Cold, and test-drive a new concept in pesticide labels

*Snow-mageddon*

In honor of the arctic blast, here is another perspective on cold damage, from U of Arkansas:

http://turf.uark.edu/turfhelp/archives/011810%20winter2010.html

It's a 4-part series of websites discussing different aspects of winter damage in turf.

*Phytotoxicity and pesticide labels*

Like most of you, I have experienced the "fun" of reading pesticide labels. But, it is important for many reasons. Here's an article that reminds us of ONE particular reason why it is important:

http://ipmnews.msu.edu/greenhouse/greenhouse/tabid/99/articleType/ArticleView/articleId/3230/Read-the-pesticide-label-Dont-get-caught-burning-your-profits.aspx

This article talks about phytotoxicity (chemical damage) in ornamentals, but I've seen plenty of warnings on turf products as well ("do not use this product on species X or doom will follow...")

*Speaking of labels*

I came across some label news through a fruit listserv that I am on. The EPA is considering some changes to labels. In particular, they are considering changing to a web-based format where you can create a specific label that is tailored to the sites and plant species that you manage.

For example you can type in your state, a product, your type of site (golf course, for example), targeted pest (select from pull-down list), etc, and then a customized label comes up. The test-drive link is below

Here's the info (from Iowa Grape News)

"The Environmental Protection Agency (EPA) may soon be implementing a new streamlined web label distributing system that will eliminate the hardcopy label on the container. The EPA’s Office of Pesticide Programs (OPP) is exploring a new initiative called “Web Distributed Labeling” (WDL) that would make the most current version of pesticide labeling available to users via the Internet or phone. The EPA OPP announced its intent to put a WDL “User Acceptance Pilot” in the Federal Register on 8-18-10. The EPA OPP is asking pesticide applicators to participate in this pilot program and then tell EPA what they think of of the WDL using short survey via Survey Monkey.

This is a GREAT idea! This streamlined web distributed labeling system has a huge potential to increase the efficacy of our pesticide labeling and application technology resources that could become available at our fingertips in the field. I HIGHLY recommend you go to the WDL pilot site, view some streamlined labels and then take the short Online anonymous survey. You start out by taking a test drive here:

http://wdl.greenbook.net

EPA will use the survey results to decide whether or not to move forward with web-distributed labeling."

Civitas Update....By Popular Demand

First, my apologies for the tardiness of this post. The pre-Thanksgiving travel crunch got the best of me last week, and of course I spent the entire weekend watching football and hockey, so I am just now getting caught up! Several people have asked what happened to the Civitas update, so here it is:

Civitas is a new product for disease and insect control in turfgrasses that was developed by Suncor, formerly known as PetroCanada. The active ingredient is mineral oil, otherwise known as 'horticultural oil', which has been used for management of plant pests for many years. It has just never been used in turf because of issues with phytotoxicity. However, Suncor developed a pigment product, called Harmonizer, that is mixed with Civitas to reduce the potential for phytotoxicity. The advantage of mineral oil as a fungicide is that it has very low environmental impacts due to its low toxicity and rapid breakdown in the environment.

Because it contains oil and pigment, Civitas has a very noticeable effect on the color and appearance of the turf. The Harmonizer pigment, depending on the application rate, is a very dark green, similar to that provided by an application of Triton Flo or Tartan. Some people have complained that transfer of the pigment to shoes and clothing has been a problem, but I haven't rolled around on our research plots yet to see how big of a problem that is.

The mineral oil component of Civitas also gives the turf a distinct greasy appearance, very similar to that caused by an application of a wetting agent like Cascade. This greasy appearance is most evident in the morning and persists for several days to a week after application. Because of these unique characteristics of Civitas, I suggest that people try it out on a nursery green or putting green before treating the whole course with it.

We've been evaluating Civitas for control of various turf diseases for three years now. For a summary of our previous results, please see my post from last year entitled Civitas shows promise for control of dollar spot and brown patch. Be sure to read the comments at the bottom provided by Wakar Uddin, Bruce Clarke, and others regarding their experiences with Civitas.

