Cool, wet weather has triggered large patch activity in golf courses – and in our research plots.
The photos below are from an ongoing research trial. You can read some details about the study in our online research update from spring. PhD student Mingying Xiang is the lead researcher on this study, under the mentorship of Megan Kennelly and Jack Fry.
The photos below show different zoysiagrass breeding lines. For each plot, one side was inoculated in Sept 2016, and the other side is protected with fungicides to allow ongoing rating of quality and agronomic traits in the absence of disease AND to serve as a “healthy check.”
As you glance through the photos, you can clearly see the large patch on the inoculated sides of many of the plots, while the fungicide-treated side is clean. However, you will also see plots where you can’t even tell which side is which. That is, even the inoculated, non-fungicide-treated side is looking clean. We are hoping those may be resistant lines to examine in further testing. Stay tuned! Turfgrass breeding takes a long time!
KSU PhD student Mingying Xiang is one of this year’s recipients of the prestigious Chris Stiegler Travel Award. She will formally receive the award next week at the annual meeting of the Crop Science Society of America/American Society of Agronomy/Soil Science Society of America.
Congratulations Mingying! She is recognized for her academic achievements in the classroom, research accomplishments, and leadership activities.
Mingying’s research is focused on evaluating zoysiagrass breeding lines for cold hardiness, quality, and resistance to the disease large patch along with studying the potential for tall fescue-zoysiagrass blends to reduce the disease brown patch while maintaining overall summer quality.
If you are not sure what the thatch situation is on a site you manage, go take a look. Take a trowel, pocket knife, or soil probe, and poke around. If it’s starting to build up in your cool-season turf, take action now. You don’t want a thatch problem to bite you in summer 2018.
Early last week we saw a couple last gasps of the summer diseases, with some Pythium on a tall fescue lawn:
It was greasy, it was mushy, and after “a night in the box” there was classic Pythium mycelium. Foliar Pythium is rare on tall fescue lawns, usually coming in during very wet weather on sites that have received a little too much water and perhaps a little too much N. When this one came in, it was after one last blast of some heat, but with cool, cool temps on the horizon. Now that we are coming into this nice, consistent cool weather it’s really too late to consider fungicides, and instead we can concentrate on fall renovations AND tweaking cultural practices to help reduce disease risk next year. There was also a last hiccup of brown patch from a golf course fairway. Same story – with lows in the low 60s and even 50s, those diseases should stay quiet and hopefully we won’t see them until 2018.
Next door in Missouri, Dr. Miller is reporting some continued sightings of Pythium root rot (which is different from foliar Pythium) and basal anthracnose. I would agree we are not out of the woods yet. You can see his photos HERE.
We humans are enjoying the cool weather, and our cool-season grasses are too. However we are coming up on the time when our warm-season grasses start to shut down, and the season when the large patch pathogen likes to infect our zoysia. Sometimes we see symptoms in fall if conditions are very cool and wet. I have not seen any around here yet, but in Missouri some is firing. Our main time of seeing the symptoms is spring.
In Kansas, applications in September have been quite effective in reducing symptoms through most or all of the following spring. With this early cool weather, leaning towards earlier rather than later in the month may be wise. Next door in Missouri they’ve seen good results with EARLY spring applications as well – read about it HERE in Dr. Miller’s excellent post about application timing. In Kansas, when we’ve tried mid/late spring applications when symptoms are already pretty apparent, they don’t work well, if at all. For details on the newest products you can check the large patch section here (click to page 18)
We recently received a sample with anthracnose crown rot. Anthracnose can be tricky to diagnose from a distance or a drive-by. The symptoms can look like other diseases or stresses such as physiological root decline. Another tricky thing is that those same stresses can make the turf more prone to anthracnose. Yikes! It’s worth investing in a high-quality hand-lens, and with a good hand lens and a steady-hand you can often see the anthracnose structures lurking down at the base of plants. Sending to the lab as a follow-up is another good step, since we can look for other pathogens that might be lurking in the roots.
The photo below is through a dissecting microscope, but those same dark spines can often be seen with a hand lens. Look for structures on green tissue, not brown/dry tissue. Anthracnose is pretty good at colonizing stuff that is already dead, as an opportunist. When we see it on juicy green tissue that is when the disease is active.
For more on anthracnose, including several photos you can check this page:
Many of the practices to reduce anthracnose also promote overall turf health. That is, when you implement agronomic practices to promote good rooting you also reduce the risk of anthracnose and other problems. You may not be able to do ALL of the beneficial agronomic practices you would like, due to budgetary limits or lack of equipment or golfers’/greens committee opinions, but the more you can fit in, the better.
On this blog we are usually talking about plant health, but here’s a quick switch to human health. We want all of our Kansas green industry folks to stay healthy and safe in the summer heat.
You already know this, but sometimes it is worth reminding ourselves that heat stress and dehydration can be very serious. A friend-of-a-friend of mine got very dehydrated once on a camping adventure, and she was very sick for several days (dizzy, vomiting).
Take extra care of new crew members who are not used to the heat. For one thing, those folks are less used to it. Second, a new crew member may feel the need to just buck up and take it and be afraid to speak up that they need some shade or a water break. So keep an eye on everyone, but especially those that may be more vulnerable.