Response of Four Deltapine Cotton Varieties to Plant Growth Regulators

TRIAL OVERVIEW

Cotton varieties all respond differently to plant growth regulator (PGR) treatments. It is important to understand the response of new cotton varieties to PGR application rates.

RESEARCH OBJECTIVE

The objective of this experiment was to evaluate the response of four Deltapine® cotton varieties to PGR application over two years for plant height and yield response.

SITE NOTES:

  • Six locations were used:
    • 2016: Suffolk, VA; Jackson, NC; Plymouth, NC; Pantego, NC; Belvidere, NC and Hartsville, SC
    • 2017: Jackson, NC; Plymouth, NC; Pantego, NC; Belvidere, NC; Maxton, NC and Blackville, SC
  • Pantego, NC and Jackson, NC locations were small plot designs with four replications. All other locations were single strip trials.
  • Treatments included two approaches to PGR management:
    • Passive – standard PGR application schedule and rate for local conditions.
    • Aggressive – 1.5 to 2x rate of Passive treatment.
  • PGR selected by grower.

UNDERSTANDING THE RESULTS

  • Treatment means are two year averages (2016-2017) across all locations.
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      Figure 1. Average plant height (inches) for each cotton variety and treatment.

       

      Figure 2. Average lint yield (lbs/acre) for each variety and treatment.

      WHAT DOES THIS MEAN FOR YOUR FARM?

      • DP 1725 B2XF was least responsive for plant height and lint yield when applying an aggressive PGR treatment followed by DP 1614 B2XF and DP 1639 B2XF.
      • DP 1646 B2XF had a greater plant height for both PGR treatments compared to the other cotton varieties tested, with DP 1614 B2XF having the shortest plant type for both PGR treatments.
      • DP 1646 B2XF was the only cotton variety that had a positive yield response from the aggressive PGR treatment.