We continue to see similar results against dollar spot and brown patch in our trials. However, this year we ran into serious problems with phytotoxicity when Civitas and Harmonizer was tank-mixed with Daconil and Banner Maxx. The injury appeared very quickly after the first application in May and became more severe as time went on. As you can see in the graph to the left, it is also interesting to note that half rates of the mixture components did not reduce the amount of phytotoxicity observed. Based on this result, we definitely recommend that Civitas and Harmonizer should not be mixed with Daconil and Banner, or with other fungicides until we have the opportunity to evaluate more mixtures for their safety.

We haven't seen significant phytotoxicity from applications of Civitas and Harmonizer alone in our trials, but some users have reported injury during times of severe stress, with high temperatures consistently above 90F. It makes sense that it could create problems to coat the turf leaves in oil under these types of conditions.

To summarize, Civitas has good activity against several important turf diseases like dollar spot, brown patch, anthracnose, and leaf spot diseases. Although it does not provide acceptable control alone in most cases, my opinion is that it could be useful as part of a disease control program. Civitas and Harmonizer should not be mixed with other fungicides or applied to severely stressed turf, or severe injury could result. However, if you are interested in using products that pose less risk to environment, then Civitas is a good choice.

More on the DMIs and Bermudagrass Greens

It is often said that good research raises more questions than it answers. Maybe the same can be said about blog posts? And no, I am not referring to Megan's California Gurls post from last Friday. (Side note: My main motivation for posting today was to bury that thing as quickly as possible. No pun intended.)

In last week's post about Torque for spring dead spot and fairy ring control, I casually mentioned that tebuconazole can injure ultradwarf bermudagrass putting greens. Since then, I've had a lot of questions about Torque and other DMIs and their safety on bermudagrass greens. It's a complex issue, and one that we don't have all of the answers to. Your questions will motivate us to do more research on this next year.

Although many of the newer DMI fungicides on the market are more safe on cool-season putting greens, they can be more injurious on bermudagrass greens. Looking at the graph to the left, you see that applications of Trinity (triticonazole) and Lynx (tebuconazole) caused severe damage to Tifeagle bermudagrass, Bayleton caused a slight reduction in quality, and Banner and Eagle had no effect. This is almost exactly the opposite of what you would see on creeping bentgrass or annual bluegrass putting greens.

Of course, application rate and time of year influence the amount of injury that is caused by DMIs, with the greatest injury caused by high rates, repeated applications, and high temperatures. You will notice that in the above example, we made 5 applications in a row at high label rates during the heat of the summer. No wonder some of them caused injury!

However, don't make the mistake of thinking that that all of the DMIs are safe on the ultradwarfs in the fall and spring or if you're only making one application. As an example, refer to my post from last fall entitled Effects of DMI Fungicides on Bermudagrass Putting Greens. In this example, we saw pretty significant phytotoxicity from some of the DMIs even after one application when temperatures were relatively mild.

I don't mean to scare everyone away from using the DMIs. We never see issues on bermudagrass fairways or athletic fields, and some of the DMIs are perfectly safe on greens. Just choose your products wisely and don't jump on the newest products right away just because they are new!

Spray, but watch the burn

With temperatures in the high 90s or even triple digits throughout many parts of the mid-Atlantic and Northeastern United States has many scrambling to protect their turf from potential diseases. In addition to the uncharacteristic high temperatures is equally unusual low relative humidity. One common thing in calls that I received this weekend was that everyone was scrambling with hoses.

Another interesting point that I generally don't think about when applying fungicides for field studies is the potential for burn when spraying. In many trials, we only apply a couple of products at a time and rarely mix to the degree that many golf course superintendents. I always joke at meetings about how the record number of items that one superintendent put in the tank was 23! So in light of this and in light of the fact that many are trying to get that next spray out, I received a couple of questions about potential burn when spraying.

In a past post, Lane spoke about the potential negative impact of some of the DMI's on cool-season turf in the summer. In past trials, we have seen some severe leaf tip burning when certain products are mixed together. One product that has gained in popularity is the various phosphites on the market. In some field work, we found that these products can be "hot" and burning can occur specifically when these are mixed with certain products like the DMI's as well as PGRs. Additional things to consider include the use of wetting agents and other products that can add to the potential for phyto. Please leave us a comment or follow the discussion that I started on the Facebook Page here.

