drive xlr8 katana manor onetime q4 plus quincept revolver...

SportsTurf 11www.stma.org

read all precautions on turfgrass sensitivity toproducts and timings.

Company websites readily allow access to andthe downloading of product labels and MSDS’s.Manufacturers and suppliers maintain toll-freenumbers for the purpose of providing answers toany technical question you may have on theirspecific products. You can also contact your localextension office. ■

Brad Fresenburg is an assistant extension pro-fessor for the University of Missouri in Turfgrass Sci-ences. He can be reached by email [email protected].

Trade Name Common Name Turfgrass Species*

Certainty sulfosulfuron B, Bh, C, K, SP, StA, Z

Dimension Ultra dithiopyr B, C, K, SP, StA, Z, KB, TF, PR

Drive XLR8 quinclorac B,SP, Z, KB, TF, PR

Katana flazasulfuron B, C, SP, Z

Manor metsulfuron-methyl B, C, StA, Z, KB

Monument 75WG trifloxysulfuron B, Z

Onetime quinclorac + MCPP + dicamba B, SP, Z, KB, TF, PR

Q4 Plus quinclorac + sulfentrazone + B, KB, TF, PR 2,4-D + dicamba

Quincept 2,4-D + quinclorac + dicamba B, Z, KB, TF, PR

Revolver foramsulfuron B, Z

Solitare sulfentrazone + quinclorac B, C, SP, Z, KB, TF, PR

Tenacity mesotrione C, KB, TF, PR

Grass and Broadleaf Weed Control Products

Trade Name Common Name Turfgrass Species*

Certainty sulfosulfuron B, Bh, C, K, SP, StA, Z

Monument trifloxysulfuron B, Z

Prosedge halosulfuron-methyl B, Bh, C, K, SP, StA, Z, KB, TF, PR

Sedgehammer halosulfuron-methyl B, Bh, C, K, SP, StA, Z, KB, TF, PR

Sedge Control Products

*Bermuda (B), Bahiagrass (Bh), Centipede (C), Kikuyugrass (K), Seashore Paspalum (SP), St. Augustine (StA), Zoysia (Z), Ky. Bluegrass (KB), Tall Fescue (TF), Perennial Ryegrass (PR)

TURFGRASS KEY:

12 SportsTurf | May 2012 www.sportsturfonline.com

ROOT SYSTEMSTurfgrasses have two different root sys-

tems during their lives. The primary systemdevelops from the embryo and emerges di-rectly from the germinating seed. This rootsystem provides for water and nutrient up-take for the tiny seedling and functions ac-tively for 6 to 8 weeks. Shortly after the firstleaf emerges, a secondary, adventitious rootsystem begins to form. This root systemoriginates from buds at nodes on the lowerpart of the crown. It will become the mainfunctioning root system for the plant. Ad-ventitious roots will also form from buds atnodes on the new crowns of the lateral

stems: stolons, rhizomes and tillers. Theseroot systems support the new plants and arecritical to increasing and maintaining adense turf shoot system.

Turfgrass roots are fibrous and multi-branched. The tip of each root is covered bya thickened cap which protects the tender

meristem (growing point) right behind itas the root bores through soil. The meris-tem replenishes the root tip and providesfor growth of new cells in the root. Asmore new cells are created, the older cellsbehind the meristem stretch and lengthen.This enlarging and elongating actionpushes against the root cap and is whathelps to make the root grow longer andwider.

As a root matures some of its cells be-come specialized. The cells of the endo-dermis (the outer layer of the root) behindthe area of cell elongation are able to de-velop the long, slender, almost micro-scopic extensions called root hairs. Thesehairs greatly increase the root surface areathat is able to actively absorb water andnutrients. While the roots of most coolseason grasses can only form root hairsfrom specialized cells in the epidermiscalled trichoblasts, warm season grasseshave the advantage of being able to de-velop root hairs from almost all cells inthe epidermis.

Healthy turfgrass roots are wellbranched. In fact, the ability of a turfgrassplant to effectively compete for water andnutrients is directly related to the extent ofbranching.

Just as different grasses vary in theirleaf texture or color or growth habit, sotoo do they vary in the size, depth anddistribution potential of their root sys-tems. Warm season grass root systemshave the potential to grow more deeplyand more extensively than the finer, shal-lower systems of cool season grasses.

A new root is white and slender. As it

ROOTS 101:building tough turf from the bottom up

>> HEALTHY ROOTS are white, substantial,and vigorous. These St. Augustinegrass rootsare particularly thick, much wider than mostcool season grass roots. As roots maturethey are able to branch and so become moreefficient in absorbing water and nutrients.

