Yield Potential of Deltapine® Cotton Varieties at Different Planting Dates

TRIAL OBJECTIVE

• One objective of this trial was to evaluate the yield potential of Deltapine^® cotton varieties across the different midsouth planting dates that range from late April through early June.
• Another objective of the trial was to evaluate potential interactions of ThryvOn^® Technology with the different planting dates.
• The data could help cotton growers make appropriate decisions about variety, planting dates, and technology choices used in cotton production systems.

RESEARCH SITE DETAILS

Table 1. Deltapine^® Brand Varieties Planted in Trial.

• All field work, tillage, and herbicide applications were per local standards.
• Single replication strip plot with 12 rows, which were each 1,000 feet long (about one acre/variety)
• Additional trial information:
  • Grown as typical mid southern cotton crop.
  • Plant growth regulator (PGR) used as needed through the season.
  • Plots scouted for insects individually.
  • When Bollgard^® 3 XtendFlex^® Cotton entries exceeded threshold within a planting date, the entire date (both technologies) was sprayed with an insecticide for the target pest.
    • This is likely an overtreatment for the Bollgard^® 3 ThryvOn^® Cotton with XtendFlex^® Technology varieties; however, it provides a baseline for study.
    • Treatment totals:
      • 4/27/24 planting date
        • 2 thrips treatments
        • 3 Lygus treatments
      • 5/15/2024 planting date
        • 1 thrips treatment
        • 3 Lygus treatments
      • 6/8/2024 planting date
        • 0 thrips treatments
        • 2 Lygus treatments
  • Data collected
    • Machine harvested yield.
    • Representative site turnouts (Heaven Cut Variety Demo) used for lint yield estimations.

UNDERSTANDING THE RESULTS

• Average turnout lint yield (lb/acre) by planting dates
  • The Deltapine^® brand ThryvOn^® Technology varieties planted on April 27 and treated for insects had the highest average lint yield of 1,482 lb/acre (Figure 1).
  • The Deltapine^® brand ThryvOn^® Technology varieties planted on May 15 and treated for insects yielded an average of 1,051 lb lint/acre (Figure 1).
  • The Deltapine^® brand ThryvOn^® Technology varieties planted on June 8 and treated for insects yielded an average of 725 lb lint/acre (Figure 1).
  • This indicates the need for selecting proper planting dates in mid-southern cotton production.

• ThryvOn^® Technology performance across dates:
  • Treated Plots – Where plots were treated for Lygus per threshold, both technology classes provided value and high yield potential to the grower. In every planting date and treatment combination, varieties containing ThryvOn^® Technology yielded more than the varieties containing Bollgard^® 3 XtendFlex^® Cotton Technology only (Figures 2, 3, and 4).
  • Untreated Plots – Across all planting dates, insect-untreated varieties containing ThryvOn^® Technology yielded more than varieties containing only Bollgard^® 3 XtendFlex^® Cotton Technology, producing up to 5.5 times the yield (Figures 2, 3, and 4). However, those yields were depressed compared to the treated yield for both ThryvOn^® Technology and Bollgard^® 3 XtendFlex^® Cotton Technology varieties (Figures 2,3, and 4). This reiterates the need for proper scouting, threshold usage, and insecticidal treatments as needed when using either technology class to obtain maximum value, and particularly when using ThryvOn^® Technology varieties.
• Insect pressure typically ebbs and flows through the season, as it did in this experiment. Generally, the highest Lygus pressure at the maximum period of fruit susceptibility was present in the May 15 planting date (Figure 3). This can be seen in both the number of treatments and yield results, as the difference between Bollgard^® 3 XtendFlex^® Cotton varieties and the Bollgard^® 3 ThryvOn^® Cotton with XtendFlex^® Technology varieties become even larger as insect pressure increases.
• Important Note – This demonstration should be viewed as a coarse evaluation of technology performance in the medium-scale plot system at the Bayer Crop Science Scott Learning Center. In grower fields, on a larger scale, some decisions are likely to be different because allowances could be made for larger fields that could potentially change the magnitude of the responses, but not necessarily the direction of the responses. Economic decision factors may be different if, for example, PGR use becomes more intense in later-planted cotton. Insect economic thresholds also vary between locations, and agronomic management should be customized for each variety/field/technology combination.
• In general, the more determinate products have historically demonstrated higher yields at the Scott Learning Center than the less determinate cottons (Deltapine^® brand DP 2127 B3XF and Deltapine^® brand DP 2333 B3XF.) As in the past, this yield difference occurred again in this trial and was particularly true in the mid and late planting dates. The later planting dates were still not as high yielding as the earliest date, but better generally based on season length/determinacy.

KEY LEARNINGS

• Planting date remains a critical decision for cotton growers regardless of the technology planted. Planting into warm, good growth conditions in a timely manner should remain a priority.
• Both Bollgard^® 3 XtendFlex^® Cotton and ThryvOn^® Technology varieties provided excellent yield potential when planted on April 27 and treated appropriately for insects using state thresholds.
• ThryvOn^® Technology varieties provided some yield advantage vs Bollgard^® 3 XtendFlex^® Cotton varieties on all planting dates, but particularly when planted on the May 15 and June 8 dates. This is likely a function of impacts on Lygus reproduction during the mid and later season. This data could provide managers with a powerful tool to manage later planted cotton crops.
• Proper scouting, threshold usage, and insecticide applications remain critical for the optimization potential of any technology used in cotton production systems.
• Please contact your local Bayer or Deltapine^® brand representative for more information.

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