GreenCast UK Articles

The grass is greener... on the Sydney Harbour Bridge!

Daria Gonetskaya — Tue, 29 Dec 2009 00:30:57 GMT

As the sun rose above Sydney on Sunday, 25th October, you could feel that spring was in the air. The birds were singing, the cows were mooing and the smell of freshly laid turf wafted through the atmosphere.

What? In the middle of Sydney? What about the traffic-the noise-the pollution? Was this the same busy capital city we said goodnight to just a few hours earlier?

As part of a massive tourism campaign by the NSW Government, one of Australia's most famous icons, the Sydney Harbour Bridge, was covered in turf to celebrate the inaugural Breakfast on the Bridge.

The normally hectic six-lane freeway was transformed into a peaceful picnic ground overlooking one of the world's most spectacular harbours.

The lawn may have not been so lush, however, without the use of Syngenta products such as PRIMO^® MAXX, MERIDIAN^® and MONUMENT^® Liquid. The supplier of the turf, Evergreen Turf, is one of Syngenta's customers.

Laying turf 1.16 hectares of turf on the Sydney Harbour Bridge was a mammoth task. It began with months of planning and the preparation.

Graeme Colless of Evergreen Turf assembled a team of 100 workers, including Syngenta's Patrick Madden (Sales Manager - Turf NSW), to lay the turf in three hours and then remove the turf in less than two hours, just in time to allow the traffic of Sydney to flow again."We started the night at 10pm with 100 staff, 16 trucks, two buses and numerous other pieces of machinery arriving at the turf farm for some last minute instructions," Patrick said.

"After travelling to the bridge, and waiting some time for other contractors to finish their jobs, the first rolls of turf went down at 2am.

"Everything was going really well until a car broke through a police checkpoint at Kirribilli and drove across the bridge - and over the turf - with the highway patrol lights flashing behind!

"We had to jump out of the way to avoid the chase. The footage even made it onto the TV news!

"Thankfully everyone was safe, and the hoon was also safe in a cell at Kings Cross Police Station," Patrick clarified.

The Kikuyu turf used on the bridge was grown at Pitt Town (an outer suburb of Sydney). It was cut on the Friday into 1.2m wide by 16m long strips, which were rolled up with a backing of Geo fabric to allow easy clean up of the bridge.

The picnickers had an early start, setting up from 5.30am. They enjoyed a feast of complimentary NSW produce including fresh fruits, breads and yoghurt and were treated to a live milking display with 15 cows on the bridge - an even more unusual sight for city-dwellers.

Then, at 8.30am, everyone was booted off the bridge so that staff could begin the clean up.

"Our time arrived again and we had to have the turf up and on the trucks by 10.30am," Patrick said.

"This time it was a little less eventful and we got the job done in just one and a half hours.

"Luck was on our side with the weather. The day started off beautifully, but as the picnic drew to a close, ominous storm clouds started rolling in.

"Not long after finishing the clean up, up to five inches of rain fell on Sydney!"

From 45,000 nominations, only 6000 Sydney-siders won the opportunity to have a picnic breakfast on the Harbour Bridge.

Syngenta's Yuumi Ishizaki, Procurement Specialist, was one of the lucky people who got to enjoy this incredible experience.

"The 5.30am start to join Breakfast on the Bridge was well worth it," she said.

"It was one of the greatest Aussie events that I have been involved in.

"We started walking from Milson's Point station, and took advantage of the free coffee, which we badly needed by 6:30am, at the freeway entrance.

"The event included entertainment such as live bands, cows on the bridge, fresh produced foods and beautiful turf to sit on.

"Many of us brought our own picnic sets with homemade breakfast and enjoyed every moment of this spectacular morning," Yuumi added.

"I'd have to say 'thanks' to the organiser for ending the event prior to the heavy storm!"

After the event, forty percent of the turf was laid on parkland at Sydney Olympic Park, while the rest will be sold to the community.

NSW Minister for Tourism, Jodi McKay, said the event will provide a fantastic international advertisement for the energy and vibrancy of Sydney.

