Roundup Ultra was applied at several rates at two growth stages of soybean. Roundup Ultra applied at the V3 growth stage of soybean did not cause any visible injury regardless of rate. Roundup Ultra at 2.5 to 4.0 qt/A applied at the V6 growth stage caused 4 to 5% stunting and 3 to 14% chlorosis 21 days after treatment. Soybean height at harvest ranged from 33 to 38 inches. Roundup Ultra at 4.0 qt/A applied at the V6 growth stage reduced height. There were no differences in soybean population. Soybean yield ranged from 54 to 60 bu/A. In most instances, yield was equal to or greater with Roundup Ultra compared to the nontreated.

I. INTRODUCTION:

The development of crops resistant to Roundup will facilitate its use as a postemergence herbicide in crop production. Therefore, this study was designed to evaluate the tolerance of Roundup Ready soybean to Roundup at several rates applied at two growth stages of soybean.

II. HERBICIDES EVALUATED:

        Roundup Ultra 4 S

III. ABBREVIATIONS USED:

        GLXMA: soybean
        GPA: gallons per acre
        V3: two trifoliates
        V6: five trifoliates

IV. RESULTS AND DISCUSSION:

Soybean Injury:

Soybean injury consisted of stunting and chlorosis. Chlorosis was characterized as a lighter shade of green of the uppermost soybean leaves.

Stunting:

Roundup Ultra applied at the V3 growth stage did not stunt plants regardless of rate. Roundup Ultra applied at 2.5 to 4.0 qt/A at the V6 growth stage caused 4 to 5% stunting.

Chlorosis:

Roundup Ultra applied at the V3 growth stage did not cause chlorosis regardless of rate. Roundup Ultra applied at 2.0 to 4.0 qt/A at the V6 growth stage caused 3 to 14% chlorosis of the uppermost leaves of the soybean plant. Chlorosis increased as rate increased.

 Height:

Soybean height at harvest ranged from 33 to 38 inches. Roundup Ultra at 4.0 qt/A applied at the V6 growth stage reduced height.

Population:

Soybean population at harvest ranged from 53,300 to 67,600 plants per acre. There were no differences in soybean population regardless of rate.

Yield:

Soybean yield ranged from 54 to 60 bu/A. In most instances, yield was equal to or greater with Roundup Ultra compared to the nontreated.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Common waterhemp control was evaluated with current commercial and experimental herbicides in Roundup Ready soybean. Authority, Authority plus chlorimuron, Broadstrike/Dual, and Treflan preplant incorporated controlled 99%, 98%, 96%, and 93% of the common waterhemp, respectively. Blazer and Roundup Ultra applied postemergence controlled 87% and 90 to 98% of the common waterhemp, respectively. Resource, Action, Expert, Basagran, Pursuit, and Raptor provided no control of common waterhemp. Soybean yield ranged from 18 to 46 bu/A.

I. INTRODUCTION:

Common waterhemp is becoming one of the most troublesome weeds in Illinois. Therefore, this study was initiated to evaluate and compare common waterhemp control with current and experimental herbicides in soybean.

II. HERBICIDES EVALUATED:

        Action 4.75 WP                                 Flexstar HL 1.88 EC
        Authority 75 WG                                Frontier 6 EC
        Axiom 68 WG                                    Lorox 50 WG
        Basagran 4 S                                   Prowl 3.3 EC
        Blazer 2 EC                                    Pursuit 2 AS
        Broadstrike/Dual 7.67 EC                       Raptor 1 AS
        Classic 25 WG                                  Resource 0.86 EC
        Cobra 2 EC                                     Scepter 70 WG
        Command 3 ME                                   Sencor 75 WG
        Dual II 7.8 EC                                 Synchrony STS 42 WG
        Expert 75 WG                                   Topnotch 3.2 ME
        Firstrate 84 WG                                Treflan 4 EC

III. ABBREVIATIONS USED:

        AMATA - common waterhemp
        PRE - preemergence
        PPI - preplant incorporated
        RR - Roundup Ready
        V3 - three trifoliates

IV. RESULTS AND DISCUSSION:

Weed control data are presented in the attached tables. There was no change in weed control following the last rating noted in the attached tables. All comments referring to weed control are in reference to the last rating unless noted otherwise. Most of the soil herbicides were incorporated as to insure the activation of soil herbicides. However, 1.7 inches of rainfall was received within 10 days of application. Herbicides were also applied postemergence at 5 inch common waterhemp. A postemergence grass herbicide was applied to all plots to control grass.

Common Waterhemp:

Treflan controlled 93% of the common waterhemp compared with 66% with Prowl. Dual II, Frontier, Topnotch, and Axiom provided unacceptable control of common waterhemp. The poor control may be related to excessive rainfall immediately after the incorporation of these herbicides which moved these herbicides through the soil profile thus control was decreased. Authority, Authority plus chlorimuron, and Broadstrike/Dual were the most effective soil herbicides with control ranging from 96 to 99%. Scepter, Classic, and Sencor provided poor control of common waterhemp. Lorox controlled 81% of the common waterhemp. Blazer was more effective than Cobra or Flexstar on common waterhemp. Blazer controlled 87% of the common waterhemp compared with 28% and 78% control with Cobra and Flexstar, respectively. Control of common waterhemp ranged from 90 to 98% with Roundup Ultra with control increasing as rate increased. Resource, Action, Expert, Basagran, Pursuit, and Raptor provided no control of common waterhemp.

The addition of Authority and Roundup Ultra with current herbicides used in soybean will increase management and control of common waterhemp.

Soybean Yield:

Soybean yield ranged from 18 to 46 bu/A. Yield tended to increase as common waterhemp control increased.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

All treatments that included Select controlled giant foxtail 96 to 99%. Control of yellow nutsedge ranged from 63 to 92% and depended on the total rate of Basagran applied. Control of common waterhemp was essentially complete with all Cobra treatments. Likewise, control of velvetleaf ranged from 92 to 99% but control of ivyleaf morningglory was slightly lower. All treatments caused substantial soybean injury but complete recovery occurred within 30 days. Soybean yield ranged from 11 to 36 bu/A and was related to control of giant foxtail, especially, but also related to control of other weeds.

I. INTRODUCTION:

This study was designed to evaluate tank-mix and premix combinations of Cobra and bentazon for broadleaf weed control in soybeans. All treatments except one included Select for control of annual grasses.

II. HERBICIDES EVALUATED:

        Bentazon (Basagran) 4 S
        Cobra 2 EC
        Select 2 EC
        V-10048 3.73 EC (Cobra/bentazon premix)

III. ABBREVIATIONS USED:

        ABONOR: above normal                           GLXMA: soybeans
        ABUTH: velvetleaf                              IPOHE: ivyleaf morningglory
        AMATA: common waterhemp                        LVS: leaves
        BROSOI: broadcast soil                         SETFA: giant foxtail
        CHEAL: common lambsquarters                    V: soybean vegetative stage
        CYPES: yellow nutsedge                         W: weeds
        DL: days later                                 ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 18 rating. Several weed species listed on the Site Description Sheet were not rated because of lack of uniformity in the study area.

