Field BindweedControl in Field Crops and Fallow

creeping, deep-rooted perennialAweed, field

bindweed(Convolvulus

arvensis L.), isnative to Europe and westernAsia. It was first found inNorth America in Virginia in1739 and probably was broughtto Kansas in infested

wheat seed from the Ukrainianregion of Russia between 1870and 1875. Field bindweed wasreported in Kansas near To-peka in 1877 and in Nebraskain 1888. It spread rapidly, andhad infested nearly 200,000acres in Kansas by 1937 andapproximately 1.2 million acresstatewide in 1988.

Crop Losses FromField Bindweed

Field bindweed competesaggressively with crop plantsfor water, nutrients, and light.It reduces crop yield andquality, reduces land value,interferes with harvesting byentwining crop plants, limitsfarmers to certain crops androtations, and increases pro-

Table of Contents

Origin and Infestation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Crop Losses from Field Bindweed . . . . . . . . . . . . . . . . . . . . . . 1The Kansas Noxious Weed Law . . . . . . . . . . . . . . . . . . . . . . . . 2

Plant Growth and Development . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Period of Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Growth of Bindweed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3How Bindweed Spreads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Bindweed Control Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Preventive Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Seed Dormancy and Seedling Control . . . . . . . . . . . . . . . . . . . . 4Field Bindweed Control in Cropland . . . . . . . . . . . . . . . . . . . . . 4

Competitive Crops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Timely Tillage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Chemical Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Review of Field Bindweed Control Data . . . . . . . . . . . . . . . . . . . . 6

Control in Conventional and No-Till Systems . . . . . . . . . . . . . . . . 9

Field Bindweed Control in Crops . . . . . . . . . . . . . . . . . . . . . . . . . . 9Wheat, Oats, and Barley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Row Crops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Conservation Reserve, Pastures, and Rangeland . . . . . . . . . . . . . . 9

Control in Fallow Preceding Wheat . . . . . . . . . . . . . . . . . . . . . . . 10

Summary and RecommendationsFor Control of Field Bindweed . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

duction costs associated withcontrol practices and the needto clean infested small grainseed Research at the Fort HaysBranch Experiment Stationover a 12-year period indicatedthat dense stands of fieldbindweed reduced cereal cropyields by 20 to 50 percent androw crop yields by 50 to80 percent. Thick alfalfa standshave been able to competewith the weed, but as the alfalfastand thinned with age,field bindweed fluorished.

The Kansas NoxiousWeed Law

Field bindweed was de clareda noxious weed in Kansas in1937 and now is one of11 weeds listed as noxious inthe Kansas Noxious WeedLaw. A copy of the law can beobtained from the Weed andPesticide Division, KansasState Board of Agriculture,Topeka, KS 66612 or from acounty noxious weed office.

Plant Growth andDevelopmentDescription

Several morphologicallydistinct biotypes of field bind-weed have been identified andmore than one biotype oftenexist in the same infested area.Although biotypes may vary inappearance and growth habit,most are low-growing,drought-tolerant plants withvigorous,twining stems up to6 feet long. Field bindweedleaves are relatively small andarrowhead-shaped withpointed basal lobes. Leaf shapeand size vary among plants,and to some extent on thesame plant. The plants have along central taproot capable ofreaching depths of 20 feet ormore. Numerous lateral roots

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develop along the taproot,mostly in the top 2 feet of soil.Buds formed along lateral rootsare capable of developing intoshoots which, upon reachingthe surface, b ecome newplants. The flowers are bell-shaped, 3/4 to 1 inch in diame-ter (about half the size of tallmorningglory), and vary fromwhite to pink. Each flowerproduces a nearly roundseedpod containing one to fourdark brown or black three-sided seeds about l/8 inch long.Two sides of the seed are flat,the third size is convex, andthe seed coat is covered withtiny raised dots. The seeds areextremely hard, impervious towater, and can remain dor-mant and viable in the soil formore than 30 years.

The seedlings have twoheart-shaped cotyledonaryleaves. Seedlings quicklydevelop a deep taproot, andnumerous lateral roots developabout 6 weeks after emer-gence. Once lateral rootsdevelop, the plant has a peren-nial growth habit.

