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A. General information

B. Turfgrass and weed names

C. Mode of action

D. Weed control
    1. Annual bluegrass
        a. Perennial ryegrass.
            1) Seed fields
            2) Golf course fairways
            3) Overseeded bermudagrass
        b. Kentucky bluegrass
        c. Creeping bentgrass
        d. Dormant bermudagrass
        e. Sequential nitrogen and ethofumesate treatments
        f. Multiple year treatments
        g. Factors that influence the performance of ethofumesate
    2. Crabgrass
    3. Other weeds
        a. Goosegrass
        b. Prostrate spurge
        c .Dandelions and henbit
        d. White clover
        e. Rattail fescue
        f. Volunteer wheat

E. Turfgrass tolerance
    1. Perennial ryegrass
        a. Used as main turf
        b. Used as overseeding turf
    2. Kentucky bluegrass
    3. Creeping bentgrass
        a. Golf course fairways
        b. Golf greens
        c. Sequential ethofumesate plus other herbicides
        d. Sequential ethofumesate plus fertilizer
        e. Sequential ethofumesate plus Fe
    4. Red -chewing fescue
    5. Tall fescue
    6. Zoysiagrass
    7. Centipedegrass
    8. Rough bluegrass
    9. Bermudagrass

F. Bermudagrass suppression
    1. Zoysiagrass
    2. St. Augustinegrass
    3. Tall fescue
    4. Creeping bentgrass
    5. Seashore paspalum

G. Seedhead suppression with ethofumesate

H. Management practices with ethofumesate
    1. Rates
    2. Intervals between treatments
    3. Dates of treatments

I. Creeping bentgrass root growth

J. Drought stress of creeping bentgrass

K. Turfgrass renovation using ethofumesate
    1. Converting annual bluegrass to a desirable turf
    2. Converting perennial ryegrass to creeping bentgrass
    3. Converting a poor quality turf to perennial ryegrass

L. Seed germination effects-greenhouse/growth chamber
    1. Perennial ryegrass
    2. Bentgrass
        a. Colonial bentgrass
        b. Creeping bentgrass
    3. Kentucky bluegrass
    4. Red fescue
    5. Tall fescue
    6. Rough bluegrass
    7. Annual bluegrass biotypes
    8. Orchardgrass, wild oat, and rattail fescue

M. Research suggestions
    1. Cool-season grasses
    2. Bermudagrass overseeded with perennial ryegrass
    3. Bermudagrass suppression in warm-and cool-season grasses

N. Names and addresses of researchers
 

A print out of 188 references on response of ethofumesate in turfgrasses was obtained from the Information Center at Michigan State University. These data included the control of weeds and turfgrass tolerance. Data from approximately 50 references were selected from this group to include in the ethofumesate search.
 

The selection of ethofumesate references used were based on selected characteristics. These characteristics were:

    1. Multiple year or multiple location treatments within a year.
    2. Most of the articles were published in referred scientific journals.
    3. Some articles were published in Proceedings such as Northeastern Weed Science Society.
    4. Some articles were published in popular trade magazines such as The Golf Course Management and Ground Maintenance .
    5. Thesis, Field Day Reports, and State Research Reports from Universities were not Included.
    6. Abstracts of papers presented at scientific meeting such as the Weed Science of American and Crop Science of America were not included except:
        a) when at least two years of data were included
        b) when the data was from more than one location within a year
        c) occasionally data from a single year was included when the amount of data was limited for a given subject such as dandelions and prostrate spurge control.
    7. Data of ethofumesate from AgrEvo and Nor Am were included in this search when the data were published in a form that included one of the above    characteristics.

Common names will be used for all herbicides in this report.

Rates for herbicides in this report will be based on pounds active ingredient per acre.
 

Chemical name for ethofumesate is: (+)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranylmethanesulfonate

Trade name for ethofumesate is: Prograss

Chemical family:

Weed Science Society of America (Herbicide Handbook, 1994) reports that no chemical family for ethofumesate has been accepted. However, Callahan reported in Tennessee (1994) that ethofumesate belongs to the benzofuran group and it is the only turfgrass chemical that being used for a herbicide.
 

Herbicidal Use:

Ethofumesate can be applied as preemergence and postemergence to selected turfgrasses for control of weeds. Although ethofumesate has activity on several weed species, it is predominately used for annual bluegrass in cool-season grasses. In the South, ethofumesate is used primarily for annual bluegrass control in bermudagrass greens overseeded with perennial ryegrass. In cool-season regions, it is used for annual bluegrass control in golf course fairways seeded with perennial ryegrass, Kentucky bluegrass, and creeping bentgrass. In recent years, ethofumesate has shown activity in suppressing bermudagrass when mixed with selected cool and warm-season turfgrasses.
 

Behavior in Plants:

Ethofumesate is readily absorbed by emerging shoots and roots, and translocated readily to the foliage. Postemergence applied ethofumesate is poorly absorbed by maturing leaves with a well developed cuticle.

Research conducted in Tennessee ( Callahan, 1994) indicated that creeping Penncross bentgrass treated with ethofumesate caused abnormalities in root tips. When this occurred, it caused an overall weakening and thinness of root cells and making it easier for the cells to shatter. Other observed injury to bentgrass roots were a slight disruption in organization of cortical roots, enlargement of the cortical cells, and sparse occurrence of root hairs.

Callahan (1994) summarized the injury to creeping bentgrass treated with ethofumesate was observed by light green leaves, sparse shoot growth, and reduction in root mass growth.
 

Behavior in Soil:

Persistence in the soil reported by Weed Science Society of America (Herbicide Handbook, 1994) that the half-life of ethofumesate ranged from > 14 weeks under dry, cold conditions to < 5 weeks under warm, moist conditions. Researchers in UK (Haggar and Passman, 1981) reported that ethofumesate applied in October to a newly planted perennial ryegrass had a half-life just over 8 weeks. However, the herbicide persistence in the soil after 28 weeks was sufficient to reduce annual bluegrass population by 50%.
 

Transformation:

Negligible loses and microbially degraded in soil.

Volatilization:

Negligible losses.
 

Mobility:

Little leaching in the soils with >1% organic matter content. Ethofumesate is not readily leached below 15 cm (6-inches). Researchers in UK (Haggar and Passman, 1981) reported that ethofumesate was confined to the upper 2 cm of soil profile after 15 months.
 

Weed Control

When herbicides are used for weed control, they must control weeds consistently and effectively. However, for a herbicide to be acceptable it must not only control the weeds, but not cause any undesirable turfgrass injury. Ethofumesate has activity on several different weed species, but it has predominantly been used for annual bluegrass control in cool-season grasses and on bermudagrass greens, tees, and fairways overseeded with perennial ryegrass.
 

Annual bluegrass control in perennial ryegrass.

Perennial ryegrass can tolerate ethofumesate treatments better than any of the other cool-season grasses. However, rates and frequency of ethofumesate application needed for effective control will depends on usage of the grass.

Seed fields. In Oregon ( Lee, 1977), ethofumesate applied as PRE (preemergence) at 0.75 lb/A in early October or early POST (postemergence) in November at 1.0 lb/A to ryegrass fields for seed production controlled annual bluegrass completely the following March or early April before rapid ryegrass growth began. However, annual bluegrass was not as good from single applied ethofumesate treatment in September to field grown ryegrass in England (Haggar and Kirkham, 1981). Over a 3- year period, ethofumesate applied at 0.75 lb/A did not reduce dry weight of annual bluegrass the following June. The 1.4 lb/A reduced dry weight by only 46% while 2.8 lb/A reduced dry weight by 78%. The differences in control between locations may be in part to the different rating dates for March or early April in Oregon and June in England.

Fairways. Annual bluegrass control in perennial ryegrass fairway in Maryland (Dernoeden and Turner, 1986;1988) varied with ethofumesate rates and frequency of application. Ethofumesate applied once at 1.0 lb/A (September) controlled < 40% the following April compared to < 93% when applied twice at 1.0 lb/A ( September and October ). The control was improved to 99% when herbicide rate was increased to 2.0 lb/A and applied in each of two applications. At this location annual bluegrass control was similar whether applied once at 2.0 lb/A or twice at 1.0 lb/A.

Overseeded bermudagrass greens. Annual bluegrass was controlled completely in bermudagrass green overseeded with perennial ryegrass in North Carolina (Lewis, 1983 ) and Virginia ( Bingham, 1983 ) when ethofumesate was applied at 1.0 lb/A at time of overseeding late September or early October and repeated at the same rate 30 days later. However, the control was not as consistent when the second application was delayed for 60 days in North Carolina (55%) and Alabama (Dickens, 1979) ( 78 to 100% ).

Summary. Optimum annual bluegrass control can be obtained in perennial ryegrass in the United States with the 1.0 lb/A rate. However, frequency of application depends on where the grass is grown. A single application controlled annual bluegrass effectively in ryegrass field used for seed production while two applications were needed at a 30 day interval when perennial ryegrass was used on fairways or on overseeded bermudagrass greens.
 

Annual bluegrass control in Kentucky bluegrass.

The tolerance of Kentucky bluegrass is not as good as perennial ryegrass and creeping bentgrass.

