Cultivar selection could influence interseeding success

Germination characteristics such as speed, synchrony, and viability determine the success of newly seeded areas. Traditional establishment from seed involves sowing seed into bare soil or turf which have been treated with non-selective herbicides. In either case, the newly emerging seedlings face little competition from surrounding plants. While germination characteristics are important when using traditional establishment methods, superior germination characteristics may be necessary when using non-traditional seeding methods such as interseeding.

Interseeding poses an interesting dilemma. The main attraction of converting through interseeding is the ability to convert to a new turf without taking the area out of play and facing the resulting economic losses. Research shows that the success of interseeding is related to the level of disruption created and the speed of germination of the interseeded species. As the level of disruption increases, the competition from surrounding plants decreases allowing the seedlings an opportunity to establish. However, the amount of disruption necessary for successful interseeding may not be conducive with a smooth uniform playing surface. Because minimal disruption is needed so as not to disrupt play, superior germination characteristics are needed.

We conducted a germination study at Iowa State with 'Penncross' and 14 improved cultivars of creeping bentgrass. The cultivars ‘L-93’, ‘T-1’, ‘Apha’, ‘Penn A-1’, ‘Penn A-4’, ‘Crystal Bluelinks’, ‘Pennlinks II’, ‘Pencross’, ‘Tyee’, ‘007’, ‘Mackenzie’, ‘SR1150’, ‘Memorial’, ‘Independence’, and ‘Declaration’ were evaluated in this study. Each cultivar was represented by two to four seeds lots from production year 2007. Standard germination tests were conducted according to the rules established by the Association of Official Seed Analysts (AOSA). The objectives of the study where to determine if improved cultivars of creeping bentgrass possess superior germination characteristics compared to 'Penncross' and if there was a relationship between seed weight and germination characteristics.

Results

Significant differences existed between 'Penncross' and the improved bentgrass varieties for germination speed (MGT), germination synchrony (T10-90), and viability (FGP) but not weight (table 1). These results indicate that improved varieties of creeping bentgrass possess greater viability and germinate faster and with greater synchrony compared to ‘Penncross’. Differences between ‘Penncross’ and each of the improved varieties can be viewed in table 2 (significant differences are highlighted in red). ‘T-1’ outperformed ‘Penncross’ in all three parameters. While some of these differences appear small numerically, it is important to remember that these tests were conducted under optimum conditions. The differences would likely be greater under field conditions when the seeds are subject to environmental stresses.

Our study also revealed a significant correlation between seed weight and speed of germination (MGT). Seeds germinated faster as the weight of the seeds increased. This information could be used to predict the germination speed of other cultivars without conducting tedious germination studies.

What does it all mean?

This study clearly shows that improved cultivars of creeping bentgrass have superior germination characteristics compared to ‘Penncross’. So is it possible that the success or failure of interseeding could depend on cultivar selection? Past interseeding research supports this very idea. Attempts at interseeding ‘Penncross’ into an established annual bluegrass putting green were largely unsuccessful (Gaussoin et al., 1989). However, in a similar study, researchers were able to establish over 70% ‘L-93’, and ‘Penn A-4’ into an annual bluegrass putting green (Henry et al., 2005). These results could be the explained by the differences in germination characteristics that we observed in our study. Clearly, not all cultivars of creeping bentgrass exhibit similar germination characteristics. And while the success of interseeding will not result from a single practice or strategy, proper cultivar selection will play an integral role as part of an interseeding conversion program.

Literature Cited

Gaussoin, R.E. and B.E. Branham. 1989. Influence of cultural factors on species dominance in a mixed stand of annual bluegrass/creeping bentgrass. Crop Sci. 29:480-484.

Henry, G.M., S.E. Hart, and J.A. Murphy. 2005. Overseeding bentgrass species into existing stands of annual bluegrass. HortScience 40:468-470.

Marcus Jones
Graduate Research Assistant

Derek Harmon Memorial Golf Tournament

The Derek Harmon Memorial Golf Tournament took place on Sunday, October 18 at Veenker Memorial Golf Course. Derek was a turfgrass student at Iowa State who possessed an unconditional love for golf courses and nature and the tournament was held to honor his memory and to create a scholarship for turfgrass students attending Iowa State. There was an overwhelming show of support from family, friends, and the industry and close to $12,000 was raised towards a scholarship in Derek’s name.