Period of GrowthField bindweed usually

emerges in early to mid-Aprilin Kansas and continuesgrowing until November oruntil the temperature drops to20°F or lower. Bindweedgrowth may be retarded atfreezing temperatures above20°F, but the vines do not die.Topgrowth will cease or dieduring severe drought, butnew topgrowth will appearafter adequate rainfall.

Growth of BindweedSeed of field bindweed will

germinate near the soil surfacethroughout the growing sea-son following rainfall, withmost germination occurring in

the spring. When not compet-ing with other plants, a bind-weed seedling may develop aroot system that will penetrateto a depth of 4 feet. Roots canhave a lateral spread of approx-imately 10 feet in one season,and may penetrate to a depthof 18 to 20 feet. In two or threegrowing seasons roots mayextend to a diameter of 17 to18 feet.

Root penetration is influ-enced by such factors as soilmoisture, permeability of thesubsoil, and bindweed bio-type. In areas where annualrainfall averages 30 inches ormore, bindweed roots havebeen found 30 feet below thesurface. On upland soils nearHays, where annual rainfallaverages 23 inches, few rootswere found below 6 feet andmore than 60 percent of thetotal weight of roots was in thesurface 2 feet of soil.

Heaviest bloom in west-central Kansas is from May15 to June 15 and seed usuallymatures from June 15 to July15, often before small grain.Under favorable conditions,field bindweed may continue

The rounded leave s of theseedlings, left, give way toarrowhead-shaped leaves afew days after emergence.Leaf shape may vary, even onthe same plant.

to bloom and produce seedduring July and August. It maybecome dormant during ex-tended drought periods, butresumes growth after adequaterainfall.

How Bindweed SpreadsField bindweed spreads both

vegetatively and by seeds.Root segments containingbuds, spread by tillage imple-ments, are capable of startingnew plants if the soil is moistor if rain follows soon aftertillage. Spreading by seedoccurs when seeds drop fromvines wrapped around tools and when vines passthrough harvesting equipment.Seed may also be collectedwith harvested grain. Then,because the seeds are difficultto remove from seeds of cerealcrops, they often are plantedalong with crop seed. Fieldbindweed seed in grain or hayfed to livestock will passthrough animals largely undi-gested, thus spreading theseed with manure. Seed also iscarried by drainage water,birds, on feet of animals, andon wheels of machinery andvehicles. Both seeds and rootsegments are spread by roadmaintenance equipment.

BindweedControl PracticesPreventive Control

All crop seed should becleaned before seeding toremove bindweed and otherweed seeds. Feeding hay orgrain contaminated with field

if possible. Livestock fedcontaminated grain or hayshould be confined, or re-stricted to areas already in-fested, until the bindweedseed passes through the ani-mals. Manure containing fieldbindweed should be spreadonly on bindweed-infestedland. Harvesting, tillage, andother machinery should bethoroughly cleaned beforemoving from infested to non-infested fields. New infesta-tions that start in waterways,roadside ditches, shelter belts,fence rows, and along railroadrights-of-way should be con-trolled immediately.

Seed Dormancy andSeedling Control

Bindweed seed is extremelyhard and can lie dormant inthe soil for 30 years or more.Seeds brought near the soilsurface by tillage, rodents, orother means will germinateunder favorable conditions,resulting in new bindweedinfestations. Under favorableconditions, 6-week-old seed-lings are capable of re-estab-lishment after topgrowth

removal. Seedlings emergingbetween crops are easilycontrolled with timely tillage.Several soil-applied herbicidescommonly used to controlannual weeds in crops alsoeffectively control field bind-weed seedlings. In situationswhere pre-emergence herbi-cides are not used or areineffective, applications of2,4-D or Banvel (dicamba) at0.25 to 0.5 pounds activeingredient per acre can be usedto control the seedlings incrops tolerant to the herbi-

Each flower produces arounded seedpod, usuallycontaining four seeds. Theseeds can remain dormant inthe soil and begin a newinfestation after more than30 years.