In Nebraska ( Shearman, 1986 ) annual bluegrass control in Kentucky bluegrass was 93% when final ratings were made at 6 months after treatment with ethofumesate at 1.0 lb/A in each of two applications. The control with bensulide applied at 12.5 lb/A ranged from 51% at one month to 58% by 6 months after treatment. There was no advantage in control when ethofumesate was applied alone at 2.0 lb/A or when the 2.0 lb/A rate was followed by 1.0 lb/A four weeks later.

Annual bluegrass control in Virginia ( Bingham and Hall, 1987 ), was effective in a mixed Kentucky bluegrass and perennial ryegrass fairway when treated either with ethofumesate at  0.5 lb/A in three applications or with 1.0 lb/A in two applications. Ethofumesate applied at  0.75 lb/A in each of two applications in the fall reduced annual bluegrass the first year, but the control after the second year was near complete. The control was 80% when 1.5 lb/A was applied once in each of two years.

Summary. Annual bluegrass control in Kentucky bluegrass was consistent when ethofumesate was applied at 1.0 lb/A in each of two fall applications. It is also necessary to retreat the turf for annual bluegrass control the second year regardless of rates used during the first year.
 

Annual bluegrass control in creeping bentgrass.

Creeping bentgrass is more sensitive to ethofumesate than perennial ryegrass. However, when using a lower herbicide rate annual bluegrass control may not be as good. Dernoeden reported in Maryland (1996) that annual bluegrass control with ethofumesate was erratic at the lower rates (< 0.75 lb/A).

Results conducted in North Carolina ( Lewis and DiPaola, 1989 ) indicated that annual bluegrass was effectively controlled for 7 to 8 months in creeping bentgrass greens when ethofumesate was applied at 0.5 to 0.75 lb/A in each of three applications. They found that the highest control was obtained when the first application was made in October than when applied earlier or at a later date. Annual bluegrass control in Rhode Island ( Taylorson and Spak, 1994 ) was also effective in creeping bentgrass when ethofumesate was applied at 0.5 to 0.75 in 2 or 3 applications. Dates of treatments in Rhode Island ranged from September + October + November, October + November + April, to October + November. However, there were some indicates from these dates that the November treatment resulted in better annual bluegrass control than did the September treatment. Adams ( NorAm, 1989 ) reported that annual bluegrass was affected with ethofumesate at > 0.78 lb/A, but annual bluegrass was most susceptible when treated prior to the four-leaf growth stage. However, the optimum ethofumesate rate for annual bluegrass control in creeping bentgrass was 0.78 lb/A.

The control of annual bluegrass in creeping bentgrass in Australia ( Neylon et al., 1998 ) was improved during winter and early spring from sequential ethofumesate and bensulide treatments. The control was only 56% by late spring when ethofumesate was applied at 0.4 lb/ A in each of three applications compared to 78% from the same ethofumesate treatments plus bensulide at 12.5 lb/A applied in the fall and spring.

Summary. To control annual bluegrass effectively with lower rates of ethofumesate  ( < 0.75 lb/A ) in creeping bentgrass it will require more applications and the timing of application may be more important than when the herbicide is applied at rates > 0.75 lb/A.
 

Annual bluegrass control in dormant bermudagrass.

Ethofumesate was applied to an infested dormant common bermudagrass with annual bluegrass in Georgia ( Johnson 1983; 1986 ) at the time similar treatments were made to a weed-free bermudagrass green overseeded with perennial ryegrass. Ethofumesate applied at 1.0 lb/A in October resulted in poor annual bluegrass control ( 28%) by mid-April. When the 1.0 lb/A rate was applied in October and repeated in November the control was > 80% at three sites in March. However, by mid-April the control at two sites dropped to 66 and 76% while the control at the third was excellent (98%). When rates for ethofumesate were increased to 1.5 lb/A and applied in two applications in October and November annual bluegrass maintained a high level throughout the spring. When ethofumesate treatments were delayed until November and December, the control was consistently lower than when treatments were made in October and November. Treatments delayed until after January had little or no activity on annual bluegrass in Georgia but was excellent for 10 weeks when ethofumesate was applied at 1.0 lb/A in December and again in January in Mississippi ( Coats and Krans, 1986).

Summary. There are many PRE herbicides that will provide excellent annual bluegrass and other winter annual weeds in dormant bermudagrass in Georgia ( Johnson 1977; 1995) and other southern states with a single fall application such as simazine, oxadiazon, pendimethalin, benefin, oryzalin, and prodiamine. The performance of these herbicides are consistently higher on many winter annuals than ethofumesate. The herbicide should be limited only to bermudagrass overseeded with perennial ryegrass. Ethofumesate can also suppress the growth of bermudagrass when applied while actively growing at time of overseeding with perennial ryegrass.
 

Effects of N with ethofumesate for annual bluegrass. 

Spak (AgrEvo, 1995) reported that N positively increased the efficacy of ethofumesate on annual bluegrass control while increasing bentgrass safety. Ethofumesate applied at 0.75 lb/A in October, November, and April controlled 38% annual bluegrass while the control increased to 82% when N at 0.5 lb N/1000 ft² was applied with the herbicide. While information in the literature on this subject is limited, Davis (AgrEvo) has put out numerous plots at many locations since the fall of 1997. His results on sequential applications of N and Fe with ethofumesate has also improved the efficacy of ethofumesate.
 
Summary. Sequential applications of N with ethofumesate offers a mean to improve the activity of ethofumesate on annual bluegrass control while improving the safety of the treated turfgrass.
 

Multiple year ethofumesate treatments for annual bluegrass control.

Although ethofumesate treatments were needed in sequential years to maintain annual bluegrass control. Bingham and Hall reported (Virginia,1987) that effective control was obtained during the second year using lower ethofumesate rates than used the first year. Ethofumesate applied at 0.75 lb/A in each of two applications in the fall reduced annual bluegrass population the first year, but when repeated at the same rates the second year, the control was near complete.
 

Factors that influence the performance of ethofumesate on annual bluegrass control.

For a herbicide to be successful, it must be used at optimum rates, dates of applications, and correct timing between applications in order to obtain optimum and consistent performance. Most persons have experience excellent results from a herbicide, only to obtain unacceptable results at a different time or location. This variation may be in part due to environment, but management of the herbicide is important for successful control.

Dates of application. Ruemmele (Rhode Island, 1996) has observed that sod growers in New England has been frustrated with the inconsistency of ethofumesate performance. The lack of annual bluegrass control may be due to improper timing of applications. A number of persons have indicated a variation in annual bluegrass control with ethofumesate from different application dates. Lewis and DiPaola reported in North Carolina (989) that ethofumesate applied in October controlled a higher percentage of annual bluegrass than when the same rate was applied in August, September, or December. The hotter temperatures in August and September probable dissipated ethofumesate before annual bluegrass seed germinated while the POST ethofumesate applied in December did not control the larger annual bluegrass plants. Similar results were noted in Georgia (Johnson, 1986) as the October and November ethofumesate treatments controlled a higher amount of annual bluegrass than when treatments were delayed until November and December. Ethofumesate applied in spring and summer in Michigan (Branham, 1990) had poor activity on annual bluegrass.

Rates and number of applications. The variation in annual bluegrass with ethofumesate can be caused by improper rates and timing of repeated applications. Although a single ethofumesate may control annual bluegrass effective at some locations, repeated applications are usually needed for consistent control. In general, the number of applications with ethofumesate at > 1.0 lb/A will be fewer than when the herbicide is applied at < 0.75 lb/A. Branham (Michigan, 1990) reported that the first ethofumesate application was less important in controlling annual bluegrass than the second or third applications. For example, the first application at 0.5 lb/ A follow by the second application at 1.0 lb/A will give better annual bluegrass control than if the first application is 1.0 lb/A and the second application is 0.5 lb/A. Annual bluegrass control in North Carolina (Lewis and DiPaola, 1989) was higher with three ethofumesate applications than with two applications. They reported no advantage in annual bluegrass control when ethofumesate was applied more than three applications.
 
Improve inconsistent control. Inconsistent annual bluegrass control may be improved from sequential PRE herbicide with ethofumesate as reported in Australia (Neylon et al., 1998) or with addition of N as reported by Spak (AgrEvo, 1995). The inconsistent control may also be related to a resistant genotypes suggested by Ruemmele (Rhode Island, 1996). Taylorson and Spak (Rhode Island, 1994) reported that the control of several biotypes of annual bluegrass collected from Georgia, Iowa, Michigan, and Rhode Island treated with ethofumesate varied in control from 13 to 100%, which indicates that resistant genotype were present.
 

Crabgrass Control

Ethofumesate applied as PRE has good to excellent activity on crabgrass. The control with ethofumesate applied once at 1.0 lb/A in Tennessee (Callahan, 1986) and 1.5 lb/A in Rhode Island (Jagschitz and Sawyer. 1988) ranged from 73 to 89%. Adams at NorAm (1989) reported > 90% control when ethofumesate was applied at 1.0 lb/A in each of two applications, but two applications at 1.5 lb/A in Maryland (Dernoeden and Krouse, 1991) controlled only 77% of the weed. These results show that the performance of ethofumesate on crabgrass will vary.

Callahan (Tennessee, 1986) evaluated the performance of ethofumesate on crabgrass in the same plots over a 4-year period. The control was > 80% for 10 weeks each year when the herbicide was applied at 1.0 lb/A in each of two years the first year and at 0.5 lb/A in each of two applications the other years. Since crabgrass control in the south and other areas require up to 6 months or more. It is questionable whether ethofumesate can be economically used for crabgrass, when several PRE herbicides such as oxadiazon, bensulide, pendimethalin, oryzalin, benefin plus oryzalin, benefin plus trifluralin, dithiopyr, and prodiamine will provide effective crabgrass control (> 90%) throughout a long season.