Healthy turfgrass roots are well branched.In fact, the ability of a turfgrass plant toeffectively compete for water and nutrients isdirectly related to the extent of branching.

Roots are the foundation of a turf. They perform functions vitalfor plant growth. This article will discuss the structure and func-tion of roots, the effects of the environment and cultural practices

on root growth, and strategies for increasing rooting.

Continued on page 16

FieldScience | By Mary Owen


FieldScience

matures, it turns brown and becomes thin-ner. Its ability to absorb water and nutrientsdeclines. Eventually the whole root will dieand will slough off just below the crown.This cycle of root growth, maturity, senes-cence, death and replacement is a naturaland ongoing process. Its rate can be dramati-cally influenced by the environment, climate,soil conditions or cultural practices.

HOW DO TURFGRASS ROOTS GROW?

Cool-season grasses. To understand thecycle of cool-season grass root growth, con-sider the cycle of carbohydrate productionand use. In photosynthesis, plants use theenergy of sunlight to produce carbohydratesfrom CO2 and H2O. These carbohydrates,when broken down through the process ofrespiration, provide energy to the plant.Roots do not contain chlorophyll and socannot photosynthesize. They depend onthe shoot system for carbohydrates for theirenergy needs. The absorption of nutrientsfrom the soil by the roots and the move-ment of water and nutrients from cell tocell within the root require energy.

The roots of cool-season grasses grow

and function most vigorously when soiltemperatures are cool. The most intense pe-riod of root initiation and growth is in thespring. A slightly less active period occurs inthe fall. The temperatures for maximumroot growth are slightly lower than those formaximum shoot growth, and so roots willbe functioning and growing before shootgrowth begins in the spring and as shootgrowth slows and stops in the fall. Carbohy-drates are moved into stems and to a lesserextent into roots as late season growthwinds down, providing for slow but contin-ued growth in cold (not frozen) soils untilactive growth resumes in spring.

Cool-season grass shoot growth is mostefficient at air temperatures of 60–75Fwhile root growth is most efficient at soiltemperatures of 55–65F.

When air temperatures rise in summer,the efficiency of photosynthesis in cool-sea-son grasses is reduced. The leaves producefewer carbohydrates. Energy available forroot growth and work is reduced and as aresult root growth slows. As root growthslows, the root system becomes limited inits ability to absorb water and nutrientsfrom the soil and transmit them to theother parts of the plant.

As air temperatures rise, soil tempera-tures will follow. As soils warm, root respi-ration in cool season grasses increases. Asrespiration increases more carbohydrates areused up. So, when temperatures warm, theuse of carbohydrates increases while thesupply decreases. Eventually this can lead toroot starvation and death. Roots will not bereplaced, and the result will be a net loss ofroots to sustain the rest of the turfgrassplant until cool weather resumes.

Under drought conditions, some grassesactively shift carbohydrates to the roots,particularly the roots which are in thelower, moister part of the rootzone. Thisshifting of carbohydrates can serve to sus-tain the root system where it can harvestwater, and thus provide a direct benefit tothe shoot system.

Warm-season grasses. Photosynthesis ismore efficient in warm-season grasses thanin cool-season grasses. As temperature andlight increase, so too do shoot and rootgrowth. Root initiation and activity peak inlate spring and summer. When tempera-tures cool down, root as well as shootgrowth slows. When the plant enters dor-mancy, root growth ceases. The peak loss ofroots for warm-season grasses occurs inwinter, particularly late winter. Warm sea-son shoot growth is most efficient at airtemperatures of 80–95F while root growthis most efficient at soil temperatures of 75–85F.

WHAT DO TURFGRASS ROOTS DO?

Roots absorb water. Roots are the prin-cipal entryway for this essential compound.Water is needed to maintain turgor, forphotosynthesis, for the transport of materi-als, and for many other processes in theplant. Water is needed to replace transpira-tional loss as well as that lost throughmown leaf ends.

Roots absorb nutrients. While carbon,hydrogen and oxygen, the main buildingblocks of organic compounds, are derivedfrom the atmosphere and from water, theremaining essential mineral nutrients areprincipally absorbed from the soil by theroots. Nutrients do not just “seep into” orpassively move into roots. The process ofnutrient uptake and absorption requires en-

>> EXCELLENT ESTABLISHMENT PRACTICES, proper wateringand prudent fertility lead to the growth of deep roots, as seenin this sample from a seedling sports turf.

Continued from page 12


Problem: Green line behind fieldTurfgrass area: Soccer fieldsLocation: Callaway, FLGrass Variety: 419 Bermudagrass

Answer to John Mascaro’s Photo Quiz on Page 33

Can you identify thissports turf problem?