Field bindweed looks similarto the less-destructive hedgebindweed. The flowe r of thehedge bindweed , left, ismuch larger than the fieldbindweed flower.

cides. Also, 2,4-D, Banvel(or combinations) and non-selective herbicides such asLandmaster BW or Cyclonecan be used instead of tillagewhen the land is fallow. Fieldbindweed seedlings betweenrows of broadleaf crops such assoybeans, sunflowers, melons,and many vegetables can becontrolled with cultivation.Seedlings within rows willlikely become establishedperennial plants unless re-moved by hand.

Field BindweedControl in

Competitive Crops. Fieldbindweed is an excellentcompetitor for limited soilmoisture, but cannot tolerate

cultivation (solid line), thepercentage of carbohydrates inbindweed roots decreased until16 days after the bindweedshoots re-emerged, and thenincreased, indicating that thebindweed plant was producingmore carbohydrates than wereneeded for growth and wasstoring the surplus in roots.Thus, repeated destruction oftopgrowth every 12 to 16 daysafter shoot-re-emergence(dashed line) weakens theplants by depleting carbohy-drate reserves in the roots andstimulates dormant bindweedseeds to germinate.

Chemical Control. Severalherbicides effectively controlfield bindweed, although asingle herbicide applicationwill rarely eliminate estab-lished stands. Rather, severalherbicide applications overseveral yea rs are usuallynecessary to reduce densestands of field bindweed andkeep it suppressed. Controlmay be enhanced by combin-ing herbicide treatments withclosely drilled, vigorouslygrowing crops.

Currently, 2,4 -D, Banvel,Roundup, Landmaster II,Landmaster BW, and Tordonare labeled individually and invarious combinations for thesupppression or control of fieldbindweed in crops or fallow.

bindweed emerges betweenharvest and seeding. Substitut-ing a herbicide for a late tillageoperation may delay bindweedemergence in the crop nextspring and hasten control ofthick stands.

Timely Tillage. Tillage is themost common way to destroytopgrowth and is most effec-tive when performed withsweep-type implements thatsever shoots from the rootsabout 4 inches below the soilsurface. As perennial plantsregenerate topgrowth, foodreserves from roots are trans-ported to the newly emergingshoots. About 12 days afterleaves are formed, they manu-facture food in sufficientquantities for the plant to startrebuilding root reserves.

Figure 1 shows the effectof single and multiple tillageoperations on food reserves inpreviously uncontrolled fieldbindweed roots. After a single

shading from tall competitivecrops. Forage sorghum orsundangrass seeded in narrowrows about mid-June, after aperiod of intensive tillage oruse of a herbicide, are excellentcompetitors with field bind-weed in areas where adequatesoil moisture fa vors rapid cropgrowth Narrow row grainsorghum may also be used asa competitive crop, but grainsorghum usually is not aseffective as taller forage crops.The effectiveness of competi-tive crops depends on herbici-dal control or intensive cultiva-tion curing fallow periodswhen the bindweed is activelygrowing.

Relatively good continuouswheat can be produced withfavorable soil moisture andfield bindweed stands greatlyreduced (but seldom elimi-nated) by early October and bytilling every 12 to 16 days after

Figure 1. Carbohydratereserves in field bindweedroots as affected by tillage.The solid line representscarbohydrate reserves beforeand after a single tillageoperation during a 2-monthfallow period; the dashed linerepresents carbohydratereserves in roots from areastilled at 2 to 3-week intervalsduring the fallow period.

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VAIL

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RB

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DAYS BEFORE OR AFTER EMERGENCE

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Figure 1

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At the time of printing, herbi-cides names in this publicationwere registered for uses sug-gested. Apply each herbicideor herbicide mixture accordingto all directions, warnings,and precautions on the prod-uct label(s). Tordon is a Re-stricted Use Pesticide. FallowMaster is a commercial pack-age mixture of glyphosate(Roundup) and dicamba(Banvel) for control or suppres-sion of emerged weeds infallow and reduced tillagecroppping systems. However,field bindweed is not listed asone of the weeds suppressedor controlled at the labeled userates for Fallow Master. Theseherbicides vary in mode ofaction, relative tolerance toplant stress, se lectivity, soilpersistence, and susceptibilityto off-site movement.

