Effective weed management is essential for profitable peanut production. Peanuts are not very competitive with weeds and thus require higher levels of weed control than most other agronomic crops to avoid yield losses. A weed management program in peanuts consists of good weed control in rotational crops; cultivation, if needed; establishment of a satisfactory stand and growing a competitive crop; and proper selection and use of herbicides.

Rotate peanuts with corn or cotton to help manage various pests, including weeds. Crop rotation allows use of different herbicides on the same field in different years. Crop and herbicide rotation, along with good weed control in the rotational crops, helps prevent the buildup of problem weeds and helps keep the overall weed population at lower levels. Crop rotation will also help reduce the chance of developing populations of weeds that are resistant to herbicides.

Cultivation is an excellent way to supplement chemical weed control. One or two "non-dirting" cultivations often improve weed control. Additionally, cultivation in combination with banded herbicide applications can reduce costs. However, cultivation can damage the crop and reduce yield if not done properly. Movement of soil onto the lower branches and around the base of the plants causes physical damage and enhances development of stem and pod diseases. Deep cultivation also destroys residual herbicide barriers and brings up additional weed seeds. Cultivate when peanuts are small. Set sweeps to run flat and shallow to avoid throwing soil onto the peanut plants.

All fields, regardless of the crop being grown, should be surveyed for weeds between mid-August and the first killing frost. Record the weed species present and note the general level of infestation of each species (light, moderate, or heavy). Weeds present in the fall will be the ones most likely to be problems the following year. Knowing what problems to expect allows you to better plan a weed management program for the following crop.

Scout peanut fields weekly from planting through mid-July to determine if or when postemergence herbicide treatment is needed. Proper weed identification is necessary because species respond differently to various herbicides. Contact your county Extension center for aid in weed identification. Timely application of postemergence herbicides is critical for effective control.

HADSS (Herbicide Application Decision Support System), a computer-based programs designed to assist in making decisions pertaining to postemergence herbicide applications, is available through the North Carolina Cooperative Extension Service. Weed density, predicted crop value, predicted weed-free crop yield, herbicide cost, and herbicide efficacy are used to develop a ranking of the economics of herbicide options for a specific weed complex. This approach does not consider the long-term affect of weed seed production if weeds are not controlled. The patchiness of weeds in each field and the time needed to scout fields are limitations to this approach. However, this decision support system is beneficial in explaining herbicide options. Listed below is the competitive index value assigned to weeds typically found in North Carolina peanut fields (Table 4-1). Cocklebur, with a ranking of 10, is considered the most competitive weed in peanut.

The combined affect of interference by the weed complex is used to predict yield loss in the HADSS program. For example, a weed complex containing 2 cocklebur, 4 pitted morningglory, 8 eclipta, and 6 redroot pigweed per 100 square feet (33 feet of row with rows spaced 3 feet apart) would reduce peanut yield by 59 percent, based on a projected weed-free yield of 3,600 pounds per acre (Table 4-2). Using HADSS and given a crop value of $610 per ton (value of quota peanuts), adequate growing conditions (good soil moisture for satisfactory herbicide performance) and medium size weeds (2 to 4 inches tall), HADSS would offer the following suggestions with various economic returns depending upon the herbicide(s) selected (Table 4-3). Although issues relative to accuracy and time required for weed scouting do exist, the HADSS program does allow a relatively quick and clear comparison of herbicide options while taking herbicide efficacy, herbicide cost, and economic return from that investment into account.
 
 

Registered herbicides and tank mixes suggested for preplant incorporated application include the following (see Tables 4-4 and 4-5 at the end of this chapter):

Prowl		Prowl + Dual or Frontier or Outlook
Sonalan		Sonalan + Dual or Frontier or Outlook
Vernam		Pursuit + Prowl or Sonalan
Dual, Dual Magnum		Pursuit + Dual or Frontier or Outlook
Pursuit		Prowl + Strongarm
Frontier		Sonalan + Strongarm
Strongarm		Strongarm + Dual or Frontier or Outlook

Prowl and Sonalan are similar products that provide similar season-long weed control. They control common annual grasses, pigweed, and lambsquarters but are inadequate for control of most other broadleaf weeds. They also do not control nutsedge. These herbicides can be applied several weeks ahead of planting (see labels for details). Incorporation of Sonalan and Prowl can be delayed 2 and 7 days, respectively. However, they should be incorporated as soon as possible after application is recommended.