"Images from the event will be sent around the world, particularly to our key tourism markets," she said.

"It will highlight that Sydney is a unique and exciting destination."

So now, as well as looking after the some of the world's most famous sporting surfaces (including the "Bird's Nest" stadium in Beijing and Etihad Stadium in Melbourne), Syngenta's turf products have contributed to turning a world-famous bridge into a world-famous picnic ground... if only for a few hours.

Story by Patrick Madden, Yuumi Ishizaki and Gemma Butler-Fleming. Photos courtesy of Elders Windsor and Yuumi Ishizaki.

A first for turf

Daria Gonetskaya — Wed, 28 Oct 2009 01:52:39 GMT

A first for turf – HEADWAY MAXX

A revolutionary fungicide has been developed by Syngenta – and it is the only fungicide available on the market to control and prevent the four most problematic and costly diseases in turf. HEADWAY MAXX is registered for the control and prevention of importantly pythium, dollar spot, winter fusarium, brown patch, anthracnose, helminthosporium complex and others.

Syngenta have taken the 28 day residual strength of HERITAGE MAXX and combined the fast knockdown technology of BANNER MAXX. What’s more, the cost of HEADWAY MAXX is far less than the combination of these two trusted fungicides.By combining azoxystrobin and propiconazole, Headway MAXX provides dual systemic control and protection, above and below the ground. Furthermore, a proportion of the azoxystrobin remains on the outside of the leaf to provide contact protection as well.

To be amongst the first to try the only fungicide to control and prevent the four most problematic diseases in turf, contact your Syngenta agent or call the Syngenta Technical Product Advice Line on 1800 067 108.

Controlling Parramatta Grass

Daria Gonetskaya — Mon, 26 Oct 2009 04:24:00 GMT

Parramatta grass is one of the most evasive and difficult weeds to control on Australian and to a lesser extent on South African golf courses. Native to Africa, there are three main species of parramatta grass: Giant Parramatta grass (Sporobolus fertilis formerly S. indicus var major), a smaller species of Parramatta grass (S. africanus), and Giant Rats Tail grass (S. pyramidalis).

Parramatta grass is a warm season perennial weed (C4) that is tolerant to high light and temperatures. It is more efficient in the use of water than couchgrass or kikuyugrass giving it a competitive advantage in semi-arid environments. During winter, Parramatta grass growth slows and its metabolic rate is reduced, which is one reason herbicidal control lacks consistency.

Parramatta grass germinates in spring and rapidly develops producing flowering stems during mid-summer. It is a profuse seed producer able to produce 300 seeds/head. Seed banks (seed in soil) have been reported as high as 600-4000 seeds/m2.

Suggestions and Ideas for Control:

Light infestation: If Parramatta grass is just beginning to appear, spot spraying with glyphosate is one possibility. In addition, you may want to dig up the clumps or patches. If the turf that is present is kikuyugrass, add sprigs to the spots. Kikuyugrass sprigs are very competitive against germinating Parramatta grass seeds. If seed stalks are present when cutting, collect the clippings and dispose off site. This may help reduce seed dispersal.

Heavy infestation: If digging up patches of Parramatta grass, or spot spraying is impractical, control becomes more difficult. One potential method would be to look into a wick wiping devise to apply glyphosate. The Australian Pesticide and Veterinary Medicine Authority (APVMA) has issued a permit (PER4697) for the application of glyphosate by wick wiper on giant Parramatta grass.

If a wick wiper method is not practical or suitable, experiment with making your own application unit. One suggestion would be to take a short pole or pipe made from something that does not absorb a herbicide (ex. polyvinyl chloride), rap a portion of it with a cotton cloth and dip with appropriate glyphosate solution, and brush it across the parramatta grass (especially effective if the weed is growing taller than the desired turf). Multiple applications will be needed, with multi-season applications.