Weed Control: All treatments that included Select controlled giant foxtail 96 to 99%. Yellow nutsedge control ranged from 63 to 92%. Despite this range, there was no significant difference except in one instance. The less than complete control of nutsedge likely was related to the relatively low rate of bentazon (Basagran) in these treatments, plus the application at 3 to 8 inch nutsedge, which is earlier than optimum control normally occurs. Common waterhemp control was essentially complete with all treatments. Velvetleaf control ranged for 92 to 99% with few significant differences between treatments. Control of ivyleaf morningglory ranged from 85 to 99%. The most complete control of morningglory was observed with a combination of V-10048 plus Cobra as a tank-mix.

Soybean Injury and Yield: All treatments caused soybean injury, ranging from 20 to 28% initially (June 26, 7 days after application). However, recovery was relatively rapid and was complete by July 18, 30 days after application. Nonetheless, some injury was evident two weeks after herbicide application. Soybean yield ranged from 11 to 36 bu/A. Because of the high population of giant foxtail in this study, there was no difference in yield between the nontreated and the V-10048 plus Cobra treatments, since no grass control was observed in the later treatment.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Treatments that included Dual controlled giant foxtail more completely than where Treflan or Prowl were used. Treatments that included Broadstrike or FirstRate provided excellent control of velvetleaf and ivyleaf morningglory. There was no injury observed in this study. Soybean yield ranged from 1 to 48 bu/A. The yield level was closely associated to the level of weed control obtained.

I. INTRODUCTION:

This study was designed to evaluate weed control in soybeans with Broadstrike and FirstRate combinations compared to several other standard treatments. FirstRate is chemically related to Broadstrike but can be used PPI, PRE, or POST, and is expected to be commercially available in 1997.

II. HERBICIDES EVALUATED;

        Blazer 2 EC                                    Pinnacle 25 WG
        Broadstrike/Dual 7.67 EC                       Poast 1.5 EC
        Broadstrike/Treflan 3.65 EC                    Prowl 3.3 EC
        FirstRate 84 WG                                Scepter 1.5 AS
        Galaxy 3.67 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           IPOHE: ivyleaf morningglory
        ABUTH: velvetleaf                              LVS: leaves
        BROSOI: broadcast soil                         SETFA: giant foxtail
        CYPES: yellow nutsedge                         W: weeds
        DATST: jimsonweed                              XANST: common cocklebur
        GLXMA: soybeans                                ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 19 rating. Several weed species listed on the Site Description Sheet were not rated because of lack of uniformity in the study area.

Weed Control: Giant foxtail control with treatments that included Treflan or Prowl ranged from 80 to 90% on June 21, 4 weeks after application, but decreased substantially July 19. The relatively poor control with several of these treatments likely was related to wet soil conditions following application, resulting in anaerobic breakdown of these herbicides. In contrast, treatments that included Dual controlled foxtail more completely for the entire season. Foxtail control with Poast was poor because of antagonism caused by Galaxy, which was applied as a tank-mix. Control of velvetleaf and ivyleaf morningglory was nearly complete in most instances where Broadstrike or FirstRate were used.

Soybean Injury and Yield: None of the herbicide caused any soybean injury in this study. Soybean yield ranged from 1 bu/A in the nontreated plots to 48 bu/A. Treatments that included Dual generally were higher in yield than those that included Treflan or Prowl, because of the greater control of giant foxtail noted above.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Axiom controlled giant foxtail, common waterhemp, and common ragweed completely but did not control any velvetleaf or ivyleaf morningglory. Combinations of Axiom plus Canopy, Scepter, or Authority controlled all weeds almost completely. No soybean injury was observed in this study. Soybean yield ranged from 2 bu/A in the nontreated plots to 43 bu/A. The highest soybean yield was associated with the most complete weed control.

I. INTRODUCTION:

Axiom is an experimental herbicides composed of BAY FOE 5043 + Sencor in a 4:1 ratio being developed for weed control in corn and soybeans. Chemically, FOE 5043 is related to Lasso, Dual, etc., thus primarily is a grass herbicide. This study was designed to evaluated Axiom alone and in combinations with several `broadleafþ herbicides.

II. HERBICIDES EVALUATED:

        Authority 75 WG                                Frontier 6 EC
        Axiom 68 WG                                    Scepter 1.5 AS
        Canopy 75 WG                                   Sencor 75 WG
        Classic 25 WG                                  Squadron 2.33 EC
        Dual II 7.8 EC                                 Turbo 8 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           FC2X+CM: field cultivate 2 times + 
        ABUTH: velvetleaf                                cultimulch 
        AMATA: common waterhemp                        GLXMA: soybeans 
        AMBEL: common ragweed                          IPOHE: ivyleaf morningglory
        BROSOI: broadcast soil                         SETFA: giant foxtail
                                                       ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 11 rating.

Weed Control: Axiom alone at the two rates evaluated completely controlled giant foxtail, common waterhemp, and common ragweed. Dual II and Frontier also controlled these weeds. In contrast, Axiom, Dual II, and Frontier did not control any velvetleaf or ivyleaf morningglory. Combinations of Axiom plus Canopy, Scepter, or Authority controlled these two weeds 93 to 99%. These results indicate that Axiom is an effective herbicide for control of giant foxtail and small- seeded broadleaf weeds.

Soybean Injury and Yield: Soybean injury was not observed in this study with any of the herbicides. Soybean yield ranged from 2 bu/A in the nontreated check to 43 bu/A. Incomplete control of one or more weed species caused a sharp decrease in yield.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Excellent control of giant foxtail, common waterhemp, and redroot pigweed was observed with most herbicides in this study. There appears to be a substantial difference in susceptibility of common waterhemp, especially to ALS type herbicides. Soybean injury was not observed in this study. Soybean yield ranged from 14 bu/A in the nontreated plots to 59 bu/A and was related to the level of weed control obtained.

I. INTRODUCTION:

Common waterhemp has become a substantial weed problem in soybeans in recent years, most likely because of the widespread use of ALS type herbicides, which do not control this weed completely or consistently. This study was designed to evaluate a wide range of herbicides specifically for the control of waterhemp.

II. HERBICIDES EVALUATED:

        Authority 75 WG                                Prowl 3.3 EC
        Broadstrike/Dual 7.67 EC                       Pursuit 2 AS and 70 WG
        Broadstrike/Treflan 3.65 EC                    Pursuit Plus 2.9 EC
        Canopy 75 WG                                   Raptor 1 AS
        Detail 4.1 EC                                  Reflex 2 EC
        Flexstar HL 1.88 EC                            Squadron 2.33 EC
        Frontier 6 EC                                  Status 2 EC
        Fusion 2.66 EC                                 Steel 2.57 EC
        Lorox 50 WG                                    Twister 1.82 ME

III. ABBREVIATIONS USED:

        ABNOR: above normal                            ECHCG: barnyardgrass
        ABUTH: velvetleaf                              FC2X+CM: field cultivate 2 times +    
        AMARE: redroot pigweed                           cultimulcher
        AMATA: common waterhemp                        GLXMA: soybeans
        AMBEL: common ragweed                          IPOHE: ivyleaf morningglory
        BROSOI: broadcast soil                         LVS: leaves
        CHEAL: common lambsquarters                    SETFA: giant foxtail
        CYPES: yellow nutsedge                         XANST: common cocklebur
        DATST: jimsonweed                              ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the Aug. 19 rating. Several weed species listed on the Site Description Sheet were not rated because their distribution was not uniform throughout the study area. Most of the comments in the following discussion relate to the Aug. 19 rating.