Variable response of fieldbindweed to herbicides iscommon and ma y be related toplant age, biotype, and envi-ronmental conditions. Leafcuticles are fully formed soonafter the leaf attains maximumsize, but the cuticle cracks andthe wax content of the cuticlegradually decreases with agethrough exposure to wind,rainfall, and scarification bywind-blown sand and dust.Thus, herbicide uptake may begreater in older plants that areactively growing than inyounger plants. Plants grow-ing u nder moisture or heatstress and exposed to fullsunlight usually have smallerleaves with more cuticular waxand slower biological processesthan shaded plants and plantsgrowing in favorable condi-tions. As plant stress increases,herbicide uptake and transloca-tion usually decrease. Conse-quently most herbicides con-trol field bindweed less

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Table 1Control of field bindweed 5 and 7 months afterherbicide application in the spring, Hays, Kansas,1963-1977.

Control, months aftertreatmenta

Herbicides Rate 5 17(lb ai/A) ----(Percent)----

2,4--D oil-soluble amine 2.0 62 (3) 44 (3)2,4--D amine b 2.0 44 (4) ------2,4--d ester 2.0 61 (10) 42 (3)Banvel 4.0 62 (9) 51 (3)Roundup 4.0 75 (5) 68 (3)c

Banvel + 2,4--D amine 0.5 + 1.5 36 (3) ------aNumbers in parentheses indicate the number of te sts included in themean.bamine = dimethylamine formulation; ester = low volatile ester formulation.c12 months after treatment.

effectively in mid-summer thanin the spring or fall. Someherbicides are more affected bydrought condidtions thanothers. The following herbi-cides are arranged from leastto greatest relative sensitivityto drought conditions: Tordon< Banvel < 2,4 -D =Roundup.

Another possible explanationof variable field bindweedresponse to herbicides involvesbiotypes. Research has indi-cated field bindweed biotypesdiffer in susceptibility to 2,4 -Dand Roundup; therefore,differences are likely to occurfor other herbicides too.

Review ofField BindweedControl Data

Summaries of several fieldbindweed control studiesconducted throughout theGreat Plains are discussedbelow. No attemp t was madeto identify bindweed biotypesresistant to a particular herbi-cide. All herbicide rates aregiven as the active ingredient.

In west-central Kansas,5 months after treatment,spring applications of oil-soluble amine or low volatileester formulations of 2,4--D at2.0 lb/A or Banvel at 4.0 lb/Acontrolled slightly more than60 percent of fi eld bindweed.This is compared to 44 percentcontrol for the dimethylamineformulation of 2,4--D at 2 lb/Aand 36 percent control for atank mixture of 2,4--D amineplus Banvel at 1.5 + 0.5 lb/A.

Flower color and leaf shapemay vary on the same plant.

Banvel or Roundup at ratesused in these studies would beprohibitive for widespread useand are not recomended forother than spot treatment.Equal or greater bindweedcontrol with lower rates ofBanvel has been reported inother states. Landmaster BW,a package mixture of glypho-sate and 2,4--D amine, hasgiven effective, economicalcontrol of field bindweed.These studies are discussedelsewhere in this publication.

Studies in the Texas Panhan-dle showed trends in bind-weed control similar to Kansasresults for fall applications of2,4--D and Roundup. Thesestudies clearly demonstratedthe effects of drought stress onthe efficacy of several herbi-cides. Roundup at 2.9 lb/A wasthe most effective spring-applied treatment (Table 3)after one year (83 percent) andtwo years (67 percent). Thesecond most effective treat-ment after one (65 percent) andtwo years (46 percent) was2,4-D at 1.0 lb/A. Fall applica-tions of Banvel and tankmixtures of Tordon plus 2,4 -D,dicamba, or Roundup weremore effective than springapplications of 2,4--D lowvolatile ester (Table 3). Fieldbindweed control for fall-applied Banvel at 1.0 lb/A was71 and 34 percent one and twoyears after treatment. Controlfor fall-applied tank mixturesof Tordon plus 2,4 -D, Banvel,or Roundup one year aftertreatment ranges from 79 to87 percent.

Field bindweed growingconditions at the time oftreatment greatly affectedherbicide efficacy in the Texasstudies. Drought stress dra-matically reduced the effective-ness of spring and fall-applied

1.0 or 2.0 lb/A (Table 2). Con-trol with Roundup increasedfrom 54 to 69 percent as therate was increased from 2 to4 lb/A. Roundup or 2,4--Dapplied individually in thespring tended to be moreeffective at the end of onegrowing season (5 months)than equivalent treatmentsapplied in the fall (12 months).

