Slide 1
Slide 1 text
Turfgrass growth potential and measuring
clipping volume
Micah Woods
13 December 2018
Chief Scientist
Asian Turfgrass Center
www.asianturfgrass.com
Slide 2
Slide 2 text
Temperature-based growth
potential
Slide 3
Slide 3 text
Grasses can grow well when temperatures
are close to an optimum for growth, and
grasses grow more slowly as the
temperature moves away from the
optimum.
Slide 4
Slide 4 text
Temperature-based growth potential
PACE Turf developed the Temperature-based GP to express the actual temperature in
terms of its proximity to optimum temperatures for shoot growth.
GP = e−0.5( t−to
var
)2
where,
GP = growth potential, on a scale of 0 to 1
e = 2.71828, a mathematical constant
t = average temperature for a location, in celsius
to
= optimum temperature, 20 for C3
grass, 31 for C4
grass
var = adjusts the change in GP as temperature moves away from to
; I suggest 5.5 for C3
and 7 for C4
Slide 5
Slide 5 text
No content
Slide 6
Slide 6 text
No content
Slide 7
Slide 7 text
No content
Slide 8
Slide 8 text
No content
Slide 9
Slide 9 text
No content
Slide 10
Slide 10 text
No content
Slide 11
Slide 11 text
No content
Slide 12
Slide 12 text
No content
Slide 13
Slide 13 text
No content
Slide 14
Slide 14 text
No content
Slide 15
Slide 15 text
No content
Slide 16
Slide 16 text
No content
Slide 17
Slide 17 text
Implications and use of GP
• mowing frequency
• fungicide duration
• heat-related stress
• topdressing requirement
• nutrient use
Slide 18
Slide 18 text
Measuring clipping volume
Slide 19
Slide 19 text
No content
Slide 20
Slide 20 text
Use of clipping volume
1. Growth rate
Slide 21
Slide 21 text
Use of clipping volume
1. Growth rate
2. Green speed
Slide 22
Slide 22 text
Use of clipping volume
1. Growth rate
2. Green speed
3. Nutrient use and supply
Slide 23
Slide 23 text
Use of clipping volume
1. Growth rate
2. Green speed
3. Nutrient use and supply
4. Consistency
Slide 24
Slide 24 text
Use of clipping volume
1. Growth rate
2. Green speed
3. Nutrient use and supply
4. Consistency
5. Topdressing
Slide 25
Slide 25 text
1. Growth rate
Slide 26
Slide 26 text
Old Course, St. Andrews
Slide 27
Slide 27 text
Kashima Soccer Stadium, Japan
Slide 28
Slide 28 text
Royal Bangkok Sports Club
Slide 29
Slide 29 text
Siam CC Plantation Course, Thailand
Slide 30
Slide 30 text
2. Green speed
Slide 31
Slide 31 text
greenkeeper Andrew McDaniel (@drumcturf) at Keya GC, Japan
Slide 32
Slide 32 text
Keya GC, Japan
Slide 33
Slide 33 text
No content
Slide 34
Slide 34 text
No content
Slide 35
Slide 35 text
No content
Slide 36
Slide 36 text
No content
Slide 37
Slide 37 text
No content
Slide 38
Slide 38 text
No content
Slide 39
Slide 39 text
Keya GC, Japan
Slide 40
Slide 40 text
Keya GC, Japan
Slide 41
Slide 41 text
No content
Slide 42
Slide 42 text
No content
Slide 43
Slide 43 text
Eric Reasor project, photo at Koshigaya GC, Saitama, Japan
Slide 44
Slide 44 text
No content
Slide 45
Slide 45 text
3. Nutrient use and supply
Slide 46
Slide 46 text
Nichino Ryokka research center at Chiba, Japan
Slide 47
Slide 47 text
Chiba, Japan
Slide 48
Slide 48 text
No content
Slide 49
Slide 49 text
For bentgrass, with every 10 mL/m2,
expect a dry matter harvest of 0.6 g/m2.
Slide 50
Slide 50 text
Then resupply as desired
For example, 200 mL/m2 of bentgrass ≈ 0.5 g N/m2.
And 0.25 g K/m2. And so on.
Slide 51
Slide 51 text
No content
Slide 52
Slide 52 text
4. Consistency
Slide 53
Slide 53 text
Augusta National GC, USA
Slide 54
Slide 54 text
Keya GC, Japan
Slide 55
Slide 55 text
No content
Slide 56
Slide 56 text
No content
Slide 57
Slide 57 text
No content
Slide 58
Slide 58 text
No content
Slide 59
Slide 59 text
5. Topdressing
Slide 60
Slide 60 text
Tifeagle, Thailand
Slide 61
Slide 61 text
“41% of members and players complain
that sanded greens play poorly, according
to turf managers who participated in
recent GCI research.”
GCI Magazine—April 2018
Slide 62
Slide 62 text
Kanto region, Japan
Slide 63
Slide 63 text
No content
Slide 64
Slide 64 text
No content
Slide 65
Slide 65 text
No content
Slide 66
Slide 66 text
No content
Slide 67
Slide 67 text
Table 1: Annual clipping volume at that location from 2013 to 2016
Year Volume Estimated dry weight N applied
L/m2 g/m2 g/m2
2013 4.4 266 NA
2014 3.4 201 13
2015 2.9 172 10
2016 2.4 142 8.5
Slide 68
Slide 68 text
For more, please see
www.asianturfgrass.com.