A big “thank you” goes out to John Newton, CGCS, and his crew along with the entire clubhouse staff, all the participants, and everyone else that was involved in the planning and preparation for this event. Derek would be very proud.

Derek, in your honor as a superfan of all Chicago sports.
http://www.youtube.com/watch?v=fJNC3dgreaU

Additional pictures from the tournament

Derek worked at Ballard Golf and Country Club, Roaring Fork (Colorado), Pinehurt (North Carolina), and Biltmore Country Club, (Illinois)

A bench in Derek's honor resides behind the green on the 15th hole.

Approximately 160 golfers played in the tournament. Thanks to everyone who participated.

Marcus Jones

Graduate Research Assistant

More on Mole crickets at Pella

Here are a couple more pictures of the mole cricket damage at Bos Landen in Pella.

The text below is from the original post on Oct. 5. There are also some additional pictures of the mole crickets that caused the damage on that post.

Nick

Do we get mole crickets in Iowa? The answer is clearly yes, although they are rare. The pictures above come from Kevin Vos and Alex Olsen at Bos Landen in Pella. They were taken on Sept. 28, 2009 on the 18th green. They were actually doing some damage to the green.

Damage is rare. I have seen it at Ankeney country club and a few other places around Iowa over the past 30 years. Finding mole crickets is not as rare. We sometimes see them at the research station and many superintendents have reported them over the years.

Contol?

Usually chemical is not necessary. If it is a few, you can step on them or collect in a bottle. They are very difficult to treat in Florida and other areas of the South, because they occur in very high populations and are protected from chemicals by being under ground much of the time. Pretty much any of our standard insecticides will kill them, if you get them on the insect.

Marcus tells me that when he was at Augusta, they would mix up soapy water and pore it in the holes. They mole crickets would come to the surface and they could then remove them.

If any one else is seeing them, let me know.

Nick

Research Update: Keith Rincker, KRincker@cdga.org

North Central Region Collaborative Effort...and the data says

Dollar spot was the talk for the last two weeks of September, but now the night temps will hold off any development except for a possible warm spell left in the year. Now is the time to look back and evaluate our dollar spot information. We had a chance to evaluate our new fairway bentgrass variety trial during the highest disease pressure of the season. The borders of ‘Alpha’ and several entries were lighting up! It has been a long road for this trial. Twenty nine bentgrass
varieties were seeded last year and then reseeded this May. Now we have lowered the height (0.75 inches) slowly over the summer and finally we got some disease.



Next year we will learn (again)
Next year we will get a better idea for disease resistance of these varieties. So far our variation is still large and another years worth of data will be needed to determine the genetic resistance in the new varieties like ‘CY-2', ‘Kingpin’, ‘Shark’, and ‘007’. This data does show that varieties have been released with comparable resistance to ‘L-93’. Hopefully with more time we can say that there are a handful of varieties with greater resistance than ‘L-93’. In National Turfgrass Evaluation Program (NTEP) trials, ‘Declaration’ has shown promise. ‘Alister’ is actually a colonial bentgrass species. In previous research on Sunshine Course, colonial varieties are damaged by brown patch and weeds become a problem.

The “take home message”...
The goal of this research conducted here in Lemont and 11 other Midwestern universities is to determine how many fungicide sprays are needed when varieties with greater resistance are used.



The L-93 Story at North Shore
This year at North Shore Country Club we set out treatments on a fairway strip of ‘L-93’. Only one application was made on May 14 and the plan was to see which treatments provided the longest control. Bayleton, Emerald, Daconil, Banner Maxx, and Chipco GT were all applied and we waited for dollar spot. Mid June came around, and no dollar spot – too cold. The beginning of July came and only a tiny bit of dollar spot. The beginning of August came around and finally dollar spot reached 1-3%in all plots. Fungicide or not, all treatments were the same for percent dollar spot incidence and plot visual quality.