Summer Pre-conditioning: PGRs

Daria Gonetskaya — Mon, 26 Oct 2009 04:23:02 GMT

Research has found that applications of cytokinin to the root system (Cytokinins are synthesized in the root tips and transported via xylem) alleviated leaf senescence and improve turf quality (Wang, et al., 2004). Further research has found that cytokinin containing seaweed and humic acid extracts increased plant cytokinin levels possibly leading to improved drought tolerance (Zhang and Ervin, 2004).

Trinexapac-ethyl (Primo® MAXX), a plant growth regulator, increases levels of zeatin riboside one of the more prevalent and bioactive cytokinins (Ervin & Zang, 2004). The increase plant levels potentially could increase the heat tolerance and drought tolerance of the turf. To get the desired effect multiple applications need to be initiated prior to the stress period.

* The potential for prestress conditioning with existing products may allow for treating plants prior to stress to survive the stress. Products that either provide cytokinins (seaweed extract for example) or stimulate plant production (trinexapac-ethyl) applied prior to the stress may provide stress tolerance.

Hunting Billbugs Active in Spring

Daria Gonetskaya — Mon, 26 Oct 2009 04:19:59 GMT

On warm season turfgrasses primarily couchgrass (Cynodon spp.) and zoysiagrass (Zoysia spp.) billbugs can cause serious damage. There are a several different billbug species that can cause damage but the predominant species is the hunting billbug (Sphenophorus venatus). Hunting billbug adults are active early spring through late autumn with the greatest activity spring through mid-summer.

Adult females may lay eggs from spring through autumn. The adult Hunting billbug is rather compared to other billbug species approximately 13 to 16 mm in length. Although adults normally appear black, they may vary from a red-brown to black colour.

Billbug larval feeding is most active during the summer months. However, damage is normally not detected at this time because of the rapid growth of couchgrass. Damage is most evident in autumn and early spring. Diagnosis is often difficult. Look for small patches of that appear dead. Look closely at the stems and leaves since they will be straw colored. You may then tug on these plants to see if they are easily removed, which is a sign of billbug damage.

LDS Research

Daria Gonetskaya — Mon, 26 Oct 2009 04:19:30 GMT

The phenomena of hot spots appearing on upslope portions of USGA constructed and California constructed putting greens has been investigated by a researcher, Dr. Edward McCoy, at The Ohio State University. Supported by field data, Dr. McCoy has developed computer models that simulate water movement in sloped USGA and California greens. In USGA constructed greens a perched water table is produced at the interface between the rootzone mix (sand and peat) and a gravel layer. The perched water table provides water to turfgrass roots in the rootzone mix. Interestingly, in Dr. McCoy s simulation a perched water table is also produced in the California constructed greens.

In the computer models a heavy rain event was simulated to both types of green with a 3% slope and then volumetric water content in the profile was monitored. In both systems the profiles can dry out substantially within 2 days. The perched water table was observed to migrates down slope. The result is little if any water is supplied by the perched water table to the rootzone mix on the up slope.

Moisture loss to sloped areas of high sand content greens occurs rapidly. These areas will begin to suffer moisture stress within days of a relatively heavy rainfall event. To anticipate the appearance of these dry areas monitor with a soil probe or similar device to detect the relative dryness. Try to anticipate the dryness and irrigate (usually by hand) these sloped areas prior to the appearance of the hot spots.

Dollar Spot Control: Spray Volume

Daria Gonetskaya — Mon, 26 Oct 2009 04:15:42 GMT

Dollar Spot is a major disease of cool season turfgrasses including creeping bentgrass (Agrostis palustris) and wintergrass (Poa annua). Since frequent fungicide applications are often required during the growing season, micro climate conditions can affect efficacy. In a recent study, researchers at the University of Maryland looked at spray volume and dew removal on the effectiveness of two fungicides for dollar spot control (McDonald, et al., 2006). The two fungicides used were chlorothalonil (contact) and propiconazole (penetrant).

Chlorothalonil (Daconil Weatherstick®) provided better dollar spot control when applied in the afternoon versus the morning hours. It also was more efficacious when applied in 468 litres of water per hectare compared to 1020 litres of water per hectare. When applications were made in the morning - when dew had been removed - were more efficacious than when applications were made with dew present. It appears that the more water that is present tends to dilute chlorothalonil and reduce its effectiveness.