Finally, I received a call from a couple of golf courses this week that were concerned about some uncontrollable summer patch on their greens this week. While summer patch may start to show up in this weather and would be fairly typical for this time of year, I call attention to a post on an unusual Pythium species that I wrote about last year. This is something that is relatively new and little is known about it. I can say that it is a real issues, however, and those of you relying on Signature for your sole Pythium control should read this post!

For those of you that follow the LPGA, check out this week's US Women's Open at Oakmont. I am here in the hotel now and ready to spend the practice rounds with John Zimmer's staff and the USGA. Wake up call tomorrow morning at 3:30AM...I am rooting for Christina Kim who just missed out on a win this past week in a four-way playoff!

Check out these photos from last year's Women's Open at Saucon Valley

lightning, phytotoxicity and thatch

Lightning: the ultimate abiotic stress?

I was riding my bike to work this morning and came across this tree:

The tree had basically exploded, with pieces of bark strewn across the street for half a block in either direction. Electricity and trees don’t mix… We had some severe t-storms last night.

There was a more extreme case recently that made the local paper:

I've never seen a lightning damage in turf in person, but I've seen photos. Pretty dramatic symptoms, but not quite as dramatic as an exploding tree.

Abiotic problems in TURF

In the turf world there have been some abiotic problems lately as well.

We had a pretty severe winter, and I have heard from a few individuals in southern Kansas that bermudagrass in some sites is slow to green up and may have some winterkill. [And, along with that, spring dead spot symptoms are now apparent.]

Back to the abiotic side of things:

I recently saw some phytotoxic effects of the herbicide product Quicksilver (carfentrazone-ethyl) on zoysiagrass at a golf course. At this course, Quicksilver had been applied to suppress moss 1 week prior in the creeping bentgrass greens. However, where the spray pattern hit the surrounding zoysia there was a slight orange/brown/yellow “off’ color.

If you check out the label for Quicksilver, it mentions that “established warm-season grasses … are generally tolerant but may be susceptible to transitory yellowing when they are under stress. Stress is typically associated with but not limited to extreme high or low temperatures… or transition into or out of dormancy.”

(As someone who is slow to transition out of night-time dormancy in the morning, I have some sympathy for the warm-season grasses. I don’t like dealing with anything other than my coffee pot until I am good and ready.)

Let me point out that in our moss studies at KSU and with our colleague Derek Settle at the Chicago District Golf Association we have not observed any phytotoxicity of Quicksilver on any bentgrass cultivars that we have worked with.

And, more abiotic stress:

When the irrigation is inadvertently turned off during a warm, sunny, windy, weekend, desiccation ensues:

And, more abiotic problems: Thatch

I’ve mentioned thatch once or twice already this spring, but it never hurts to mention it again. The following two photos are from a putting green that is having a hard time coming out of winter. In the first picture you can see the layers of thatch building up in the sand. In the second photo the sand has been washed off and you can see that the thatch is about 1-inch thick which is pretty severe. Has anyone out there ever dealt with a 1-inch thatch layer? I bet the aerifier will have some difficulty punching through that.

Every year I receive numerous samples from lawn, landscapes, and golf courses where thatch building is causing a variety of problems. Not only does it directly affect plant health, a thick thatch layer can tie up and bind fungicides and insecticides and thus reduce their efficacy.

An amazing fact

This has nothing to do with turf but is pretty amazing: There have been 153 distinct viruses described in cucumber. 153!! Also astonishingly high: 136 viruses have been described in tomato, 49 in pepper, 53 in lettuce, 46 in melon, 54 in potato, 44 in eggplant.

1) Large patch; 2) Economic and aesthetic comparison of turf management; 3) Mystery zone of turf death

Hello,

I have a few unrelated things today: large patch, a guest blog about different management systems, and then a turfgrass mystery.

First, I'll just mention quickly that as our zoysia grass is greening up, large patch is firing. We have had some heavy rains over the past 2 days so the fungus will be happily growing. Here is some large patch in our research plots:



Second, here is a guest post by my colleague Dr. Cale Bigelow at Purdue University. I must admit that Cale and I were both sorely tempted to post on Monday in order to get the honorable Dr. Kaminski all riled up, but then I opted to just post it today. Watch out, though, John...