Bac

kgro

und

illus

trat

ion

cour

tesy

of is

tock

phot

o.co

m

John Mascaro’s Photo QuizJohn Mascaro is President of Turf-Tec International


FieldScience

ergy. This energy comes from respiration:the breakdown of carbohydrates in the pres-ence of oxygen with a subsequent release ofenergy. When carbohydrate reserves are lowor not available, roots will not have the en-ergy needed to absorb nutrients.

Deep, extensive root systems are able toaccess more nutrients and more water froma larger volume of soil than can weaker,shallower root systems.

Roots anchor plants. Plants with exten-sive root systems are less likely to divot andslip. Plants with deep and extensive rootsprovide a more stable and safer playing sur-face.

Roots encourage microbial activity.Healthy functioning roots exude organic

materials that can serve as an energy sourcefor the populations of various microorgan-isms in the zone immediately around theroot, the rhizosphere. Many of these mi-crobes have the capacity to mineralize or-ganic matter, that is, break down organicmatter into compounds that can provide forsome of the nutritional needs of the plant.The amount of root exudates can highly in-fluence soil microbial communities. Whengrass growth is suppressed by high tempera-ture stress, as may happen with cool-seasongrasses, the production of root exudates hasbeen shown to decline. This decline is likelythe result of the lack of initiation of newroots in combination with root mortality.

HOW CAN YOU ENHANCE ROOT GROWTH?

Know the factors that will compromiseroot growth, and manage so as to minimizetheir negative effects. Excessive wear andcompaction, shade, incorrect watering prac-tices including excessive or inadequate irri-gation, drought, temperatures notconducive to root development, and exces-sive or inadequate fertility will all lead to re-duced rooting.

Pay attention. Make regular inspectionof the root system a habit. Note its depthand distribution. How does its conditionrelate to time of year, climate and yourmanagement? Increased depth and breadthof rooting allow the roots to harvest from agreater volume of soil, thus requiring lessneed for irrigation and applied nutrients,particularly nitrogen. Making good rootsmakes good environmental sense.

Maintain a well aerated rootzone. Thedepth and extent of roots as well as rootbranching increase when the rootzone iskept well aerated. Roots expend less energyas they bore through the soil. Roots inpoorly aerated soil tend to be thicker in di-ameter and less branched than roots grow-ing in well aerated soil. These roots areinefficient at water and nutrient uptake.

Good drainage, both surface and subsur-face, management of thatch, relief of com-paction and appropriate topdressing inconjunction with aeration practices will en-sure a well aerated soil.

Manage thatch. While a small amountof thatch can be beneficial to the perform-

ance of a sports field, excess thatch cancause problems. In addition to interferingwith proper water and air movement,thatch provides a harbor for insects and dis-ease organisms. Excess thatch will result inreduced rooting with a subsequent reduc-tion in water and nutrient uptake. Rootsthat do develop within the thatch layer willfind little nutrients to absorb there, and willhave difficulty absorbing water. The sportsfield management plan should provide stepsthat keep thatch in check.

Manage traffic. Wear can lead to a sig-nificant reduction in rooting. Using agro-nomic and field scheduling strategies thatminimize wear and encourage shoot densitycan result in increased root biomass anddepth. The greater the mass and the deeperthe roots, the more nutrients and water theplant can access to support the shoot sys-tem.

Irrigate intelligently. Irrigation eventsshould be spaced as far apart as possiblewithout sacrificing turf quality. Frequencyand duration of irrigation will be deter-mined by type of rootzone, environmentalconditions, amount and intensity of traffic,and many other factors. Turf watered deeplyand infrequently, using a wilt-based irriga-tion strategy, has been shown to have adeeper, more extensive and efficient rootsystem than turf watered frequently andshallowly.

New seedings should be watered so as toprovide adequate moisture for the germi-nating and developing seedlings. Keepingthe seedbed moist and gradually decreasingthe frequency and increasing the durationof irrigation events as the seedlings grow arecritical to encouraging rapid and deep root-ing and successful establishment.

Overwatering results in reduced rooting.As water fills the spaces in the soil, less oxy-gen is available for respiration, and the re-sult is less energy available for the grassroots to take up and absorb not only waterbut also nutrients.

Fertilize judiciously. Provide adequatenutrients at the proper time for balancedturfgrass shoot and root growth, with par-ticular emphasis on prudent use of nitro-gen.