Timing of ethofumesate treatments will also influence crabgrass control. Crabgrass control was not as effective when ethofumesate was applied as early POST compared with the same rate applied as PRE in Rhode Island (Jagschitz and Sawyer, 1988).
 
Summary Ethofumesate has PRE activity on crabgrass, but the response was not consistent. Multiple applications during the same year did not always improve the consistency. In most instances, ethofumesate did not perform as effectively as did regular recommended crabgrass herbicides. For instance two applications of ethofumesate controlled crabgrass 77% in Maryland (Dernoeden and Krouse, 1991) while > 90% control was obtained with dithiopyr, prodiamine, and oxadiazon at the same location.
 

Other Weed control.

The control of several weed species have been evaluated only once with ethofumesate. Therefore, the information given for these weeds are preliminary and results should be reviewed with this in mind.
 
Goosegrass control. Goosegrass control was poor in Tennessee (Callahan, 1986) as the control with ethofumesate at 2.0 lb/A was 15% by 10 weeks after treatment. When treatments were repeated at 1.0 lb/A the following 3-years, goosegrass control increased to only 59% which was unacceptable by the end of the fourth year.

Prostrate spurge. Prostrate spurge control was poor in Rhode Island (Jagschitz and Sawyer, 1988) (33%) when ethofumesate was applied at 1.5 lb/A.

Dandelions and henbit control. Ethofumesate applied at 4.0 lb/A in Maryland  (Dernoeden and Nash, 1982) did not control any of the dandelions and only 29% of henbit.

White clover control. White clover control in perennial ryegrass in Maryland  (Dernoeden and Nash, 1982) was >90% early September when treated with ethofumesate at 2.0 lb/A in early June. There was no advantage in control from a 4.0 lb/A rate compared with the lower rate.

Rattail fescue control. Rattail fescue is a severe weed in ryegrass fields maintain for seed production. Ethofumesate applied as PRE or early POST in ryegrass seed fields in Oregon (Lee, 1977) effectively controlled rattail fescue. Lee stated that at least 80% of rattail fescue was needed to obtain optimum ryegrass seed yields. Ethofumesate applied at 1.0 lb/A as a PRE or 1.5 lb/A as early POST controlled at least 80% of the weeds. To obtain complete rattail fescue control, it was necessary to increase ethofumesate rate up to 2.0 lb/A when applied either as PRE or early POST.
 
Volunteer wheat control. Ethofumesate applied as PRE or early POST to fall planted perennial ryegrass effectively controlled volunteer wheat in Oregon (Lee, 1980). Ethofumesate applied as early POST controlled the volunteer wheat at a lesser rate than required when applied as a PRE. Volunteer wheat control with ethofumesate was similar (> 93%) when 1.0 lb/A was applied as early POST or 1.8 lb/A applied as PRE.

These results show that volunteer wheat can be effected controlled in perennial ryegrass seed production fields with ethofumesate.
 
Summary of other weeds. Ethofumesate had excellent activity on rattail fescue, white clover, and volunteer wheat, but not on goosegrass, prostrate spurge, dandelions, and henbit.
 

Turfgrass Tolerance

When herbicides are applied to turfgrasses to control weeds, it is desirable that the herbicide not cause any injury to the turf. When injury occurs it is classified either as acceptable or unacceptable. The level of acceptable injury means that the turfgrass injury is temporary and the turf will recover within a short period. However, the level of acceptable injury may vary according to turfgrass species or where the grass is used. For example, an acceptable level of injury for a golf green is 10 to 15% compared to up to 30% on fairways and roughs. Acceptable injury will include leaf discoloration, but no stand loss. Unacceptable turfgrass injury means that the herbicide injured the turf too severely to be acceptable and generally caused a reduction in stand density.

The cool-season grasses that ethofumesate is primarily used for annul bluegrass control are perennial ryegrass, Kentucky bluegrass, and creeping bentgrass.
 

Perennial ryegrass tolerance.
 
When used as the main turfgrass. Perennial ryegrass is considered to be the safest turfgrass to ethofumesate treatments. Adams at Nor-Am (1989) listed the descending order of tolerance from ethofumesate as:
    perennial ryegrass
        > tall fescue
            > zoysiagrass = creeping bentgrass
                > Kentucky bluegrass
                    > annual bluegrass
Adams reported that established perennial ryegrass tolerated rates of ethofumesate as high as  4.0 lb/A. Similar results were observed in Maryland (Dernoeden and Turner, 1986) and Rhode Island (Cisar and Jagschitz, 1984) from the same rate.

In a green-house study in Oregon (Lee, 1977), the stand of Italian ryegrass was reduced when ethofumesate was applied above 1.0 lb/A. Perennial ryegrass tolerated higher ethofumesate rates than Italian ryegrass. At 1.0 lb/A the stand of Italian ryegrass was 80% compared to 100% for perennial ryegrass. At 2.0 lb/A the stands were 37% for Italian ryegrass and 80% for perennial ryegrass. Even though the 4.0 lb/A rate reduced stand of Italian ryegrass, it did not adversely affect seed production. The germination of ryegrass seed harvested from ethofumesate treated plots at < 4.0 lb/A was not affected.
 
Summary of perennial ryegrass growing alone. Ethofumesate can be effectively used for annual bluegrass control in perennial ryegrass in seed production fields and on golf course fairways and other similar managed turf sites. A single herbicide application controlled annual bluegrass in seed fields, while two applications were needed in areas where the grass was maintained as a turf.
 
When used as overseeding bermudagrass greens. Bermudagrass greens are overseeded throughout the south with perennial ryegrass to maintain a desirable playing surface during the late fall and winter. Since annual bluegrass is a major weed problem, ethofumesate is one of few choices that golf superintendents have in controlling this weed. When ethofumesate was applied at 1.0 lb/A at time of overseeding bermudagrass green with perennial ryegrass in Georgia  (Johnson, 1983), the quality of overseeded turf was reduced 26% within one month. When no additional treatments were made, the treated turf recovered within two months. When a second 1.0 lb/A application was made, the discoloration was observed until January or February. Even through leaf discoloration occurred from these treatments, they did not cause permanent injury and the turf fully recovered. Dickens reported similar results in Alabama (1979) where rate of ethofumesate in excess of 0.5 lb/A caused slight to moderate reduction of perennial ryegrass stand at 10 days. Stand reductions from October application were evident at 30 days in some years. In general, ethofumesate applied at < 1.0 lb/A in October and December did not affect the overseeded perennial ryegrass after late February.

When ethofumesate is used on bermudagrass greens overseeded with perennial ryegrass, the golf course superintendent has to be concern not only with initial injury, but what effects it will have on the transition the following spring and summer. Ethofumesate applied in Georgia (Johnson, 1983) to bermudagrass green overseeded with perennial ryegrass maintained a smooth transition the following spring and summer regardless of rate or time of treatment. However, the transition was delayed in June and July when ethofumesate was applied initially in October while bermudagrass was actively growing. There was no delay when treatment was delayed until November when the bermudagrass was dormant. Dickens reported similar results in Alabama (1979) where the October treatment caused cessation of bermudagrass growth. Ethofumesate applied in February in Alabama and February and March in Georgia, delayed transition from overseeding cool-season turf back to bermudagrass turf the following spring.

The establishment of the overseeded perennial ryegrass in a bermudagrass fairway was not affected when ethofumesate was applied at 1.0 lb/A in each of two application in Virginia  (Bingham, 1983).
 
Summary-overseeding perennial ryegrass. Ethofumesate can be safely used for annual bluegrass control in bermudagrass greens overseeded with perennial ryegrass. However, treatments must be applied after bermudagrass goes dormant to prevent a delay in transition the following spring and summer. A delay in transition also occurred when ethofumesate was applied too close to bermudagrass green-up in the spring. When the herbicide is not applied at the proper timing, the transition from cool-season back to bermudagrass can be delayed from 6 to 8 weeks. If bermudagrass greens does not have at least five months of dormancy, ethofumesate treatments should not be used for annual bluegrass control.
 

Kentucky bluegrass tolerance.

When ethofumesate is used for annual bluegrass in Kentucky bluegrass, extra caution is needed in selecting a ethofumesate rate. Adams at Nor Am (1989) concluded that Kentucky bluegrass was more susceptible to ethofumesate than perennial ryegrass and creeping bentgrass. He determined that rates > 1.25 lb/A caused unacceptable Kentucky bluegrass injury. Researchers in Rhode Island (Jagschitz, 1985) and Maryland (Dernoeden and Nash, 1982) also reported that severe injury occurred at rates > 2.0 lb/A. Dernoeden (Maryland, 1996) stated that  0.75 lb/A was the maximum safe rate of ethofumesate for Kentucky bluegrass.
 
Summary Kentucky bluegrass. Ethofumesate can be used for annual bluegrass control in Kentucky bluegrass turf. However, rates should never be higher than 0.75 lb/A. Some of the Kentucky bluegrass cultivars may be severely injured with ethofumesate rates less than 0.75 lb/A. Therefore, it is important to know the cultivars readily susceptible to ethofumesate. Do not treat until this is known.
 