The cost of applications of

The most effective springtreatment was Roundup at4.0 lb/A, which gave 75 per-cent control. Control for mosttreatments had decreased by10 to 20 percent by the end ofthe second growing season(17 months after treatment).Applications of 2,4--D lowvolatile ester at 1.5 lb/A in thefall were only slightly moreeffective than applications of

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Table 2Control of field bindweed 12 months after herbi-cide application in the fall, Hays, Kanas,1963-1977.Herbicides Rate No. of tests Control

(lb ai/A) (Percent)2,4--D estera 1.0 4 422,4--D ester 1.5 7 502,4--D ester 2.0 4 45Roundup 2.0 5 54Roundup 3.0 19 63Roundup 4.0 4 69aester = low volatile ester formulation.

Table 3Control of field bindweed one and two years afterpostemergent herbicide application near Bushlandin the Texas Panhandle, 1976-1982a.

Season of Herbicideapplicationb

Herbicides Rate Spring Summer Fall(lb ai/A) ----(Percent controlled 1 yt

after treatment----)Roundup 2.9 83 (5) 77 (8) 60 (9)Banvel 1.0 56 (5) 41 (8) 71 (9)2,4--D ester 1.0 65 (5) 49 (8) 55 (9)Tordon + 2,4--D 0.25 + .05 55 (2) 56 (6) 84 (4)Tordon + Banvel 0.25 + 0.25 47 (2) 73 (4) 87 (5)Tordon + Roundup .020 + 1.6 52 (2) 73 (5) 79 (2)

----Percent controlled 2 yrsafter teratment)----

Roundup 2.9 67 (5) 63 (5) 32 (6)Banvel 1.0 31 (5) 37 (5) 34 (6)2,4--D ester 1.0 46 (5) 42 (5) 10 (6)aNumbers in parentheses indicate the number of tests included in the mean.bSpring = April or May; Summer = June, July, or August; Fall = Septem-ber or October.

2,4--D, spring-applied Banvel,and fall-applied Round up(Table 4). However, fall appli-cations of Banvel at 1.0 lb/A orTordon plus 2,4--Day at 0.25 +0.5 lb/A were equally effectiveon stressed or non-stessedbindweed.

Control of field bindweed inthe northern Great Plains alsowas better when Banvel wasapplied alone or in combina-tion with Roundup or 2,4--D inthe fall than in the spring(Table 5). Banvel tended to bemore effec tive when appliedafter one or more hard freezesthan before a freeze, but therewas little or no difference incontrol between pre-freeze andpost-freeze applications ofBanvel plus Roundup or 2,4--D(data not presented).

Banvel, Roundup, and 2,4--Dapplied alone or in combina-tions were least effective onfield bindweed when appliedduring July or August, regard-less of location. Also, mid-summer applications of Tordonplus 2,4--D (0.25 + 0.5 lb/A) orBanvel (0.25 + 0.25 lb/A) inTexas were less effective thanequivalent treatments appliedin the fall (Table 3). However,in southeastern Wyoming,tank mixtures of Tordon at0.125 or 0.25 lb/A plus 2,4--Damine at 1.0 lb/A applied inmid-summer controlled 81 and92 percent of field bindweed,respectively, approximately12 months after treatment(Table 6). In comparison,control with 2,4--D amine aloneor in combination with glypho-sate (Roundup), either as atank mixture or package mix-ture (Landmaster BW), was57 and 67 percent approxi-mately 10 months after treat-ment. Control had decreasedto 26 and 18 percent ap-roximately 12 months aftertreatment.

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Table 4Effect of plant condition at the time of post-emergent herbicide application on the control offield bindweed one year after treatment nearBushland in the Texas Panhandle, 1976-1982a.

