Evaluating Corn Hybrid Plant Population Density for Yield and Phenotypic Responses

By Eric J Knoll

Overview •  Personal history •  Project background and objectives •  Materials and methods •  Results •  Conclusions •  Acknowledgements

Family

•  Amy •  Sam (7) •  Anna (3) •  Max (5 months)

Background •  Childhood

–  Warren, MN •  Youngest of six kids •  15 nieces and

nephews •  One great niece

•  Currently –  Owatonna, MN

Warren

Owatonna

Interests

•  Kids •  Hockey, baseball, and football •  Wood working •  Auto body work •  Gardening •  Hunting •  Camping

Education •  Bachelor of Science in Agronomy majoring in Crop

and Weed Science (North Dakota State University 1995-1999)

•  Currently pursuing a Master of Science in Agronomy (Iowa State University 2008-2011)

Work Experience •  Knoll Family Farm, Warren, MN (1985 – 1997)

–  Hard red spring wheat, barley, and sunflower •  Pau Seeds, Olivia, MN (2000 – 2002)

–  Assistant Breeder •  AgReliant Genetics LLC, Kenyon, MN (2002 – Present)

–  Nursery Manager (2002 – 2006) –  Assistant Breeder (2006 – 2010) –  Assistant Station Manager (2010 – Present)

Reasons for Choosing this Project •  Breeding program

– Company plant population discussion – Select germplasm that respond to higher plant

populations – Develop stable products

•  Optimize corn yields •  Minimize farming costs •  Identify agronomic responses to various populations

Why are Plant Populations Important?

•  Maximize yields •  Minimize negative agronomic affects •  Reduce seed costs •  Maximize profits

Introduction

•  Hybrid corn (Zea mays L.) •  Plant population refers to number of plants per

acre (PPA) •  Over time increasing plant populations has

been one way of increasing corn yields •  With increased populations what are affects

other than yield

Study Objectives

•  To determine a general yield responses of corn hybrids to different corn plant population densities.

•  To determine a general phenotypic responses of corn hybrids to different plant population densities.

Experimental Design •  These field trials were conducted in 2009 •  Three locations with three replications per location •  Randomized complete block

–  Main plot (plant population) –  Subplot (specific hybrids)

•  Five different plant population (20, 26, 32, 38, and 44 thousand plants per acre)

•  Eight hybrids ranging in relative maturity from 90 to 101 days (all hybrids contained Monsanto’s Yield Guard VT3® technology)

Field Layout Kenyon Column 1 Column 2 Column 3 Column 4 Column 5 Column 6 Column 7 Column 8 PPA Rep

Range 15 Producers 5734 W7289VT3 DKC42-91 LG2426 W7309VT3 DKC50-44 LG2411 Producers 5624 20 Range 14 LG2426 Producers 5734 Producers 5624 W7309VT3 DKC50-44 W7289VT3 DKC42-91 LG2411 32 Range 13 LG2411 Producers 5734 W7289VT3 DKC50-44 Producers 5624 DKC42-91 LG2426 W7309VT3 44 3 Range 12 Producers 5734 W7289VT3 LG2411 Producers 5624 DKC42-91 W7309VT3 DKC50-44 LG2426 38 Range 11 LG2411 LG2426 DKC50-44 W7309VT3 W7289VT3 Producers 5734 Producers 5624 DKC42-91 26 Range 10 LG2411 W7289VT3 DKC42-91 DKC50-44 W7309VT3 Producers 5734 Producers 5624 LG2426 38 Range 9 Producers 5734 W7289VT3 DKC50-44 LG2426 Producers 5624 LG2411 DKC42-91 W7309VT3 26 Range 8 W7309VT3 DKC42-91 Producers 5624 W7289VT3 DKC50-44 LG2426 Producers 5734 LG2411 44 2 Range 7 DKC42-91 Producers 5624 W7309VT3 LG2426 DKC50-44 LG2411 W7289VT3 Producers 5734 20 Range 6 W7309VT3 LG2411 LG2426 Producers 5624 W7289VT3 DKC42-91 DKC50-44 Producers 5734 32 Range 5 Producers 5734 W7309VT3 DKC42-91 LG2426 DKC50-44 W7289VT3 Producers 5624 LG2411 38 Range 4 W7289VT3 Producers 5624 LG2411 Producers 5734 DKC50-44 W7309VT3 LG2426 DKC42-91 26 Range 3 LG2411 Producers 5734 Producers 5624 DKC50-44 LG2426 DKC42-91 W7289VT3 W7309VT3 44 1 Range 2 Producers 5624 W7289VT3 DKC50-44 Producers 5734 LG2426 W7309VT3 DKC42-91 LG2411 32 Range 1 LG2426 W7289VT3 LG2411 Producers 5734 W7309VT3 Producers 5624 DKC50-44 DKC42-91 20 •  Ranges go down the field •  Columns go across the field •  Three Replications per location •  Plants per acre (PPA) is listed on the right