Creeping bentgrass tolerance.

Ethofumesate use in creeping bentgrass for annual bluegrass is primarily used on golf course fairways. In recent years, the herbicide has been evaluated under green conditions in the Southeast. Adams at NorAm (1989) indicates that creeping bentgrass has more sensitively to ethofumesate than perennial ryegrass and tall fescue, but not as much as Kentucky bluegrass.
 
Fairways conditions. Adams at NorAm (1989) reported that rates > 1.25 lb/A caused unacceptable injury to creeping bentgrass maintain under fairway conditions. Dernoeden (Maryland, 1996) indicated that caution should be made when selecting a rate of ethofumesate to be applied to creeping bentgrass. He suggested that 0.75 lb/A is the maximum rate for creeping bentgrass.

Greens conditions. It should be emphases that when creeping bentgrass is growing in compacted soils, has shallow roots, and growing in stress conditions, the turfgrass will be more susceptible to ethofumesate and other herbicide treatments. When the turf has any of these conditions, do not treat with ethofumesate.

Lewis (North Carolina, 1984) reported that creeping bentgrass green had acceptable tolerance when ethofumesate was applied at 0.75 to 1.0 lb/A. Although slight discoloration may occur following each herbicide application, creeping bentgrass tolerated ethofumesate applied at 0.75 lb/A in each of three applications. He found that the > 2.0 lb/A rate of the herbicide did not have acceptable turfgrass tolerance. Similar response was observed in Georgia (Johnson, 1989) as maximum creeping bentgrass injury was only 18% when treated at 1.0 lb/A in September and repeated at the same rate in October. However, the timing of the second application was an important factor as related to turfgrass tolerance. Severe injury occurred to creeping bentgrass in Georgia when ethofumesate was applied at rates higher than 1.0 lb/A in October or at any rate in November. It was observed in Georgia and North Carolina that creeping bentgrass injury was higher in January when ethofumesate was applied during the coldest part of the year. The mean air temperature for 6 weeks after the November 30 treatment in Georgia was 11⁰F colder during the year with the highest turfgrass injury.
 
Summary creeping bentgrass. Ethofumesate can be applied in the fall to a healthily creeping bentgrass green in the Southeast for annual bluegrass control providing the rates used are < 1.0 lb/A and applications not made later than October.
 
Sequential ethofumesate with other herbicides on tolerance of creeping bentgrass. There are times when a turf manager must make a decision whether to apply two different chemicals together as sequential treatments. However, the turfgrass tolerance from these treatments may not be as good as from each chemical alone. The quality of creeping bentgrass in Australia (Neylon, et al, 1998) was similar from ethofumesate alone or when applied with bensulide. However, when oxadiazon was used, creeping bentgrass was injured 36% from sequential ethofumesate and oxadiazon treatments. Since oxadiazon can cause moderate to severe injury to creeping bentgrass (Johnson, 1987), the injury from this sequential applications was probable due to oxadiazon and not from ethofumesate in the ethofumesate plus oxadiazon combination.
 
Summary. Care should be taken when more than one chemical is applied to various turfgrasses. Selected chemicals can safely be used on turf, but additional information is needed when ethofumesate is applied with other chemicals.
 
Effects of fertilizer applied with ethofumesate on creeping bentgrass. Spak (AgrEvo, 1995) reported that when nitrogen (N) was applied with ethofumesate, the discoloration of creeping bentgrass during November, December, and March was reduced by 50%. Turf cover was slightly higher (8%) in April and turf color was better in May from the additional of N. In Georgia  (Johnson, 1990) when a fertility by ethofumesate interaction occurred on creeping bentgrass green, the quality of turf at the medium and high fertility levels was consistently higher than at the low fertility level.
 
Summary. Fertility applied in sequence with ethofumesate to creeping bentgrass either reduced discoloration or improved recovery compared to ethofumesate applied alone

Effects of iron (Fe) applied with ethofumesate on creeping bentgrass. Sequential applications of ethofumesate plus flurprimidol has suppressed bermudagrass growing in creeping bentgrass in Georgia (Johnson and Carrow, 1993), but the treatments can cause moderate injury to the creeping bentgrass. When Fe was applied in Georgia (Johnson and Carrow, 1995) at 1.5 lb/A with the ethofumesate plus flurprimidol treatments, the quality of creeping bentgrass was 17 to 31% higher at 2 to 3 weeks than with ethofumesate plus flurprimidol alone in 2 of 3 years. The results in Georgia and the preliminary results that Davis (AgrEvo, 1998) has observed that the Fe and N with ethofumesate indicates that both elements are beneficial to creeping bentgrass when ethofumesate is included as a chemical treatment.
 
Summary. Some creeping bentgrass discoloration caused by ethofumesate can be masked with Fe treatments.
 

Red-chewing fescue tolerance.

Lewis (North Carolina, 1984) reported that chewing fescue in a mixed cool-season grass overseeded in the fall on bermudagrass green was not tolerant to fall applied ethofumesate treatments. When ethofumesate was applied at 3.0 lb/A in each of two applications in the spring to established red fescue in Rhode Island (Yahres and Jagschitz, 1982), severe injury occurred. When ethofumesate was limited to a single spring application in Rhode Island (Cisar and Jagschitz, 1984 and Jagschitz, 1985) ethofumesate did not cause any undesirable turf injury. Therefore, the use of ethofumesate for annual bluegrass control in red/chewing fescue turf is questionable.
 
Summary. These results show that newly overseeded chewing fescue to bermudagrass green in the South was not tolerant to ethofumesate while the tolerance of established red fescue in the Northeast varied with rates and frequency of applications. Single application at < 4.0 lb/A did not cause any undesirable injury while repeated applications at 3.0 lb/A resulted unacceptable turf injury.
 

Tall fescue tolerance.

Adams (NorAm, 1989) reported that tall fescue was not as tolerant to ethofumesate treatment as perennial ryegrass, but higher than zoysiagrass, creeping bentgrass, and Kentucky bluegrass.
 

Zoysiagrass tolerance.

Adams (NorAm, 1989) reported that zoysiagrass was not as tolerant to ethofumesate treatment as perennial ryegrass and tall fescue, but equal to creeping bentgrass and higher than Kentucky bluegrass.
 

Centipedegrass tolerance.

Ethofumesate applied to centipedegrass sod mid-March did not affect regrowth followed a frost that killed centipedegrass foliage in Alabama (Dickens, 1986). A 1.0 lb/A applied early July caused foliage discoloration at 5 days, but disappeared within 7 to 10 days. At 7 weeks after treatment, centipedegrass was less dense than untreated, but no difference was observed at 9 weeks.
 

Rough bluegrass tolerance.

Rough bluegrass is considered to be a desirable turfgrass in the South when used for overseeding bermudagrass greens in the fall. However, when it is mixed with creeping bentgrass and other cool-season grasses where cool-season grasses are permanently grown it is considered to be a weed. Sabra rough bluegrass seeded in the fall in North Carolina ( Lewis, 1984) was susceptible to fall ethofumesate treatments.
 

Bermudagrass cultivars.

The green-up of bermudagrass cultivars in the spring varies with dates of ethofumesate during the previous fall and winter. In Georgia (Johnson, 1983) the green-up early April from ethofumesate at 1.0 lb/A in October and November was delayed only 7% for Tifdwarf, 16% for Tifway, 20% for Tifgreen, and 25% for Ormand bermudagrass cultivars. When the same rates were applied early February and March, the delay in green-up was > 82% for all cultivars.

The delay in green-up of Tifgreen bermudagrass in Mississippi (Coats and Krans, 1986) ranged from 11% when ethofumesate at 1.0 lb/A was applied in December to 93% when the 1.0 lb/A rate was applied in December and January. Plots treated with ethofumesate in December and January reduced Tifgreen bermudagrass green-up for 6 weeks. Higher rates resulted in longer delays in spring growth.

In North Carolina (Lewis, 1983) ethofumesate caused a premature onset of dormancy to all bermudagrass cultivars that was not dormant at time of ethofumesate treatment. He also reported that when ethofumesate was applied to bermudagrass after February 1, early spring growth may be temporarily delayed.
 
Summary. The growth of bermudagrass can be expected to be delayed 6 to 7 weeks in the spring when ethofumesate was applied prior to dormancy in the fall or when applied after January or February.
 

Bermudagrass suppression.

Bermudagrass is extensively used throughout the Southern United States for many turf areas, including athletic fields, golf courses, parks, and other turf areas. However, when it is mixed with other grasses and not wanted in this mixture, it becomes a severe weed problem. Bermudagrass contamination with other grasses that has a different leaf texture and growth habit will result in a poor quality turf.
 
Bermudagrass suppression in zoysiagrass. A mixed stand of common bermudagrass and zoysiagrass often results in an unacceptable turf. This is especially true when grown at sod farms for marketing, on golf course fairways, lawn of businesses in elite areas, and some home lawns.

Zoysiagrass treated with ethofumesate was severely injured in Maryland (Dernoeden, 1996) and Georgia (Johnson, 1882). In Georgia, ethofumesate applied at 1.5 lb/A in each of two applications for two consecutive years reduced zoysiagrass over a 3-year period from 65 to 12% while common bermudagrass population increased from 35 to 49%. For comparison, zoysiagrass population in the same study increased from 65 to 80% when fenoxaprop was applied at 0.18 lb/A in each of four applications for two consecutive years. During this period common bermudagrass population decreased from 35 to 4%.
 