Plant ConditionMonths Good- Poor-

Herbicides Rate applied Excellent Fair(lb ai/A) ----(Percent)----

Roundup 2.9 May-June 85 (4) 77 (2)Sept.-October 72 (3) 36 (4)

Banvel 1.0 May-June 71 (4) 29 (2)Sept.-October 60 (3) 79 (4)

2,4--D ester 1.0 May-June 78 (4) 47 (2)Sept.-October 67 (4) 46 (4)

Tordon + 2,4--D 0.25 + 0.5 May-June 63 (1) -----Sept.-October 78 (1) 90 (3)

aNumbers in parenthesis indicate the number of tests included in themean.

Table 5Control of field bindweed 10 to 12 months afterherbicide application in June, August, or Septem-ber, North Dakota and South Dakota, 1978-1982.

Month of herbicide applicationHerbicides Rate June August September

(lb ai/A) ------------(Percent)------------Banvel 1.0 40 30 83Banvel 2.0 56 33 94Banvel + Roundup 0.5 + 1.5 81 3 96Banvel + 2,4--D 1.0 + 3.0 60 3 94

Table 6Control of field bindweed approximately 10 and12 months after postemergent herbicide applicationin southeastern Wyoming, 1985-1987.

Months after treatmentNo. of

Herbicides Rate Studies 10 12(lb ai/A) ----(Percent)----

Tordon + 2,4--Damine 0.12 + 1.0 2 89 81

Tordon + 2,4--Damine 0.25 + 2.0 3 98 92

2,4--D amine +Roundup 0.56 + 1.1 2 67 26

2,4--D amine 1.0 2 57 18

broadleaf weeds, but fieldbindweed usually does notemerge in spring until afterspraying small grains. Apreharvest application of 2,4 -Dester can be used to controlfield bindweed and othersusceptible weeds after smallgrains have reached the softdough stage. Roundup orLandmaster products can beused for spot treatment of fieldbindweed, but crop plants inthe treated area will be killed.

Row CropsNo herbicides currently

registered selectively controlfield bindweed in broad-leavedrow crops, alfalfa, or otherlegumes. Banvel and 2,4--Dmay be applied postemergenceto corn and grain sorghum forcontrol of field bindweed andsusceptible anual weeds.Crop tolerance to these herbi-cides may vary depending onhybrid, environmental condi-tions and growth stage at thetime of application. Consultthe seed dealer for informationon the relative tolerance ofparticular hybrids to post-emergent appli cations of 2,4 -Dor Banvel. Read and follow theherbicide label for the recom-mended use rate and time ofapplication. Roundup orLandmaster products can beused for spot treatment of fieldbindweed, but crop plants inthe treated area will be killed.

Conservation Reserve,Pastures, andRangeland

Banvel, Tordon, and 2,4--D,alone or in combinations, maybe applied to established grassstands. They should not beapplied to newly seededgrasses, such as in Conserva-

tant, Landmaster BW, andFallow Master applied in thespring controlled field bind-weed significantly better in no-till than in tilled productionsystems 20 and 60 days aftertreatment (Table 7). Increasedinitial control in no-till mayhave been due to more uni-form bindweed emergence andlush, vigorous growth. Control60 days after treatment forconventional tillage decreasedfrom initial control by 24 to63 percent, depending onherbicide treatment. Thedramatic reduction in controlmay have been due to post-treatment tillage stimulatingemergence of new bindweedshoots from buds along under-ground rhizomes.

Field BindweedControl in CropsWheat, Oats, and Barley

Spring applications of Banveland 2,4--D are registered forselective control of winterannual and summer annual

Control inConventional andNo-Till Systems

Although many perennialweeds are known to increase inno-till production systems,field bindweed is an exception.A 10-year study at the FortHays Experiment Station inwest-central Kansas indicatedthat field bindweed was con-trolled as well or better withherbicides in no-till than inconventional productionsystems of continuous wheat,wheat-fallow, and wheat-grain sorghum-fallow (datanot presented). Dense standsof field bindweed were re-duced more rapidly in wheat-fallow and wheat-grainsorghum-fallow rotations.Control was maintained in allrotations when combinationsof herbicides and tillage wereused to control bindweed ascompared to tillage only.

Other studies in westernKansas indicated that 2,4--Damine plus surfactant, Banvelplus 2,4--D amine and surfac-

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Table 7Control of field bindweed in no-till and conventional-till production systems 20 and 60 daysafter treatment near Hays, Kanas, 1985a.