In the case of propiconizole (Banner MAXX®) applied alone or in combination with chlorothalonil spray volume and/or dew removal had no effect on dollar spot control.

From this study, disease control is influenced by the type of fungicide and conditions present at time of application. As a general recommendation, fungicide applications for dollar spot should be made when the turf is dry.

Reference
McDonald, S.J., P.H. Dernoeden, C.A. Bigalow. 2006. Dollar spot control of creeping bentgrass as influenced by fungicide spray volume and application timing. Online. Applied Turfgrass Science dol:10.1094/ATS-2006-0531-01-Rs.

Danger from Lightning

Daria Gonetskaya — Mon, 26 Oct 2009 04:12:44 GMT

From destruction of trees, irrigation control systems, and even death to maintenance facility workers to golfers, lightning is probably the most prevalent weather risk faced by golf courses. Below are some facts regarding lightning and suggested precautions to take during a storm.

Lightning Facts

* The earth hosts over 16 million storms and 3 billion lightning strikes a year.

* Lightning can heat up to 33316 degrees Celsius (~ 5 times the temperature of the sun). * Lightning carries 1 billion volts and 10,000 to 20,000 amperes of current.

* Lightning can travel 40 to 75 kilometres horizontally prior to turning downward to the ground.

* A flash can be ten to thirteen kilometres long.

* The actual thickness of a lightning bolt is that of a 50-cent piece, though the surrounding light makes it seem much larger.

* The ground surface can be lethal up to a 18-meter radius at the time of the strike. If the strike occurs in water, that increases to 185 meter radius.

Facts compiled from The Weather Channel, National Weather Service, and Automated Weather Service, Inc.

Estimating the Distance from a Thunderstorm

Because light travels much faster than sound, the lightning flash is observed before the thunder is heard. You can estimate the number of miles you are from a thunderstorm by counting the number of seconds between a flash of lightning and the next clap of thunder and then dividing by five. It should be noted that you are in danger from lightning if you can hear thunder. Knowing how far away a storm is does not mean that you're in danger only when the storm is overhead.

Precautions to Take When Outdoors

* Attempt to get into a building or car.

* If no structure is available, get to an open space and squat low to the ground as quickly as possible. If in the woods, find an area protected by low clump of trees - never stand underneath a single large tree in the open.

* Crouch with hands on knees.

* Don't stand in water.

* Avoid tall structures such as towers, tall trees, fences, telephone lines, or power lines

* Stay away from natural lightning rods such as golf clubs, car carts, or maintenance equipment.

* Stay away from bodies of water.

* If you are isolated in a level field and you feel the hair stand on end (which indicates that lightning is about to strike), bend forward, putting your hands on your knees. A position with feet together and crouching while removing all metal objects is recommended. Do not lie flat on the ground.

Source: FEMA, www.fema.gov/hazards/thunderstorms/thunderf.shtm

Facts on Poa Annua

Daria Gonetskaya — Mon, 26 Oct 2009 04:12:05 GMT

Below are some interesting research facts regarding Poa annua seedhead potential and growth (source: Lush, W.M. 1988. Journal of Applied Ecology 25,977-988.)

* Poa annua uses 4 to 35% of its top growth (dry weight) for seed production. As a reference, annual plants like cereals invest 20 to 50% of their top growth for seed production.

* Annual seed production on a golf green is between 150,000 to 650,000 seeds per metre squared per year. The majority of this seed would be produced in early spring through the middle of summer.

* Approximately 75,000 to 225,000 tillers per metre squared per year flower.

* During the growing season Poa annua tiller mortality is roughly 100,000 tillers per metre squared per month. Poa annua has a strong potential for replacing dying tillers with new ones. Obviously sustaining favorable growth through the season is critical in maintaining Poa annua turf.

* Poa annua dispersal is passive. The mechanism of dispersal is by human (animal) or equipment. Poa annua has been found where human disturbance has occurred (all 7 continents).