Dual, Dual Magnum, Outlook, and Frontier control broadleaf signalgrass, crabgrass, crowfootgrass, fall panicum, foxtails, goosegrass, and pigweed but are weak on Texas panicum. They also control or suppress yellow nutsedge. Dual may be applied up to 14 days before planting and incorporated anytime during that period. Control normally lasts for 8 to 10 weeks. Frontier and Outlook are in the same herbicide family as Dual and Lasso, and selectivity is generally the same for all three herbicides.

Mixtures of Prowl or Sonalan plus Dual, Dual Magnum, Outlook, or Frontier provide somewhat better initial grass control, especially in heavily infested fields. These mixtures also suppress many broadleaf weeds better than the individual herbicides applied alone. However, the primary reason to apply these tank mixes is to provide full-season annual grass control plus nutsedge control; see later section on nutsedge.

Strongarm can be applied preplant incorporated to control common ragweed, eclipta, common lambsquarters, morningglories, cocklebur, and other broadleaf weeds. Weed control with Strongarm is generally better when applied with Prowl, Sonanlan, Dual, Dual Magnum, Outlook, or Frontier. It does not control annual and perennial grasses. Strongarm only suppresses yellow and purple nutsedge. Rotation restrictions include corn, tobacco, and sorghum, but not cotton.

Pursuit 70 DG is registered for preplant-incorporated, preemergence, at-cracking, and postemergence application to peanuts at the rate of 1.44 ounces per acre. The maximum total amount that can be applied per season is 1.44 ounces. Split applications of a half rate preplant incorporated and a half rate at late cracking or early postemergence have tended to give the most consistent control of a range of weed species. Pursuit has activity on some grasses and often has given good control of broadleaf signalgrass, especially when applied postemergence. However, it is suggested that Pursuit be used in combination with a soil-applied grass herbicide. Prowl, Sonalan, Dual, Dual Magnum, Outlook, or Frontier may be tank mixed with Pursuit and incorporated.

As a split application, Pursuit has generally provided good control of cocklebur, jimsonweed, pigweed, prickly sida, smartweed, and spurred anoda (Table 4-5). For effective postemergence control, the Pursuit must be applied to small weeds. Pursuit will not control common ragweed, eclipta, Florida beggarweed, sicklepod, and tropic croton. It also may be weak on lambsquarters.

Pursuit will suppress or control yellow and purple nutsedge, with purple nutsedge usually being the more susceptible. Research shows variable results when comparing different application methods. However, split application (preplant incorporated followed by late at-cracking or early postemergence) has tended to give the best control. Pursuit works slowly and may take 3 to 4 weeks for a noticeable response by nutsedge. Control is better when rainfall occurs within a week after postemergence application. See later section on nutsedge.

There are rotational restrictions of concern following use of Pursuit. Wheat and rye may be planted 4 months after Pursuit application. Corn, tobacco, and barley may be planted 8.5, 9.5, and 9.5 months, respectively, after Pursuit application. In most cases, there is an 18-month rotational restriction for cotton. Cotton may be planted 9.5 months after Pursuit application if all of the following conditions are met: Pursuit applied postemergence only, soil texture is sandy loam or loamy sand, and greater than 16 inches of rainfall and/or irrigation received following Pursuit application through October of the application year. Research in North Carolina has shown no significant carryover to cotton from Pursuit applied at-cracking to a previous peanut crop. However, planting cotton the year following Pursuit application is not recommended except for the special conditions mentioned above.

