1996jul36
- 1. pring 1996 broughtwith it sur- A variety of things cause winter Desiccation hit the S prises for many golf courses in the Midwest. After years of relatively mild winters and successful spring damage. Cold-temperature diseases, frost heaving, ice cover, direct low-tem- perature damage and desiccation are transitions, the past winter left many all potential turf killers in this region. nation's midsection hard courses with some severe damage. So, what was the problem this spring? From Iowa west into Nebraska, north into the Dakotas, south into Kansas Looking for a culprit this spring. A noted and even down into Texas,superinten- Iowa golf course superintendents dents reported some of the most severe gathered April 30 in Des Moines to dis- researcher in the area winter damage in years. cuss the cause of the winter damage, Even the bentgrass on my research and I had a chance to visit a number of area near Iowa State University in the courses. From what I've seen and heard assesses the damage. central part of the state suffered signif- around the region, winter diseases icant damage. In western Iowa, we played a minor role in most areas. have to go back to the early 1980s to Snow mold was present in localized find comparable conditions. Superin- areas, but in amounts no greater than tendents in Nebraska characterize this usual. I saw signs of frost heaving on Nick Christians, Ph.D. spring as the worst in 40 years. some greens, but this is rarely a source of significant damage. Ice cover occa- sionally causes spring damage and has played a role in the loss of Poa annua in localized regions the past few years. There may have been some localized ice cover problems this year, but it clearly didn't playa role in most of the widespread damage. Direct low-temperature damage this spring varied by region. In central Iowa, there was practically none. I anticipated that we would lose some perennial ryegrass and probably some tall fescue because of the extremely low temperatures in the Midwest this winter. Evidently, snow cover was suf- ficient to protect the turfgrass from this type of damage. I saw little dam- age on golf courses that was attributable to low temperatures. On my research area, I have 96 perennial Creeping bentgrass fairways in central Iowa in late April. The Kentucky bluegrass/perennial ryegrass rough ryegrass cultivars and 64 tall fescues. shows no damage, but the bentgrass fairways are severely desiccated. Bentgrass normally would have com- If direct low-temperature damage had pletely recovered from winter dormancy by this time. been a problem this year I would have 36 Golf Course Management / July 1996
- 2. seen it onthe more sensitive cultivars. But all these cultivars recovered from the winter satisfactorily. Another story entirely Western lowa~ parts of Nebraska and the Dakotas are another matter. Reports of significant loss of perennial rye are common. My guess is that the snow cover in this region melted ear- lier, and significant temperature drops in late winter caused the damage. No damage occurred in areas where the snow cover persisted longer. In areas where perennial ryegrass kill was the problem, reseeding has been the solu- The creeping bentgrass survived the winter without damage on this uncovered Iowa green, but the tion. It's turning out to be a good year apron died. The apron was a combination of bentgrass and annual bluegrass. for seed dealers in the region. The primary problem this spring was desiccation. I would not have pre- might yield clues to why it occurred on the reason for this phenomenon. dicted this type of damage given the and what to do about it in the future. I Mike Daley of Ciba offered this expla- conditions this winter. It was an normally would suspect fertility to nation: The high-stress conditions of extremely cold winter with significant play some role. However, I had a last summer and fall required heavier- snow cover. We would normally number of different fertility trials than-normal irrigation on the sandy expect to see desiccation in mild, dry established on my research area, and media of the green. This resulted in winters, and the moisture the area I've seen absolutely no differences overwatering of grass on the area sur- received should have been sufficient to between treatments~ I also conducted rounding the green, which in turn prevent this type of damage. There some injection treatments with vari- resulted in a reduction of rooting. This must have been just the right combi- ous fertilizers on a golf course and grass went into the winter weakened nation of conditions in February and haven't seen any differences to date, and was more susceptible to the dam- March to result in surface drying, even either in initial damage or in recovery age that occurred this spring. though the underlying soil was still on these plots. We may never really know the moist. Courses and areas of courses I did note one interesting pattern exact cause, but that is a reasonable exposed to northwest winds received that superintendents at the state explanation. the greatest damage. Windswept areas meeting also mentioned. Damage were damaged, and protected areas appeared to be worse on longer- Recent establishments recovered normally. mowed creeping bentgrass than on also damaged February and March temperatures shorter-mowed areas. This wasn't uni- Meeting attendees also pointed out varied somewhat over the region versally true, but it was clearly the that damage appeared to be worse on where the damage occurred. Even case in some areas. more recently established bentgrass though the early winter and midwin- On my research area north of courses. While there are some older ter were fairly moist, these two Ames, the fairway-height bentgrass courses showing damage, the newer months were very dry. Temperatures sustained more damage than the same layouts clearly have been hit