Summary. Ethofumesate severely injured zoysiagrass and the herbicide should not be applied when it is the primary grass. However, it would be a desirable treatment to remove zoysiagrass from creeping bentgrass.
 
Bermudagrass suppression in St Augustinegrass. St. Augustinegrass sod production requires several months to complete and thus, exposes vast areas of soil to weed invasion. The most severe weed problem in St. Augustinegrass sod production is the invasion of common bermudagrass.

Several herbicides were applied in Florida (McCarty, 1996) to suppress common bermudagrass in St. Augustinegrass. Herbicides included ethofumesate, ethofumesate plus flurprimidol, ethofumesate plus siduron, and ethofumesate plus atrazine.

Ethofumesate applied at 3.0 lb/A in each of three applications varied in acceptable (> 80%) common bermudagrass suppression from 4 to 12 weeks. However, ethofumesate plus atrazine applied in three applications in March at 3.0 + 4.0 lb/A and followed by 3.0 + 1.0 lb/A in April and May was the best as the common bermudagrass control was > 96% when final ratings were made early August. The ethofumesate plus atrazine treatments had no affect on quality of St. Augustinegrass.

Inconsistent and/or poor suppression of common bermudagrass was obtained with ethofumesate plus either flurprimidol or siduron. The quality of St. Augustinegrass was reduced for 4 to 8 weeks when treated with ethofumesate plus siduron and 8 to 12 weeks when treated with ethofumesate plus flurprimidol.
 
Summary. Ethofumesate plus atrazine applied in three applications in March, April, and May effectively suppressed common bermudagrass without affecting the quality of St. Augustinegrass.
 
Bermudagrass suppression in tall fescue. Bermudagrass is a severe weed problem when mixed with tall in a turfgrass area. A mixture of the two grasses will results in a poor quality turf, due to different leaf texture and growth habit. Tall fescue will have a medium to course leaf texture compared to a finer leaf texture for bermudagrass. Since bermudagrass goes dormant after the first frost in the fall, the turf area will be partial green in the winter from tall fescue and partial brown from dormant bermudagrass.

Prinster and Russell reported in Georgia (Tru-Green Chemlawn, 1997) that 3 to 4 monthly spring/summer applications of either fenoxaprop plus ethofumesate (0.35 + 2.0 lb/A) or triclopyr plus ethofumesate (1.0 + 2.0 lb/A) effectively suppressed common bermudagrass throughout the season. Herbicides applied at 4 week interval injured tall fescue more than treatments were made at 6 week intervals. However, turf injury was temporary and tall fescue completely recovered.

In a second study conducted in Georgia (Johnson and Carrow, 1995) common bermudagrass was controlled > 96% by late summer when growing in a mixed tall fescue turf when treated with fenoxaprop plus ethofumesate at 0.18 + 1.5 lb/A. The control was obtained when the first application was made in April and repeated at 3 to 4 weeks for a total of four treatments in one year and five treatments the second year. In most instances, tall fescue was injured slight to moderate for 1 to 2 weeks but fully recovered. Tifway bermudagrass was not controlled from fenoxaprop plus ethofumesate treatments at either location in Georgia.
 
Summary. Common bermudagrass was effectively suppressed in fall fescue when treated with 3 to 5 applications of fenoxaprop plus ethofumesate. Higher rate required fewer herbicide applications.
 
Bermudagrass suppression in creeping bentgrass green. Encroachment of bermudagrass into creeping bentgrass greens continues to be a major problem in the southern United States where both grasses are grown. This occurs because creeping bentgrass is not adapted to the hot, humid climate of the southern United States, as is bermudagrass. Therefore, bentgrass in a golf green cannot compete with bermudagrass growing in collars and aprons around the green and encroachment will usually occur. Since the mixture of the two grasses results in a poor-quality putting surface, it is desirable to prevent encroachment of bermudagrass with chemicals without injuring bentgrass.

Studies on suppressing bermudagrass in creeping bentgrass were conducted over a 5-year period in Georgia (Johnson and Carrow, 1989; 1991; 1993). During this period ethofumesate and ethofumesate plus flurprimidol were applied with other herbicides at various dates and frequency of applications needed to suppress bermudagrass growing in creeping bentgrass green. Ethofumesate applied alone at 1.5 lb/A in April suppressed bermudagrass very little. However, sequential application of ethofumesate plus flurprimidol at 1.5 + 0.75 lb/A in April suppressed > 70% bermudagrass for 4 to 6 weeks. There was no advantage in bermudagrass suppression when treatments were applied in September and April compared to April alone. However, creeping bentgrass was moderately injured (< 30%) for 3 to 4 weeks after treatment in April, but severely injured (< 44%) when applied in September.

Ethofumesate plus flurprimidol at 1.5 + 0.75 lb/A applied mid-April and repeated at 0.75 + 0.38 lb/A at 6 and 12 weeks later, suppressed bermudagrass 96% by late August in 1 of 2 years. The suppression the second year was only effective until mid-June. However the suppression was  (> 70%) regardless of bermudagrass cultivar by late summer when the full (1.5 + 0.76 lb/A) rate was applied mid-March or early April and followed by four one-quarter rates. Creeping bentgrass tolerated the one-quarter rate of ethofumesate plus flurprimidol during late spring and summer.
 
Summary. The suppression of bermudagrass growing in a creeping bentgrass green was effective when treated with ethofumesate plus flurprimidol. However, it was necessary to follow the initial full (1.5 + 0.75 lb/A) rate in mid-March or early April with four one-quarter rates. It was also important to follow the initial treatment with timely repeated treatments. The second application must be applied at 6 weeks after the initial full rate followed by 3 week intervals for remaining applications. Creeping bentgrass was moderately injured for 3 to 4 weeks following the full herbicide treatment, but bentgrass tolerated the one-quarter rates.
 
Bermudagrass suppression in seashore paspalum. Preliminary results in Georgia (Johnson and Duncan, 1999) has shown that ethofumesate plus flurprimidol will safety suppress bermudagrass in paspalum turfgrass. Treatments applied early April appears to suppress bermudagrass better than when treatments were delayed until mid-summer. The rates and frequency of treatments will not be known until additional data are obtained.
 

Seedhead suppression with ethofumesate.

Spak (AgrEvo, 1995) reported that ethofumesate suppressed annual bluegrass 74% when applied alone at 0.75 lb/A, compared to 92% seedhead suppression when a fertilizer with N was applied with the herbicide at the same rate. The higher seedhead suppression was related to the higher annual bluegrass control obtain from the sequential treatments.

Seedhead suppression of bahiagrass in Florida (McCarty et al.,1993) was poor when treated with ethofumesate at < 2.0 lb/A throughout the summer.
 

Management practices with ethofumesate.

When ethofumesate or any herbicide is used for annual bluegrass control, it is important to include optimum management practices that will favor maximum benefin from herbicide treatment.
 
Rates of ethofumesate. Most turfgrass weed researchers have indicated that the optimum rates for annual bluegrass control are 0.75 lb/A applied in each of three applications and 1.0 lb/A applied in each of two applications. These results occurred in Alabama, Georgia, North Carolina, Virginia, and Maryland. For turfgrass safety with ethofumesate, perennial ryegrass can be treated with a maximum rate of 2.0 lb/A per application while more susceptible grasses such as creeping bentgrass and Kentucky bluegrass should be treated with a maximum rate of 0.75 lb/A per application. Branham (Michigan, 1990) reported that the first ethofumesate application was less important in controlling annual bluegrass than the second or third application. This was due to the first ethofumesate treatment sets up the annual bluegrass plant for injury from subsequent applications.
 
Intervals between ethofumesate treatments. Branham (Michigan, 1990) reported that one week between ethofumesate treatments were not affective in controlling annual bluegrass. He determined that ethofumesate applied 20 to 30 days apart results in the best annual bluegrass. Lewis (North Carolina, 1983) indicated that ethofumesate applied at 1.0 lb/A controlled annual bluegrass better when the herbicide was applied in a second application at 30 day interval than at 60 day internal.
 
Dates of ethofumesate treatments. In Georgia (Johnson, 1986), the optimum treatment date was related to the rate of ethofumesate application . When the herbicide was applied in October and November, annual bluegrass control was effective from 1.0 lb/A rate applied at each application. However, when treatments were delayed until November and December a 1.5 lb/A rate was required at each application date for similar control. Tayloron and Spak (Rhode Island, 1994) found that rate of ethofumesate determined when treatments should be applied. They stated that the 0.5 lb/A rate needed four fall applications while the 0.75 lb/A rate needed only 2 or 3 fall applications. The data from their studies indicated that the November treatment date was better than September. When a single ethofumesate application was made in North Carolina (Lewis and DiPaola, 1989), the highest annual bluegrass control was obtained in October and followed by November. While the August, September, and December treatments dates resulted in poorest control. When single treatments were made in Michigan (Branham, 1990), annual bluegrass control was the highest the following late-May when treatments were made mid-August than when applied 2 and 4 weeks later.
 
Summary management practices with ethofumesate. Ethofumesate applied for annual bluegrass control was generally the highest when applied at 1.0 lb/A in each of two applications at 30 day internals.
 

Ethofumesate treatments on creeping bentgrass root growth.
 