Preemergence Herbicides

Herbicide and tank-mix options include Dual, Dual Magnum, Outlook, Frontier, Lasso, Pursuit, Dual + Pursuit, Dual Magnum + Pursuit, Lasso+ Pursuit, Outlook + Pursuit, and Frontier + Pursuit. (See Tables 4-4 and 4-5). Lasso (alachlor) is registered for use on peanuts but some marketing contracts exclude alachlor-treated peanuts. Before using Lasso, ask buyers if marketing restrictions exist.

Dual, Dual Magnum, Lasso, Outlook, and Frontier control annual grasses (except Texas panicum) and pigweed. Dual, Dual Magnum, Outlook, and Frontier applied preemergence may adequately control light infestations of yellow nutsedge. (Dual, Outlook, Dual Magnum, and Frontier incorporated is preferred for moderate to heavy infestations). Lasso, Outlook, and Frontier generally require less rainfall for activation, but Dual or Dual Magnum may last about 2 weeks longer on light soils receiving high amounts of rainfall. Apply preemergence herbicides as soon after planting as possible.

Pursuit may be applied preemergence and may be tank mixed with Dual, Dual Magnum, Outlook, Frontier, or Lasso. However, split applications (preplant incorporated followed by late at-cracking or early postemergence) generally are suggested. See comments for Pursuit under the Preplant Incorporated Herbicides section.

Strongarm can be applied preemergence as well as pre-plant incorporated. See comments under pre-plant incorporated. Nutsedge control may be better if Strongarm is incorporated.

Valor received federal and state labels for use in peanut in 2001. In North Carolina the rate of application is 2 ounces per acre and should be applied immediately after planting and no later than 3 days after planting. Considerable injury occurred in 2001 in North Carolina. Injury was also noted in Virginia and throughout the peanut belt. Weather conditions most likely contributed to the level of injury. However, there is not a conclusive answer as to the cause of injury. Therefore, Valor should be used on only a fraction of acreage until a more complete understanding of the 2001 injury becomes apparent.

At-Cracking Herbicides

Herbicide and tank-mix options include Dual, Dual Magnum, Outlook, Frontier, Lasso, paraquat (Boa or Gramoxone MAX) + paraquat + Basagran, paraquat + Dual or Dual Magnum or Outlook or Frontier, Pursuit, and Pursuit + Dual or Dual Magnum or Outlook or Frontier. (See Tables 4-4 and 4-5).

Dual, Dual Magnum, Lasso, Outlook, and Frontier will provide residual control of annual grasses and pigweed to supplement control provided by the preplant or preemergence herbicide(s). Dual, Dual Magnum, Lasso, Outlook, and Frontier will not control emerged weeds. See comments on Dual, Dual Magnum, Frontier, Outlook, and Lasso under Preemergence Herbicides. Dual or Frontier would be preferred in fields with yellow nutsedge or with very coarse soil.

Boa or Gramoxone MAX (paraquat) will control small annual grasses and most small broadleaf weeds. For consistent results, the weeds should be 1 inch or shorter. Paraquat controls only emerged weeds; it does not provide residual control. Application of paraquat is of benefit only if weeds are present. Dual, Dual Magnum, Outlook, or Frontier may be added to Paraquat to provide residual control of annual grasses and small-seeded broadleaf weeds. Tank mixing 0.5 to 1 pint of Basagran with paraquat may improve control of ragweed, prickly sida, spurred anoda, and lambsquarters and reduce paraquat burn on peanuts. See comments in Table 4-4, which is at the end of this chapter.

Pursuit may be applied at-cracking and may be tank mixed with Dual, Dual Magnum, Outlook, Frontier, or paraquat. Although late at-cracking application (small weeds) has generally given good control of many species, split application may be preferred. See comments for Pursuit under the Preplant Incorporated Herbicides section.

