Many areas of the Southeast saw consistently cold weather this winter, some areas colder than normal, with an overabundance of rainfall. This has left some greens, as well as fairways and roughs, weaker than normal. Cart and foot traffic coupled with suboptimal weather can amplify stress symptoms and leave courses looking rougher than usual heading into spring.
As temperatures start moving up, bermudagrass and zoysiagrass are coming out of dormancy or increasing their growth rate. Diseases such as large patch or zoysia patch can decrease the vigor with which grasses greenup. There are inexpensive fungicides like tebuconazole that can help hasten recovery as a spot treatment on fairways or tees when rings become apparent. Be careful before using this product on putting greens as a curative – in addition to other members of the DMI or SBI chemical classes – due to potential for reducing greenup from PGR side effects, even if diseases other than large patch are identified.
Keep an eye out for Pythium root rot. When there are very high moisture levels, delivering a root-active fungicide into the rootzone with water can be very difficult. Needle-tine aeration, or venting, in conjunction with applying potassium phosphite products is an economical way to achieve some Pythium control while also delivering much-needed potassium. Venting helps improve oxygen delivery to the roots while also reducing moisture levels. Be on the lookout for black algae or cyanobacteria. This organism is especially quick to develop in thin, weak areas. Its establishment can further weaken an already tenuous spring transition for bermudagrass or creeping bentgrass greens.
The cold weather has been beneficial for weed control where freezes occurred. However, as moist soils warm up there can be a heavier than normal flush of weeds. Pay attention to any outbreaks following your preemergence herbicide applications. Some herbicides are more mobile than others, and when they move laterally high areas or areas with a slope can lose protection earlier – leading to outbreaks of crabgrass, goosegrass and other weeds.
Cold, wet winters can also be conducive to outbreaks of insects like mole crickets and various grubs as soils warm up. Depending on past history, and mapping if performed, identified hot spots should be monitored for early activity whether or not an insecticide application was made. When these insects get larger in size, they can become more mobile and more difficult to control.
Although a cold and wet winter causes its problems, I would anticipate a pretty good bermudagrass or zoysiagrass spring transition this year. Warm-season turfgrass that “goes to bed” for a long winter’s nap benefits from having most of the previous year’s accumulated energy reserves conserved and ready for more-uniform spring growth flushes. Monitor your clippings, especially on greens. Low rates of foliar-active growth regulators are best thought of as a “tap of the brakes” in keeping growth steady – holding strong areas from overly lush, excessive growth without undue suppression of greenup in weak areas. Start low on rates and frequency of applications and work your way up in conjunction with foliar nutrients. Adjust your rates according to clipping yield and turf appearance.
Golf in the Southeast saw increased interest and rounds last year. With continued diligence, 2021 could be an excellent year – hopefully better in many respects than 2020.
Southeast Region Agronomists:
Chris Hartwiger, director, USGA Course Consulting Service – chartwiger@usga.org
Steve Kammerer, Ph.D., senior consulting agronomist – skammerer@usga.org