No-till ConventionalHerbicidesb Rate 20 DAT 60 DAT 20 DAT 60 DAT

(lb ai/A) ------------(Percent)------------2,4--D + S 2.0 + 0.5% v/v 100 80 64 252,4--D + Banvel 2.0 + 1.0 + 100 74 64 40

+ S 0.5% v/v2,4--D/glyphosate/

S 0.5/0.38 93 82 73 10Dicamba/glyphosphate/S 0.5/0.2 94 91 62 23aData are the mean of four studies; DAT = days after treatment.b2,4--D = amine formulation; S = surfactant; 2,4--D/glyphosate/S =Landmaster BW, 54 fl oz/A; dicamba/glyphosphate/S = Fallow Master, 42 floz/A.

tion Reserve acres, until afterthe grass has developed sec-ondary roots. Some grassspecies may not germinate andbecome sufficiently developedto tolerate a herbicide applica-tion until late summer. Thismay limit herbicide applicationthe year of seeding. A con-certed effort to control fieldbindweed on land to be seededto grass should be made in theyear prior to grass seeding.However, application of Tor-don during the season prior toseeding is not recommendedbecause of possible herbicidecarry-over that can injure orkill germinating grass seed-lings. Grass may be seeded90 days (excluding days whensoil is frozen) after an applica-tion of Banvel at 0.5 lb/A or180 days after applications at1.0 lb/A. Applications of2,4-D, Roundup, or Landmas-ter BW can be made to fieldbindweed in the fall with littledanger of herbicide carry-overaffecting germinating grassesseeded the following spring.

There is no waiting periodfor grazing non-lactatinganimals on pasture or range-

land treated with Banvel, butanimals should be removedfrom treated areas 30 daysprior to slaughter. Consult theBanvel label for time restric-tions on grazing or feedingBanvel-treated hay to lactatingdairy animals. If more than0.5 lb/A of Tordon is applied,do not cut the grass for feed orgraze lactating dairy animalson treated areas within2 weeks after treatment. Non-lactating animals should beremoved from treated areas atleast 3 days prior to slaughter.Do not allow animals to grazeareas treated with 2,4-D within7 days after treatment.

Control in FallowPreceding Wheat

Control of field bindweed, asindicated, is least effectivewhen most herbicides areapplied in mid-summer (orafter wheat harvest). A herbi-cide application or tillageimmediately after harvest,however, may reduce theproduction of viable seeds andweaken the plant. This could

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increase the effectiveness offollow-up herbicide applica-tions in the fall or spring.

Tank mixtures of 2,4-D plusBanvel or Tordon and 2,4-Dalone are widely used forcontrolling field bindweedduring the fallow period priorto seeding winter wheat. Inrecent years, the use of Land-master II or Landmaster BWhas increased for the control ofannual weeds and suppressionof field bindweed in fallow.When possible, treatmentsshould be made when bind-weed is actively growing withrunners 8 to 12 inches long andin mid to full bloom. Tordonplus 2,4-D at 0.12 to 0.25 +0.5 to 1.0 lb/A should be ap-plied at least 60 days prior toseeding winter wheat to avoidpossible crop injury. Similarly,Banvel plus 2,4-D at 0.5 +1.0 lb/A should be appliedat least 45 days prior to seed-ing. Winter wheat can besafely seeded 2 weeks afterrainfall of .5 inch or morefollowing an application of2,4-D or Landmaster products.Bindweed control is reducedwhen treated areas are tilledanytime after a Landmasterapplication.

Although wheat is a bettercompetitive crop than asummer-planted crop, fieldbindweed infestations canreduce wheat yields by 20 to50 percent.

Summary and RecommendationsFor Control of Field Bindweed

1. Uncontrolled field bindweedis a deep-rooted perennialweed that severely reducescrop yields and land value.

2. The most effective controlprogram includes preventivemeasures over several yearsin conjunction with timelytillage and herbicide applica-tions. Closely drilled, vigor-ous, competitive crops suchas winter wheat or foragesorghum may also aidcontrol.