Postemergence Herbicides

Postemergence herbicide and tank-mix options include 2,4-DB, Basagran, Basagran + 2,4-DB, Blazer, Blazer + 2,4-DB, Basagran + Blazer, Storm, Storm + 2,4-DB, paraquat, paraquat + Basagran, paraquat + 2,4-DB, Pursuit, Pursuit + Basagran, Pursuit + Blazer, Pursuit + 2,4-DB, Pursuit + paraquat, Classic, Tough, Tough + 2,4-DB, Poast, Poast Plus and Select. (See Tables 4-4 and 4-5 at the end of this chapter).

2,4-DB. 2,4-DB (Butyrac 200, Butoxone, Chemnut, others) can be applied twice per season anytime from 2 weeks after planting up to 45 days before harvest. It primarily controls cocklebur and morningglories. Unless treated when small, pitted morningglory may not be killed by 2,4-DB. Late-season applications of 2,4-DB are discouraged because of potential injury and possible adverse affects on seed quality.

Basagran. Basagran is registered for multiple applications, with the major restriction being a maximum use rate of 4 pints per acre per season. It controls cocklebur, jimsonweed, smartweed, prickly sida, spurred anoda, velvetleaf, and yellow nutsedge. Control of common ragweed and lambsquarters may be adequate if Basagran is applied when these weeds are small. A crop oil concentrate should be added to improve control of common ragweed, lambsquarters, velvetleaf, and yellow nutsedge. Basagran is safe on peanuts at all growth stages and may be applied at any time during the growing season. However, the label warns that in-furrow insecticides may predispose peanuts to injury from Basagran. Injury, sometimes severe, has occasionally been noted in North Carolina when Basagran was applied to peanuts receiving an in-furrow application of Di-Syston.

2,4-DB may be added to Basagran to improve control of morningglory and spurred anoda. This tank mix may be applied from 2 weeks after planting up to 45 days before harvest. The tank mix may be applied twice per season.

Blazer. Multiple postemergence applications of Blazer can be made so long as the amount of applied postemergence does not exceed 2 pints per acre per season. Allow at least 15 days between applications. The maximum rate per application is 1.5 pints per acre. Blazer may be applied anytime from cracking up to 75 days prior to harvest. Blazer controls morningglories, jimsonweed, smartweed, common ragweed, tropic croton, pigweed, and small lambsquarters. Addition of nonionic surfactant is recommended; see label for details. Blazer may cause leaf crinkling and bronzing and sometimes leafburn. Peanuts recover and yield is generally not affected.

2,4-DB may be added to Blazer to improve control of cocklebur and large morningglories. This tank mix may be applied once per season from 2 weeks after planting up to 75 days before harvest.

A Blazer plus Basagran tank mix will control a broader spectrum of broadleaf weeds than either product applied alone. Labeled application rates are 1 to 2 pints of Basagran plus 1 to 1.5 pints of Blazer per acre. The best rate of each product to apply will depend upon weed species present, weed size, and growing conditions; see labels for details. Add crop oil or surfactant according to label directions. This tank mix may be applied anytime from cracking up to 75 days before harvest. Multiple applications may be made so long as the total rate per season does not exceed 2 pints per acre of Blazer or 4 pints per acre of Basagran.

Storm. This prepackaged mixture contains the active ingredients in both Basagran and Blazer. Application of 1.5 pints per acre of Storm is equivalent to applying 1 pint of Basagran plus 1 pint of Blazer. Addition of 1 pint per acre of crop oil concentrate is recommended. Storm may be applied anytime from cracking up to 75 days before harvest. This herbicide controls most common annual broadleaf weeds. Unless applied when weeds are small, however, Storm may not give consistent control of lambsquarters, prickly sida, spurred anoda, and velvetleaf. When these weeds are predominant problems, applying 1.5 to 2 pints per acre of Basagran alone or in combination with Blazer provides better control.

Storm may be applied twice per season. The rate for an individual application should not exceed 1.5 pints per acre, and no more than 3 pints per acre per season should be applied. Do not make a second application within 15 days of the first application.

