Even though we don't get enough rain in the desert, it's important to know that there are two different kinds of rain when it comes to greens management. They are quite different from each other and serve specific and unique purposes.
It's very tenuous and hard work to maintain bentgrass greens in the Arizona summer. Traffic, decreasing root depths, hot spots, thatching tendency (of some heat tolerant bentgrasses) and thinning turf. Summer stress means specialized watering practices. Daytime irrigation can be of tremendous value when performed properly.
Rain 1: Syringing
Syringing is actually a misting of the greens. Misting is accomplished by providing small droplets of water over the turf canopy. When the water evaporates from the leaf, it decreases the temperature of the leaf. Since evaporation is a cooling process, the leaf temperature is quickly lowered. In addition, the gradient for water movement from the leaves to the air is minimized. Both of these results relieve plant stress.
What does the turf look like and how do I syringe my greens?
The turf can look Jim-dandy. In fact syringing prevents visual stress from dry, hot and windy weather conditions. Syringing does not cure dry soil conditions, nor is it intended too!
Syringing is achieved by applying the thinnest mist of water above the turf which then falls to the canopy of the green. True syringing is not achieved by irrigating for 2-3 minutes or less with the regular heads. Rather, it is achieved by using an adjustable hose nozzle from the quick coupler which can provide a true mist.
The operator should walk across the green with the hose tilted up 60E. Let it mist, just like a fine rain. The higher it goes in the air and the smaller the droplets, the better the syringe. You can quickly do a green in 2 minutes or less! Remember, syringing is not watering dry spots!
Syringing should be done at least once a day, especially when the air is hot and dry. Syringe in the early afternoon when the weather is hottest and driest. Don=t wait until 5:00 pm to syringe. You will receive minimal benefit and may induce a humid condition for disease.
Rain II: Hand Watering
Hand watering is the practice of curing dry spots from becoming burnt leaves from soil drought. Soil drought is caused from either (1) under irrigation (rarely), (2) uneven irrigation (poor uniformity), and (3) localized dry spot (LDS). A combination of the latter two above makes for one of the hottest turf problems.
Hand watering is practiced to recharge the greens rootzone with available plant water! Hand watering is applied essentially to round spots in the green which turn off color and visibly wilt most often (dry spots).
Simply irrigate those areas with the quick coupler hose by spraying the water in a diffuse pattern over the turf. Let it soak in and move it to the next dry spot, or to the next green.
If you return to the green an hour later and it doesn=t look any better, try pushing a small pen knife into the green. If it sounds gritty when you push the blade in then chances are the green is still dry!
These same areas can require hand watering every day in the summer. Often a wetting agent will help, and so will driving some narrow holes in the green with a homemade peg board to provide aeration.
Use some eight penny finishing nails. Drive them on 3/8" centers through a 3/4" thick pine board (1 x 4). Install a handle and away you go!
Micro aerify when the soil is moist!
Remember, these are two types of rain! Use them to your advantage!
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.