Locations

Locations

•  Kenyon, MN – Maxfield-Klinger association – Uniform – Tiled – High yield potential – Corn hybrids from 90 to 103 day relative maturity

Locations

•  Farmington, MN – Ostrander loam – Sandier – Slightly sloped – Well drained soil – Can show signs of drought stress – Moderate yield potential – Corn hybrids from 85 to 101 day relative maturity

Locations

•  Eyota, MN – Port Byran – Level – Uniform – Well drained – High yield potential – Corn hybrids from 90 to 105 day relative maturity

Hybrids

•  Eight different hybrids – LG2411, LG2426, Producers 5624, Producers

5734, W7289VT3, W7309VT3, DKC42-91, DKC50-44

•  These hybrids had a wide variety of genetic backgrounds

•  Relative maturities ranging from 90 – 101 days

Planting

•  An Almaco Seed Pro planter was use to plant the plots

Over Planting

•  Almaco hand planters were used to over plant higher populations (left)

•  Plants prior to thinning (right)

Thinning

•  Plots were thinned to the correct population during the V4 – V6 stage

Notes Taken •  Plant and ear height •  Stalk diameter •  Stalk and root lodging •  Kernel weight •  Ear diameter and length •  Moisture •  Test Weight •  Yield

Plant and Ear Heights

•  Plant height was measured from the ground to the base of the tassel

•  Ear height was measured from the ground to the highest ear node

Stalk Diameter •  Stalks were measured

using a digital caliper •  Measurements were

taken just below the top ear

•  Stalk width was measured at the narrower part of the stalk

Ear Measurements

•  A ruler was used to measure ear length (left) and ear diameter (right)

Kernel weights

•  The ears were shelled after ear measurements were taken

•  Three hundred kernels were counted and weighed

•  Each weight was divided by three to get a one hundred kernel weight

•  Shelled weights were added back into over all plot weight

Plant Standability

•  At all locations root and stalk lodged plants were counted prior to harvest •  Root lodging at the Farmington location (left) •  Stalk lodging at the Kenyon location (right)

Harvest

•  New Holland TR88 Twin Plot research combine was used to harvest the plots for yield, moisture, and test weight

Data Analysis •  Student T test at the 95% confidence interval

– Least significant differences (LSD) were used to identify differences between entries

•  Statistical programs – SAS®

–  JMP®

Ear Length and Diameter

•  As plant populations decreased –  Generally ear size increased –  Producers 5624 had the smallest ear size reduction

LSD 0.9 cm LSD 0.2 cm

Kernel Weights •  As plant populations decreased

in increments of six thousand plants per acre, there was a two to three gram reduction in kernel weight

•  Twenty thousand plants per acre had the highest kernel weights

•  Forty four thousand plants per acre had the lowest kernel weights

•  Producers 5624 had the lowest kernel weight

LSD 1.4 g

Plant Height

•  Plant height was not affected by different plant populations

•  LG2411, W7289, and W7309 are the tallest hybrids with an average height greater than 241 cm

•  Producers 5734 was the shortest hybrid with an average plant height of 221 cm

Ear Height

•  The 44 thousand plant population had the highest ear height of 109 cm

•  Seven cm higher than 20 thousand plants per acre which had an average of 102 cm

•  W7309 had the highest ear height at 111 cm

•  DKC42-91 had the lowest average ear height of 95 cm

LSD 3.5 cm

Stalk Diameter •  In general as

populations increased stalk diameters decreased

•  W7309 and W7289 had the largest increase in stalk diameter as populations were reduced.