Spring Disease: Microdochium Patch

Daria Gonetskaya — Mon, 26 Oct 2009 04:11:47 GMT

Microdochium patch (pathogen: Microdochium nivale) also known as fusarium patch and pink snow mold is active during cool wet weather of spring. Microdochium patch is mainly a problem on winter grass (Poa annua) and creeping bentgrass. Symptoms may appear as circular patches reddish-brown in colour. Symptoms also appear in a streaking pattern along drainage areas, in mowing patterns or in low-lying areas. Microdochium nivale produces an abundance of spores that spread by water causing the streaking pattern. Often times this streaking pattern is mistaken as cool temperature pythium. If you think you have cool temperature pythium, you probably have Microdochium patch.

Yellow Patch

Daria Gonetskaya — Mon, 26 Oct 2009 04:11:29 GMT

On both warm and cool season turfgrasses, Yellow patch can occur during early spring. This disease is caused by Rhizoctonia cerealis and has numerous common names include yellow patch, cool-weather brown patch, cool-temperature brown patch, and winter brown patch. Symptoms appear as light brown, yellowish rings or patches with leaf lesions often absent. On warm season turfgrasses, this disease occurs less often however can occur on couchgrass and kikuyugrass (photograph). Patches may reach several metres in diameter. Favourable conditions for disease development on both cool and warm season turfgrasses include prolonged cool wet conditions.

Leaf Spot on Kikuyugrass

Daria Gonetskaya — Mon, 27 Jul 2009 01:45:45 GMT

During periods of cool wet weather leaf spot is a serious disease of kikuyugrass (Pennisetum clandestinum). The disease is commonly found on kikuyugrass race tracks, and golf course fairways and roughs. The pathogen Bipolaris australiensis (teleomorph: Cochliobolus australiensis), is active across a wide range of temperatures, however the optimal temperature is 15-18 C. A moisture film is necessary across the leaf blade for infection to occur. Prolonged periods of foggy or overcast days favor disease development.

Leaf lesions are irregularly shaped and brownish green to black. The leaves may eventually die and appear a light tan color. If infection spreads to the crown, stolons or rhizomes, extensive plant damage can occur. Cultural practices should be targeted to minimise stress to the plant. Avoid excessive rates of nitrogen during times of disease development.

Kikuyugrass Captures Light Efficiently

Daria Gonetskaya — Mon, 27 Jul 2009 01:45:25 GMT

Kikuyugrass (Pennisetum clandestinum) is a warm season grass (C4 grass) similar to that of couchgrass or zoysiagrass. Kikuyugrass however maintains a higher rate of photosynthesis at cooler temperatures than most warm season grasses including couchgrass. The ability to capture energy at cooler temperatures especially during autumn may account for large amount of leaf area accumulated during the warmer temperatures. This accumulated leaf area probably makes kikuyugrass more productive than any other C3 or C4 grass grown under the same conditions.

To account for the large accumulation of plant material, management practices need to be designed with this in mind. Vertical mowing on a monthly basis is a means of reducing leaf tissue and minimising thatch accumulation. Coring, at least two or three times a year is needed to help manage thatch accumulation and promote rhizome development.

Nitrogen should be applied judicially. The nitrogen requirements of kikuyugrass are considerably less than those of couchgrass. If effluent water is used for irrigation the amount of nitrogen also applied is sufficient in many cases.

Looking Ahead: Establishing Seashore Paspalum

Daria Gonetskaya — Mon, 27 Jul 2009 01:44:48 GMT

Seashore paspalum (Paspalum vaginatum) is native to tropical and subtropical regions of the world. As a turfgrass, seashore paspalum is adapted to high salinity soil or water conditions. When maintained at mowing heights below 2.5 cm it can produce a turf surface comparable to couchgrass.

In saline soil situations, initial establishment of seashore paspalum is difficult. Juvenile roots whether those of seashore paspalum or couchgrass are sensitive to salt concentrations during establishment, especially root hairs.

The initial steps in preparing for planting should begin 2 or more weeks prior to panting date. The planting date is similar to when you would establish couchgrass.

