InteractiveTurf Newsletter newsletter@interactiveturf.com May 2, 2003 Spring Progress Weather update: Following our drought "pest alert", welcome rains fell across most of the state, and most northern Illinois sites have received 2.5 to 3 inches of precipitation since the evening of April 29. Because of these totals, many stations will report near to above normal precipitation for the month of April, but we are still running on a moderate to severe yearly rainfall deficit in northern Illinois (5+ inches below normal). Average daily soil temperatures are hovering in the low to mid 50 F range away from the lake, (the mid 40s around the lake) in northern IL, although the recent rain and some warmer conditions have released some turf fertility. The turf on most courses has greened up nicely, and flowering trees and shrubs are adding to the beauty of spring. However, some varieties of Kentucky bluegrass and clones of bentgrass are coming along more slowly, and remain off color after the last hard frost. These grass types will need warmer air and soil temperatures before the color and growth rates improve. Spring fertilization reminder: While soil temperatures remain cool, very little nutrients applied as fertilizer become available. Many N sources need some heat to solubilize while others require microbial activity to release the nitrate form. Microbes are not very active at cool soil temps. A common mistake in spring is to add extra slow release N fertility to bentgrass turf to try to improve the color and growth, but nothing much will happen until soil temps warm. Then all that stored N releases at once and the growth rate of the grass becomes excessive, turf can get puffy and scalpy, etc… (see ITF Turf Tip on N sources and uses). Diseases: We have received reports of anthracnose activity, on both creeping bents (in central IL) and on Poa annua (in northern IL). Also don't forget that rain and cool, cloudy weather may increase the likelihood of Microdochium (Fusarium) patch, especially on shaded Poa annua. All in all though, due to the prolonged cool and dry weather, spring disease activity has been slow to develop (but that’s okay!). We have had reports of some cool weather Rhizoctonia or other cool temp patch and ring fungi, and we have seen some active early season fairy rings. These fairy rings have all been the relatively innocuous “Type 2” darker green rings. Again, once soil and air temperatures increase (and we get some rain), fertility releases, and the turf color and growth rates improve, cool temp brown patch and "Type 2" fairy rings will be less visible and worrisome. Weeds: Since many of us consider Poa annua to be a weed and the flowers to be objectionable, we will discuss Poa control and seedhead suppression issues here. Some Poa annua biotypes have finally begun to seed in the northern part of the state. Our test plot 'checks' have only about 1-5% of Poa shoots with seedheads (as of May 2). We treated test plots with Poa seedhead suppression treatments beginning on April 11 (Trimmit only). Proxy + Primo tank mixes for seedhead suppression were applied on April 18 (on green height turf) and on April 22 (tee/fairway height turf). See our publication of recent data on the IT website or on the USGA Turfgrass and Environmental Research Online journal for a summary of past data and application rates we have tested. With the recent warm up in air and soil temperatures, early spring broadleaf weeds and some grasses have made an appearance. Dandelions are becoming pervasive in the northern part of the state - obviously our difficult winter had no effect on their survival. We have also noticed some types of clover growing and wild mustards germinating. Remember it is much more effective to spray broadleaf herbicides on warm sunny days with warmer soil temperatures, so the herbicides will be absorbed and translocated more effectively through the target weed's root systems (click here to see additional post emergent control tips). Also having trouble with identifying some of those broadleaf weeds (I know I am)? View some photos and descriptions from this article in the latest UIUC Pest Management Newsletter. Insects: We are hearing reports from central and southern Illinois (Urbana & Bloomington) that the first cutworm feeding activity of the season has occurred. This should come as no surprise since first captures of the moth have been reported now in almost all areas of the state, including Dekalb, Grundy, Lee, Ogle, Piatt, Stephenson, Whiteside, Will, and Winnebago counties. Intense captures (7-8 moths/day) have been reported in several counties as well. There is a prediction model used for cutworm feeding activity on corn based on these intense captures which I reported in the past newsletter. The model predicted cutworm activity in mid-May based on the flights. With the recent reports as early evidence, I no longer feel this model will be applicable to our turf systems, and just the monitoring of adult moth captures will be a better scouting tool. To learn more about the recent cutworm captures please go to the article on the UIUC Pest Management Newsletter. Also sign up to get the newsletter in your email, it's free. Black Turfgrass Ataenius beetles (BTA) have also been reported on some golf courses in northern and central IL. It is possible that they might be beginning to emerge now, but this is a bit early for BTAs to be officially swarming, as is the case when the Vanhoutte spirea is blooming, which should be a week or two away yet. Some of this reported beetle activity may be corn flea beetles which have been reported in high numbers in corn fields this season. This corn flea beetle is smaller, but similar in appearance to BTA, feeds on Kentucky bluegrass, and has been numerous enough in the past near agricultural areas to drive golfers off of the course. The BTA beetle is much bigger and will not be nearly as mobile as the corn flea beetle. Below are pictures of the beetles side by side for comparison. Black Turfgrass Ataenius Beetle Corn Flea Beetle Other insect pests that we should be on the look out for aren't between our toes but in the trees. I know some of us would rather some of our trees would go down in the favor of better growing conditions for our turf, but I would bet there is a tree or two that has a place in your heart somewhere on the course. The three major pests I have heard of recently are the gypsy moth, Asian long-horned beetle, and Emerald Ash borer (at the last MAGCS meeting). Reported from a recent article in the Chicago Tribune (Metro West section - Sunday, April 13 edition), the Illinois Department of Agriculture will be targeting gypsy moths by spraying 3,900 acres with Bacillus thuringiensis kurstaki (BTK) and 26,300 acres with pheromone flakes in DuPage, Kane, Cook, McHenry, and Will counties. Helicopters will be used in this eradicative effort, with applications of BTK to be made in conjunction with caterpillar feeding in late May, and pheromone applications made in conjunction with mating in late June. From what I have just recently read and heard though, the Emerald Ash Borer (EAB) seems to be a serious threat, with a potential epidemic that could rival the devastation caused by Dutch Elm Disease. The EAB has been found in southeastern Michigan, (prompting a quarantine on Ash from the Detroit area), and one location in northwest Ohio . Stay tuned for future articles. I am just learning about these pests so here are a few websites. Gypsy Moth : (provided by Donna Danielson from the Morton Arboretum) General Information: http://www.fs.fed.us/ne/morgantown/4557/gmoth/ Slow the Spread program: http://www.ento.vt.edu/STS/ Maps where they will spray in 2003 in Illinois: http://www.agr.state.il.us/Environment/Pest/maps.html Good publication with great photos: http://na.fs.fed.us/spfo/pubs/fidls/gypsymoth/gypsy.htm Asian Longhorned Beetle : http://www.na.fs.fed.us/spfo/alb/index.htm Emerald Ash Borer: http://www.na.fs.fed.us/spfo/eab/ http://www.msue.msu.edu/reg_se/roberts/ash/#something +++++++++++++++++++++++ Thanks for your support of this, as well as all of our research programs, Randy Kane CDGA Director of Turfgrass Programs Midwest Golf House 11855 Archer Ave Lemont, IL 60439 630-257-8126 Lee Miller CDGA Manager of Turfgrass Research Midwest Golf House 11855 Archer Ave Lemont, IL 60439 630-257-2005 x.111