By Chris Tyson
The Gleaner combine making its way through our corn test plots.
For the last several years, we have planted a corn variety trial behind the Vidalia Onion test plots at the Vidalia Onion and Vegetable Research Center. Cliff Riner started this variety trial when corn prices were higher and there was much interest in growing corn as a double crop behind Vidalia Onions. Many onion growers would take advantage of some of the residual fertility from the onions to help grow the corn crop. This trial is intended to simulate an onion producer growing corn behind onions as a second crop. Every year when all of the onions are harvested at the research center, we put in a corn variety trial to see which varieties do best. Depending on the year, the corn is planted between mid-May and early June after the onions are harvested. This isn’t the ideal time to plant corn, but it is the situation that onion growers are faced with if they want a crop of it behind onions. The corn is subject to hotter temperatures during pollination, high disease pressure from Southern Rust, and greater insect pressure since it is planted later than the optimal time. Sometimes the varieties that are typically higher yielding don’t always do as well in a more stressful situation, and this trial gives us the opportunity to see how many of the popular or new varieties on the market perform in this situation.
Our main goal of doing this trial has been to see which varieties perform well when planted late in less than optimal conditions, particularly in a double crop situation behind onions. We hope this gives some good information about varieties that growers are familiar with as well as new ones.
3 reps of each corn variety are weighed on a grain cart with built in scale.
Well, we harvested this year’s late planted corn trial behind onions last Thursday (October 8th, 2015) and have the yield results to share. We would like to thank all of the seed companies for donating the seed for this trial (Dekalb, Pioneer, Mycogen, and AgDepot) and DuPont for the fungicide used during the season. Before we get into yield numbers, here are the particular details about this year’s trial.
Plant Date: May 19th
Plant Population: 36,300
Row Spacing: 36 inches
Herbicides Applied: Roundup+Atrazine+Prowl (POST)
Fungicides Applications: Aproach (V6 stage) and Aproach Prima (tassel)
Fertility: When corn was about 12″ tall, 200 lbs of nitrogen + 20 lbs sulfur per acre was applied in one application, no additional P or K was applied
Irrigation: followed UGA water recommendations.
Each corn variety was planted in 3 different replications. Each rep was 4 rows wide by 500 feet long.
Late Planted Corn After Onions Variety Trial | | | |
Variety | Plot Weight (lbs) | Moisture % | | | Bushel Per Acre Yield |
Phoenix 7914 | 1170 | 18.3 | | | 145.8 |
| 1222 | 17.4 | | | 154.0 |
| 1114 | 17.1 | | | 140.9 |
Variety Average | | | | | 146.9 |
| | | | | |
Pioneer 1319 HR | 1314 | 17.2 | | | 165.9 |
| 1334 | 16.9 | | | 169.1 |
| 1230 | 16.4 | | | 156.8 |
Variety Average | | | | | 164.0 |
| | | | | |
Dekalb 67-72 | 1624 | 17.3 | | | 204.8 |
| 1572 | 17.96 | | | 196.7 |
| 1492 | 17.8 | | | 187.1 |
Variety Average | | | | | 196.2 |
| | | | | |
Mycogen 2D848 | 1490 | 17.75 | | | 186.9 |
| 1500 | 17.5 | | | 188.7 |
| 1530 | 18 | | | 191.4 |
Variety Average | | | | | 189.0 |
| | | | | |
Phoenix 6706A4 | 1454 | 16.6 | | | 185.0 |
| 1542 | 15.8 | | | 198.0 |
| 1414 | 16.3 | | | 180.5 |
Variety Average | | | | | 187.8 |
| | | | | |
Pioneer 1529 YHR | 1374 | 17 | | | 173.9 |
| 1212 | 17.6 | | | 152.3 |
| 1330 | 17.7 | | | 166.9 |
Variety Average | | | | | 164.4 |
| | | | | |
Dekalb 6208 | 1400 | 16.6 | | | 178.1 |
| 1326 | 16.3 | | | 169.3 |
| 1162 | 16 | | | 148.9 |
Variety Average | | | | | 165.4 |
| | | | | |
Mycogen 2C797 | 1428 | 16.36 | | | 182.2 |
| 1550 | 16.9 | | | 196.5 |
| 1473 | 17.3 | | | 185.8 |
Variety Average | | | | | 188.1 |
| | | | | |
Pioneer 1794VYHR | 1534 | 16.86 | | | 194.5 |
| 1388 | 16.8 | | | 176.1 |
| 1436 | 17.3 | | | 181.1 |
Variety Average | | | | | 183.9 |
| | | | | |
Dekalb 6714 | 1596 | 17.4 | | | 201.1 |
| 1546 | 17.6 | | | 194.3 |
| 1502 | 17.3 | | | 189.5 |
Variety Average | | | | | 194.9 |
| | | | | |
Mycogen 2C786 | 1418 | 17.4 | | | 178.6 |
| 1474 | 17.2 | | | 186.1 |
| 1384 | 17 | | | 175.2 |
Variety Average | | | | | 180.0 |
| | | | | |
Pioneer 1637 VYHR | 1372 | 17.15 | | | 173.4 |
| 1246 | 16.9 | | | 157.9 |
| 1292 | 16.9 | | | 163.8 |
Variety Average | | | | | 165.0 |
| | | | | |
Dekalb 64-69 | 1312 | 17.1 | | | 165.9 |
| 1230 | 17.13 | | | 155.5 |
| 1306 | 16.7 | | | 165.9 |
Variety Average | | | | | 162.4 |