It's been a rough few weeks....
Well folks, it's been a rough few weeks for a number of us, especially if you're a Democratic, Pot Smoking, Texas Rangers fan. Superintendents in the West are still having a good amount of diseases. Anthracnose has been diagnosed from Poa greens from several locations ranging from southern California to Washington State and a freak rash of Pythium, large patch and even pink snow mold broke out on warm season turf in California about 2-3 weeks ago.
Here's a shot of bermudagrass from southern California that was hit with Pythium graminicola around October 25.
Above normal temperatures in the 90s in the second week of October followed by a solid week of cool, wet weather likely triggered the freak appearance of the disease on warm season turf in southern California. Although Pythium is normally thought of as a hot weather disease, anytime you have lots of moisture and weakened plants, there's a window of opportunity for Pythium to break out.
I've been getting several calls from superintendents in the Pacific Northwest asking about Pythium this week. The winter of 2009-2010 is likely one that a lot of guys from that area would want to forget. Although we did diagnose Pythium root rot from several courses there last winter, a hot summer followed by early freezes in December was also to blame for some of the widespread damage that was seen on greens.
My best advice or PNW guys going into the winter this year is to try to improve surface and soil drainage as much as possible and apply a preventive systemic Pythium fungicide prior to wet weather. The Pythiums we diagnosed last year tended to be considered 'weak' pathogens like P. torulosum so hopefully a little prevention will go a long way this winter in avoiding any turf loss due to these pathogens. Just in case any body was wondering, we did not pick up any P. volutum (Pythium root dysfunction) from the PNW last year associated with the winterkill on Poa greens. However we have found it one time in eastern Washington on creeping bentgrass, but it does not appear to be common in the West at this time.
Q: What do you call 50 turf nerds on a bus in southern California? A: The Crop Science Turf Tour.
As some of my colleagues mentioned this week, a number of us were at the Crop Science Society Meetings in Long Beach California from Oct 31 to Nov 3. About 50 turf scientists from all over the U.S. had the pleasure of visiting Riviera Country Club, Bel Air Country Club and Jackie Robinson stadium at UCLA last Oct 31st.
Co-organizer Larry Stowell put together this quick video recap you can see here:
Thanks again to Matt Morton at Riviera, Brian Sullivan, Nic Hoisington and Justin Carroll at Bel Air, Kevin Borg and Chris Romo at UCLA and Greg Fukumitsu and Dean Mosdell from Syngenta Professional Products for helping us put together a successful event for these turf science geeks!
Anthracnose Action from the Crop Science Society Meetings
Although I didn't have a chance to catch all of the plant disease talks at the Crop Science Society Meeting, here are a few highlights from some of the research presented there (I'll continue to highlight some of the presentations over the next few weeks as time allows):
Charles Schmid, James Hempfling and Joseph Roberts (Rutgers University)
In a series of three talks looking at cultural control impacts on anthracnose severity, these three students in the labs of Bruce Clarke and Jim Murphy, help shed some more light on factors that affected anthracnose severity.
Chas Schmid's research on nitrogen effects showed that both low and high nitrogen rates applied in the summer caused more anthracnose than moderate rates. An experimental putting green was treated with 0.1 to 0.5 lb N (ammonium nitrate) per 1,000 sq ft at 7-day intervals in June and mid-July to mid-August. The most anthracnose was found in plots treated-weekly with 0.1, 0.4 and 0.5 lb N while those treated with 0.2 and 0.3 lb N per 1,000 sq ft had the least amount of disease. Again, it goes to show that anthracnose is a disease of the 'sickly' --- greens that are too lean or too fat are more likely to get disease vs. ones that have 'adequate' nitrogen fertility.
James Hempfling examined the effects of spring and summer sand top-dressing on anthracnose development. Greens were topdressed with either 0, 3.9 or 7.9 cu ft of sand per 1,000 sq ft in the spring or 0, 0.25, 0.49, 0.98, or 1.97 cu ft of sand per 1,000 sq ft at 14-day intervals in the summer. Not surprisingly, the 7.9 cu ft rate in the spring was more effective than 3.9 or 0 cu ft rates in reducing disease and at least 0.98 cu ft of sand had to be applied in the summer to get a significant reduction in anthracnose. Bottom line: sand topdressing is your friend when it comes to reducing anthracnose severity.
Joe Roberts presented his research on the effects of greens rolling on anthracnose. He used both a vibratory roller and heavier sidewinder roller in his experiments. Rolling every other day reduced disease by 2 to 13%, and surprisingly, the effect of the sidewinder rollers was slightly better than the vibratory rollers. He also observed that areas that received higher equipment traffic also tended to have slightly less disease. The mechanism of this reduction is still under investigation, but it did show that rolling can be an effective cultural practice in helping to prevent anthracnose on putting greens.
Dr. Robert M. Endo (1925-2010)
Dr. Endo's research helped identify Ophiosphaerella korrae as one of the causal agents of Spring Dead Spot
Last week, I was very saddened to learn of the passing of Dr. Bob Endo. He was a University of California (Los Angeles and then Riverside) professor for 30 years who made significant contributions to the understanding of dollar spot, southern blight, and spring dead spot
Dr. Endo was also one of the Japanese-American volunteers who formed the 442nd Infantry Regiment in World War II. Despite facing questions of loyalty to the U.S. and being placed into internment camps after the bombing of Pearl Harbor, these men volunteered for duty and served in combat in Italy, France and Germany, gaining the distinction of the most highly decorated regiment in the history of the US Armed Forces.
Dr. Endo will be missed by all who knew him.
Until next week, signing off from the Right Coast....