Ethofumesate applied in the fall in Georgia (Johnson, 1990), did not reduce root growth of creeping bentgrass in December, but the growth in June was reduced by 5% in plots treated at 1.0 lb/A and 21% when treated at 2.0 lb/A compared to untreated bentgrass. In Australia  (Neylon et al., 1998), creeping bentgrass root length and root health was not affected when treated with ethofumesate alone, ethofumesate plus oxadiazon, or ethofumesate plus bensulide when compared with untreated check. However, new root initiation was less in plots treated with ethofumesate plus bensulide than with ethofumesate alone and ethofumesate plus oxadiazon.
 
Summary. The root growth of creeping bentgrass was generally not affected with ethofumesate when applied at < 1.0 lb/A.
 

Ethofumesate treatments on creeping bentgrass drought stress.

Creeping bentgrass in Australia (Neylon et al, 1998) was not affected by drought stress when treated with ethofumesate alone or ethofumesate plus oxadiazon when compared with untreated turfgrass. However, turfgrass treated with ethofumesate plus bensulide had a significantly higher drought stress than ethofumesate alone and combinations of ethofumesate plus oxadiazon.
 
Summary. It was observed at a single location that ethofumesate did not affect drought stress of creeping bentgrass.
 

Turfgrass renovation with ethofumesate.

Renovation of a turf area can mean several things. In this survey it will be referred to as changing a undesirable mixed turf of annual bluegrass and cool-season to a desirable cool-season turf with the use of ethofumesate. This program is limited to Kentucky bluegrass, perennial ryegrass, and creeping bentgrass.
 
Converting mostly annual bluegrass to a desirable turf. Two different renovation programs were presented in Michigan (Branham and Hanson, 1987; Branham, 1990) to convert a poor quality turf into a higher quality turf.
 
First program. If the desirable turf species is less than 75% in the turf area, it is best to gradually reduce annual bluegrass population while increasing the turfgrass. If have 40 to 50% annual bluegrass, ethofumesate will control the weed and will leave the turf area in poor conditions with lots of bare ground. Branham (Michigan, 1990) suggest that plant growth regulators such as flurprimidol and paclobutrazol be used to increase the turf population up to 75%. This process may require an much as 3 years. When the turf reaches the 75% level, start with ethofumesate treatments to control the remaining annual bluegrass and improve the turf coverage.
 
Second program. A mixed turf of 95% annual bluegrass and 5% Kentucky bluegrass can be treated in the fall with ethofumesate at low rates (0.75 lb/A) in September and October. The 0.75 lb/A rate seem to weaken the annual bluegrass allowing a shift during the winter and early spring from the original 5% to 47% population by spring the first year. It is important not to apply ethofumesate above 0.75 lb/A because of outright kill. Ethofumesate must be repeated each year until the desired turf level is reached and then repeated to maintain annual bluegrass control.

Adams (Nor Am, 1989) reported that the optimum ethofumesate rate was 0.78 lb/A for annual bluegrass in a turf area to be renovated. He suggested that ethofumesate treatment be delayed for 6 weeks following emergence of creeping bentgrass and 8 weeks following emergence of Kentucky bluegrass.
 
Converting perennial ryegrass to creeping bentgrass . Christians reported in Iowa (1990), on converting from perennial ryegrass to creeping bentgrass turf that the treatments used depended on amount of annual bluegrass.
 

Program to use when annual bluegrass population mostly > 80% .

First year. Seed ryegrass in the fall followed by multiple ethofumesate treatments to reduce annual bluegrass population to at least 50% the following spring without losing grass coverage.

Second year. Seed creeping bentgrass in the fall followed by lower ethofumesate rates to control annual bluegrass, but not injure the creeping bentgrass.

Third year. Reduce mowing height and continue overseeding with creeping bentgrass and ethofumesate treatments.
 

Program to use when annual bluegrass population 50 to 60%.

First year. Seed both creeping bentgrass and perennial ryegrass in the fall followed by two ethofumesate rates.

Second year. Reduce mowing height to one-half inch. Seed with creeping bentgrass in late summer and follow with two ethofumesate treatments.

Third year. To complete the conversion to bentgrass, overseeding and ethofumesate should be continued. A complete conversion should be made in 3 years.
 
 
Converting a poor quality turf to perennial ryegrass. Christians reported in Iowa (1996) that the existing turf can be killed with glyphosate, re-established with perennial ryegrass, and treated with ethofumesate to keep annual bluegrass from becoming re-established.
 
Summary conversions/renovations. A poor quality annual bluegrass turf or a mixed annual bluegrass with a desired cool-season turfgrass can be renovated into a higher quality turf. A turfgrass manage can select from several programs. However, regardless of program, the conversion or renovation may require several years. The renovation of the old turf can be converted into either perennial ryegrass, Kentucky bluegrass, or creeping bentgrass. Warm-season turfgrass can not be renovated using these programs.
 

Effects of ethofumesate on seed germination.

For maximum turfgrass safety with herbicides, it is important to know the response of treatments on germinations of turfgrass seed. There are instances when ethofumesate will be applied for annual bluegrass to a bermudagrass green or fairway just after overseeding with perennial ryegrass or to fairways seeded to cool-season grasses following a renovation program.
 
Perennial ryegrass. In Mississippi, Coats and Krans (1986) conducted greenhouse studies on the effects of ethofumesate applied to seed of several turfgrasses at seeding (PRE), one-half at seeding (PRE) plus one-half at 2 weeks after seeding (POST). Stand rating at 40 days after seeding shown that ethofumesate at 1.0 lb/A reduced stand of Pennfine perennial ryegrass 31% when applied as PRE. Stand reduction was 40% when ethofumesate was applied at 0.5 lb/A as PRE and 0.5 lb/A as POST. The perennial ryegrass stand decrease significantly as ethofumesate rates increased from 1.0 to 4.0 lb/A.

The stand reduction from and an average of 14 other perennial ryegrass cultivars in Mississippi was 41% when ethofumesate was applied PRE at 1.0 lb/A; 33% when 0.5 lb/A was applied as PRE and 0.5 lb/A applied as POST; and 24% when 1.0 lb/A was applied as POST.

In the same Mississippi study, stand of Italian ryegrass was reduced 36% at 40 days when treated with ethofumesate as PRE at 1.0 lb/A and reduced 32% when treated as PRE at 0.5 lb/A and 0.5 lb/A as POST. Ethofumesate applied as POST at 1.0 lb/A had no affect on Italian ryegrass stand.

In a greenhouse study in Oregon (Lee, 1977), ethofumesate applied at 1.0 lb/A at planting did not affect the stand of perennial ryegrass at 7 weeks. During this period the stand was reduced 20% when treated at 2.0 lb/A and 38% when treated at 4.0 lb/A. The stand of Italian ryegrass was reduced 20% with ethofumesate at 1.0 lb/A, and reduced > 63% at higher rates.

A different type study was conducted in a germination growth chamber in Ohio (Bell et al., 1997) on the inhibition of cool-season turfgrass germination. A 50 seed sample was used in each method and germination was conducted 14 days after treatment. Ethofumesate was applied in a chemical solution (0, one-half, full, and double rates) to perennial ryegrass using three methods as follows:
 
Soaked blotter germination method. This method consisted of placing 4.0 ml of ethofumesate solution on a blue blotter in a petri dish where dry seed samples were placed.
 
Imbibed germination method. Seed samples in this method were imbibed in chemical solutions (same as above) for 3 hours and then placed onto a blotter soaked in 4.0 ml pure water.
 
Dipped germination method. This method consisted of placing the seed samples on a cheese cloth and spraying with the different chemical solutions and placing the samples on a dry germination paper and dried for 24 hours at room temperature. Samples were then placed on blue blotters soaked in pure water.
 
The germination with ethofumesate was 89% for soaked, 94% for imbibed, and 90% for the dipped method. For comparisons, the germination of perennial ryegrass treated with flurprimidol (Cutless) was > 91%, while the germination with trinexapac-ethyl was 70% for the soaked germination method and > 92% for the other germination methods.
 

Bentgrass.
 
In the greenhouse study conducted in Mississippi (see perennial ryegrass) ethofumesate applied as POST at 2 weeks after planting reduced stand of Highland colonial bentgrass only 26% at 40 days, but reduced shoot dry weight 97%. The results were similar for either Penncross, Emerald, and Penneagle creeping bentgrass.
 
In the growth chamber study in Ohio (see perennial ryegrass), creeping bentgrass germination ranged from 1 to 13% using the soaked and imbibed germination methods to 93% using the dipped germination method.
 

Kentucky bluegrass.
 
In the greenhouse study in Mississippi (see perennial ryegrass), ethofumesate applied as PRE at 1.0 lb/A or 0.5 lb/A applied as PRE and repeated as POST 2 weeks later reduced the stand of Adelphi Kentucky bluegrass < 15%. When the herbicide was applied as POST at 1.0 lb/A stands of Adelphi and Touchdown were not affected while the stand of Glade was reduced 24%, Flying was reduced 46% and Baron and Nugget were reduced > 50%.
 

Red fescue.
 
In the greenhouse study in Mississippi (see perennial ryegrass) , ethofumesate applied as POST at 1.0 lb/A (2 weeks after planting) reduced stand of Highland red fescue 18% and reduced dry weight 90% at 40 days after planting. The results were similar for K4-21 and K5-29 cultivars.
 