No differences...
We found no differences in our statistics. What did we learn? Maybe May 14 is too early for dollar spot control. Maybe we can reduce our fungicide inputs by utilizing genetic resistance and eliminating one or two applications early in the summer. Our heads are already spinning around to design research in 2010.

Emerald for next year’s research...
So far our thoughts are to pick one fungicide and apply on selected dates from May through June or July on each ‘L-93’ and a bentgrass/Poa mixture. This will give us an optimal timing for first application to control dollar spot on two different turfgrasses. For now we will write down our thoughts and continue to analyze the research.

Keith Rincker
KRincker@cdga.org
Chicago District Golf Association
11855 Archer Avenue
Lemont, IL 60439

Derek Harmon Memorial Golf Outing and Fun Day

Sunday October 18th, 2009 - Veenker Memorial Golf Course
Host Superintendent: John Newton, CGCS
Registration 10 – 10:45
Shotgun Start 11:00
Format of Play: 4 Player Best shot
Awards and Social Immediately Following Golf
Entry Fee: $30 / player, lunch included at the turn
Additionally, In-Kind Donations will be accepted.
ALL proceeds from this event will go to establish a scholarship through the ISU Horticulture Dept.

Registration Form

Update on Interseeding Research

Marcus Jones
Graduate Research Assistant

Living with the Emerald Ash Borer: by Jeff Iles

While not an “official” resident of the state of Iowa, yet, the highly destructive emerald ash borer has been found within a stone’s throw of our northeastern border. And if you’re a pessimist or perhaps a realist, you might be convinced the insect is already here, but has managed to escape detection. After all, it’s not the easiest of pests to locate. Just ask our colleagues in southeastern Michigan. Either way, it’s probably a safe bet that very soon EAB will be with us, and its impact will be dramatic and widespread.

So, what do we do? What do you do as a golf course superintendent? Do you put the blinders on and pretend the insect will never find your course? Do you adopt a scorched earth policy and “fell” every green, white, black, and blue ash on your property just so you don’t have to worry about EAB in the future? Move to Nebraska? My answers to these questions are no, no, and heck no!

Here’s what I would do. I’d take inventory of every ash tree under my care. Those found to be in a serious state of decline would become intimately acquainted with Mr. Chainsaw. No sense hanging on to trees that look bad and detract from the appearance of the course. But what about the thousands of ash that line your fairways, frame a green, or otherwise look pretty good and contribute to the overall beauty and ambiance of your course. Well, if it were up to me, I’d continue to prune, water, and mulch them, and…enjoy them. We all might be surprised just how long these trees are with us, even after EAB enters the state.

Notice, however, that I haven’t yet mentioned preventive insecticide treatments. And why would I? Unless your golf course has miraculously survived the recent economic downturn without a scratch, you simply can’t afford to protect every ash tree on the course. But, if you have one or several extremely old, historic, or noteworthy specimens you simply can’t afford to lose, then relying on an insecticide to protect your investment makes perfect sense.

These are trying times for golf course managers. Heck, these are trying times for most businesses in Iowa and the last thing the “green industry” needs is the loss of popular, dependable, and heretofore trouble-free tree species. But that is the hand we’ve been dealt and it’s the hand we must play. That is, unless you’d rather fold and go home? I didn’t think so.

So, let’s stop trembling in fear of this little green beast from the east and begin making a plan for the future. Of course, the plan does not include planting more ash, but look on the bright side. Ash are overrepresented in most Iowa landscapes anyway, so now’s the perfect time to diversify your tree population. Looking for some examples? Try these on for size.

Acer ×freemanii 'Sienna' (Sienna Glen® Freeman maple) (Picture Above)
Acer miyabei 'Morton' (State Street® miyabe maple)
Acer saccharum 'Bailsta' (Fall Fiesta™ sugar maple)

Ginkgo biloba (Picture Above) – choose male cultivars if you don’t want fruit litter
Gleditsia triacanthos var. inermis 'Harve' (Northern Acclaim™ honeylocust)
Gymnocladus dioicus (Kentucky coffeetree)
Platanus × acerifolia 'Morton Thornhill' (Exclamation™ London planetree)
Quercus macrocarpa (bur oak)
Quercus muehlenbergii (chinkapin oak)
Taxodium distichum (baldcypress)
Tilia americana 'Boulevard' (American linden)
Ulmus americana 'Princeton' (American elm) (Picture to right)
Ulmus × 'Morton Glossy' (Triumph™ elm)

And there are many, many more!

