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Dr. Frank Rossi: Frankly Speaking


Why Not?

Posted in By the Numbers 29 March 2014 · 3,347 views

Maybe Spring will show up in much of the northern US states? Still, well before many are mowing north of the Mason-Dixon line, the annual bluegrass seedhead suppression discussion is underway; "What combination of products do you use?, What growing degree day (GDD) timing model do you look at?, Do you use phenological (plant) indicators?" All good questions but....

 

Why not use soil moisture?

 

In other parts of the world where chemical technology is more restricted and less available, you become more in-tune with the way annual bluegrass flowers. You have to understand the ambiguity in the triggers such as light, temperature and moisture for timing the flush. This information then allows better timing of cultural approaches such as brushing and grooming programs employed to "harvest" the seedhead.

 

So why in our part of the world do we focus almost exclusively on temperature via GDD models? Especially now that most facilities can reliably measure soil moisture?

 

There is a ton of ecological research on this issue regarding the prominent influence MOISTURE has on annual bluegrass adaptation and phenology (the appearance and development). Much of this work comes from the west Youngner and Gibbeault, as well as more recent work by Paul Johnson and my old pal Tom Cook! In all these cases there are distinct adaptations and phenological responses to moisture.

 

There is a ton of ecological research on this issue regarding the prominent influence MOISTURE has

 

Professor Bill Johnston of Washington State University published a paper in 2005 on the influence of climatic region in the Pacific Northwest on greens-type annual bluegrass adaptation. They found clearly that the best turfgrass quality and fewest seedheads were found on plants that came from cool moist climates. Now what does this tell us about seedhead production. To me it confirms what I often see, dry Spring's result in the most defined and prolific seedhead flush.

 

So why not consider looking at your temperature models AND take soil moisture measures? How often do you spray all the greens within two hours of each other and see the dramatic difference in seedhead suppression? This could be light and moisture in addition to temperature. But now that you have a reliable method for measuring soil moisture, WHY NOT track that as well.

 

 




What Is Your Number?

  Posted in By the Numbers 10 May 2012 · 1,130 views

I know no subject more disparate around the country than water management, especially of golf putting greens. In the desert southwest every drop is accounted for when water can consume up to $1 million annually. While in northern states water is applied gratuitously measured in minutes (not inches) with little regard for cost or precision.

With the simple poke of the meter into the ground golf course superintendents now have a number.

Recently the use of moisture meters such as Spectrums Field  Scout 300, provide an easy to use method for determining soil moisture and a defacto increase in precision. With the simple poke of the meter into the ground golf course superintendents now have a number. The meter actually provides percent soil moisture measurements that will vary for every soil or sand rootzone. Hence the question, whats your number?, i.e., what is the level of soil moisture you feel will get you the best turf without stress, or if you start the day at 14 percent can you make it without chasing wilt?

 

Posted ImageThere is an old saying in education that what gets measured gets done. It seems odd that both numbers we manage putting greens for come from the end of a metal stick! Nevertheless, developing a number for your greens will add precision to the single most important management factor during the stressful seasons, water management.

The new water withdrawal legislation is a harbinger of things to come.

There are few regular management decisions made on a putting surface that influence performance as much as water. Hot is okay, hot and wet is the kiss of death. If you are not paying for water now, the writing is on the wall for Great Lake States and much of the northeast. The new water withdrawal legislation is a harbinger of things to come. It is best to become more precise now. At some point just like golfers ask about stimpmeter readings, when they start getting the water bill they will start asking, hey-whats your number?








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