PACE Turf - Turfgrass Information Center

2019 GIS Kikuuyugrass

Wendy and Larry both participated in the Kikuyugrass A-Z session at the Golf Industry Show (GIS) this year. In addition, Pat Gross from the USGA, Fernando Varela from Guadalajara Country Club, Pat Gradoville from Palos Verdes Golf Club, and Dr. Marta Pudzianowska from UC Riverside provided some great information. The presentations are available at the links below:

Growth potential for C3 and C4 grasses

The animated GIFs for cool season grasses (C3_GP) and warm season grasses (C4_GP) were created by plotting Growth Potential (GP)  based upon 30 year normal average monthly temperature (data from National Oceanic and Atmospheric Administration 1950-1980 - tempertures are likely a little higher now, but the trends will be similar) for each zipcode by latitude and longitude. There are about 40,000 data points plotted per month. The GP model has been modified a couple of times over the years, most recently to maximize C4 growth potential when average temperature exceeds the estimated optimum temperature for C4 grasses (88 F or 31.1 C). Refer to this graph for an illustration of the GP model functions.

Climate Appraisal Form

The Climate Appraisal Form is a powerful tool that can serve as the foundation for all of your annual turf management planning activities. It is available in US units (degrees F, pounds, inches) and in metric units (degrees C, grams, meters square) for both cool season and warm season grasses.

  • Cool season C3 grass Climate Appraisal spreadsheet (bentgrass, poa, ryegrass, fescue, etc.)
  • Warm season C4 grass Climate Appraisal spreadsheet (bermudagrass, zoysiagrass, paspalum, etc.)

Based on climate data from the weather station that is closest to your site, it will give you an overview of the month–to–month weather, turf growth and nutrient demand conditions at your location. Our newest version of the form now also incorporates the principles of the Minimum Levels for Sustainable Nutrition (MLSN) Guidelines. This new approach to nutrient management is helping more and more turf managers to reduce fertilizer inputs and costs, while still maintaining deseribed turf quality and playability.

What is the Climate Appraisal Form used for?

  • Predicting turf growth, performance, stress, nutrient demand
  • Planning management strategies to optimize turf growth
  • Completing your site-specific management plan

Instructions: You will need to have Excel installed on your computer or you will have to download the Excel Climate Appraisal Form and then upload this Excel file into Google Sheets in order to generate a Climate Appraisal Form.

  1. Visit a climate information web site such as
  2. Locate the average monthly air temperatures and average monthly precipitation for your location. Print this information out. Make sure that the information you print out is for average monthly temps, and NOT average high and low temperatures.
  3. Open the Climate Appraisal Data Entry Form on the PACE Turf web site. It is available as either a Climate Appraisal Data Entry form in Metric Format (degrees C, grams and meters) or as a Climate Appraisal Data Entry Form in US Format (degrees F, pounds, inches).
  4. Once the data entry form is open, type in your location (facility name, city and state) and then type the following information onto your spreadsheet, using the monthly data that you printed out in step 2:
    • the average air temperature for each month
    • the average precipitation information (in either inches or centimeters, depending on the format you selected) for each month
    • the maximum rate of nitrogen that you wish to use each month on your cool season turf (the number should not exceed 1.0 lbs/1000 per month [or 4.9 grams/sq meter per month] per month)
    • the maximum rate of nitrogen that you wish to use each month on your warm season turf (the number should not exceed 1.0 lbs/1000 per month [or 4.9 grams/sq meter per month] per month)
  5. A Climate Appraisal that is specific to your location will be generated. Print out this form. You should also save it onto your computer for future reference

Reading your Climate Appraisal Form: The form that you have just generated now includes the following information about weather and turf growth at your location:

  • Normal average temperature: the average monthly air temperature at your site, based on the past 30 years of air temperature data
  • Normal precipitation: the average monthly precipitation (rain and snow) based on the past 30 years
  • Turf growth potential: The growth potential for cool season turf (Cool GP) and warm season turf (Warm GP) at your location has been calculated. Explained in greater detail in the this PACE Turf Update, turf growth potentials are estimates of the growth of cool and warm season turf based on expected monthly air temperatures. GP values range from 0 to 100 percent, and the higher the value, the greater the turf growth. When air temperatures are either too high or too low for optimal growth of turf, the growth potential values will decrease.
  • Periods of turf stress: As growth potential values fall below 50 percent, the turf is increasingly under stress. Many people find it convenient to use a yellow highlighter to note stress periods on the Climate Appraisal Form. Knowing when high stress periods are likely to occur can help you to schedule agressive activities, such as aerification, topdressing or even tournaments, so that they can (hopefully) occur when turf is less likely to be stressed.
  • Monthly nutrient demand forecast: Use these values to estimate turf nutrient demand for each month. For each month, the Climate Appraisal form calculates the maximum amount of each key nutrient that will be used by both cool season and warm season turf that month. These values are shown in lbs/1000 sq ft or grams/sq meter, depending on which form you use. You should not exceed the maximum monthly values shown, unless you are in an area of heavy rainfall (greater than 5 inches or 12.7 cm per year). Remember that nitrogen rules the roost when it comes to nutrient demand — if you increase nitrogen fertilization, the turf will need a commensurate increase in all other nutrients. Similarly, if you decrease nitrogen applications, the demand for all other nutrients will decrease in the same way.
  • MLSN overview: Use the column at the right, labeled "Plus MLSN ppm", in conjunction with your most current soil test results to assess the condition of your soil. We suggest that you do this at least once or twice a year.
    • The "Soil ppm" column is the amount of each element predicted to be used by the turf for the year. Thus, this is the amount of each nutrient that will be lost from the soil if clippings are removed. With clippings returned, even lower levels of fertilizers will be needed.
    • The "Plus MLSN ppm" takes the value from the "Soil ppm" column, and adds the amount of each nutrient identified in the MLSN Guidelines. The values that are obtained gives the the amount of each nutrient (in parts per million, or ppm) that you need to have in the soil, in order to stay above the MLSN minimum guideline to provide sufficient nutrient supply for the entire year.
    • Refer to the "Deficit" tab to determine if and how much of each fertilizer component will be needed to supply plant needs for the entire year. To address any deficits, apply the nutrient in question using common sense and guidelines on fertilizer labels. Be careful not to apply a higher rate than is identified on the product label.

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