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PUTTING GREEN CARE
IN SUMMARY
• Primo Maxx influences growth in two
phases: a suppression phase followed
by a rebound phase of increased
turfgrass growth compared to an
untreated control.
• The length of the growth suppression
phase in influenced by air temperature
not a calendar.
• Using a simple growing degree day
model can be a useful tool to predict
the level of growth regulation on a golf
putting green. Before 250 GDD units
the grass growth is suppress and after
250 GDD units growth is enhanced on
a creeping bentgrass putting green.
• Re-applying Primo every 200 GDD
units will provide consistent growth
suppression on a creeping bentgrass
putting green during a growing season.
It is impractical to re-apply Primo
on exactly 200 GDD in a golf course
setting. However the GDD model can
be like a fuel gauge. When the Primo
fuel gauge is getting near empty it is
time add Primo to the next spray tank.
• Mowing higher will lead to slower
growth in general and increased
growth suppression when Primo
is applied. Applying Primo at rates
greater than 0.125 oz/1000 ft2 will not
result in increased growth suppression
on golf course putting greens.
• Re-applying Primo every 200 GDD
provides a constant boost in turfgrass
color and quality in a similar as
increased nitrogen fertilization. Re-
applying Primo properly can reduce
nitrogen fertilization requirements
substantially.
• For more information, contact
djsoldat@wisc.edu or
wkreuser2@unl.edu.
By Doug Soldat and Bill Kreuser
GETTING THE MOST FROM YOUR
Primo
Maxx
PROGRAM
How to use Primo Maxx
growth regulation most
effectively on putting greens
