Written June 2002

During this trying time of drought, many Turf Managers are facing a reduction in the amount of water available for irrigation and/or the politics of this drought is forcing many to shorten their water window. There are some turf practices that could assist in the management of turf under reduced irrigation practices.

Golf Enviro Systems has assembled this packet of information to assist you in preparing both yourself and the plants you manage for this reduction in water usage. The heat of the summer is upon us and with more water restrictions sure to come, now is the time to reevaluate your fertilization and water use program.

Don’t Neglect Basic Fertility:

Extended periods of drought and high temperature lead to poor vigor and shallow rooting. A decrease in external water potential results in a reduction of cellular growth and thus root and shoot growth. Drought stress, among other negative effects, inhibits protein synthesis and enzyme activity, inhibits chlorophyll formation, increases transpiration, and decreases photosynthetic capacity of turfgrass and other plants.

During periods of heat stress, mechanisms of food production may slow as respiration and the use of food reserves increases for survival. This, over time, can lead to a weakened plant that is more susceptible to the many stresses it is exposed to during the hot summer months. If conditions persist, death of the grass plant may well result and while many may blame the hot and dry conditions, it is more likely that the plant literally starved from the lack of available nutrients. Contrary to reports in the media, it is critical to feed turf during periods of heat stress. Bentgrass in Dallas during the summer declined rapidly under no nitrogen conditions, where as, light frequent fertilizations (.25#N/m every 2 weeks) proved to be the key to plant survival.

During heat/drought stress periods, choose fertilizer formulas that contain a higher percentage of potash and iron (1-0-2 ratios). Potash and iron are important for hardening off plants. Also, choose formulas that contain higher percentages of slow-release nitrogen.

Nature Safe offers a low salt index source of plant nutrition especially helpful during periods of heat. Nature Safe products contain natural chelated secondary elements to provide a complete and value-added nutrient package or optimizing IPM program effectiveness. Nature Safe is a 90% slow-release organic fertilizer which promotes good residual color and density with slow even growth.

Perk Stress Relief Formula (4-0-10 w/ 10% Fe & 2% Mg) is able to provide the essential turfgrass nutrients potash, iron, and magnesium with a low nitrogen level so good plant nutrition is achieved without excessive growth.

Nutri-Rational Foliar Fertilizers: Classified as a “true foliar,” Nutri-Rational products enter the leaf not only through stomates, but also through transcuticular pores in the leaf. These pores, on the surface of the leaf blade, are open all of the time versus stomates, which are closed more often than they are open. The idea behind a true “foliar” is to produce a product with a high efficiency of absorption by the plant that allows for lower total nutritional inputs.

Suggested Fertilizers with high Potassium percentages:

Andersons: Contec 13-2-26, Super K 0-0-45, TT 10-5-25, Premier 19-3-24

Lange: Greens 18-2-24, Fairway 11-3-22, Fairway 16-0-33

Nature Safe: Fine 7-1-14

Nutri-Rational: Foliar K 2-0-16 plus micros

ROOTS: Standup 0-2-12 w/ Silica

Every Turf Manager understands what stress is to a grass plant. However, stress is cumulative. A grass plant rarely dies from just one stress factor. Stress conditioning is basically implementing practices that harden off the plant allowing for the increased potential for survival during the time of year a plant is in direct contact with the highest number of stress factors.

Biostimulants on turfgrass have been proven to reduce drought stress. In a study by Dr. Richard Schmidt at Virginia Polytechnic Institute and State University entitled “Influences of Soil Moisture, A Plant Biostimlulant and Chelated Iron on Kentucky Bluegrass Performance”, the results of this study were that “the biostimulant (ironRoots 2) either alone or in conjunction with chelated Fe lowered water stress of bluegrass seedlings under limited soil moisture. With applications of growth stimulants plus chelated Fe to Kentucky bluegrass we obtained even larger and deeper root systems in dry soil. Plants with larger and deeper roots are naturally capable of absorbing water that is stored in the deeper soil zones during periods of moisture stress.” Bengton at al (1979) concluded that a leaf water deficit results in the suppression of cytokinin synthesis. The present study provides evidence that biostimulants used either alone or in conjunction with chelated Fe lowered water stress of bluegrass seedlings under limited soil moisture regimes.

Plants naturally increase their concentration of free L-amino acids during periods of water stress. It has been suggested that plants may use proline and other amino acids as sources for carbon and nitrogen or to adjust themselves osmotically when they are under drought stress. Plants under stressful conditions such as drought and high temperatures are unable to perform their normal physiological functions to synthesize their L-amino acids. Therefore, supplemental applications of these L-amino acids increase chlorophyll formation, improve photosynthesis, improve leaf water potential, and reduce the total energy requirements of plants.