2,4-DB may be added to Storm to improve control of larger morningglory, cocklebur, common ragweed, pigweed, and jimsonweed. This tank mix may be applied to peanuts that are at least 2 weeks old but not after the pod-filling stage begins and not within 75 days of harvest. Make only one application of the tank mix per season. Add either a surfactant or crop oil concentrate according to label directions.

Boa or Gramoxone MAX (paraquat) may be applied postemergence in addition to an at-cracking application. The total amount applied per acre per season should not exceed 11.2 ounces (Gramoxone MAX) or 13.2 ounces (BOA), and paraquat should not be applied later than 28 days after cracking. One pint of nonionic surfactant per 100 gallons of spray solution should always be included.

Paraquat controls small annual grasses and most small broadleaf weeds (see ratings under at-cracking in Table 4-5). For consistent control, it is suggested that weeds be 1 inch tall or less. For improved control of morningglory and large cocklebur, 2,4-DB may be tank mixed with paraquat.

Paraquat applied to emerged peanuts will cause varying amounts of leaf burn. However, peanuts recover and yield is not affected. A second application of paraquat should not be made if peanuts are showing injury symptoms from the first application. Also, paraquat should not be applied to peanuts showing thrips damage.

A tank mix of paraquat plus 1 pint of Basagran will provide better control of weeds, such as cocklebur, common ragweed, prickly sida, smartweed, spurred anoda, and velvetleaf, than paraquat alone. Adding at least 0.5 pint of Basagran to paraquat also reduces peanut injury from paraquat and is highly recommended. This tank mix may be applied anytime from cracking until 28 days after cracking.

Pursuit. Pursuit can be applied postemergence to peanuts alone or tank mixed with Basagran, Blazer, 2,4-DB, or paraquat. Pursuit generally is recommended as a split application—preplant incorporated followed by late at-cracking or early postemergence. See comments for Pursuit under the Preplant Incorporated Herbicides section. If used postemergence, it is important that Pursuit be applied to small weeds. Adding 2,4-DB to Pursuit will enhance control of broadleaf weeds.

Cadre. Cadre 70 DG at 1.44 ounces per acre controls broadleaf weeds except croton, ragweed, lambsquarters, and eclipta. Cadre also controls purple and yellow nutsedge (see section on nutsedge control). Apply before weeds exceed 3 inches. See the product label for specific weeds and sizes. Add a nonionic surfactant at 1 quart per 100 gallons spray solution or crop oil concentrate at 1 quart per acre. Although Cadre will control escaped broadleaf signalgrass, fall panicum, and Texas panicum, a soil-applied grass control herbicide should be used. See label for rotational restrictions, especially cotton. Do not apply Cadre within 90 days of harvest.

Tough. Tough can be applied alone, but a tank mixture with 2,4-DB is generally recommended. Labeled rates are 1.5 to 2.25 pints of Tough 5 EC, plus 8 to 16 fluid ounces per acre of Butyrac 200. Tough plus 2,4-DB can be applied from 2 weeks after planting until 68 days prior to harvest. The tank mixture controls many broadleaf weeds; see Table 4-5. Note that ragweed, smartweed, and croton are not controlled. Tough is particularly effective on lambsquarters. Tough is an option for lambsquarters control when the weed exceeds the size controlled by Basagran, Blazer, Storm, or paraquat. Adjuvants (crop oil concentrate, nonionic surfactant, or liquid fertilizers) can be applied with Tough tank mixes. Good control of a mixture of lambsquarters and other broadleaf weeds has been obtained with tank mixes of normal rates of Basagran, Blazer, or Storm plus 6 to 8 fluid ounces of Tough. Peanut tolerance of Tough is excellent.

Classic. Classic is registered for late postemergence application to peanuts for control of Florida beggarweed only. Apply only from 60 days after crop emergence to within 45 days of harvest. Earlier application will stunt peanuts and reduce yield. Make only one application of 1/2 ounce per acre per year. Add 1 quart of nonionic surfactant per 100 gallons of spray solution. Do NOT use crop oil concentrate. See comments on the Classic label concerning varietal tolerance. Do NOT apply to peanuts under drought stress. Recommended as a salvage treatment only.