•  Producers 5624 had the lowest increase in stalk diameter with reduced populations

LSD 0.8 mm

•  At Kenyon, 38 thousand PPA had the highest amount of stalk lodging while 26 thousand PPA had the least amount

•  In general as plant populations increased so did the root lodging percentage

•  In both cases the lowest plant populations had the smallest amount of stalk and root lodging

Stalk and Root Lodging

Moisture

•  DKC42-91 and DKC50-44 had an increase in moisture by 2% from 20 to 44 thousand PPA

•  W7309 had a decrease in moisture by 1.6% from 20 to 44 thousand PPA

LSD 4.0 %

Yield •  In general, yields

increased until 32 thousand PPA, but had no further yield increase as PPA increased

•  Similar results to other studies

LSD 9.4 bu/ac

Yield

•  Response of corn yield potential to plant population, averaged over 34 comparisons from 2005 to 2008 at Lamberton and Waseca, MN. Coulter. 2009

Grain yield potential (%)

Plant population (thousands/a)

Yield •  Producers 5734 was

the only hybrid that showed a decrease in yield among 44 thousand PPA compared to 32 and 38 thousand PPA

•  The lowest yielding population for every hybrid was 20 thousand PPA

LSD 19.6 bu/ac

Conclusion •  In general, yields increased until 32 thousand plants per acre;

after that there appeared to be no yield increase with increasing plant populations.

•  Increasing plant populations also decreased stalk diameter, ear length, ear diameter, and kernel weight.

•  Plant populations did not affect plant height and test weight with limited affects on ear height and moisture.

•  Specific hybrids respond differently in yield and phenotypic response under various growing conditions, locations, and plant populations.

•  Farmers should continue to evaluate different hybrids at various plant populations to find ones that are going to work best.

Acknowledgements •  POS Committee

–  Dr. Roger W. Elmore –  Dr. Kenneth Moore –  Dr. Tom Loynachan

•  Family –  Amy (wife) –  Sam, Anna, and Max

(kids)

Acknowledgements •  AgReliant Genetics LLC

–  Christina Morland –  Jerry Courson –  Helmer Bauer –  Darryld Oistad –  Linda Cordes –  Gonzalo Andrade –  Jacob Gavelinger –  Andres Gordillo

Questions?

References •  Asgrow and Dekalb. 2008. Seed Source Guide [Online]. Available at

http://www.asgrowanddekalb.com/seedresourceguide/product/CORN/DKC4291.pdf. (Verified 8 Aug. 2010).

•  Asgrow and Dekalb. 2008. Seed Source Guide [Online]. Available at http://www.asgrowanddekalb.com/seedresourceguide/product/CORN/DKC5044.pdf. (Verified 8 Aug. 2010).

•  Coulter, J. 2009. Optimum Plant Populations for Corn in Minnesota. University of Minnesota Extension. [Online] Available at http://www.extension.umn.edu/distribution/cropsystems/M1244.html. (Verified 8 Aug. 2010).

•  Coulter, J., 2009. Think Carefully About Corn Plant Population to Maximize Profits. University of Minnesota Extension. [Online] Available at http://www.extension.umn.edu/cropenews/2009/09MNCN03.html. (Verified 8 Aug. 2010).

References

•  LG Seeds. 2009. Product Sheet [Online]. Available at http://www.lgseeds.com/corn_details.asp?id=LG2411&state=MN. (Verified 8 Aug. 2010).

•  LG Seeds. 2009. Product Sheet [Online]. Available at http://www.lgseeds.com/corn_details.asp?id=LG2426&state=MN. (Verified 8 Aug. 2010).

•  Producers Hybrids. 2008. Corn Profile Sheet [Online]. Available at http://www.producershybrids.com/index.php/www/products/corn/90. (Verified 8 Aug. 2010).

•  Producers Hybrids. 2008 Corn Profile Sheet [Online]. Available at http://www.producershybrids.com/index.php/www/products/corn/91 . (Verified 8 Aug. 2010).

References

•  Wensman Seed. 2010. Product Sheet [Online]. Available at http://www.wensmanseed.com/2010/hybrids/corn/w7289vt3.html . (Verified 8 Aug. 2010).

•  Wensman Seed. 2010. Product Sheet [Online]. Available at http://www.wensmanseed.com/2010/hybrids/corn/w7309vt3.html. (Verified 8 Aug. 2010).