A study conducted by Dr. T. Watschke at Penn State University in 1996 showed that turfgrass treated with Nutramax L-amino acid based products took longer to wilt as compared to the untreated turfgrass. By the same token, when the drought stress was relieved, the turfgrass treated with the L-amino acid biofertilizers recovered faster than the untreated turfgrass.

“In 1999 we suffered from the worse drought in recorded Maryland history. We incorporated Macro-Sorb Foliar as well as the Quelant-Ca and Macro-Sorb Radicular into our IPM program full time. The Foliar, Radicular, and Quelant-Ca were utilized to help reduce the stress for the turfgrass that was suffering from the extended drought and the high temperatures. I also found that the use of the Quelant-Ca has reduced my wear patterns in the high traffic areas such as the walk off areas on the greens and tees.”

Charles Ulevich, Golf Course Supt., Hayfields Country Club, Hunt Valley, M.D.

Growth regulators continue to increase in popularity due to the advantages they provide especially during times of heat stress and water restrictions. The key issue with any growth regulator is to apply only to healthy turf. Applications to healthy turf make the turf stronger. Applications to weak turf only result in making the turf weaker. The regular use of growth regulators can lead to a 10-30% reduction in water usage by the plant.

Research at several universities including Cornell, Kansas State, Texas A&M, and the University of California-Riverside indicate that Syngenta’s Primo MAXX improves plant rooting which increases the plants ability to reach soil moisture at greater depths. Primo MAXX also produces a plant with smaller leaves containing less gibberellic acid, which in turn, will reduce the amount of water loss from transpiration due to less leaf surface.

Andersons Turf Enhancer 2SC and 14-0-28 + Turf Enhancer is an excellent way to increase turf density and at the same time improve the plants root mass. Turf Enhancer will reduce the growth rate of the grass plant and reduce its water consumption.

The use of wetting agents in turfgrass management has been commonplace for years. Wetting agents are used primarily to reduce the surface tension of water and increase the infiltration and percolation rate of water into a growing media. The use of wetting agents has been proven to increase the efficiency of irrigation water and can result in a 10-20% reduction in overall water usage.

Commonly found on golf courses, especially on sand putting greens is Localized Dry Spots (LDS). Symptoms of LDS begin as small irregular shaped areas of turfgrass that wilt. This is a result of hydrophobic soil conditions. Research has shown that the sand particles in the localized dry spots are covered with an organic coating, which renders them water repellent. Wetting agents are used to reduce this organic coating and/or they contain water-loving molecules that attach to soil particles allowing the soil to readily re-wet.

There are a myriad of wetting agent products available in the marketplace. Rising above the pack is Cascade Plus. The advantages of Cascade Plus include the length of residual with 2 applications at a 30-day interval resulting in season long control of LDS. Applications of Cascade Plus at the recommended rates move water deeper and faster into the soil profile and for a longer period of time than other soil wetting agents. (Sports Turf Research Institute 1997)

An irrigation efficiency experiment was initiated January 13, 2000 in the University of Georgia Agricultural Greenhouses. Under the conditions of this study, it appears that Cascade Plus can increase irrigation efficiency. The data indicates that dry (VWC-1.4%), untreated water repellent soils required more than 2X as much irrigation to reach a comparable VWC as Cascade Plus-treated water-repellent soils.

On a replicated trial at Ganton Golf Course in North Yorkshire, the properties of four wetting agents were compared. Applied at varying rates and intervals over a seven-month period, assessments were made to determine their effect on plot color and turf cover. Droplet tests suggested Cascade to be the most effective wetting agent tested, particularly when applied at a single high rate at the beginning of the trial.

Cultural Practices: 

Aeration, spiking, vertical mowing, deep irrigation cycles, and selective hand watering are cultural practices that can all help turf endure periods of heat and drought stress. Even slight adjustments in mowing height have an effect on rooting and the storage of carbohydrates, even more so than mowing frequency. (Beard) A turfgrass plant has the innate ability to balance roots and shoots. The old adage of raising mowing heights during heat stress periods to reduce overall plant stress is a misconception. Raising a mowing height once heat stress occurs will actually increase the stress on a plant. Increasing the shoot length by raising the mowing height leaves the plant struggling to support this added leaf tissue at a time when the plant is unable to balance itself.

Research reports show that bluegrass in Colorado requires an average of 2-2.5” of moisture per week. By using a program implementing the techniques and products described above, a significant reduction in water usage can be achieved.

Contact your Golf Enviro Representative to assist you in developing a drought survival plan that is effective, proactive, and fits within your budget. For information or additional literature on any of these products, contact GES at 1-800-225-1311.

Copyright © 2002-2008 Golf Enviro • All Rights Reserved