 Weed Control:

Most of the herbicides evaluated controlled giant foxtail greater than 95%. Likewise, most of the treatments controlled common waterhemp and redroot pigweed greater than 95%, with little difference in control between the two weeds. Pursuit controlled waterhemp 98% and redroot pigweed 99%. Based on results from this and other studies in 1996, our observations suggest that there is a wide range of susceptibility of common waterhemp to ALS type herbicides such as Pursuit. In some studies, essentially complete control was obtained with Pursuit whereas in other studies control was much less complete.

Soybean Injury and Yield:

Soybean injury was not observed in this study. Soybean yield ranged from 14 bu/A in the nontreated plots to 59 bu/A. The highest soybean yield was associated with the most complete weed control.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

A single application of Liberty controlled giant foxtail, common ragweed, ivyleaf morningglory, and cocklebur almost completely, even at 75% of the anticipated label rate. Substantial injury and control of yellow nutsedge also was provided by Liberty, which in combination with a dense soybean canopy resulted in almost complete control by late August. Liberty caused 17 to 23% soybean injury initially but recovery was rapid and complete. Soybean yield ranged from 15 bu/A in the nontreated plots to 68 bu/A. Poor control of nutsedge appeared to be the major weed that affected yield.

I. INTRODUCTION:

Liberty is a nonselective herbicide that is being developed for weed control in transgenic soybeans and corn. It controls a wide spectrum of summer annual weeds. This study was conducted to evaluate tolerance of Liberty Link soybeans and weed control with Liberty.

II. HERBICIDES EVALUATED:

        Canopy 75 WG                                   Prowl 3.3 EC
        Galaxy 3.67 EC                                 Pursuit 70 WG
        Liberty 1.67 EC                                Squadron 2.33 EC
        Poast 1.5 EC                                   Treflan 4 EC

III. ABBREVIATIONS USED:

        ABNOR: above normal                            LVS: leaves
        ABUTH: velvetleaf                              REGR: regrowth
        AMBEL: common ragweed                          SETFA: giant foxtail
        BROSOI: broadcast soil                         W: weeds
        CYPES: yellow nutsedge                         XANST: common cocklebur
        GLXMA: soybeans                                ZEAMX: corn
        IPOHE: ivyleaf morningglory

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the Aug. 19 rating. Velvetleaf was listed on the Site Description Sheet but was not rated because it was not distributed uniformly in the study area.

Weed Control:

A single application of Liberty controlled giant foxtail 94 to 97% on Aug. 19. Control of foxtail that was emerged at application was 100%. Control decreased slightly by Aug. 19 because of some late emerging plants. Liberty also provided considerable control of yellow nutsedge. Initial control on July 1 ranged from 88 to 93%, depending on rate applied. Control decreased at the July 8 and 22 ratings with the two lower rates but not with the highest rate. On Aug. 29, control of nutsedge was 99%. The increase in control between July 22 and Aug. 19 reflects the control obtained from the dense soybean canopy. Past experience indicates that yellow nutsedge is intolerant of a high level of shade, such as occurs under a dense soybean canopy. Liberty alone at all rates controlled common ragweed, ivyleaf morningglory, and common cocklebur 96 to 99%.

Soybean Injury and Yield:

Liberty caused some initial soybean injury but essentially complete recovery occurred within one week. The injury consisted primarily of a type of þbronzing.þ Soybean yield ranged from 15 bu/A in the nontreated plots to 68 bu/A. The highest yield was in plots treated with Liberty plus handweeded all summer to maintain weed-free conditions. In plots where nutsedge control was not complete until late season, yield was lower than where nutsedge control was complete all season.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Most treatments that included Authority plus companion herbicides controlled giant foxtail, yellow nutsedge, common ragweed, velvetleaf, and ivyleaf morningglory almost completely. Treatments that included Authority caused no soybean injury in this study. Soybean yield ranged from 12 to 61 bu/A.

I. INTRODUCTION:

This study was designed to evaluate weed control and soybean tolerance with Authority and chlorimuron combinations. Authority is an experimental herbicide with a new mode of action for soil herbicides that is excellent in controlling many of the currently most difficult to control weeds such as waterhemp, morningglory, nightshade, nutsedge, etc. However, it is especially weak on ragweeds, thus this study was designed to improve control of especially ragweeds with chlorimuron.

II. HERBICIDES EVALUATED:

        Assure II 0.88 EC                              Lexone 75 WG
        Authority 75 WG                                Prowl 3.3 EC
        Blazer 3 EC                                    Pursuit 2 AS and 70 WG
        Canopy 75 WG                                   Scepter 70 WG
        Classic 25 WG                                  Squadron 2.33 EC
        Command 3 ME                                   Synchrony STS 42 WG
        Commence 5.25 EC                               Treflan 4 EC
        Dual II 7.8 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           FC2X+CM: field cultivate 2 times +
        ABUTH: velvetleaf                                  cultimulch
        AFR: after first rating                        G: grass
        AMARE: redroot pigweed                         GLXMA: soybeans
        AMBEL: common ragweed                          IPOHE: ivyleaf morningglory
        BL: broadleaf                                  LVS: leaves
        BROSOI: broadcast                              SETFA: giant foxtail
        CYPES: yellow nutsedge                         XANST: common cocklebur
        DIGSA: large crabgrass                         ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached tables. There was no change in weed control following the July 19 rating. Several weed species listed on the Site Description Sheet were not rated because of lack of uniformity in the plot area.

 Weed Control:

Almost complete control of all weeds was obtained with most herbicides or herbicide combinations. Essentially all combinations of Authority plus companion herbicides controlled giant foxtail, yellow nutsedge, common ragweed, velvetleaf, and ivyleaf morningglory almost completely.

Soybean Injury and Yield:

Treatments that included Authority caused no soybean injury in this study. Soybean yield ranged from 12 bu/A in the nontreated plots to 61 bu/A. The highest yield was associated with the most complete control of all weeds.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Liberty alone controlled giant foxtail 94%, ivyleaf morningglory 95%, and common ragweed and common cocklebur 99%, whereas control of yellow nutsedge was only 33%. Two applications of Liberty improved control of yellow nutsedge to 83% but control of other weeds was increased only slightly. Liberty alone caused bronzing and chlorosis of soybeans but recovery was rapid and complete. Soybean yield ranged from 9 bu/A in the nontreated plots to 53 bu/A.

I. INTRODUCTION:

Liberty is an experimental, non-selective herbicide that controls many annual weeds, but injures or kills non-transgenic soybeans. Liberty Link soybeans are a genetically engineered type of soybeans developed to be tolerant/resistant to Liberty. This study was designed to evaluate weed control with Liberty and tolerance of Liberty Link soybeans to this herbicide.

II, HERBICIDES EVALUATED:

        Flexstar HL 1.88 EC
        Liberty 1.67 EC
        Poast Plus 1 EC
        Prowl 3.3 EC
        Pursuit 70 WG
        Sencor 75 WG

III. ABBREVIATIONS USED:

        ABONOR: above normal                           LL: Liberty Link
        ABUTH: velvetleaf                              LVS: leaves
        AMATA: common waterhemp                        PANDI: fall panicum
        AMBEL: common ragweed                          RG: regrowth
        AMBTR: giant ragweed                           SETFA: giant foxtail
        BROSOI: broadcast soil                         V: vegetative stage
        CYPES: yellow nutsedge                         W: weeds
        GLXMA: soybeans                                XANST: common cocklebur
        IPOHE: ivyleaf morningglory                    ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the Aug. 2 rating. Several weed species listed on the Site Description Sheet were not rated because of lack of uniformity in the plot area.

