to maximum plant populations and N fertilizer. Low Check Plot yield.

G07F23-3111:

High yield response to narrower row spacing and to maximum plant population.

G09E98-3122-EZ0:

Above average response to intermediate plant population. High yield response to N fertilizer, but low Check Plot score.

44

G10S30-3220-EZ0:

High yield response to intermediate plant population and Check Plot score. Below average response to N fertilizer.

G10T63-3000GT:

High yield performance and stability across environments. Highest yielding hybrid of the trial. Versatile hybrid with high ‘Racehorse’ and ‘Workhorse’ indices.

G11F16-3111A:

Above average for Check Plot score. High yield response to narrower row spacing and intermediate plant population.

G12J11-3111A:

High yield response to N fertilizer and narrower row spacing. High ‘Racehorse’ index, but doesn’t tolerate increased plant densities at 30 inch row spacing.

45

G12W66-3000GT:

Combines high Check Plot and high yield response to narrower row spacing. High ‘Workhorse’ index.

G14R38-3122GT:

High ‘Workhorse’ index with high Check Plot score. Above average response to increased plant population (38,000 plants acre-1).

G15Z99-3111:

High yield response to maximum plant population, but low yield response to narrower row spacing. High yield response to N fertilizer.

G16K01-3122:

Low yield response to N fertilizer and narrower row spacing. High yield response to increased plant population.

46

PIONEER

G18D87-3000GT:

Excellent yield response to N fertilizer, but low tolerance to N loss conditions. Above average response for increased plant population and narrower row spacing. High ‘Racehorse’ index.

P1197AMXT:

Highest yielding hybrid for Pioneer brand in the trial. High yield response to N fertilizer and increased plant density. High ‘Racehorse’ index.

P1257AMXT:

High yield response to N fertilizer, but below average score for other characters.

P1311AMXT:

High yield response to N fertilizer. Low Check Plot score and low yield response to increased plant density.

47

STONE

P1479AM:

Average and stable yield performance across environments. High yield response to intermediate plant population and narrower row spacing.

6068RIB:

High yield response to increased plant density. Above average response to increased plant population. Low yield performance under low N conditions.

6458RIB:

Average and stable yield performance across environments. Excellent Check Plot score, but low yield response to N fertilizer. High ‘Workhorse’ index.

6718RIB:

Combines high Check Plot score and yield response to N fertilizer. High yield response to maximum plant population. High ‘Workhorse’ index.

48

References Bertin, P., and A. Gallais. 2001. Genetic variation for nitrogen use efficiency in a set of recombinant

inbred lines. II. QTL detection and coincidences. Maydica 46:53–68.

Boomsma, C. R., J. B. Santini, M. Tollenaar, and T. J. Vyn. 2009. Maize morphophysiological responses to intense crowding and low nitrogen availability: an analysis and review. Agron. J. 101: 1426-1452. doi:10.2134/agronj2009.0082

Coque, M., and A. Gallais. 2007. Genetic variation among European maize varieties for nitrogen use efficiency under low and high nitrogen fertilization. Maydica 52:383-397.

Duvick, D.N. 2005. The contribution of breeding to yield advances in maize (Zea mays L.). Adv. Agron. 86:83–145. doi:10.1016/S0065-2113(05)86002-X

Hazel, L.N. 1943. The genetic basis for constructing selection indexes. Genetics 28:476-490.

Haegele, J. W., K. A. Cook, D. M. Nichols, and F. E. Below. 2013. Changes in Nitrogen use Traits Associated with Genetic Improvement for Grain Yield of Maize Hybrids Released in Different Decades. Crop Sci. 53:1256-1268. doi:10.2135/cropsci2012.07.0429

Holland J.B. 2006. Estimating genotypic correlations and their standard errors using multivariate restricted maximum likelihood estimation with SAS Proc MIXED. Crop Sci. 46:642-645.

National Corn Growers Association. 2015. www.ncga.com/home (verified 01 Aug. 2016). NCGA, Chesterfeld, MO.

Ruffo, M. L., L. F. Gentry, A. S. Henninger, J. R. Seebauer, and F. E. Below. 2015. Evaluating Management Factor Contributions to Reduce Corn Yield Gaps. Agron. J. 107:495-505. doi:10.2134/agronj14.0355.

SAS Institute. 2013. SAS 9.4 user’s guide. SAS Inst., Cary, NC.

Tokatlidis, I.S., and S.D. Koutroubas. 2004. A review of maize hybrids’ dependence on high plant populations and its implications for crop yield stability. Field Crops Res. 88:103–114. doi:10.1016/j.fcr.2003.11.013

Tollenaar, M., and E.A. Lee. 2002. Yield Potential, Yield Stability and Stress Tolerance in Maize. Field Crops Res. 75: 161-169. doi:10.1016/S0378-4290(02)00024-2

2016 management yield potentialcropphysiology.cropsci.illinois.edu/documents/2016... · conversely,...

Documents