In a greenhouse study in Oregon (Lee, 1977), ethofumesate applied to newly planted red fescue at 1.0 lb/A severely injured the turf at 6 weeks.
 

Tall fescue.
 
The stand of tall fescue in Oregon (Lee, 1977) was severely reduced at 7 weeks after planting in a greenhouse study when ethofumesate were applied at > 1.0 lb/A at time of planting. The stand was reduced 37% when treated at 1.0 lb/A and 88% when treated at 2.0 lb/A.
 

Rough bluegrass.
 
In the greenhouse study in Mississippi (see perennial ryegrass), ethofumesate applied at 1.0 lb/A as a POST 2 weeks after planting did not affect rough bluegrass stand, but reduced dry weight 89%. The 2.0 lb/A caused a stand reduction of 33% with 97% reduction in dry weight.
 
In the growth chamber study in Ohio (see perennial ryegrass), germination of rough bluegrass was 4 to 14% in the soaked and imbibed germination methods and 75% with the dipped germination method. Results were similar when treated with flurprimidol and trinexapac-ethyl.
 

Annual bluegrass biotypes.
 
Taylorson and Spak (Rhode Island, 1994), evaluated ethofumesate on 15 different biotype of annual bluegrass in the greenhouse. All biotypes were treated twice with ethofumesate at 0.75 lb/A as:
        PRE + 28 days after planting (DAP)
        28 + 56 DAP
        56 + 84 DAP
 
In the PRE + 28 DAP treatment stand thinning was 95 to 100% for all except one biotype (51%).
 
In the 28 + 56 DAP treatment, control of the biotypes least susceptible to the PRE + 28 DAP was 53%. The control of other biotypes ranged from 84 to 100%.
 
In the 56 to 84 DAP treatment, only 2 biotypes were effectively controlled with ethofumesate while the control of the others ranged from 13 to 65%.
 
These results suggest that different annual bluegrass biotypes will perform differently to ethofumesate treatments. Note that the PRE + 28 DAP was the best timing for ethofumesate treatments. However, one biotype was not controlled from these treatments The non-controlled biotype could be resistant to ethofumesate. Also, note that the 56 and 84 DAP ethofumesate treatments controlled the least number of biotypes. However, the 2 biotypes that were controlled at these dates suggest that these biotypes were easier to control with ethofumesate than the other 13 biotypes. Annual bluegrass would be much easier to control with ethofumesate if all annual bluegrass in the United States were these 2 biotypes.

Orchardgrass, wild oat, and rattail fescue.
 
In the greenhouse study in Oregon (Lee, 1977), ethofumesate applied at 1.0 lb/A at time of seeding either orchardgrass, wild oat or rattail fescue severely injured these plants when rated at 7 weeks.
 
Summary of seed germination treated with ethofumesate. The safety of any herbicide is usually not as good on turfgrasses when evaluated in greenhouses and growth chambers than when evaluated under field conditions. These researchers indicate that in most instances when ethofumesate is applied closer to day of seeding in greenhouses and growth chambers, the expected turfgrass injury will probable be higher than when treatments are delayed until normal growth has occurred.
 
Ever though ethofumesate has activity on several weeds, it appears from this review that the herbicide is best adapted for annual bluegrass control in cool-season grasses. The review shows some variation in annual bluegrass, but the biggest concern is turfgrass safety.
 
Cool-season grasses. In most instances, annual bluegrass control was acceptable using selective rates, dates, and frequency of application in perennial ryegrass, Kentucky bluegrass, and creeping bentgrass maintained as fairways. There were a couple of references showing that N and Fe applied with ethofumesate improved turfgrass safety. This was also evident from preliminary data that Davis (AgrEvo, 1998) has collected . Therefore, I would recommend that research using N and Fe with ethofumesate be expanded to eliminate the scary injury that most researchers and turfgrass managers may have with ethofumesate.
 
Bermudagrass greens, tees, and fairways overseeded with perennial ryegrass. Golf course superintendents that manage bermudagrass greens has a continued annual bluegrass problem trying to control the weed during the fall, winter, and early spring. They generally have four choices that can be used:
 
    1- Apply a PRE herbicide 45 to 60 days prior to overseeding. This practice will normally result in poor annual bluegrass control by mid to late winter. The poor control occurred from the dissipation of the PRE herbicide by the time of overseeding with perennial ryegrass, thus poor weed control will follow.
 
    2- Apply pronamide about 2 weeks before overseeding to control the emerged annual bluegrass and follow by activated charcoal 2 to 3 days prior to overseeding. The pronamide will control the emerged annual bluegrass, but has little effects on the weed after the charcoal has been applied.
 
    3- Apply fenarimol (Rubigan ) only to greens at 2 and 4 weeks before overseeding with perennial ryegrass and follow by a reduced rate in January.
 
    4- Apply ethofumesate at 4 and 8 weeks after bermudagrass is overseeded with perennial ryegrass (greens not recommended). Ethofumesate should be applied only after bermudagrass is dormant and do not apply within 3 months of green-up in the spring. Therefore, ethofumesate treatments will have some limitation as to where it can be used.

Ethofumesate can cause perennial ryegrass discoloration through most of the fall but will usually recover fully by January or early February. There has been no research conducted using N and Fe with ethofumesate on overseeding perennial ryegrass. These treatments could also reduce the discoloration or shorten the recovery period as reported on cool-season grasses in the northern region.
 
 
 
 Suppressing bermudagrass growth when mixed with warm- and cool-season grasses.
 
Mixtures of bermudagrass with desired turfgrasses presents a major problem for all turfgrass managers.
 
    1- We know that ethofumesate with flurprimidol has effectively suppressed bermudagrass in creeping bentgrass and shows promise for suppressing bermudagrass in seashore paspalum.
 
    2- Ethofumesate applied with atrazine has good bermudagrass suppression in St. Augustinegrass.
 
    3- Ethofumesate applied with fenoxaprop has given good suppression of common bermudagrass in tall fescue.
 
    4- Ethofumesate applied alone will suppress zoysiagrass in creeping bentgrass.

    5- What are other possibilites?
 

Names and addresses of researchers used in this review.
 
The address for each person is given for the location where research was conduced at time the paper was published. In some instance, the person may have retired or moved since the paper has been published. This information will be included, when known.
 

Adams, James C.
Nor-Am Chemical Company
( Now AgrEvo Chemical Company)
Wilmington, DE
 
Bell, G. E.
The Ohio State University
2021 Coffey Rd.
Columbus, OH 43015
 
Bingham, S. W. ( Retired)
Virginia Polytechnic Institute
and State University
Blacksburg, VA 24061
 
Branham, B. E.
Department of Crop and Soil Science
Michigan State University
East Lansing, MI
 
Callahan, L. M.
Ornamental Horticultural
and Landscape Design
University of Tennessee
Knoxville, TN
 
Canaway, P. M.
The Sports turf Research Institute, Bingley
West Yorkshire, BD 161AU
 
Christians, N. E.
Horticulture Department
Iowa State University
Ames. Iowa
 
Coats, G. E.
Department Plant Pathol. And Weed Science
Mississippi State University
Mississippi State, MS 39762

Dernoeden, P. H.
Department of Agronomy
University of Maryland
College Park, MD
 
Dickens, Ray (Retired)
Department on Agronomy and Soils
Auburn University
Auburn, AL 36830
 
Haggar, R. J.
Agricultural Research Council
Weed Research Organization
Begbroke Hill
Yarnton, Oxford OX51PF, U.K.
 
Jagschitz, J. A. (Retired)
Department of Plant Sciences
University of Rhode Island
Kingston, RI 02881
 
Johnson, B. J. (Retired)
Department of Crop and Soil Sciences
University of Georgia
Georgia Station
Griffin, GA 30223

Lee, W. O.
Department of Agronomy and Crop Science
Oregon State University
Corvallis, OR 97331
 
Lewis, W. M. (Retired)
Crop Science Department
North Carolina State University
Raleigh, NC
 
Mazur, A. R.
Horticultural Department
Clemson University
Clemson, SC 29634
 
McCarty, L. B.
Horticultural Department
Clemson University
Clemson, SC 29634
 
Neylon, J.
Turfgrass Technology Pty Ltd
Victoria, Australia
 
Prinster, M. G.
TruGreen/ChemLawn
Douglasville, GA 30134
 
Ruemmele, B.
Department of Plant Science
University of Rhode Island
Kingston, RI 02281
 
Shearman, R. C.
Department of Horticulture
University of Nebraska
Lincoln, NB 68583-0724
 
Spak, D. R.
AgrEvo Chemical Company
Narvon, PA 17555
 
Taylorson, R. B.
Department of Plant Science
University of Rhode Island
Kingston, RI 02881

Adams, J. C. 1989. Control of Poa annua in the United States in cool-season turf with ethofumesate. pp. 323-324. IN  H. Takatoh (Ed.). Proc. Sixth Intern. Turfgrass Res. Conf., Tokyo, Japan.

Bell, G. E, T. K.  Danneberger, and M. B. McDonald. 1997. Chemical inhibition of cool season turfgrass germination. Part I. Intern. Turgrass Soc. Res. J. 8: 411-417.

Bingham. S. W. 1983. Annual bluegrass control during overseeding of bermudagrass. Proc. Southern Weed Sci. Soc. 36: 123-127.

