By Dr. Milt Engelke

Professor Emeritus, Texas A&M University

Consulting Agronomist

“Meant for the insiders only.”

Since this is an “inside” message, I will tell you in my opinion that the biggest problem we have with guys wanting to make a hit with zoysiagrass is the mentality that more soluble nitrogen will encourage the grass to grow faster. The crux of the problem is the use of excessive nitrogen fertilizer. It is important, regardless of the climate, to understand that

excessive means different things to different grasses. Zoysiagrasses are slower growing and will not respond to nitrogen the way that Bermuda or paspalums do! Having said that, zoysiagrass also has a much reduced need for nitrogen and so the amount of nitrogen provided to either Bermuda or paspalum would be considered excessive. Further, the timing and form of the nutrient is very important as the microenvironment includes many other critters that also depend and take advantage of the presence of free Nitrogen.

As pointed out, high humidity and heat also compound the problem as the patch disease organism requires free moisture and optimum temperatures to flourish. Most often in the sub-temperate climates as we have in the southern does viagra lower blood pressure US, the patch diseases are most rampant in late fall or early spring. We must recognize that the soil temperatures are cold even though the canopy and turf temperatures may be much warmer. When soil temperatures are below 65 F (18C) the plant is not growing at its optimum and when canopy temperatures warm up, the pathogen can easily outgrow the grass. These soil temperatures are recognized in the late spring and early fall. When combined with spring or fall rains, the pathogen will outgrow the grass. Where high humidity and temperature are persistent such as in the tropical climates (the Philippines as one example), it becomes much more important to recognize the application of free nitrogen (soluble) not only feeds the turf, but also feeds the pathogen and it’s like putting gasoline on the fire.

I mentioned quantity as being part of the problem, the form in which Nitrogen is delivered is equally important. I recommend the use of slow release type (organic, sulfur coated or polyon type carriers) which does not provide the free nitrogen element into the turf canopy. The slow release fertilizers allow for the fertilizer to be migrated deeper into the turf canopy and soil surface before release and well below where the pathogen thrives. Further combine the use of less fertilizer in buy cialis online a slow release format with a good cultural program that will open the turf canopy (specifically grooming, vs verticutting). The open canopy will dry more quickly following rain. A micro environment with a drier canopy, little or no free nitrogen will reduce the incidence and severity of disease.

One of the best programs that I support and recommend is the use of turf groomers (set 10 – 30% below Height of Cut HOC) continuously with mowing. The groomer results in less thatch, more vertical growth and a much drier canopy reducing the pathogens’ ability to dominate and cause disease. It is possible to find nearly any pathogenic organism in a turf canopy at any time. It is when the environmental conditions favor the pathogen over other organisms (including the plant) that disease outbreaks become an issue.

Zoysiagrass can really be considered the native grass of the warm season world as it is indigenous to nearly every climatic condition in the tropical to sub-temperate growth zones.

We continually respond to questions from these many different environmental conditions and stress the concept of understanding the basics. Zoysiagrasses require less N than most other warm season grasses! The pharmacy canada pathogenic organisms which plague zoysiagrass are ever present and we must understand how our cultural practices impact these living organisms as well. There is an optimum environment for growing grass, and there is an optimum environment for diseases to dominate. The cultural program must be managed around these limitations. When we discuss good cultural programs for the zoysiagrasses it is important that we continue to emphasize that other organisms can impact the outcome as well. Yes we can use various

chemistries – for Patch such as Heritage, Prostar and others — but those chemicals

also impact the native microorganism population and can put

us into a Catch 22 approach to turfgrass management. Let’s help the guys understand that properly managed, zoysiagrass is one of the easiest to deal with by minimal inputs.

Bottom Line: Control soil moisture through having good internal (venting soils to maximize soil porosity) and surface drainage; control canopy moisture by properly grooming the turf and encouraging vertical growth so excessive moisture can escape; apply nutrients as needed by the plant and in a form that will provide optimum delivery to the root zone where the active growing turf can take it up, not on the leaf surface or upper canopy where pathogenic organisms optimize development.