Cale was part of a study that compared the economics and turf quality aspects of four different management systems. While this study was focused on a home lawn type of environment I think those in the golf course world will find it interesting, too.

Comparing Cool-season Lawn Fertilizer and Pesticide Programs: Aesthetic and Economic Trade-offs

Guest post by Cale Bigelow

There is increasing public interest in alternatives to traditional cool-season lawn fertilizer and pesticide application programs. Historically these programs have been based on calendar driven fertilization and the attitude toward pesticide applications has been a prophylactic approach for controlling broadleaf and annual grassy weeds as well as insects like white grubs. As consumer attitudes toward the perception of a “perfect lawn” begin to change, alternative management methods that involve more judicious pesticide applications and engaging in Integrated Pest Management (IPM) and scouting approaches these practices may become more publicly accepted. Furthermore, there is a very strong interest in “organic” products and approaches to lawn care. Currently, the information regarding longer-term performance of organic products in the field is very limited.

To examine the effects of these potential lawn management alternatives, an interdisciplinary field study was conducted between the Entomology and Agronomy Departments at Purdue University in West Lafayette, IN. Ph.D. student, Victoria Caceres, working with Drs. Doug Richmond, Tim Gibb, Cliff Sadof and Cale Bigelow evaluated four disparate lawn management programs which were: a traditional calendar driven consumer program (CP), a natural organic program (NOP), an integrated pest management/scouting program (IPM) and all were compared to a no input program (NIP). All programs with the exception of the NIP received approximately 3 # N/1000 ft2 annually with the NOP relying on manure-based fertilizers, corn gluten and entomopathogenic nematodes for annual grassy weed and insect control, respectively. The IPM program used traditional products but pesticides were only applied when warranted or thresholds were met. The turf was in full sun, maintained at 3 inches and irrigated only to prevent severe stress and facilitate product applications. The plots were regularly assessed for appearance, greenness, and periodic growth. Individual program maintenance costs were calculated based on product cost and estimated labor costs for product applications/scouting.

Study results:
While there were seasonal differences for appearance, all programs except the NIP program provided a satisfactory appearance and green color that would be suitable to most homeowners. While the NOP was sufficiently green there were significantly more broadleaf weeds in this program, which detracted from overall appearance. This result emphasizes the need to develop effective natural organic products for broadleaf weed management. Additionally, the economic benefits of scouting were demonstrated in the IPM program (Table 1) and illustrates a potential reduction in unnecessary pesticide applications and reduced input costs.

It is important to note that these results are observations over only two growing seasons and the long-term implications of this study should be carefully considered. For example, it is possible that some weed or insect pests could become problematic, canopy greenness/turf density could decline in time and the overall appearance may be objectionable to some consumers. Nonetheless, this study provides the framework for future studies and may begin to allow lawncare professionals an opportunity to consider the possibility of providing an IPM/scouting service to clients that desire this management approach. It should, however, be noted that these consumers should also be willing to accept a less than perfect lawn at certain times through the growing season.

The photo shows a visual comparison of the 4 management systems.

For a more detailed description of this study it can be found in: HortTechnology 20:418-426. Caceres et al., 2010. Aesthetic and economic impacts associated with four different cool-season lawn fertility and pesticide programs.

Table 1. Comparative product and estimated labor costs for four disparate cool-season lawn management programs over two growing seasons.

Management program..................... Cost* ($/A)

1. Consumer/calendar driven ............... 2,743.00
2. IPM/scouting .................................. 1,989.00
3. Natural organic ............................... 3,498.00
4. No input ........................................... 0.00

*Note this value is for two growing seasons and does not include mowing costs.



And, finally, here is a turf mystery to solve:



I know it's another home lawn, not golf course, but spills can happen anywhere. This certainly looks like a spill, eh? The top part (the totally dead zone) occurred last fall, and then this spring it started moving out (downhill).