Because peanuts can tolerate only late applications, Classic should not be considered for control of other broadleaf weeds, such as sicklepod. By the time peanuts are old enough to receive Classic, sicklepod and most other weeds will be too large to control with Classic.

Poast, Poast Plus, and Select. Poast, Poast Plus, and Select provide good to excellent control of annual grasses. If applied twice, Poast, Poast Plus or Select also will control bermudagrass and rhizome johnsongrass. Peanuts at all growth stages tolerate Poast, Poast Plus, and Select. Do not apply Poast or Poast Plus within 40 days of harvest. Select can be applied up to 7 days before harvest. Add 2 pints per acre of crop oil concentrate.

Check product labels for Poast, Poast Plus, and Select for potential tank mixtures with broadleaf herbicides. These tank mixes generally are not recommended; one will obtain better control with properly timed sequential applications.

Layby Herbicides

Dual, Dual Magnum, Outlook, and Frontier are registered for layby application to peanuts. The value of a layby herbicide application depends upon the soil texture, organic matter content, and amount of rainfall received during the first 4 to 5 weeks after planting. If above-normal rainfall is received during the first 4 to 5 weeks after planting, especially on coarse, sandy soils with very low organic matter, a layby application of Dual or Frontier banded in the row middles may improve digging efficiency or yield. The layby herbicide should be applied to a weed-free surface (cultivate first or treat with appropriate herbicide if emerged grasses, pigweed, or eclipta are present). If rainfall is at or below normal levels during the first 4 to 5 weeks after planting, a layby application will seldom be economically justified for annual grass control. These herbicides do not control emerged weeds.

A layby application of Dual, Dual Magnum, Outlook, or Frontier also may be beneficial in managing eclipta. See comments under Annual Broadleaf Weeds. Look closely to make sure eclipta has not emerged. These herbicides will not control eclipta that has emerged.

There is a maximum amount of Dual, Dual Magnum, Outlook, and Frontier that can be applied in one season. See comments in Table 4-4 at the end of this chapter.

Annual Grasses

Crabgrass, Fall Panicum, Foxtails, Goosegrass. Begin the management program with either a preplant-incorporated or preemergence herbicide. Prowl, Sonalan, Dual, Dual Magnum, Outlook, Lasso, or Frontier provide good control.

Heavily infested fields will benefit from a preemergence or at-cracking application of Dual, Dual Magnum, Outlook, Lasso, or Frontier following a preplant-incorporated treatment or an at-cracking application following a preemergence treatment. Dual, Dual Magnum, Outlook, or Frontier applied at layby also is an option under certain conditions; see previous discussion of layby herbicides. Alternatively, a postemergence application of Poast, Poast Plus, or Select may be used to control escaped annual grasses.

Broadleaf Signalgrass. Broadleaf signalgrass is a major problem in all peanut-producing counties. A management program for broadleaf signalgrass should begin with a preplant incorporated application of Prowl, Sonalan, Dual, Dual Magnum, Outlook, or Frontier.

If broadleaf signalgrass escapes the above treatments, a shallow cultivation would be an option. Alternatively, apply Poast, Poast Plus, or Select. A layby application of Dual, Dual Magnum, Outlook, or Frontier is also an option. See previous discussion of layby herbicides.

Texas Panicum. This annual grass has been observed in most peanut-producing counties in North Carolina. Infestations are relatively isolated, but further spread is expected. Management programs for Texas panicum may vary from those recommended for other annual grasses. Therefore, proper identification during fall scouting of the preceding crop is critical.

Texas panicum can be controlled with a preplant-incorporated application of Prowl or Sonalan. Dual, Dual Magnum, Outlook, Lasso, and Frontier do not provide adequate control. Because of its large seed, Texas panicum can emerge from deeper in the soil than other annual grasses. Prowl or Sonalan should be incorporated to a depth of 3 inches (this is deeper than specified on Prowl label).

