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.

Transcript

1. What to expect from plant growth regulators Micah Woods November 20, 2018 Chief Scientist Asian Turfgrass Center www.asianturfgrass.com
2. 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
3. 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
4. from Reicher et al., 2013
5. Today’s outline 1. Healthier plants 2. Better playing conditions 3. Lower resource use 4. Optimal application scheduling
6. 1. Healthier plants
7. Manila Golf Club
8. Manila Golf Club, February 2013
9. Manila Golf Club, February 2013
14. • slower growing • improved stress tolerance • improved shade tolerance • more efficient photosynthesis
16. Table 1 from Grime, 1977
17. 2. Better playing conditions
18. More plant density manilagrass at Keya GC, Japan
19. Tolerance to lower mowing manilagrass at Keya GC, Japan
20. Improved performance in shade manilagrass at Keya GC, Japan
21. Possible root enhancement manilagrass at Keya GC, Japan
22. 3. Lower resource use
23. 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.
24. 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 .
25. The growth rate is slower, so there can be … lower irrigation water use
27. “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
28. 4. Optimal application scheduling
29. 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
31. 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
32. Figure 1 in Reasor et al., 2018
33. from Figure 1 in Reasor et al., 2018
36. 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.
37. https://greenkeeperapp.com
43. https://greenkeeperapp.com
44. 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
45. For more, please see www.asianturfgrass.com.