InteractiveTurf Newsletter newsletter@interactiveturf.com July 9, 2003 More Fireworks After the Fourth of July Weather review: A warmer and more humid summertime weather pattern has settled over the upper Midwest since the first of July. A long stationary front stretching from Iowa to Ohio along I-80 has caused a series of hot and humid days interrupted by brief and sometimes violent thunderstorms with heavy rain and high winds. The winds, some in excess of 75 mph, toppled many large trees in northern IL, with Rockford being the most seriously hit, (the paper described it as a "war zone"). Rockford courses have reported 30 and 75 trees down respectively, with some damage to structures as well. In addition, the heavy, repeated rains falling in NE Illinois and north central Indiana along the front have also caused extensive flooding. Fortunately, the rains held off enough here at Cog Hill for completion of the Western Open, despite several lightning delays. The course was in great condition and absorbed the showers very well. Rainfall amounts vary greatly from an inch or less south of a line from Peoria to Bloomington to Urbana, to 4 or more inches in the northern third of the state (click here to see Midwest Regional Climate Center Precipitation Map). Here at Golf House, we have received over 3 inches of rain the last few days, (mostly due to a cell that dumped an inch on us in an hour Monday morning), with more in the forecast today. The forecast shows the stormy pattern breaking by Thursday and hopefully leaving some cooler air over us for a little while, until warmer (above 90) and more humid air comes in again early next week. Heavy rain, uncomfortable humidity, and high temperatures lead to concerns about developing disease problems (see below), but sometimes more important is turf loss that can occur where low or poorly drained areas become saturated then are cooked by the sun later that afternoon or the next day. This phenomenon is often referred to as “scalding.” Also, even if no significant damage is observed above ground, this type of weather pattern often leads to anaerobic soils, algae blooms, and other conditions that lead to root loss – part of the summer root decline syndrome that cool season grasses often go through. Diseases: This recent warm-up has kicked dollar spot fungi into gear – even if it isn’t high gear (yet!). We are finally seeing some disease on our dollar spot trials, which would typically be getting hammered by now. The heat and humidity of the last few days has also stimulated some Pythium blight and Rhizoctonia brown patch activity (click here to see a summary of IT weather data and pest predictions). We have heard 10 Pythium reports in the past two days from many sites in the northern half of the state. For the most part, this activity has not been severe, and has been limited to intermediate roughs and fairway edges. Epidemics would probably have been more serious if we didn't get these cooler nighttime temperatures the last day or two as the stationary front moves around, and thunderstorms cool the atmosphere (or is it the cooler atmosphere triggering the thunderstorms?). Needless to say, this is our first activity of the year, and you should be keeping a close eye on known Pythium and brown patch ‘hot spots’ for possible increases in activity. There has also been some increasing activity of anthracnose and Bipolaris leaf spot on creeping bentgrass. Both of these diseases have similar symptoms - primarily small, scattered patches of thinning, reddish-brown to darker brown colored turf. The leaf spot was first observed a few years ago on scattered clones of Penneagle on putting greens, but has been turning up more often on other varieties including Pennlinks, Penn A4 and L-93. Interestingly, the early symptoms of Bipolaris leaf spot look very similar to bacterial wilt or ‘C-15 decline’ on Toronto and other vegetative bentgrasses, and you may recall that the disease was originally misdiagnosed as ‘red leaf spot.’ Insects: A few Japanese beetle adults have been spotted around Golf House and points to the south and west. Our computer model for peak adult emergence (based on growing degree days) hasn’t sounded the alarm everywhere yet, but it should be getting close in most areas (degree day target = 1,049). If you have small, valuable trees/shrubs that JBs love to feed on (lindens, crabs, other ornamentals), a preventive insecticide treatment (e. with a pyrethroid such as Tempo, Deltaguard, etc, or Sevin) in the next few days could help reduce or eliminate damage to the tree. We now are pretty sure that once JB adults start feeding on a tree, the injured tree responds by sending out signals that attracts more beetles! So stop the feeding as early as possible (see July 2nd U of I Home Yard and Garden Newsletter). So far, this doesn’t seem to be a banner year for black cutworm damage. Also, we have seen no more of the mysterious beetle making holes in, and leaving small piles of sand on putting greens. Weeds: With the recent warm-up and precipitation, crabgrass and other annual grassy weeds will probably start to show up in untreated areas. Clover, oxalis, black medic and chickweed have all been problematic here on our new 3-hole course. Remember to be careful using herbicides in the heat of the summer – there is a much higher probability of injuring desirable turf (eg bentgrass) at higher temperatures than at cooler temps. Moss and algae reports continue unabated – recent heavy rains may spark some algal blooms even in fairly dense, healthy looking turf. Topical applications of mancozeb (eg Fore) or Daconil Zn (or other chlorothalonil products) can limit the spread of algae and help maintain healthy turf. We also have a recent report of another possible moss suppression program other than baking soda. . . this time it is a tank mix of thiram and mancozeb on a 14 day schedule. It appears this tank mix gradually removes moss competition and doesn’t injure the turfgrass, allowing the turf to fill back in more evenly. +++++++++++++++++++++++ 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 Summary of IT data for July City or Town Rain in last 5 days Summer Disease Predictions (color level & dates) Degree days Libertyville 2.89 inches Brown Patch (orange: 7/3 to 7/8) Pythium (orange: 7/4) 898 N. Barrington 1.50 inches Brown Patch (orange: 7/3 - 7/8) 848 Lemont 3.03 inches Brown Patch (orange: 7/3 - 7/7, red: 7/8) Pythium (orange: 7/4, 7/6) 1,021 Naperville 2.50 inches Brown Patch (orange: 7/3-7/5, red: 7/6 - 7/8) Pythium (orange: 7/4) Summer Patch (orange: 7/2-7/4, red: 7/6) 1,024 Frankfort 1.80 inches Brown Patch (orange: 7/3, 7/5 - 7/7, red: 7/8) Pythium (orange: 7/4, 7/6 - 7/7) Summer Patch (orange: 7/3) 1,039 Elmhurst 1.66 inches Brown Patch (yellow: 7/5 -7/6, 7/8, orange: 7/7) Pythium (orange: 7/4) 1,042 Wheaton 1.68 inches Brown Patch (orange: 7/3 - 7/8) Pythium (orange: 7/4) 1.044 Aurora 2.53 inches Brown Patch (orange: 7/3 - 7/5, red: 7/6 - 7/8) Pythium (orange: 7/4) Summer Patch (orange: 7/3 -7/4, red: 7/5 - 7/6) 1,099 Orland Park 1.86 inches Brown Patch (orange: 7/5 - 7/8) Pythium (orange: 7/4, red: 7/6) 1,171 Rock Island 1.2 inches Brown Patch (orange: 7/1 - 7/7, red: 7/8) Pythium (orange: 7/3 - 7/5, 7/7) Summer Patch ( orange: 7/4 - 7/6, red: 7/7) 1,340 Bloomington 1.43 inches Brown Patch (orange: 6/30 - 7/3, 7/7 - 7/8) Pythium (orange: 7/3 - 7/8) Summer Patch (orange: 7/7, red: 7/8) 1,396 Carbondale 0 inches Brown Patch (red: 6/30, orange: 6/17 - 19, 7/1 - 7/8) Pythium (orange: 7/5 - 7/8) Summer Patch (orange: 7/3 - 7/8) 1,707