Advanced Grazing School:
Increasing Yields by 15-20% with Plant Growth Regulators?
Increasing Yields by
15-20% with Plant Growth
Regulators?
Bakanae (“Foolish Seedling”)
Disease in Rice
Dr. Dennis Hancock
Extension Forage Specialist
Crop and Soil Sciences – UGA
Gibberellins are Derived from
Gibberella fujikuroi fungus
Use of GAs in Agriculture
•  Increase sugar yield in sugarcane
•  Stimulate barley-malting process in beerbrewing industry
•  Increase size of seedless grapes
•  Increase fruit set and size in apples/pears
•  Delay fruit ripening
•  Increase foliage and forage yield?
Use of GAs for Forage
Management is NOT New.
GA3 Available As:
Review by Matthew et al., 2009 (NZ J. Ag Res.):
•  13 studies around the world
•  Yield responses generally 8-20% inc. in yield
•  These studies included rates of 0.6 – 10 oz.
GA3/acre
§  Current product recommended rate range: 0.3 –
1.0 oz./acre
•  Cost of producing GA3 is much lower now.
Dr. Dennis Hancock
Extension Forage Agronomist
UGA Extension
1
Advanced Grazing School:
Increasing Yields by 15-20% with Plant Growth Regulators?
Rye+Ryegrass Response to
RyzUp (App Date = Dec. 6, 2011)
Rye+Ryegrass Response to
RyzUp (App Date = Dec. 20, 2011)
2500
2500
0
0.33
0.66
0.99 oz./acre
2000
Forage Yield,
lbs of DM/acre
Forage Yield,
lbs of DM/acre
2000
1500
1000
@ $7/acre,
The added yield
cost $0.007
500
0
0
7
Dr. John Niezen, ECRDairy
14
21
28
35
Days Since Application
@ $7/acre,
The added yield
cost $0.007
1500
1000
500
0
0
42
0
Dr. John Niezen, ECRDairy
0.33
0.66
7
14
0.99 oz./acre
21
28
Days Since Application
An Early RyzUp Application (1/2/11)
and Harvest 45 d later (2/12/11)
Gainesville, GA
1200
@ $7/acre,
The added yield
cost $0.026
b
Yield,
lbs of DM/acre
1000
800
a
a
a
600
400
200
0
0
RyzUp SmartGrass
Untreated
Dr. Yoana Newman, UFL
Two Application Dates (1/29/11, 3/5/11) and
Three Harvests (2/12/11, 3/5/11, 3/12/11)
No RyzUp
RyzUp
2500
ab
b
b
800
600
400
2000
1500
@ $7/acre,
The added yield
cost $0.022
1000
500
200
0
0
Dr. Yoana Newman, UFL
3X
3000
Forage Yield,
Lbs of DM/acre
Yield,
lbs of DM/acre
1000
2X
RyzUp Affected Forage Yield
1600
@ $7/acre x 2 apps,
The added yield
1400
cost $0.031
a n.s. n.s.
1200
1X
Rate of RyzUp
1X
2X
0
3X
1/21/13
Rate of RyzUp
Dr. Dennis Hancock
Extension Forage Agronomist
UGA Extension
1/29/13
Jeremy Kichler, Macon Co. Extension
2
3/4/13
Date
3/14/13
Advanced Grazing School:
Increasing Yields by 15-20% with Plant Growth Regulators?
Response of Winter Annual Grass* to
Mid-Season Application of
RyZup Smartgrass®
Response of Winter Annual Grass* to
Early Season Application of
RyZup Smartgrass®
Harvest Early Season Applica0on** RyZup None Diff. Harvest Mid-­‐Season Applica0on** RyZup None Diff. Feb. 17, 2012 Feb. 29, 2012 Mar. 15, 2012 Apr. 25, 2012 Season Total 1429 -­‐ 2143 2090 5186 Feb. 17, 2012 Feb. 29, 2012 Mar. 15, 2012 Apr. 25, 2012 Season Total -­‐ 2038 2366 2684 4831 (lbs/acre) 1120 -­‐ 1984 1961 4691 (%) 21.60% -­‐ n.s. n.s. 9.50% * Averaged over rye, ann. ryegrass, and rye+ARG plots.
** Fall application made on Nov. 4, 2012 (plants were at 2-4 leaf stage).
Early + Mid-­‐Season Applica0on** RyZup None Diff. Feb. 17, 2012 Feb. 29, 2012 Mar. 15, 2012 Apr. 25, 2012 Season Total 1390 -­‐ 2217 2300 5445 (lbs/acre) 1006 -­‐ 1890 1796 4357 (%) -­‐ n.s. n.s. 11.80% n.s. Possible Negatives to Using
GAs for Forage Management
Matthew et al., 2009 (NZ J. Ag Res.):
•  Really only works if inducing the plant to
grow when it wouldn’t ordinarily (e.g., winter,
late fall)
(%) 27.6% -­‐ n.s. 21.9% 20.0% §  No benefit to adding if plant is already growing at
max growth rate.
•  Not all grass species respond similarly
§  Small grains > ann. ryegrass > tall fescue
•  Reduces nodulation in legumes
* Averaged over rye, ann. ryegrass, and rye+ARG plots.
** Fall application made on Nov. 4, 2012 (plants were at 2-4 leaf stage),
winter application made on Feb. 29, 2012.
www.georgiaforages.com Possible Negatives to Using
GAs for Forage Management
Matthew et al., 2009 (NZ J. Ag Res.):
•  Yield lag in later cuttings (at very high rates)
•  Reduction in root mass (at very high rates)
•  Reduction in tiller number (at very high rates)
•  No significant change in forage quality
observed, but possible?
•  Could increase need for moisture and N.
Dr. Dennis Hancock
Extension Forage Agronomist
UGA Extension
-­‐ 1990 2286 2366 4454 * Averaged over rye, ann. ryegrass, and rye+ARG plots.
** Winter application made on Feb. 29, 2012.
Response of Winter Annual Grass* to
Early and Mid-Season Application of
RyZup Smartgrass®
Harvest (lbs/acre) GeorgiaForages.com Email Updates 3