Weed Control:

Liberty alone at 1.72 pt/A as a single application controlled giant foxtail 94%, ivyleaf morningglory 95%, common ragweed and common cocklebur 99%, and yellow nutsedge 33%. Two applications of Liberty at 1.72 pt/A each time improved control of giant foxtail to 99%, yellow nutsedge to 83%, but did not improve control of broadleaf weeds to any extent because a single application controlled them almost completely. A single application of Liberty plus one cultivation controlled all weeds 90 to 99%. Weed control with a single application of Liberty was equal to that with competitive products.

Soybean Injury and Yield:

Liberty initially caused 10 to 15% soybean injury but recovery was rapid and complete. Injury was characterized primarily by a `bronzingþ of some leaves with slight chlorosis. When Liberty plus Flexstar HL were applied as a tank-mix, injury observed was 23%, but again recovery was rapid and complete. Flexstar HL plus POAST caused similar injury. Soybean yield ranged from only 9 bu/A in the nontreated plots to 53 bu/A in the no herbicide plus cultivate plus handweed plots. Although yield in most plots treated with herbicides were somewhat lower in yield, these differences were not significant.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Expert caused an initial 10 to 21% injury to soybeans but recovery was rapid and complete, but was somewhat dependent on soybean height at application, Action caused little soybean injury. There was no significant difference in yield between the no herbicide/handweeded treatment and any treatments that included herbicides.

I. INTRODUCTION:

Action and Expert are experimental POST herbicides for broadleaf weed control in soybeans. Action is especially effective in controlling velvetleaf whereas Expert is relatively broad spectrum in controlling many broadleaf weeds. In 1995, Expert caused some soybean injury that persisted for several weeks. Presumably, this was related to the `formulationþ of the herbicide. In 1996, the Expert formulation was supposed to be different to preclude/reduce the injury observed in 1995. Therefore, this study was designed to evaluate whether the 1996 formulation of Expert would cause or not cause soybean injury. However, the 1995 formulation was not available for comparative purposes.

II. HERBICIDES EVALUATED:

        Action (CGA-248757) 4.75 WP
        Classic 25 WG
        Expert (CGA-277476) 75 WG
        Pinnacle 25 WG
        Prowl 3.3 WG
        Pursuit 70 WG
        Scepter 70 WG
        Select 2 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           GLXMA: soybeans
        ABUTH: velvetleaf                              IPOHE: ivyleaf morningglory
        AMATA: common waterhemp                        SETFA: giant foxtail
        BROFOL: broadcast foliar                       V: vegetative stage
        BROSOI: broadcast soil                         XANST: common cocklebur
        CYPES: yellow nutsedge                         ZEAMX: corn
        G: grass

IV. RESULTS and DISCUSSION:

Soybean injury ratings and yield data are presented in the attached table. Weed species in this study are identified on the Site Description Sheet. However, weed control ratings are not presented since all plots that had herbicides applied were kept weed-free by cultivation and hand- weeding. The major focus of this study was to evaluate soybean injury from herbicides applied, especially from Expert.

 Soybean Injury:

Action (plus Select) caused little or no soybean injury in this study (0 to 11%) and recovery was rapid and complete. Expert caused somewhat more injury (10 to 21%) but was dependent on soybean height at application. Over a period of several weeks, soybeans recovered essentially completely from the initial injury. The injury from Expert in 1996 was much lower than in 1995, and recovery was much more rapid.

Soybean Yield:

Soybean yield ranged from 65 to 72 bu/A in this study. There were no significant differences in yield between the no herbicide/handweeded study and any of the other treatments, indicating that neither Action, Expert, or Action plus Expert had any effect on yield.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Roundup Ultra at 1 pt/A controlled giant foxtail and common ragweed 99%, velvetleaf 94%, ivyleaf morningglory 88%, and yellow nutsedge 63%. The most complete control of all weeds was with Authority plus Lexone PRE plus Roundup Ultra POST. Little or no soybean injury was observed in this study. Yield ranged from 26 to 61 bu/A.

I. INTRODUCTION:

Roundup Ready soybeans became commercially available in 1996 and likely will have an impact on herbicides used in soybeans. Although Roundup Ultra controls many weeds, control of some species may require multiple applications. One alternative is to use companion herbicides that have greater control of some weed species. This study was designed to evaluate weed control with Roundup Ultra plus companion PRE and POST herbicides.

II. HERBICIDES EVALUATED:

        Authority 75 WG                                Poast Plus 1 EC
        Cobra 2 EC                                     Pursuit 70 WG
        F6025 25 WG (Authority+chlorimuron)            Roundup Ultra 4 S
        Frontier 6 EC                                  Scepter 70 WG
        Lexone 75 WG                                   Storm 4 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           IPOHE: ivyleaf morningglory
        ABUTH: velvetleaf                              SETFA: giant foxtail
        AMARE: redroot pigweed                         W: weeds
        AMBEL: common ragweed                          WL: weeks later
        BROSOI: broadcast soil                         XANST: common cocklebur
        CYPES: yellow nutsedge                         ZEAMX: corn
        GLXMA: soybeans

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 17 rating. Several weed species listed on the Site Description Sheet were not evaluated because of lack of uniformity in the plot area.

Weed Control:

Roundup Ultra alone at 1 pt/A controlled giant foxtail and common ragweed 99%, velvetleaf 94%, ivyleaf morning 88%, and yellow nutsedge 63%. Increasing the rate to 1.5 pt/A did not improve control of any of the weeds. Roundup Ultra plus Cobra improved control of velvetleaf only slightly but increased control of morningglory from 88% with Roundup Ultra only to as high as 99%. The most complete control of all weeds was with a combination of Authority plus Lexone PRE plus Roundup Ultra POST.

Soybean Injury and Yield:

Little or no soybean injury was observed in this study. Soybean yield ranged from 26 bu/A in the nontreated plots to 61 bu/A.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

No treatments in this study controlled all weeds adequately. Control of specific weeds was highly dependent on the overall weed control observed. Soybean yield ranged from 3 bu/A in the nontreated plots to 48 bu/A.

I. INTRODUCTION:

This study was designed to evaluate weed control in soybeans mostly with experimental POST herbicides compared to several commercially available ones.

II. HERBICIDES EVALUATED:

        Action 4.75 WP                                 Pursuit 2 AS and 70 WG
        Blazer 2 EC                                    Raptor 1 AS
        Dual II 7.8 EC                                 Squadron 2.33 EC
        Expert 75 WG                                   Status 2 EC
        Pinnacle 25 WG                                 Steel 2.57 EC
        Prowl 3.3 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           LVS: leaves
        ABUTH: velvetleaf                              SETFA: giant foxtail
        BL: broadleaf                                  V: vegetative stage
        BROSOI: broadcast soil                         W: weeds
        CYPES: yellow nutsedge                         XANST: common cocklebur
        GLXMA: soybeans                                ZEAMX: corn
        IPOHE: ivyleaf morningglory

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 16 rating. Yellow nutsedge was not rated as it did not occur with uniformity in the plot area.