Bingham, S. W. and J. R. Hall. 1987. Ethofumesate for annual bluegrass control in Kentucky bluegrass and perennial ryegrass fairways. Southern Weed Sci. Soc. 40: 116.

Branham, B. 1990. Dealing with Poa annua. Golf Course Management 59 (9): 46-60.

Branham, B. E. 1990. A selective annual bluegrass control-finally! Green Section Record. 28 (1): 6-8.

Branham, B. E. and K. V. Hanson. 1987. 1986.  PGR and weed control research. 57th annual Michigan Turfgrass Conference Proc. 16: 78-83.

Callahan, L. M. 1986. Effects of herbicides in bentgrass greens. p 131-136. IN  B. G. Joyner and K. A. Hurto ( Eds.). Advances in turfgrass weed control. Hammer Graphics, Inc., Piqua, OH.

Callahan, L. M. 1986. Crabgrass and goosegrass control in a bentgrass green in the transition zone. Agron. J. 78: 625-628.

Callahan, L. M. 1994. Turfgrass phytotoxicity from preemergence herbicides. pp 71-107  IN A. J. Turgeon Turf Weeds and Their Control. Agronomy Monograph 32, American Soc. Agron., Crop Sci. Soc of Am. Madison, WI.

Christians, N. 1990. The annual bluegrass to rye to bent approach. Golf Course Management 58 (4): 36-38.

Christians, N. 1996. A historical perspective of annual bluegrass control. Golf Course Management 64 (11): 49-57.

Cisar, J. L. and J. A. Jagschitz. 1984. Turgrass tolerance to post- and preemergence herbicides. Proc. Northeast. Weed Sci. Soc. 39: 298-302.

Coats, G. E. and J. V. Krans.1986. Evaluation of ethofumesate for annual bluegrass ( Poa annua) and turfgrass tolerance. Weed Sci. 34: 930-935.

Davis, S. 1997. Performance of  N with ethofumesate for annual bluegrass control, a preliminary report. AgrEvo.

Davis, S. 1998. Performance of ethofumesate when applied with Fe and N creeping bentgrass, a preliminary report. AgrEvo.

Dernoeden, P. H. 1996. Control grassy perennial weeds in turf. Grounds Maintenance 31 (11): 16-24.

Dernoeden, P. H. and J.  M. Krouse. 1991.  Selected crabgrass control evaluations for Maryland in 1990. Proc. Northeast. Weed Sci. Soc 45: 117-118.

Dernoeden, P. H. and A. S. Nash. 1982. Control of various broadleaf weeds in turf using experimental and commercial herbicides. Proc. Northeast. Weed Sci. Soc. 36: 321-325.

Dernoeden, P. H. and T. R. Turner. 1986. Selective control of Poa annua in perennial ryegrass and creeping bentgrass with ethofumesate. Proc. Northeast. Weed Sci. Soc. 40: 276-277.

Dernoeden, P. H. and T. R. Turner. 1988. Annual bluegrass control and tolerance of Kentucky bluegrass and perennial ryegrass to ethofumesate. HortScience 23: 565-567.

Dickens, R. 1979. Control of annual bluegrass (Poa annua) in overseeded bermudagrass (Cynodon spp.) Golf greens. Weed Sci. 27: 642-644.

Dickens, R. 1986. Herbicide tolerance in centipedegrass. pp 137-141 IN  B. G.  Joyner and K. A. Hurto (Eds.) Advance in turfgrass weed control. Hammer Graphis, Inc. Piqua, OH.

Haggar, R. J. and F. W. Kirkham. 1981. Selective herbicide for establishing weed-free grass. I. Evaluation of ethofumesate and methabenzthiazuron. Weed  Res. 21: 141-151.

Haggar, R. J. and A. Passman.1991. Soil persistence and distribution of ethofumesate applied to autumn-sown perennial ryegrass for Poa annua control. Weed  Res. 21: 153-159.

Herbicide Handbook. 1994. pp125-126 Weed Society of American herbicide handbook, Seventh Edition, Champaign, IL.

Jagschitz, J. A. 1985. Crabgrass control in turfgrass with herbicides. Proc. Northeast. Weed Sci Soc. 40: 274-278.

Jagschitz, J. A. and C. D. Sawyer. 1989. Preemergence control of crabgrass, spurge, and oxalis and  PRE-POST, POST control of crabgrass in turf. Proc. Northeast. Weed Sci. Soc. 43: 96-97.

Johnson, B. J. 1977. Preemergence winter weed control in dormant bermudagrass turf. Agron. J. 69: 573-576.

Johnson, B. J. 1983. Response to ethofumesate of annual bluegrass (Poa annua) and overseeded bermudagrass (Cynodon dactylon). Weed Sci. 31: 385-390.

Johnson, B. J. 1986. Response to vertical mowing and ethofumesate treatments for annual bluegrass control in bermudagrass turf. Agron. J. 78: 495-498.

Johnson, B. J. 1987. Tolerance of bentgrass to dates and frequency of preemergence herbicide treatments. Agron. J. 79: 992-996.

Johnson, B. J. 1990. Herbicide X annual fertility programs influence creeping bentgrass performance. Agron. J. 82: 27-33.

Johnson, B. J. 1992. Common bermudagrass (Cynodon dactylon) suppression in Zoysia spp. with herbicides. Weed Technol. 6: 813-819.

Johnson, B. J. and R. N. Carrow. 1989. Bermudagrass encroachment into creeping bentgrass as affected by herbicides and plant growth regulators. Crop Sci. 29: 1220-1227.

Johnson, B. J. and R. N. Carrow. 1991. Frequency of flurprimidol-herbicide treatments on bermudagrass (Cynodon spp.) encroachment into creeping bentgrass (Agrostis stolonifera ). Weed Sci. 39: 221-226.

Johnson, B. J. and R. N. Carrow. 1993. Bermudagrass (Cynodon spp.) suppression in creeping bentgrass (Agrostis stolonifera ) with herbicide-flurprimidol treatments. Weed Sci. 41: 120-126.

Johnson, B. J. and R. N. Carrow. 1994. Chemical suppression of bermudagrass in creeping bentgrass greens. Golf Course Management 62 (3): 90-104.

Johnson, B. J. and R. N. Carrow. 1995. Influence of fenoxaprop and ethofumesate treatments of suppression of common bermudagrass (Cynodon dactylon ) in tall fescue (Festuca arundinacea ) turf. Weed Technol. 9: 789-793.

Johnson, B. J. and R. N. Carrow. 1995. Response of creeping bentgrass to iron applied in combination with herbicide-flurprimidol. J. Turfgrass Management 1 (2): 25-34.

Johnson, B. J. and R. R. Duncan. 1999. Performance of ethofumesate and flurprimidol on bermudagrass suppression in seashore paspalum, a preliminary report. Georgia Agric. Exp. Sta. University of Georgia.

Johnson, B. J., G. W. Landry, Jr., and K. J. Karnok. 1989 Tolerance of bentgrass to amount, frequency, and  timing of ethofumesate applications. HortScience 24: 102-104.

Lee, W. O. 1977. Winter annual grass weed control in Italian ryegrass with ethofumesate. Weed Sci. 25: 252-255.

Lee, W. O. 1980. Control of volunteer wheat ( Triticum aestivum ) in fall-planted perennial ryegrass (Lolium perenne) with ethofumesate. Weed Sci. 26: 292-294.

Lewis, W. M. 1983. Prograss for Poa annua control in golf greens. Proc. 21st annual North Carolina Turfgrass Conf. 4: 35-37.

Lewis, W. M. 1984. Poa annua control in golf greens. Proc. 22nd annual North Carolina Turfgrass Conf. 5: 28-30.

Lewis, W. M. and J. M. DiPaola . 1989. Ethofumesate for Poa annua control in bentgrass. (Ed.). Proc. Sixth Intern. Turfgrass Res. Conf., Tokyo, Japan.

McCarty, L. B., D. L. Colvin, and R. D. Baker. 1993. Sequential year application of PGR's for bahiagrass seedhead suppression. Southern Weed Sci. Soc. 46: 232.

McCarty, L. B. 1996. Selective control of common bermudagrass in St. Augustinegrass. Crop Sci. 36: 694-698.

Neylan, J. and M. Robinson. 1998. Control of Poa annua in creeping bentgrass. Golf & Sports Turf, Australia. 7 (2): 12-18.

Prinster, M. G. and T. A. Russell. 1997. Common and hybrid bermudagrass control in tall fescue with various herbicides and applications strategies. Proc. Southern Weed Sci. Soc. 50: 71.

Ruemmele, B. 1996. Poa annua management. TurfGrass Trends 5 (3): 11-14.

Shearman, R. C. 1986. Kentucky bluegrass and annual bluegrass responses to ethofumesate. HortScience 21: 1157-1159.

Spak, D. R. 1995. Ethofumesate X fertilizer combinations for annual bluegrass control in creeping bentgrass turf. Proc. Northeast. Weed Sci. Soc. 49: 103.

Taylorson, R. B. and D. R. Spak. 1994. Control of annual bluegrass with ethofumesate-field studies and effects of biotypes and growth stage. Proc Northeast. Weed Sci. Soc. 48: 123.

Yahres, R. D. and J. A. Jagschitz.1982. PRE- and postemergence herbicides for the control of crabgrass in lawn areas. Proc Northeast. Weed Sci. Soc. 36:292-297.