Introduction

The performance of corn hybrids is annually evaluated in the official variety trials (OVTs) by LSU AgCenter researchers. The purpose of these trials is to provide Louisiana growers, seedsmen, county agents and consultants with unbiased performance data for commercial corn hybrids submitted for evaluation by private companies. Selection of superior hybrids that are well-adapted for a given region is essential for maximizing yield and profit. In 2018, 51 corn hybrids were entered by the commercial seed companies. Locations of these trials included the Dean Lee Research and Extension Center in Alexandria; Red River Research Station in Bossier City; Northeast Research Station in St. Joseph; and Macon Ridge Research Station in Winnsboro (Table 1).

Suggestions for Selecting Hybrids

Hybrid selection is one of the most important decisions a producer will make and is essential for successful corn production. Seed companies offer multiple hybrids for sale to producers for good reasons. Each corn producer has somewhat different soil conditions, irrigation practices and crop rotations compared to other growers located in each farming community. Some hybrids will tend to perform better than others based on soil type, planting date, environmental conditions and location.

Yield is important when selecting a corn hybrid; however, maturity, stay green, lodging, shuck cover, ear placement and disease and insect resistance need to be considered. Yield data from multiple locations and years are good indicators of the consistency of a hybrid’s performance.

Hybrid maturity is rated using the relative maturity (RM) or growing degree day (GDD) rating systems. These two methods are based on the number of days or degree days for a hybrid to reach physiological maturity. Louisiana producers can grow early, midseason, and full-season hybrids. In Louisiana, 112-to-121-day-maturity hybrids usually produce the best yields. Full-season hybrids do not consistently out-yield midseason hybrids. It appears there is more variability in yield among hybrids within a given RM rating than there is between maturity groups.

Hybrids that stay green later into their maturity usually retain better stalk strength and have less lodging potential. Shuck cover is important for protecting the ear and kernels from weathering and fungi. At later planting dates, a corn hybrid will grow taller because of an increase in day and night temperatures causing the internodes of the stalks to be longer. Therefore, ear placement will be higher when compared to an earlier planting date. This usually means that the lodging potential will be greater. When planting late in the season, consider planting a hybrid that has a low ear placement.

Also, corn hybrids have different insect and herbicide traits. These biotechnology traits will need to be considered and should be based on which one best fits into your production system.

Select several hybrids that are consistently top performers over multiple locations or years within a region. Consistency over multiple environments is important because we cannot predict next year’s growing conditions.

Procedures

The experimental design at each location was a randomized complete block design with four or five replications. Corn variables measured and rating scales are listed in Table 2. Analysis of variance and least-significant differences (LSD) were calculated only if differences existed at the 90 percent confidence level. If differences were significant, an LSD at the 10 percent probability level was calculated. If the LSD (0.10) for yield in a trial is 10 bushels per acre, there is a 10 percent chance that two hybrids with a reported yield difference of 10 bushels per acre are genetically equal and a 90 percent probability they have a difference in genetic potential in that particular environment. LSD values are influenced by how well soil fertility, stand establishment, plot length, harvest efficiency and other variables are controlled and by number of replications for each hybrid. The letters NS are used in the text and tables to indicate lack of significance (not significantly different) at the 10 percent probability level. The coefficient of variation (CV) reflects the magnitude of experimental error (random variation not accounted for by hybrids and replications) in relation to the trial mean. A high CV means that relative differences among hybrids were not consistent among replications, which reduces the precision of the test.

Yield data for 2018 across locations and two-year averages across locations are summarized in Tables 3 and 4. To be considered for a two-year average, hybrids must have the same seed traits each year (refer to Table 10). For each individual location, a summary of cultural practices, growing conditions, temperatures and rainfall is listed prior to the yield and agronomic data (Tables 5-9). Seed traits and hybrid maturities are listed in Table 10 and participating seed companies are listed in Table 11.

Corn Hybrid Performance Trial, Dean Lee Research & Extension Center, Alexandria

Crop Summary

Soil moisture conditions were very good at planting and throughout the month of April. However, during the months of May and June, rainfall was below normal, and temperatures were above normal (see graph below). Grain yields ranged from 143.5 to 187.2 bushels per acre with a trial average of 166.01 bushels per acre in this dryland trial (Table 5). Lack of rainfall in May and June limited the yield potential at this location. There were 24 hybrids that fell within the high-yielding group for 2018. Other agronomic data are presented in Table 5.

Corn Hybrid Performance Trial, Red River Research Station, Bossier City

Crop Summary

During the months of May and June, rainfall was below normal, and temperatures were above normal (see graph below). Grain yields ranged from 103.2 to 168.8 bushels per acre with a trial average of 137.5 bushels per acre in this irrigated trial (Table 6). There were four hybrids that fell within the high-yielding group for 2018. Other agronomic data are presented in Table 6.

Corn Hybrid Performance Trial, Northeast Research Station, St. Joseph (Silt Loam Soil)

Crop Summary

Cool temperatures were experienced during March and April with soil moisture being adequate. During the months of May and June, rainfall was below normal, and temperatures were above normal (see graph below). Grain yields ranged from 215.2 to 269.4 bushels per acre with a trial average of 242.6 bushels per acre in this irrigated trial (Table 7). Excellent yields were produced at this location. There were four hybrids that fell within the high-yielding group for 2018. Other agronomic data are presented in Table 7.

Corn Hybrid Performance Trial, Northeast Research Station, St. Joseph (Clay Soil)

Crop Summary

Cool temperatures were experienced during March and April with soil moisture being adequate. During the months of May and June, rainfall was below normal, and temperatures were above normal (see graph below). Grain yields ranged from 184.4 to 270 bushels per acre with a trial average of 225.6 bushels per acre in this irrigated trial (Table 8). There were two hybrids that fell within the high-yielding group for 2018. Other agronomic data are presented in Table 8.

Corn Hybrid Performance Trial, Macon Ridge Research Station, Winnsboro

Crop Summary

Cool temperatures were experienced during March and April, with soil moisture being adequate. During the months of May and June, rainfall was below normal, and temperatures were above normal (see graph below). Grain yields ranged from 169.6.4 to 204.1 bushels per acre with a trial average of 189.7 bushels per acre in this irrigated trial (Table 9). There were 22 hybrids that fell within the high-yielding group for 2018. Other agronomic data are presented in Table 9.