Weed Control:

All comments refer to the July 16 rating. No treatment controlled all weeds adequately in this study. Velvetleaf control was most complete with 93 to 99% control. The total lack of control of giant foxtail with Pursuit plus Blazer was related to rapid leafburn with Blazer, likely decreasing absorption and translocation of the Pursuit. Control of morningglory was relatively poor with most herbicides in this study. Treatments that included Expert, Blazer, and Status controlled morningglory the most completely. Most treatments also controlled cocklebur poorly, even with herbicides that normally afford excellent control.

Soybean Injury and Yield:

Little soybean injury was observed in this study. Yield ranged from 3 bu/A in the nontreated plots to 48 bu/A and were closely related to the level of weed control achieved.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Control of giant foxtail, ivyleaf morningglory, and cocklebur was highly related to the specific herbicides used whereas all herbicides controlled velvetleaf completely. All herbicides caused slight to moderate soybean injury with recovery complete within three weeks. Soybean yield ranged from 6 bu/A in the nontreated plots to 48 bu/A with the most complete weed control.

I. INTRODUCTION:

This study was designed to evaluate weed control in soybeans with POST herbicides only. Most treatments included Poast, Basagran, or Blazer or some combination of these herbicides. Competitive products also were evaluated.

II. HERBICIDES EVALUATED:

        Assure II 0.88 EC                              Pinnacle 25 WG
        Basagran 4 S                                   Poast 1.5 EC
        Blazer 2 EC                                    Poast Plus 1 EC
        Concert 25 WG                                  Pursuit 2 AS
        Flexstar HL 1.88 EC                            Resource 0.86 EC
        Fusion 2.66 EC                                 Select 2 EC
        Galaxy 3.67 EC                                 Storm 4 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           LVS: leaves
        ABUTH: velvetleaf                              SETFA: giant foxtail
        AMATA: common waterhemp                        V: vegetative stage
        BROFOL: broadcast foliar                       W: weeds
        CYPES: yellow nutsedge                         XANST: common cocklebur
        GLXMA: soybeans                                ZEAMX: corn
        IPOHE: ivyleaf morningglory

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 16 rating. Several weed species listed in the Site Description Sheet were not rated because their occurrence was not uniform in the plot area.

Weed Control:

Control of giant foxtail, ivyleaf morningglory, and cocklebur were highly related to the specific herbicide(s) used. Many companion herbicides reduced the efficacy of Pursuit on giant foxtail. Treatments that included Blazer (or Galaxy or Storm) or Flexstar were most effective in controlling morningglory. All herbicides controlled velvetleaf completely.

Soybean Injury and Yield:

All herbicides caused moderate initial soybean injury, ranging from 7 to 32% but complete recovery occurred within three weeks. Soybean yield ranged from 6 bu/A in the nontreated plots to 48 bu/A. The highest yields were related to the most complete weed control observed in this study.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Select, Raptor, Dual II and Frontier controlled giant foxtail completely. Control of velvetleaf and common ragweed also was complete except in a few instances. In contrast, control of ivyleaf morningglory and cocklebur was highly dependent on the specific treatment. No treatment controlled morningglory and cocklebur completely. All herbicides caused moderate soybean injury but recovery was relatively rapid and complete. Yield ranged from 1 bu/A in the nontreated plots to 43 bu/A. Overall, yield was low and likely reflected the incomplete weed control.

I. INTRODUCTION:

Resource is a POST herbicide that became available commercially in 1996 and is especially effective on velvetleaf whereas V53482 is an experimental PRE broadleaf herbicide. This study was designed to evaluate these two herbicides compared to commercially available PRE and POST herbicides for weed control in soybeans. Resource II has the same active ingredient as Resource but has a different solvent system.

II. HERBICIDES EVALUATED:

        Canopy 75 WG                                   Raptor 1 AS
        Classic 25 WG                                  Reflex 2 EC
        Dual II 7.8 EC                                 Resource 0.86 EC
        Frontier 6 EC                                  Resource II 0.86 EC
        Galaxy 3.67 EC                                 Select 2 EC
        Lexone 75 WG                                   Storm 4 EC
        Pinnacle 25 WG                                 V-53482 50 WP
        Pursuit 2 AS

III. ABBREVIATIONS USED:

        ABONOR: above normal                           IPOHE: ivyleaf morningglory
        ABUTH: velvetleaf                              LVS: leaves
        AMBEL: common ragweed                          SETFA: giant foxtail
        BL: broadleaf                                  SIDSP: prickly sida
        BROSOI: broadcast soil                         V: vegetative stage
        BROFOL: broadcast foliar                       XANST: common cocklebur
        CYPES: yellow nutsedge                         ZEAMX: corn
        G: grass                                       70L-IN: 7 days later - if needed
        GLXMA: soybeans

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 12 rating. Several weed species listed on the Site Description Sheet were not rated because they did not occur with uniformity in the study.

 Weed Control:

All herbicides controlled giant foxtail completely in this study. Complete control of common ragweed also was obtained except where Resource or Resource II were used as the only broadleaf herbicide. Excellent control of velvetleaf was observed with all treatments, in all instances except one, complete control occurred. Control of morningglory and cocklebur was highly dependent on the specific herbicides that were used. V-53482 plus Classic, Lexone, or Canopy controlled morningglory 72 to 91% but control of cocklebur with these herbicides was only 17 to 25%. Resource and Resource II as the only POST broadleaf herbicides also did not give good control of morningglory or cocklebur.

Soybean Injury and Yield:

All herbicides caused moderate soybean injury initially but recovery was rapid and complete. Soybean yield ranged from 1 bu/A in the nontreated plots to 43 bu/A. The relatively low yield likely was a reflection of incomplete control of one or more weed species with all treatments.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Almost all grass herbicides controlled giant foxtail and velvetleaf essentially completely. The only herbicide that controlled yellow nutsedge greater than 90% was Basagran, when used with the lower rate of Stellar. Control of lambsquarters, ivyleaf morningglory, and cocklebur was highly dependent on the herbicides(s) used but no treatment controlled these three weeds adequately. All herbicides caused moderate soybean injury and in most instances took up to three weeks for complete recovery. Soybean yield was relatively low and reflected the incomplete control of one or more weed species.

I. INTRODUCTION:

Stellar is a premix of Resource and Cobra and became available commercially for the 1996 use season. Resource is especially effective on velvetleaf and contributes to the control of other broadleaf weeds. This study was designed to evaluate total POST weed control in soybeans with these and several competitive products when applied at 1 to 3 and 4 to 6 inch weed height.

II. HERBICIDES EVALUATED:

        Assure II 0.88 EC
        Basagran 4 EC
        Fusion 2.66 EC
        Pinnacle 25 WG
        Poast Plus 1 EC
        Select 2 EC
        Stellar 3.1 EC

III. ABBREVIATIONS USED:

        ABONOR: above normal                           SETFA: giant foxtail
        ABUTH: velvetleaf                              V: vegetative stage
        CHEAL: common lambsquarters                    W: weeds
        CYPES: yellow nutsedge                         XANST: common cocklebur
        G: grass                                       ZEAMX: corn
        GLXMA: soybeans                                3 DA 1-3: 3 days after 1-3" application
        IPOHE: ivyleaf morningglory

IV. RESULTS AND DISCUSSION:

Weed control ratings ans soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 11 rating.