The first thing that came to my mind was a spill of herbicide, fertilizer, or de-icing salt but the client insisted that this did not happen. Of course, people do forget, and they do not always know what other members of the household (or golf course) have been up to! But, what are some other possibilities? Well, notice that the damage is right by the front door. It is easy to imagine that someone may have worked with a household cleaning chemical, a paint thinner, etc and then dumped the bucket outside. Or, they deep-fried a turkey on the front patio at Thanksgiving and then dumped the grease. Or, they spilled lawnmower gas. Or, Clifford the Big Red Dog is real.

There are plenty of scenarios you could imagine where something got spilled or dumped but at the time it did not seem like something that would cause a problem.

If YOU have a crazy idea on what caused this, leave a comment. Maybe I'll have a prize for the best story!

Effects of DMI Fungicides on Bermudagrass Putting Greens

Those of you that follow this blog know that I am not a big fan of using DMI fungicides on creeping bentgrass and annual bluegrass putting greens during the heat of summer. The impacts of these fungicides on bermudagrass greens, however, are not as well understood. Some of the newer DMIs, like Trinity, Triton and Tourney, are not labeled for application to ultradwarf bermudagrass varieties. Even though these products are safer on the cool-season grasses, they can cause severe phytotoxicity and thinning of 'Champion', 'Tifeagle' and 'Miniverde' greens.

A recent trial we performed on 'Champion' bermudagrass in Rocky Mount, NC showed some unexpected results. Each fungicide was applied once, on August 20, the day after the greens were hollow-tine aerified and topdressed. The plots were evaluated for phytotoxicity, turf quality, and recovery from aerification on September 1.

Not surprisingly, plots treated with Trinity, Tourney, and Triton FLO exhibited significant phytotoxicity and reduced turf quality as compared to the untreated control. Banner and Bayleton had similar effects, just not as severe as the others.

What was unexpected was the effect of the DMIs on recovery from aerification, as measured by the number of aerification holes still visible on Sept 1. Plots treated with Trinity, Tourney, and Triton FLO recovered almost as quickly as the untreated plots, whereas both Bayleton and Banner dramatically slowed recovery, especially Banner.

So, the take home message is, even though Bayleton and Banner are labeled for application to bermudagrass greens, these products can have adverse affects on the turf, in this case, slower recovery from aerification. More research is needed to fully characterize the effects of the DMIs on bermudagrass greens. In the meantime, I'd recommend avoiding applications of DMI fungicides either before or after hollow-tine aerification practices.

Beware of the DMI Fungicides

As temperatures climb in the southeast US, it is time to put the DMI fungicides on the shelf until fall. All of them.

The DMIs can cause significant damage to bentgrass and bermudagrass putting greens if temperatures exceed 90 degrees after an application is made. Note that the temperature at the time of application is not important, it is the weather in the days and weeks after an application that leads to problems.

The DMI fungicides include Banner, Bayleton, Eagle, Rubigan, Tourney, Trinity, and Triton.

All of the DMIs have growth regulating properties. The effects are minimal when the turf is healthy and actively growing, but significant thinning of the canopy can occur during hot weather, even on otherwise healthy turf. Combine a DMI application, hot weather, and severely stressed turf and the consequences can be disastrous.

Several new DMI fungicides have been released in the last two years, and many of them are promoted as "safe". Admittedly, they are safer, but by no means are they safe. Severe damage has been observed where these new DMIs were applied to stressed cool-season grasses prior to or during hot weather. We have also observed that these new DMIs are more injurious to bermudagrass than the older DMIs. Tourney, Trinity, and Triton are not labeled for application to bermudagrass greens for this reason.

Most golf course superintendents in the southeast don't need DMIs during the summer anyway. Effective alternatives are available for control of most diseases, but anthracnose is an exception. Many superintendents with older bentgrass varieties or Poa annua greens battle this disease, and most anthracnose populations have become resistant to the QoI and benzimidazole fungicides. If you are in this situation, you pretty much have to use a DMI. The newer DMIs (Tourney, Trinity, and Triton) are very effective against anthracnose and should be worked into a preventative anthracnose program. Just be sure to use low rates, tank-mix with chlorothalonil to prevent algae invasion, and do not apply more than once a month to minimize the potential for injury.