Preemergence, at-cracking, or layby applications of Dual, Dual Magnum, Outlook, Lasso, and Frontier are of little benefit in controlling this species. A shallow cultivation could be considered if Texas panicum begins to emerge in the row middles. Also, Texas panicum is very susceptible to Poast, Poast Plus, or Select.

Nutsedge

Both yellow and purple nutsedge can be found in peanut fields. In recent years, purple nutsedge has been increasing and is now the predominant nutsedge species in many areas. Because management programs may vary for the two species, it is important to determine which species is present during fall scouting of the preceding crop.

Nutsedge-infested fields should receive a preplant-incorporated application of either Dual, Dual Magnum, Outlook, or Frontier. Vernam is no longer widely available. If the annual grass population is heavy or is predominantly broadleaf signalgrass or Texas panicum, tank mix Prowl or Sonalan with Dual, Dual Magnum, Outlook, or Frontier. Follow with a preemergence or at-cracking application of Dual, Dual Magnum, Outlook, and Frontier where yellow nutsedge is expected. Dual, Dual Magnum, Outlook, and Frontier will not control purple nutsedge.

If an economic infestation of yellow nutsedge is present after making the above treatments, Basagran may be applied postemergence when the yellow nutsedge is approximately 7 inches tall. See the comments in Table 4-4. Basagran does not control purple nutsedge.

As an alternative to the above strategies, one may use a split application of Pursuit. Incorporate 0.72 ounces of Pursuit 70 DG plus a grass control herbicide. Dual, Dual Magnum, Outlook, or Frontier would be the preferred grass herbicides unless a grass species is present that these herbicides do not control (see Table 4-5 at the end of this chapter). Follow with a late at-cracking or an early postemergence application of 0.72 ounces of Pursuit 70 DG when yellow nutsedge is no more than 2 inches tall or purple nutsedge is no more than 2 inches tall. Depending upon the broadleaf species present, an additional broadleaf herbicide may be needed. See the comments in Table 4-4 for potential postemergence tank mixes with Pursuit. Use Table 4-5 as a guide in determining whether an additional broadleaf herbicide should be tank mixed with the postemergence portion of the Pursuit.

Split applications of Pursuit have sometimes given better nutsedge control than single applications. However, a single late at-cracking or early postemergence application of 1.44 ounces of Pursuit 70 DG may be made for suppression or control of either species of nutsedge or for a mixture of the 2 species. The nutsedge should be small (2 inches) when treated postemergence with Pursuit. Basagran is preferred if the infestation is predominantly yellow nutsedge. Pursuit is preferred if the infestation is predominantly purple nutsedge or a mixture of yellow and purple nutsedge. Do not mix Basagran with Pursuit as the combination may be antagonistic on both yellow and purple nutsedge.

Strongarm suppresses both purple and yellow nutsedge, but it does not completely control these weeds. Follow-up applications of postemergence herbicides are generally needed. If Strongarm is applied, do not apply Cadre postemergence. Strongarm followed by Cadre most likely will injure cotton or corn planted the following year.

Cadre 70 DG at 1.44 ounces is also effective on purple and yellow nutsedge. Applications should be made when nutsedge is small. Research indicates that rainfall or irrigation that sufficiently moves Cadre into the soil improves control, so significant rainfall or irrigation is needed following postemergence application of Cadre to obtain desirable control. Although Cadre is applied after nutsedge and other weeds have emerged and a portion of Cadre is absorbed through emerged foliage, a considerable amount of weed control results from root absorption. See Tables 4-4 and 4-5 to determine appropriate herbicides to apply with Cadre for broad-spectrum control.