Weed Control:

Almost all treatments controlled giant foxtail completely whether the grass herbicide (Assure II, Fusion, Poast Plus, or Select) were applied at the 1-3 or 4-6 inch weed height or as a tank-mix with the broadleaf herbicide or as a sequential several days following application of the broadleaf herbicide. This indicated little or no antagonism in this study. The only treatment that controlled yellow nutsedge greater than 90% was Stellar at 0.31 pt/A plus Basagran at 1 pt/A. When the Stellar rate was increased to 0.44 pt, plus Basagran at 1 pt/A, nutsedge control decreased to 17%, suggesting the higher rate of Stellar antagonized control with Basagran. All herbicides controlled velvetleaf 96 to 99%. IN contrast, control of lambsquarters, ivyleaf morningglory, and cocklebur was highly dependent on the specific herbicide(s). None of the treatments adequately control these three species.

Soybean Injury and Yield:

All herbicides injured soybeans moderately and complete recovery took three weeks. Soybean yield ranged from 7 bu/A in the nontreated plots to 39 bu/A. The relatively low yields likely reflect the poor control of one or more species with the herbicides evaluated.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

ALL RATES MENTIONED IN THIS REPORT ARE ACTIVE INGREDIENT RATES.

The herbicides were applied preemergence and the first significant rainfall (0.96 inches) occurred five days after application. Authority alone controlled 91 to 98% of the giant foxtail compared to 50% control with Scepter and Sencor alone. Authority alone controlled 98 to 100% of the yellow nutsedge, velvetleaf, and ivyleaf morningglory, and 52 to 88% of the common cocklebur. Authority at 0.375 lb/A tank- mixed with Sencor at 0.188 lb/A increased common cocklebur control to 93%. Scepter controlled 42% of the common cocklebur. No visible soybean injury was observed. Soybean yield ranged from 2 to 32 bu/A.

I. INTRODUCTION:

Authority is an experimental broadleaf herbicide for use in soybean. It controls several weeds that are prevalent in southern Illinois such as ivyleaf morningglory, yellow nutsedge, pigweeds, waterhemp, common lambsquarters, velvetleaf, and black nightshade. However, it is weak on common cocklebur and ragweeds. Therefore, a tank-mix partner may be required to control a broad spectrum of weeds. This study was designed to evaluate and compare weed control with Authority alone and in combination with other herbicides.

II. HERBICIDES EVALUATED:

        Authority 75 DF
        Fusion 2.66 EC
        Scepter 1.5 AS
        Sencor 75 DF

III. ABBREVIATIONS USED:

        ABUTH: velvetleaf                              IPOHE: ivyleaf morningglory
        AFR: after first rating                        PRE: preemergence
        COC: crop oil concentrate                      SETFA: giant foxtail
        GLXMA: soybean                                 XANST: common cocklebur

IV. RESULTS AND DISCUSSION:

Weed control and soybean injury and yield data are presented in the attached tables. There was no change in weed control following the last rating noted in the attached tables. Weeds that are listed in the 'Site Description Sheet' that were not distributed uniformly throughout the study area were not rated. All comments referring to weed control are in reference to the last rating unless noted otherwise.

Giant Foxtail Control 21 Days After Planting:

The herbicides were applied preemergence and the first significant rainfall (0.96 inches) occurred five days after application. Authority alone controlled 91 to 98% of the giant foxtail compared to 50% control with Scepter and Sencor alone. Authority tank-mixed with Sencor did not significantly improve the control of giant foxtail compared with Authority alone, regardless of rate. Giant foxtail control was increased to 100% with the postemergence application of Fusion.

Yellow Nutsedge:

Authority alone controlled 98 to 100% of the yellow nutsedge. Authority tank-mixed with Sencor did not improve the control of the yellow nutsedge compared with Authority alone, regardless of rate. Scepter controlled 90% of the yellow nutsedge.

Velvetleaf Control:

Authority alone controlled 100% of the velvetleaf. Authority tank-mixed with Sencor did not improve the control of velvetleaf compared with Authority alone, regardless of rate. Scepter controlled 97% of the velvetleaf.

Ivyleaf Morningglory Control:

Authority alone controlled 100% of the ivyleaf morningglory. Authority tank-mixed with Sencor did not improve the control of the ivyleaf morningglory compared with Authority alone, regardless of rate. Scepter controlled 85% of the ivyleaf morningglory.

Common Cocklebur Control:

Authority alone controlled 52 to 88% of the common cocklebur. Authority at 0.375 lb/A tank- mixed with Sencor at 0.188 lb/A increased common cocklebur control to greater than 90%. Scepter controlled 42% of the common cocklebur.

Soybean Injury and Yield:

No visible soybean injury was observed. Soybean yield ranged from 2 to 32 bu/A. 

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

All herbicides gave excellent control of common waterhemp, common ragweed, Pa. smartweed, and ivyleaf morningglory. Likewise, excellent control of giant foxtail occurred except in two instances where antagonism occurred between Poast and Galaxy or Storm applied as a premix. All POST herbicides caused moderate soybean injury but complete recovery occurred. Yield was dependent on the level of weed control obtained.

I. INTRODUCTION:

Common waterhemp has become a major weed problem in soybeans in the last several years. This likely is a result of greater use of POST herbicides, especially the ALS type, that control this weed poorly. With the frequent use of these types of herbicides for several years, an initially low population of this weed has become a major problem. This study was designed to evaluate several commercially available soil and POST herbicides for control of this weed.

II. HERBICIDES EVALUATED:

        Action (CGA-248745) 4.75 WP                    Poast 1.5 EC
        Blazer 2 EC                                    Poast Plus 1 EC
        Broadstrike/Dual 7.67 EC                       Prowl 3.3 EC
        Canopy 75 WG                                   Pursuit 70 WG
        Cobra 2 EC                                     Raptor 1 AS
        Dual II 7.8 EC                                 Select 2 EC
        Expert (CGA-277476) 75 WG                      Squadron 2.33 EC
        Galaxy 3.67 EC                                 Storm 4 EC
        Pinnacle 25 WG

III. ABBREVIATIONS USED:

        ABONOR: above normal                           GLXMA: soybeans
        ABUTH: velvetleaf                              IPOHE: ivyleaf morningglory
        AMARE: redroot pigweed                         LVS: leaves
        AMATA: common waterhemp                        POLPY: Pa. smartweed
        AMBEL: common ragweed                          SETFA: giant foxtail
        AMBTR: giant ragweed                           V: vegetative stage
        BROFOL: broadcast foliar                       W: weeds
        BROSOI: broadcast soil                         XANST: common cocklebur
        CYPES: yellow nutsedge                         ZEAMX: corn
        DL: days later

IV. RESULTS AND DISCUSSION:

Weed Control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the July 29 rating. Several weed species listed on the Site Description Sheet were not rated because they were not uniformly distributed in the plot area.

 Weed Control:

Control of giant foxtail was 99% in most instances. The only exceptions were tank-mixes of Poast plus Galaxy or Storm where antagonism apparently reduced control to 50 to 55%. Yellow nutsedge control was poor, in most instances less than 80%. Control of common ragweed, Pa. smartweed, and ivyleaf morningglory was excellent with all herbicides, in most instances 99%. Likewise, control of common waterhemp was excellent with all herbicides, ranging form 96 to 99%. These herbicides were selected specifically because of their efficacy on 'pigweed' species, thus this level of waterhemp control was not unexpected.

