What to expect from plant growth regulators

C62291821dac0dd5b7ef3b72a30cd137?s=47 Micah Woods
November 20, 2018

What to expect from plant growth regulators

This seminar was held at Manila Southwoods Golf and Country Club at a seminar organized by Nutranta Inc.

I explained what to expect from the use of plant growth regulators in the Philippines, specifically related to effects on plant health, turf quality, and resource requirements. I close by discussing application timing.

C62291821dac0dd5b7ef3b72a30cd137?s=128

Micah Woods

November 20, 2018
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Transcript

  1. 1.

    What to expect from plant growth regulators Micah Woods November

    20, 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
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    What has the potential to occur? from “Insecticides, fungicides, herbicides,

    and growth regulators used in turfgrass systems,” Reicher et al., 2013 • improve heat stress tolerance • improve performance in shade • increase green speed • decrease sod heating • improve density and color • increase drought and heat tolerance • delay fall dormancy of warm-season grasses • hasten spring green-up
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    What has the potential to occur? • improve heat stress

    tolerance • improve performance in shade • increase green speed • decrease sod heating • improve density and color • increase drought and heat tolerance • delay fall dormancy of warm-season grasses • hasten spring green-up • reduced mowing requirement • reduced nutrient requirement • reduced water requirement
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    Today’s outline 1. Healthier plants 2. Better playing conditions 3.

    Lower resource use 4. Optimal application scheduling
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    • slower growing • improved stress tolerance • improved shade

    tolerance • more efficient photosynthesis
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    The growth rate is slower, so there can be …

    less mowing Peak clipping yield suppression at label rates is about 50% of untreated. Mowing frequency reduction may be possible.
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    The growth rate is slower, so there can be …

    lower CO 2 emissions Mowing fairways on an average 18 holes produces about 92 kg of CO 2 . With 150 fairway mows a year, that’s almost 14 tons of CO 2 .
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    “by using a surfactant, a PGR, or both, bermudagrass quality

    can be maintained with 15 to 30% less irrigation water …without a reduction in color or quality.” Serena et al., 2018
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    How much growth reduction? “Peak suppression values after a [trinexapac-ethyl]

    application at 0.034 kg a.i. ha-1 [280 mL/ha] in this study ranged from 49 to 62%” Reasor et al., 2018
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    When does the growth reduction happen? “Peak suppression occurred between

    166 and 177 GDD calculated using 10°C as the base temperature (GDD10C )” Reasor et al., 2018
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    Recommended reapplication interval Based on the suppression of ultradwarf bermudagrass,

    Reasor et al. suggest a reapplication interval of 216 to 230 accumulated GDD10C . In days, with Manila weather, that works out to reapplication every 12 days on average to maintain consistent growth regulation.
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    Minimal use recommendation • 3 applications prior to tournament •

    first app 33 days before tournament • second app 21 days before tournament • final app 9 days before tournament