Liquid “Overseed” January 10, 2011 By Todd Lowe

Spray program with Foursome pigment (L), and without Foursome pigment (R).

Several frosts have occurred since the previous regional update, and temperatures have dropped into the upper 20’s at night on a few occasions.  These temperatures have caused warm season turf to stop growing and go off-color, especially on golf courses with increased golf cart traffic.  Several winter management strategies were discussed in the previous regional update and can be reviewed by clicking on the link below.  

I recently visited Vanderbilt Country Club in Naples, Florida where they have the fertility spray program down to a science.  Golf Course Superintendent Stuart Bothe has been gracious enough to share a few valuable tips on the success of this program.

From a distance, it almost appears as if the fairways are overseeded with a cool-season turfgrass, but a closer inspection reveals a healthy base bermudagrass that exhibits excellent overall quality.  A hard frost occurred on the morning prior to my visit, and a light frost occurred on the day of my visit. This made the fairways stand out even more prominently, as the roughs were yellow to brown.  Mr. Bothe has conducted a fairway spray program for several years now, and supplemental fertility with mower striping has yielded excellent results.  An additional element was added this winter to make the fairways even more striking, and it included a pigmented colorant.

Unlike tracker dyes, pigments like PAR and Foursome are longer-lasting and do not appear artificial.  In fact, many golf courses have been spraying them on putting greens this winter with excellent results.  The pigment coats the leaf tissue and changes turf color from light yellow to darker green, and this provides a healthier appearance and actually increases canopy temperature.  Mr. Bothe recorded a 5° F increase in sprayed areas versus non-sprayed areas with an infrared thermometer.  While this may seem slight, every little bit helps!

Fairways are sprayed in early October when the bermudagrass is actively growing, and fairways remain green throughout the entire winter play season.  When fairways are mowed, the same patterns are used so that mower striping is prominent.  Fairways are sprayed every 14-days with a combination of products that include the primary plant nutrients -- nitrogen and potassium -- a blend of micronutrients with particular emphasis on iron and manganese, wetting agents, and the colorant.  Colorant dosage varies between 4 to 10 oz/acre, depending on turf growth and temperature.  Mr. Bothe remarked that it is important to have a good sprayer and fertilizers that solubilize well, especially when using the colorant.  Any imperfection or clogged nozzle can cause streaking that lasts for several days.

Source:  Todd Lowe, or 941-828-2625