Summer 2016 - 107
www.turftrends.com
The following is a summary of the
work the authors have done over the
years regarding Primo Maxx growth
regulation on putting greens. Doug
Soldat spoke on this topic in March
at the Inland Empire GCSA's Spring
Meeting at the Wenatchee (WA) Golf
& Country Club.
How long does primo maxx reduce
putting green clipping production?
The Primo Maxx label states that
re-applying the product every four
weeks will maintain approximately
50 percent clipping reduction.
However many turfgrass managers
have seen a dramatic increase in
putting green clipping production
sooner than four weeks after the last
application.
This is especially true during
midsummer. The truth of the
matter is that Primo's longevity is
controlled by plant metabolism
and not by a calendar. The rate
of plant metabolism is related to
temperature. Increasing temperature
by only 10°C doubles the rate of
plant metabolism which includes
the rate of Primo degradation. The
daily average air temperature for
Madison, Wis., during the month of
May is 14°C while in July the average
temperature is 22°C.
According to our data, this means
that Primo will effectively reduce
clipping production on bentgrass
putting greens for 18 days in May
and only 11 days during an average
July. After the reduction phase the
bentgrass putting greens experience
a rebound phase of increased
clipping production compared
to untreated grass. Typically this
rebound phase lasts as long as the
reduction phase did. For example
during a hot stretch of weather
(think: Pythium), Primo will cause
growth suppression for a week
followed by one week of increased
putting green growth with the result
