2023 DEKALB® Brand Corn Product Comparisons Following Cover Crop Mix

May 20, 2024

TRIAL OBJECTIVE

  • Testing various corn products is crucial to better understanding how to position products in the right field and under the right management conditions to meet the farmer’s needs.
  • The objective of this trial was to test a broad spectrum of DEKALB® brand corn products that are currently recommended for the western Central Plains in a high-residue environment.

RESEARCH SITE DETAILS

Site details

  • The trial was arranged in a randomized complete block design with four replications. The only treatment factor was the corn product.

List of field operations, products, and rates in 2023.

  • Early stand counts and Normalized Difference Vegetation Index (NDVI) were measured on 6/26/2023 when the corn was about the V7 growth stage.
  • Final stand counts, intactness ratings, lodged plants, and ear height were measured at harvest time.
  • The total rainfall accumulated during the 2023 corn growing season was 13.5 inches. This trial was irrigated with a linear overhead irrigation system and the total irrigation applied was 2 inches. The trial had a wind storm a few days prior to harvest that impacted intactness ratings and stalk lodging percentages.

DEKALB® brand corn products in this trial.

UNDERSTANDING THE RESULTS

  • During the spring of 2023, the predominant species in the cover crop mix were cereal rye and winter barley. Cover crop biomass averaged 1,062 lb/acre at the time of termination on 05/20/2023.
  • DEKALB® DKC61-41RIB brand blend had the highest recorded yield at 214.8 bu/acre, while DEKALB® DKC64-65RIB brand blend had the lowest recorded yield at 186.6 bu/acre, 13.1% less (Table 3). The yield differences across DEKALB® brand products were not statistically significant, which indicates that any differences in yield were likely due to chance and not true differences in yield potential between the products.
  • Early stand counts for DEKALB® DKC111-33RIB brand blend were 33,977 plants/acre, 5.6% less than the seeding rate of 36,000 seeds/acre (Table 3). DEKALB® DKC105-33RIB brand blend had the lowest stand count at 32,314 plants/acre, or 10.2% less than the seeding rate. Despite the numerical differences, there was no statistical difference in early stand across the ten DEKALB® brand products.
  • Normalized Difference Vegetation Index (NDVI) at the V6 growth stage was the highest (0.57) with DEKALB® DKC105-33RIB brand blend, while DEKALB® DKC62-89RIB brand blend was the lowest (0.47) (Table 3). Those differences could be justified by their distinct relative maturities and Growing Degree Units (GDUs), where a late-maturity product would be a growth stage behind and consequently have lower biomass, a key indicator of NDVI. However, those differences were not statistically significant.
  • Late-season stand counts were the highest with DEKALB® DKC111-33RIB brand blend at 34,531 plants/acre, or 4.1% less than the seeding rate of 36,000 seeds/acre. DEKALB® DKC101-33RIB brand blend had the lowest stand count of 31,046 plants/acre or 13.8% less than the seeding rate (Table 3). Despite the numerical differences, there was no statistical difference in late stand across the ten DEKALB® brand products.
  • Stalk lodging was significantly different between the DEKALB® brand products with DEKALB® DKC62-89RIB brand blend having the highest lodging percentage (32.3% of total final stand) while DEKALB® DKC101-33RIB brand blend had the lowest lodging percentage at 1.6% of total final stand (Table 3). The trial had a wind storm a few days prior to harvest that impacted intactness ratings and stalk lodging percentages.
  • DEKALB® DKC105-33 brand blend had the best intactness rating (3.5) among the ten DEKALB® brand products tested (Table 3).
  • There was a significant difference in ear height among the DEKALB® brand products in this trial (Table 3). DEKALB® DKC62-89RIB brand blend had the highest average ear height at 51.6 inches while DEKALB® DKC101-33RIB brand blend had an average ear height of 41.5 inches (20% lower than DEKALB® DKC62-89RIB brand blend). There was a trend of lower ear heights with low relative maturity products.

Aerial overview of the DEKALB® brand product testing at the Gothenburg Learning Center
Figure 1. Aerial overview of the DEKALB® brand product testing at the Gothenburg Learning Center (A), and replications and lodged plants in the trial (B). Pictures were taken on October 23, 2023.


. DEKALB® brand blend product yield, percent yield difference from the highest yield, early stand count, percent early stand vs seeding rate, normalized difference vegetation index (NDVI), final stand count, percent final stand vs seeding rate, percent stalk lodging, intactness, and ear height by corn product under no-till and cover crop mix residue.

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