3. Banvel, Tordon, 2,4-D,Roundup, and Landmasterproducts alone or in variouscombinations are registeredfor suppression or control offield bindweed in fallow

and/or in certain crops,pastures, and rangeland.Apply each herbicide orherbicide mixture accordingto directions, warnings, andprecautions on the productlabel(s). Single herbicideapplications rarely eliminateestablished bindweedstands.

4. Applications of 2,4-D,Roundup, and Landmasterproducts are most effectivewhen spring-applied tovigorously growing fieldbindweed in mid to fullbloom. However, Banveland Tordon applications aremost effective when applied

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Preventive control measures,along with tillage andherbicide applications, aremost effectiv e for controllingfield bindweed.

in the fall. Most herbicidetreatments are least effectivewhen applied in mid-summer or when bindweedplants are stressed.

5. Tillage sooner than 3 weeksafter treatment may reducebindweed control with someherbicides. Tillage afterLandmaster products areapplied may reduce theirsuppression of fieldbindweed.

6. Preharvest applications of2,4-D may be made towinter wheat to prevent orreduce bindweed seedproduction. The mosteffective post-harvest appli-cations include combina-tions of Tordon, Banvel, or2,4-D.

References

1. DeGennaro, F. P. and S. C.Weller. 1984. Differentialsusceptibility of fieldbindweed (Convolvulusarvensis) biotypes to gly-phosate. Weed Science32:472-476.

2. Derscheid, L. A., J. F.Stritzke, and W. G.Wright. 1970. Field bind-weed control with cultiva-tion, cropping, and chemi-cals. Weed Science18:590-596.

3. Miller, S. D., T. Whitson,M. Farrell, and K. J. Forn-strom. 1986. Research inWeed Science: 1986 Pro-gress Report. B-886, Wyo-ming Agricultural Experi-ment Station. 162 pp.

4. Miller, S. D., K. J. Forn-strom, J. M. Krall, T.Whitson, and M. Ferrell.1987. Research in WeedScience: 1987 ProgressReport. B-906, WyomingAgricultural ExperimentStation. 172 pp.

Dallas PetersonExtension Specialist

Weed ScienceKansas State University

5. Phillips, W. M. 1961.Control of Field Bindweedby Cultural and ChemicalMethods. Technical Bulle-tin 1249. United State sDepartment of Agricul-ture. 30 pp.

6. Special Session on FieldBindweed. 1978. NorthCentral Weed ControlConference Proceedings33:140-158.

7. Schweizer, E. E., J. F.Swink, and P. E. Heikes.1978. Field bindweed(Convolvulus arvensis)control in corn (Zea mays)and sorghum (Sorghumbicolor) with dicamba and2,4-D. Weed Science26:665-668.

8. Tichota, J. and J. Foster.1981. Controlling fieldbindweed with dicamba

and tankmixes of glypho-sate or 2,4-D with evalua-tions on sunflowers andcereal crops. North CentralWeed Control ConferenceProceedings 36:50-52.

9. Timmons, F. L. 1941.Results of Bindweed Con-trol Experiments at the FortHays Branch ExperimentStation, Hays, Kansas,1935 to 1940. Kansas Agri-cultural Experiment StationBulletin No. 296. 50 pp.

10. Weise, A. F. and D. E.Lavake. 1985. Control offield bindweed (Convolvulusarvensis) with postemer-gence herbicides. WeedScience 34:77-80.

11. Whitworth, J. W. and T. J.Muzik. 1967. Differentialresponse of selected clonesof field bindweed. Weeds15:275-280.

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Phillip W. StahlmanResearch Weed Scientist

Fort Hays BranchKansas Agricultural Experiment Station

Hays, Kansas

Mention of product tradenames is done to help identify the herbicides. No endorsement is intended, noris any criticism implied of similar products not mentioned.

Kansas State University Agricultural Experiment Station and Cooperative E xtension S ervice_ _March 1989

It is the policy of Kansas State University Agricultural Experiment Station and Cooperative Extension Service that all persons shall have equal opportunity and access to its educational programs, services, activities, and materials without regard to race, color, religion, national origin, sex, age or disability. Kansas State University is an equal opportunity organization . Issuedin furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, as amended. Kansas State.University, County Extension Councils, Extension Districts, and United StatesDepartment of Agriculture Cooperating, Marc A. Johnson, Director .