By Ward Upham
(Linked from K-State Horticulture e-Newsletter)
Orchardgrass often infests tall fescue lawns. Unfortunately, orchardgrass is lighter green and faster growing than tall fescue, so it is very visible. Homeowners complain of the light green tufts of grass wherever this weed has become established. To read more about this week, visit the website.
By Judy O’Mara
I was out working in the garden last weekend and I saw the first appearance of iris leaf spot (Didymellina macrospora). This is a very unattractive fungal disease. The iris planting puts out nice looking flowers each year but for the rest of the season everything looks rough, with heavy leaf spotting and leaf scorch. Iris leaf spot will show up in most years but will be severe in years that are wet.
Iris leaf spot is not an easy disease to clean up because it overwinters in the residue. So the first step for management is to clean up the flower bed in the fall after frost has killed the tops. This will help to reduce the amount of disease that is carried over. Unfortunately it won’t get rid of the disease. If the planting is old and crowded, digging them up and respacing them will improve air flow. This can help to reduce disease severity.
Start fungicide protection (chlorothalonil or mycloblutanil) when leaf spotting first shows up early in the spring. Four to six applications may be needed at 7-10 day intervals. Adding a spreader sticker will help coverage and effectiveness of the treatment.
For more information on iris leaf spot check out the following K-State Horticulture fact sheet. https://hnr.k-state.edu/extension/info-center/common-pest-problems/common-pest-problem-new/Iris%20Leaf%20Spot.pdf
By Dr. Jack Fry
Crabgrass emergence was evident last weekend – at least in Olathe, KS (picture below).
Crabgrass seedlings (inside white border) emerging on April 19, 2020 in Olathe, KS.
This was on bare soil next to a paved sidewalk. It can take a few weeks longer for crabgrass to emerge within areas of thin turf due to cooler soil temperatures (see article on timing herbicide applications here: Flowering Ornamentals and Crabgrass Emergence). So, on a lawn of acceptable quality (and no bare areas), you should still have time to get a preemergence herbicide out. Once you see crabgrass such as this emerging within a lawn, consider using a preemergence herbicide that has postemergence activity, such as dithiopyr (Dimension) or mesotrione (Tenacity). Of course, there are also a number of postemergence herbicides that can be used for crabgrass control as well.
Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!
***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***
Dr. Raymond Cloyd from KSU Entomology has observed some activity of the Eastern tent caterpillar. You can read more about it on the KSU Entomology blog.
Dr. Raymond Cloyd from KSU Entomology has developed a new publication related to Japanese beetle, a serious pest of turf and landscape plants.
You can find the publication by clicking here: Japanese beetle: Insect pest of horticultural plants and turfgrass.
“This growing season may be a challenge for producers/applicators in more ways than one. With the critical need for N95 respirators for health care workers, it is anticipated that applicators may experience a shortage of personal protective equipment (PPE) that will be available to use this growing season if not previously purchased.”
You can read full article on the KSU Entomology Blog
By Dr. Jack Fry
This is the time of year when we hope all warm-season grasses green up uniformly with no signs of winter injury. K-State researchers have been working with Dr. Yanqi Wu, bermudagrass breeder at Oklahoma State University (OSU), for the past several years. Dr. Wu is consistently working to improve bermuda cold hardiness and release improved cultivars for the transition zone region of the U.S. ‘Latitude 36’ and ‘Northbridge’, a couple of high quality, vegetatively propagated bermudas, were released by OSU in 2010. These have been used extensively on sports fields and golf courses. However, there have been some winters in which significant winter injury occurred to these cultivars in Kansas. In the article linked below, you’ll see that some of the new bermudas that are being evaluated by OSU and K-State have superior freezing tolerance to any of the existing cultivars in use. This likely means that in the next several years, we’ll have improved bermudas for our region that will be more likely to tolerate extremely cold winters.
Hello everyone here are some Covid19 updates that may be useful to your operations.
Please watch for additional information from state and local authorities. As you know, the situation changes daily in terms of case loads, etc.
At present, golf courses in Kansas are open related to policies about “engaging in an outdoor activity.” However, all the rules described in this document must be followed. Click the following link to open the document: 20-16-1 Guidance v2 – Essential Activities Functions
Best practices for sharing vehicles
The following document was developed by Colorado State related to farm vehicles but many of the health and safety practices make sense to the “green industry.” Please be sure to watch for any additional guidance or policies from state or local authorities in your area. This is just a general set of practices to consider. You can click for a larger view.