Jeff Iles

Department of Horticulture

Iowa State University

Mole Crickets in Iowa?

Do we get mole crickets in Iowa? The answer is clearly yes, although they are rare. The pictures above come from Kevin Vos and Alex Olsen at Bos Landen in Pella. They were taken on Sept. 28, 2009 on the 18th green. They were actually doing some damage to the green.

Damage is rare. I have seen it at Ankeney country club and a few other places around Iowa over the past 30 years. Finding mole crickets is not as rare. We sometimes see them at the research station and many superintendents have reported them over the years.

Contol?

Usually chemical is not necessary. If it is a few, you can step on them or collect in a bottle. They are very difficult to treat in Florida and other areas of the South, because they occur in very high populations and are protected from chemicals by being under ground much of the time. Pretty much any of our standard insecticides will kill them, if you get them on the insect.

Marcus tells me that when he was at Augusta, they would mix up soapy water and pore it in the holes. They mole crickets would come to the surface and they could then remove them.

If any one else is seeing them, let me know.

Nick

The Story of the 1/3 Rule

Recently, I was skimming through a textbook about maintenance reduction practices for turfgrass settings and I stumbled upon a section that discussed the one-third rule of mowing. I’m sure most everyone has heard about this recommendation as it appears in almost every textbook and extension publication. This common rule states that no more than one-third of the plant should ever be removed in a single mowing. However, this rule is commonly ignored. You probably remember many other “rules” from your introductory turfgrass classes that are also commonly violated: irrigate deeply and infrequently, never mow when the grass is wet, avoid fertilization during the summer months, etc… So are there any absolute truths when it comes to turfgrass management practices? The truth of the matter is that turfgrass management often deals in shades of gray. There seems to be exceptions to almost every rule.

Most recommendations stem from research, which is usually a good thing. But sometimes the inference space of the research is extended beyond the original scope of the project. For instance, a study investigating the growth of bentgrass cultivars will only provide information about the growth of bentgrass cultivars. The results of the study should not be applied to other species of turfgrass such as bluegrasses or ryegrasses. The recommendation of the one-third rule is a classic example of a research project being extended beyond its inference space.

The 1/3 Rule is Born
The one-third rule originated from a greenhouse study done by U.S. Department of Agriculture scientists about 60 years ago on forage type Kentucky bluegrass. The goal of the study was to investigate the effect of cattle defoliation on the growth of the roots. Results of the study showed the grass (or roots) didn’t die when more than one-third was removed. The growth of the roots simply paused for a short time before resuming normal growth. The findings from this study were eventually morphed into the creation of the one-third rule.

More Recent Research
A similar defoliation study was recreated in 1986 by a group of turfgrass scientists at North Carolina State University (Shepard et al, 1989). This study was conducted in the field with a “high” and “low” maintenance tall fescue maintained at 3 and 6 inches, respectively. Each grass was allowed to grow 30, 50, 100 and 300% taller than the maintained height before being mowed. The 50% defoliation treatment signified the maximum guideline of the one-third rule – 30% was within the recommended guideline, and the 100 and 300% treatments violated the one-third rule. The researchers found that the tall fescue could grow to double the original height before being defoliated without negative consequences (tall fescue maintained at 3 inches could grow to 6 inches before being cut without serious consequences). The 300% treatment resulted in senescence to a portion of the tall fescue stand. The results of the NC State study indicated that the one-third rule has little merit, yet the recommendation lives on. One reason could be the detrimental effect of excess grass clippings that shade the turf underneath. Either way, the one-third rule is by far an unconditional truth.

So what is the moral of this story? Recommendations should not always be taken at face value. Ask questions and spend some time investigating how they came about before taking action. You may just be surprised when you learn the rest of the story.

NC State University Citation:
Shepard, D.P., J.M. Dipaola, and W.M. Lewis. 1989. Effects of clipping regime on turf quality and mowing requirement. Agron Abstr. p.165

Marcus Jones

Graduate Research Assistant