Soybean Injury and Yield:

All POST herbicides caused slight to moderate initial soybean injury, but complete recovery occurred within several weeks. Soybean yield ranged from 20 bu/A in the nontreated plots to 57 bu/A. Significant differences in yield were related to poor control of giant foxtail and/or yellow nutsedge.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Roundup Ultra POST at rates of 0.75 pt/A controlled foxtail almost completely. There was no second emergence, thus the addition of CGA-77102 II with Roundup Ultra did not improve control. Pursuit POST controlled foxtail only 42%, thus because of the incomplete control, there was no benefit in applying CGA-77102 II with the Pursuit.

I. INTRODUCTION:

CGA-11702 II has the same active ingredient as Dual II. The only difference between the two products is that CGA-77102 II has only the active `isomerþ in it, thus the use rate will be lower. This study was designed to evaluate weed control in Roundup Ready soybeans with several CGA-77102 II combinations and with Roundup Ultra. CGA-771-2 II was applied POST with Pursuit and Roundup Ultra as a possible measure to prevent multiple emergence of giant foxtail and small-seeded broadleaf weeds.

II. HERBICIDES EVALUATED:

        CGA-77102 II 7.57 EC
        Pursuit 70 WG
        Roundup Ultra 4 S
        Scythe 8 AL

III. ABBREVIATIONS USED:

        ABONOR: above normal                           CYPES: yellow nutsedge
        ABUTH: velvetleaf                              GLXMA: soybeans
        AMARE: redroot pigweed                         SETFA: giant foxtail
        AMATA: common waterhemp                        SORVU: grain sorghum
        AMBEL: common ragweed                          W: weeds
        BROSOI: broadcast soil                         XANST: common cocklebur

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached tables. There was no change in weed control following the July 22 rating. Several weed species listed in the Site Description Sheet were not rated because their distribution was not uniform in the plot area.

Weed Control:

CGA-77102 II alone applied POST did not control any giant foxtail. Pursuit controlled foxtail only 42%. A tank-mix of CGA-77102 II plus Pursuit did not improve foxtail control compared to Pursuit alone, since CGA-77102 II has no foliar activity. Roundup Ultra alone at 0.75 pt/A controlled foxtail 96% or greater. There was no benefit from using CGA-77102 II with Roundup Ultra because the latter herbicide controlled the foxtail almost completely. None of the herbicides controlled yellow nutsedge greater than 50%. Roundup Ultra controlled waterhemp almost completely compared to zero control with CGA-77102 II or Pursuit. Both Pursuit and Roundup Ultra controlled common ragweed and velvetleaf almost completely, thus again there was no benefit in adding CGA-77102 II to these herbicides.

Soybean Injury and Yield:

Little or no soybean injury was observed with the herbicides evaluated. Soybean yield ranged from 21 bu/A in the nontreated plots to 55 bu/A.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Weeds were allowed to compete with Roundup Ready soybeans for different time periods based on weed height at application. When Roundup Ultra was applied at 3 or 6 inch weed height followed by cultivation and handweeding, yield was not different compared to a PRE treatment plus cultivation plus handweeding. However, when weeds were allowed to compete with soybeans until the weeds were 9 or 12 inches tall, significant reduction in yield occurred.

I. INTRODUCTION:

Postemergence herbicides are becoming more numerous and their usage is increasing annually. About 60% of the total U.S. soybean acreage is treated with one or more POST herbicides, either as the planned program, or to control weeds not controlled with soil herbicides. One of the longstanding concerns regarding an all POST program is whether crop yield declines because of competition with weeds during the first several weeks following emergence, before the POST herbicides control the weeds. This study was designed to determine the effect on soybean yield if the application of Roundup Ultra was delayed by various time intervals, based on weed height. Roundup Ultra was applied at 3, 6, 9, and 12 inch weed height, which was 29, 35, 40, and 44 days after planting. All plots that received herbicides also were cultivated and hand weeded as necessary to maintain weed-free conditions throughout the season.

II. HERBICIDES EVALUATED:

        Galaxy 3.67 E.C.
        Microtech 4 ME
        Poast 1.5 E.C.
        Prowl 3.3 E.C.
        Pursuit 70 WG
        Roundup Ultra 4 S
        Scepter 70 WG

III. CULTIVATION AND HANDWEEDING DATES:

        1.  Treatments 1, 2, 3, 4, 5, and 8 cultivated July 1 and 22; also these               treatments
        were handweeded July 9-10.
        2.  Treatment 6 cultivated July 8 and 22 and handweeded July 12.
        3.  Treatment 7 cultivated and handweeded July 12 and cultivated second time July      22.

IV. OTHER HERBICIDES:

Because of a dense stand of yellow nutsedge in the entire plot area, 1 qt/A Basagran + Prime Oil COC at 1 qt/A was applied to treatments 1, 2, 3, 4, 5, and 8 on June 29, to treatment 6 on July 4, and to treatment 7 on July 8.

 V. ABBREVIATIONS USED:

        ABONOR: above normal                           DATST: jimsonweed
        ABUTH: velvetleaf                              GLXMA: soybeans
        AMARE: redroot pigweed                         IPOHE: ivyleaf morningglory
        AMATA: common waterhemp                        POLPY: Pa. smartweed
        BELNOR: below normal                           SETFA: giant foxtail
        BROFOL: broadcast foliar                       SIDSP: prickly sida
        BROSOI: broadcast soil                         V: vegetative stage
        CHEAL: common lambsquarters                    W: weeds
        CYPES: yellow nutsedge                         XANST: common cocklebur
        DAT: days after treatment                      ZEAMX: corn

VI. RESULTS AND DISCUSSION:

Soybean injury and yield data is presented in the attached table. Weed control ratings were not taken because of the cultivation and handweeding that was done during the season, resulting in complete weed control except in the cultivate only and nontreated plots. In the 'cultivate only' plots, the only weeds that were not controlled 95% or greater were giant foxtail and yellow nutsedge. These two weeds were controlled approximately 85 to 90% with the two cultivations.

Soybean 'Injury':

The soybean 'injury' observed was primarily a height reduction caused by competition from the weeds, before they were controlled. This was especially evident when application of the Roundup Ultra was delayed until the weeds were 9 or 12 inches tall. Complete 'recovery' never occurred when Roundup Ultra application was delayed until the 12 inch weed height. In contrast, soybean height reduction was 50% in the nontreated plots at 56 DAT.

Soybean Yield:

Soybean yield in the nontreated plots was only 12 bu/A, reflecting the effect of season-long weed competition. IN plots where two cultivations were the only weed control practice (85 to 90% weed control), yield was 56 bu/A. Soybean yield was not different between PRE or PRE plus POST treatments and where Roundup Ultra was applied at 3 or 6 inch weed height. When the Roundup Ultra application was delayed until the 9 and especially the 12 inch weed height, soybean yield decreased significantly, indicating the influence of the extended period of weed competition. These results substantiate research elsewhere that if weeds are allowed to compete too long with soybeans, a reduction in yield likely will occur.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

RATES NOTED IN THIS REPORT ARE ACTIVE INGREDIENT RATES.