As the levels of N applied to turfgrassesincrease, the amount of shoots increases

>> AERATION IS AN IMPORTANT TOOL for en-hancing root growth. This single plant was takennear the side of an aeration hole on a grass ten-nis court in early spring. Note the improved root-ing that is beginning as a result of aeration.

while the amount of rooting decreases.Focus on providing the lowest amount of Npossible without sacrificing the qualityneeded for sports field performance andsafety. The goal should be a dense, wear andstress tolerant shoot system and a deep,dense, stress tolerant root system.

While encouraging rooting, the practiceof keeping N levels at the minimum neededhas the added benefit of also lowering evap-otranspiration (ET), and so contributes towater use efficiency.

Time nitrogen applications so as to maxi-mize root growth; strive to maintain ahealthy balance between root and shootgrowth. Apply potassium before expectedstresses of heat, cold and possible droughtmay occur. Take care not to overly stimulateshoot growth during periods environmen-tally unsuitable for root growth (i.e. in thesummer for cool-season grasses).

Maintain soil pH at 6.0 – 6.8. Turfgrassroots grow very poorly at reduced pH, espe-cially at pH less than 5.0.

Mow appropriately. Maintain turf-

grasses at the highest height of cut (HOC)within their mowing tolerance range to en-courage deeper and more extensive rooting.Select cultivars of turfgrass species that havebeen selected for their adaptation to themowing height required of the sport.

Warm-season grasses are less dramaticallyaffected by low mowing. Bermudagrass es-pecially will tolerate low mowing withoutsignificant reduction in rooting.

Mow cool-season grasses as high and asinfrequently as possible given the use of theturf. This is especially important duringtimes of environmental stress. Low mowingcan dramatically reduce the depth and ex-tent of roots of cool-season grasses, thoughbentgrass is not as severely affected as theothers.

Maximize available sunlight. Turf-grasses grown in reduced light situations aremore prone to have weak, sparser root sys-tems. Where shade can be remediedthrough tree canopy pruning, it should bedone. Where shade cannot be remedied,then shade tolerant species and cultivars

should be chosen. Cultural practices shouldbe adjusted: reduce traffic, irrigation andfertility. Some professional stadia are experi-menting with supplementary lighting todeal with shade.

Take care with herbicide applications.Avoid using herbicides when turf is understress or when root growth is restricted.Bensulide, benefin, oxadiazon, oryzalin,pendimethalin, prodiamine, siduron, DCPAand other herbicides may inhibit rootgrowth. Healthy turf may be able to recoverfrom this quickly. However, a turf stressedby drought, heat, traffic or with a compro-mised root system may be more seriouslydamaged and take a longer time to recover.

Roots are the foundation of a turf. Atten-tion to the growth, development and healthof the root system can ensure not only a vig-orous, highly performing sports field, butalso result in the conservation of preciousenvironmental resources. ■

Mary Owen is extension educator & turfspecialist, University Of Massachusetts,



Facility&Operations | By Mark Lucas

IT ALL STARTED IN 2008with the economic downturn.Budgets were reduced and welaid off one groundskeeper on

the sports turf crew. I didn’t thinkthe state level of funding would beimproving in the foreseeable future.I also realized that my customers’ ex-pectations were not going to changelike the value of my house. Mostcoaches’ expectations would onlycontinue to rise with every road tripto schools with larger budgets. Thecompetition for recruiting athletes isimpacted by our facilities.

With consideration for thebudget and our needs for high-qual-ity athletic facilities, I started outtrying to find ways to maintain our

sports fields at UC-Davis with lessfunding. This is when I began to useorganic fertilizer on our campuscommon turf area that we call theQuad. It is 5 acres and has veryheavy traffic. Any given day we seehundreds of stu-

dents playing Frisbee, having lunch, relaxing, enjoyinglive music and holding rallies.

I wanted to see if we could achieve acceptable levels ofturf quality with organic materials, building the soil for amore sustainable nutrient release. By feeding micro-or-ganisms we are creating a living system in the soil thatproduces carbon, with an even flow of nutrients to theplant. We started using a bio-solid type (6-7-0) of fertil-izer that is a by-product of sewage treatment. The resultswere very positive with just two applications per year the

Economic solutionsand the environmentalbenefits at UC-Davis

We started using a bio-solid type (6-7-0) offertilizer that is a by-product of sewagetreatment. The results were very positivewith just two applications per year the quadhad a deeper green color with good growth.

>> EVERY COLLEGE TURF MANAGER knows that facilities are veryimportant in recruiting athletes.

>> SPORTS TURF MANAGER MARK LUCAS is part of a campus-wide sustainability effort at the University of California, Davis.

drive xlr8 katana manor onetime q4 plus quincept revolver...

Documents