Gypsum should be applied to replace Sodium in the surface layer and improve water infiltration. The recommended rate would be 100 to 200 grams m-2 (20 to 40 lbs/1000 sq.ft.). Irrigation should begin immediately after application and keep the soil moist. Prior to planting an intense irrigation should be done to leach as much salts downward past the root zone.

Once the leaching process is accomplished, plant seashore paspalum while the soil is still moist and water to maintain field capacity. If the soil dries, the salts will rise back into the rootzone through capillary pore driven by evaporation. After planting frequent irrigation is needed to prevent any excessive drying in thee upper 5 to 20 cm of the soil surface.

Microdochium Patch

Daria Gonetskaya — Mon, 27 Jul 2009 01:40:51 GMT

Microdochium patch (pathogen: Microdochium nivale) is active in many areas of southern Australia (NSW, Victoria). The disease, also known as pink snow mold where snow cover is present, and as Fusarium patch or Winter Fusarium where no snow cover has been present, is attacking both short cut wintergrass (Poa annua) and ryegrass. Microdochium patch is active under cool wet conditions. Temperatures in the range of 0 to 7 C are ideal for this pathogen to infect along with prolonged periods of wetness.

Symptoms initially appear as small patches that commonly increase in size reaching 25-cm in diameter. Leaves become water soaked, turn reddish-brown, then bleach. Pink mycelia may be visible in early morning. In cool wet weather, the leaves are matted together, which is especially true on high cut turf, and covered with a whitish pink mycelial growth that is slimy when wet. The circular patches may exhibit a pink coloration when exposed to light.

Click on picture to view a larger image Microdochium patch may be misdiagnosed as cool temperature pythium. The pathogen, Microdochium nivale produces a profuse number of spores (canoe shaped) that are easily spread where water flows. Under wet conditions, symptoms may appear as streaks caused by the spores being washed along drainage areas.

NEW ADVANCES IN HERBICIDE USE

Daria Gonetskaya — Fri, 24 Jul 2009 01:51:09 GMT

WHEN Wednesday 9 September 2009, 0900 - 1530

WHERE Epping Club Rawson Street Epping

Easy rail access from Epping station

For full details see website www.nswweedsoc.org.au or contact:

Mike Barrett 98753087 Mobile 0407 062 494

Alan Murphy 43413574 Mobile 0404 097 732

Please click here to download a payment slip

High Shoot Density Bentgrasses Need Topdressing

Daria Gonetskaya — Mon, 20 Jul 2009 01:53:23 GMT

Increasingly we are seeing the high shoot density creeping bentgrass cultivars like the Penn "A" and "G" series being established on putting greens throughout Australia. It's obvious the popularity of these cultivars is due to their almost billiard table look and the ability to mow these cultivars at a low height of cut. In addition they appear to be more competitive against annual bluegrass than the older cultivars like "Penncross".

The major agronomic problem with these greens is the rapid rate in which thatch can accumulate. An excessive thatch layer on any creeping bentgrass green reduces their ability to tolerate environmental stresses including heat and drought. In addition, thatch mitigates or buffers ball roll thus reducing the ability to increase roll rapidly. Practices that minimise thatch accumulation are critical. Topdressing is one practice that is important in minimising/diluting the thatch layer. With these high shoot density cultivars a light weekly topdressing program is required. Less frequent topdressing just does not seem to cut it.

In a recent research paper out of Texas, they looked at controlling ultradwarf bermudagrass thatch with topdressing and found that light biweekly applications or twice yearly heavy applications were not effective in minimising thatch accumulation (1).

Although topdressing is only one practice that can help manage thatch, a weekly topdressing program will be needed to minimise thatch accumulation on high shoot density creeping bentgrass cultivars.

Overseeding Sports Fields

Daria Gonetskaya — Mon, 20 Jul 2009 01:52:53 GMT

How effective is over-seeding on high traffic areas? Is the practice of over-seeding a waste of money if there is no grow-in time for the seed between field use? Clearly, the alternative to over-seeding high traffic areas is to do nothing at all, save the money and play on mud.