FirstRate at 0.031 lb ai/A alone controlled 60%, 0%, 100%, 97%, and 95% of the yellow nutsedge, common waterhemp, common ragweed, ivyleaf morningglory, and common cocklebur, respectively. Authority at 0.313 lb/A alone controlled 98%, 100%, 63%, 98%, and 90% of the yellow nutsedge, common ragweed, ivyleaf morningglory, and common cocklebur, respectively. Canopy controlled 93%, 77%, 100%, 88%, and 100% of the yellow nutsedge, common ragweed, ivyleaf morningglory, and common cocklebur, respectively. FirstRate tank-mixed with Authority increased common waterhemp control with FirstRate to 100%. Authority tank-mixed with FirstRate increased common ragweed control with Authority to 100%. No visible soybean injury was observed. Soybean yield ranged from 15 to 54 bu/A.

I. INTRODUCTION:

Authority and FirstRate are experimental broadleaf herbicides for use in soybean. Authority controls several weeds that are prevalent in southern Illinois such as ivyleaf morningglory, yellow nutsedge, pigweeds, waterhemp, common lambsquarters, velvetleaf, and black nightshade. However, it is weak on common cocklebur and ragweeds. FirstRate also controls several weeds that are prevalent in southern Illinois such as common cocklebur, ragweeds, and velvetleaf. Therefore, Authority and FirstRate may be complementary. This study was designed to evaluate and compare weed control with Authority and FirstRate alone and in combination.

II. HERBICIDES EVALUATED:

        Authority 75 DF
        Canopy 75 DF
        Classic 25 WG
        FirstRate 84 DF
        Fusion 2.66 EC

III. ABBREVIATIONS USED:

        AMATA: common waterhemp                        IPOHE: ivyleaf morningglory
        AMBEL: common ragweed                          PPI: preplant incorporate
        DAP: days after planting                       SETFA: giant foxtail
        CYPES: yellow nutsedge                         XANST: common cocklebur
        GLXMA: soybean

IV. RESULTS AND DISCUSSION:

Weed control and soybean injury and yield data are presented in the attached tables. Weeds that are listed in the 'Site Description Sheet' that were not distributed uniformly throughout the study area were not rated. There was no change in weed control following the last rating noted in the attached tables. All comments referring to weed control are in reference to the last rating unless noted otherwise.

 Giant Foxtail Control 21 Days After Planting:

The herbicides were preplant incorporated twice with a field cultivator. FirstRate alone controlled 33 to 45% of the giant foxtail 21 DAP. Authority alone controlled 33 to 90% of the giant foxtail 21 DAP with control increasing as the rate increased. Canopy controlled 78% of the giant foxtail 21 DAP. Giant foxtail control with a tank-mix of Authority and FirstRate ranged from 78 to 93% 21 DAP. Giant foxtail control was increased to 100% with the postemergence application of Fusion.

Yellow Nutsedge:

Yellow nutsedge control was 60%, 98%, and 93% with FirstRate, Authority, and Canopy at label rates, respectively. A tank-mix of FirstRate and Authority at half their label rate controlled 93% of the yellow nutsedge. A tank-mix of Authority and Classic at reduced rates controlled 98% of the yellow nutsedge.

Common Waterhemp:

Common waterhemp control was 0%, 100%, and 77% with FirstRate, Authority, and Canopy at label rates, respectively. A tank-mix of FirstRate and Authority at half their label rate controlled 100% of the common waterhemp. A tank-mix of Authority and Classic at reduced rates controlled 100% of the common waterhemp.

Common Ragweed:

Common ragweed control was 100%, 63%, and 100% with FirstRate, Authority, and Canopy at label rates, respectively. A tank-mix of FirstRate and Authority at half their label rate controlled 100% of the common ragweed. A tank-mix of Authority and Classic at reduced rates controlled 100% of the common ragweed.

Ivyleaf Morningglory:

Ivyleaf morningglory control was 97%, 98%, and 88% with FirstRate, Authority, and Canopy at label rates, respectively. A tank-mix of FirstRate and Authority at half their label rate controlled 97% of the ivyleaf morningglory. A tank-mix of Authority and Classic at reduced rates controlled 100% of the ivyleaf morningglory.

Common Cocklebur:

Common cocklebur control was 95%, 90%, and 100% with FirstRate, Authority, and Canopy at label rates, respectively. A tank-mix of FirstRate and Authority at half their label rate controlled 97% of the common cocklebur. A tank-mix of Authority and Classic at reduced rates controlled 100% of the common cocklebur.

Soybean Injury and Yield:

No visible soybean injury was observed. Soybean yield ranged from 15 to 54 bu/A. In most instances, yield was reduced where common ragweed was less than 70%.

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Pursuit alone controlled giant foxtail only 58%. When Prestige was added to it, control increased to as high as 93%. Little or no soybean injury was observed with the Pursuit plus Prestige combinations. Yield ranged from 5 bu/A in the nontreated plots to 38 bu/A.

I. INTRODUCTION:

Prestige is a brand name for sethoxydim that is marketed by American Cyanamid. This study was designed to evaluate tank-mix applications of Pursuit plus Prestige to aid in the control of annual grasses.

II. HERBICIDES EVALUATED:

        Assure II 0.88 E.C.
        Concert 25 WG
        Prestige 1 E.C.
        Pursuit 70 WG
        Raptor 1 E.C.
        Scepter 70 WG
        Squadron 2.33 E.C.

III. ABBREVIATIONS USED:

        ABONOR: above normal                           GLXMA: soybeans
        ABUTH: velvetleaf                              IPOHE: ivyleaf morningglory
        AMATA: common waterhemp                        LVS: leaves
        AMBEL: common ragweed                          SETFA: giant foxtail
        AMBTR: giant ragweed                           V: soybean vegetative stage
        BROFOL: broadcast foliar                       W: weeds
        BROSOI: broadcast soil                         XANST: common cocklebur
        CYPES: yellow nutsedge                         ZEAMX: corn

IV. RESULTS AND DISCUSSION:

Weed control ratings and soybean injury and yield data are presented in the attached table. There was no change in weed control following the Aug. 14 rating. Several weed species listed in the Site Description Sheet were not rated because they were not distributed uniformity in the plot area.

Weed Control:

Pursuit controlled only 58% of giant foxtail when Prestige was added at rates of 0.75 to 1.5 pt/A to Pursuit, foxtail control increased, but not consistently. The most complete control of foxtail was with Raptor and Assure II. Control of broadleaf weeds was highly dependent on the weed species and herbicide used.

Soybean Injury and Yield:

Little or no soybean injury was observed with any of the Pursuit treatments. Soybean yield ranged from 5 bu/A in the nontreated plots to 38 bu/A. Incomplete control of several weeds likely reduced yield in this study. 

The Site Description Sheet lists pertinent information such as planting and application dates, weed species present, and soil characteristics.

Treatment Lists and Data Tables will require the Adobe Acrobat and WebLink (TM) plug-ins.

The best way to look at our Treatment Lists and Data Tables is to print them using your laser printer.

If you are unable to access our Data Tables using Adobe Acrobat and your laser printer .

Go to the Weed Control Progress Reports Homepage .

Go to the Plant and Soil Science Department Homepage .

Go to the Southern Illinois University at Carbondale Homepage .