hardest. were extremely cold in early February cultivars maintained at green height. It's common for creeping bentgrass to and again in early March. The cold Areas where the apron was mowed at become "puffy" in the first couple of conditions in February came after 1/2 inch were dead, but the same vari- seasons, meaning that a mass of mild conditions in late January, result- ety of creeping bentgrass on the green stolons form on the surface. This isn't ing in some snow melt and standing was fine. I found this most surprising. I a true thatch layer, but rather a zone water. It's likely ryegrass was injured would expect damage to the closer- comprised primarily of living stolons. during this period. Some of the bent- mowed turf on the sandy soil media of Much of the root system can remain grass desiccation likely occurred Feb. the green and no damage to the in this layer, and it's sometimes possi- 10-11. Northwest winds during this longer-mowed turf on the heavier soil ble to peel the grass off of the soil period gusted up to 41 mph. March 25 of the apron. because of poor rooting. This condi- was also very windy, with northwest Annual bluegrass in the apron may tion goes away as the area matures. winds gusting up to 45 mph. have caused some of these patterns. This puffy bentgrass was particularly But there were areas where both the subject to damage this spring. Looking for patterns apron and the green were the same Other superintendents reported Since the damage first appeared, variety of creeping bentgrass. People at their worst damage on areas aerified I've been looking for patterns that the superintendents meeting speculated Continued Golf Course Management / July 1996 37
- 3. WINTERKILL fromp.37 What should I do? Most of the bentgrass I saw was late last fall. Aerification holes in these not killed completely. It looked bad, areas didn't have a chance to fill in but the buds on the stolons were before winter and became desiccated alive. The turf will recover with time. easil y this spring. On one course, I If you have this problem, keep the saw that aerification tines had pulled area moist (not saturated) and give it the root system away from the soil as a moderate amount of fertilizer. I the tines emerged. This resulted in a would recommend between 1/2 to 1 washboard pattern of green and desic- pound N/l,OOO square feet in the first cated turf. Areas where fall application, followed by a similar A creeping bentgrass fairway on a northwest- aerification holes were still open in application 30 days later. facing slope. The protected areas of this course recovered normally. April had the most spring damage. The temptation will be to push the grass too hard with N during Why me? the recovery stage. If bentgrass 'I'm planning some research on our Superintendents dealing with prob- is overfertilized in the spring, it damaged areas at the ISU facility. We lems this year generally have a series can become puffy and will be more will look at the effects of increasing of questions about the damage. The susceptible to summer problems, levels of N on recovery. We also will first one is obvious: Why me? such as Pythium blight. The best do some seeding studies to investigate As mentioned earlier, turf species recommendation I can give superin- the proper seeding rates to bring back and wind exposure appear to have tendents and golfers is to be patient. severely damaged areas. had the greatest impact. In the case of The turf on your course will take one damaged course I viewed, there is some time to recover, but it should Preventing future damage a bluegrass/ryegrass course across the recover fully. Winter covers, heavy topdressing road in beautiful shape. Within 15 In some cases, seeding is neces- and winter watering could help pre- miles are two older courses with bent- sary. This is a judgment call you will vent this type of damage. But these grass fairways that were more have to make on site. I've noticed that methods are expensive, and the protected from the wind. These desiccated bentgrass where the buds problem is rare enough that you'll courses saw only minor damage on are still alive 'takes on a straw-like want to consider carefully whether highly exposed areas. You can imagine brown (almost tan) color. Dead bent- it's worth the added expense in your the questions members ask when this grass is more of a white color. If climatic region. This year, of course, sort of thing happens. Fortunately, recovery is taking place from the it would have been worth it. But in word is spreading among golfers that buds, you're better off leaving it alone most years it may not, at least on all this problem affected a lot of courses and waiting for recovery. If it's dead, areas of the course. this spring. of course, you'll have to seed. Greens covers are becoming popu- lar and you may want to consider them if your greens were damaged this year. Turning the water on as early as possible in the spring also will help. But this may result in freeze damage to pumps and other equip- ment, so do it with great care. Try to complete fall aerification early enough that aerification holes fill in before winter. Holes still open at the beginning of winter probably will be all right if there is sufficient mois- ture through the winter. If the late winter is mild and windy, water these areas if you can. The best advice I can give is just to accept that there are occasionally The fairways and tees on this Sioux City, S.D., course are a combination of Penncross and Penneagle going to be problems beyond your con- trol. You have just got to do your best ,to repair the damage and go on. * creeping bentgrass, and the roughs are bluegrass and perennial ryegrass. This photo was taken in early May, several weeks after the bentgrass should have recovered. Nick Christians is a professor of horticulture at Iowa State University. 38 Golf Course Management / July 1996