Research on overseeding high traffic areas was undertaken by Dr. Frank Rossi at Cornell University*. The research area was not irrigated, received 10 g/m2 N over the year and was subjected to simulated traffic 5 days/week. Following is an overview of those results:

Non-overseeded plots were less than 50% covered with turf and in some cases 20% weeds.
Among the species, Kentucky bluegrass (Poa pratensis) and tall fescue (Festuca arundinacea) had lower density than perennial ryegrass (Lolium perenne)species without overseeding.
Overseeding with Kentucky bluegrass proved completely ineffective under regular traffic.
Weekly overseeding with either perennial ryegrass or tall fescue at 30g/M2 provided excellent season long turf density. Perennial ryegrass was able to maintain 90% density when overseeded weekly.
There was no difference between the 30 and 50 g/M2 rate.* Monthly overseeding of perennial ryegrass provided equal to or better density than the weekly tall fescue overseeding, independent of seed rate.

Reference:
Dr. Frank Rossi "Field Renovation via Overseeding", Cornell University Turfgrass Times, Summer 2002

Off Type Couch?

Daria Gonetskaya — Mon, 20 Jul 2009 01:52:18 GMT

In vegetative established couch varieties like Tifdwarf, Tifeagle, Tifgreen and Champion, off-type couch may occur over time in putting greens. Two major reasons given for the occurrence of these off-types are 1) mutations occur due to genetic instability, and 2) contamination of the desirable plant materal with a foreign source. In a recently published article (Capo-chichi, et al. 2005) the authors were able to induce off-type couch in Champion and other vegetative couch varieties with repeated applications of dinitroaniline herbicides. From a research perspective these mutational changes resulted in genetically diverse off-types that could be important in evolutionary processes regarding couchgrass off-types. From a management perspective avoiding overuse or excessive use of dinitroaniline herbicides may delay off-type occurrance in vegetatively established greens.

Reference:
1. Capo-chichi, L.J.A., J.M. Goatley Jr., W. Philley, J. Krans, D. Davis, A. Kato, and E. van Santen. 2005. Dinitroaniline-induced genetic changes in bermudagrass. Crop Science 45, 1504-1510.

Phosphorus Fertilisation

Daria Gonetskaya — Mon, 20 Jul 2009 01:51:50 GMT

Phosphorus is a major element that is especially critical during turf/seedling establishment. In mature stands, phosphorus is a critical component important in the energy (ATP) required for growth. Deficiencies show as a slowing of growth and phosphorus deficient symptoms can eventually appear (bluish color leaf blades). A proper balance between soil phosphorus levels and that needed for growth is both environmentally sound and necessary for maintaining quality turf.

Dr. Wayne Kussow at the University of Wisconsin wrote a recent article (Phosphorus fact or fiction Landscape Management 42:56-58,60,62) where he mentions 2 general hints that might help you plan your phosphorus program. The first is major nutrient analysis of leaf clippings remains rather constant for turfgrasses. The ratio of nitrogen (N), phosphorus (P2O5) and potassium (K2O) roughly falls in a 4:1:3 ratios. By using a fertiliser with an N: P2O5 ratio of 4:1 you will roughly maintain the current soil test levels of phosphorus. If you use a ratio less than 4:1 such as 2:1 or 3:1 you will contribute to the phosphorus levels in the soil. On the other hand if you use a fertiliser ratio greater than 4:1 like 8:1 or 10:1 you will slowly deplete the phosphorus in the soil. You can either build-up, maintain, or deplete phosphorus levels over time by the fertiliser you use.

In addition, from research at the University of Wisconsin, it takes roughly 5 grams P2O5/ m2/year to maintain soil test levels when clippings are removed. If clippings are returned that amount drops in half to 2.5 grams P2O5/m2/year. Phosphorus levels in the soil are impacted by climate, growing season, and soil texture to name just a few. However, the 4:1 ratio and 1 lb rule for clippings removed is a good base to start designing a phosphorus fertility program