Annual Broadleaf Weeds

Common Broadleaf Weeds. Preplant or preemergence herbicides used for annual grass control usually will provide good control of certain small-seeded broadleaf weeds, such as pigweed, carpetweed, Florida pusley, common purslane, and lambsquarters (although Dual, Dual Magnum, Outlook, Frontier, and Lasso are weak on lambsquarters). These herbicides also will suppress a number of other broadleaf weeds. Tank-mix applications with Prowl or Sonalan are most effective for suppressing broadleaf weeds.

If broadleaf weeds are emerged at the cracking stage of peanuts, paraquat or paraquat plus Basagran would be an economical option. If additional control is needed for subsequent flushes, one of the postemergence herbicides or tank mixes previously discussed could be applied. See Table 4-5 for assistance in selecting the most appropriate treatment. Timing of postemergence herbicide

application is critical. See labels for recommended weed sizes for treatment and recommended application rates.

Sicklepod. Apply paraquat or paraquat plus Basagran at-cracking or early postemergence when the sicklepod are in the cotyledonary to first true leaf stage. A second application of paraquat or paraquat plus Basagran is an option if a new flush of sicklepod emerges. For control of sicklepod later in the season, apply 1 pint per acre of 2,4-DB before sicklepod exceeds 12 inches tall. Make a second application about 2 weeks later. Alternatively, Cadre controls sicklepod very well. Rotation restrictions, however, limit utility of Cadre.

Florida beggarweed. This broadleaf weed has traditionally been confined to the southeastern counties in North Carolina. Isolated infestations are now beginning to appear in some of the northern peanut-producing counties. Since Florida beggarweed is particularly troublesome in peanuts, growers should learn to recognize this weed and strive for the best control possible in all crops in the rotation before the weed becomes widely established. Hand-removal of isolated plants is highly recommended.

For early-season control of Florida beggarweed, apply Dual, Dual Magnum, Outlook, Frontier, or Lasso preemergence. Apply paraquat when the beggarweed is 2 inches tall or less. A second application of paraquat can be made if needed to control beggarweed emerging after the first application. Basagran, Storm, or 2,4-DB may be tank mixed with the Starfire for additional control of other broadleaf weeds. See Table 4-5. If additional beggarweed control is needed later in the season, 1/2 ounce per acre of Classic plus surfactant can be applied. The peanuts must be at least 60 days old and the beggarweed should be 10 inches tall or less. Do not apply to drought-stressed peanuts.

Eclipta. Eclipta tends to be more of a problem in lower areas of fields and in wetter years. Except for extremely heavy infestations, eclipta probably is not very competitive in peanuts because it tends to be a mid- to late-season problem and is a low-growing weed. Additionally, it does not appear to greatly interfere with digging since it usually dries down before digging time.

Dual, Dual Magnum, Outlook, Lasso, or Frontier will suppress eclipta (see Table 4-5). Hence, one or more of these herbicides should be applied in fields with a history of eclipta problems. An at-cracking application of paraquat will control very small eclipta (1/4 inch). Blazer, Storm, or Tough applied postemergence will control small eclipta (1 inch or less). Strongarm does an excellent job controlling eclipta.

Most eclipta appears to emerge after the normal postemergence herbicide application for broadleaf weeds. In fields with a history of eclipta, growers are encouraged to scout closely for 4 weeks after the normal postemergence broadleaf herbicide application. If enough eclipta emerges to indicate a problem, another postemergence herbicide application (Blazer, Storm, or Tough) may be in order.

A layby application of Dual, Dual Magnum, Outlook, or Frontier may be of value in fields with a history of eclipta problems. Enhanced control of eclipta has been observed where these herbicides were applied at layby. See comments under Layby Herbicides. Remember that Dual, Dual Magnum, Outlook, and Frontier will not control emerged weeds.

Perennial Broadleaf Weeds

Perennial broadleaf weeds, such as horsenettle, trumpetcreeper, maypop passionflower, and bigroot morningglory, cannot be controlled in peanuts. Blazer or 2,4-DB may give suppression but control will not be adequate. These weeds are best controlled in corn grown in rotation with peanuts. In corn, make a layby application of 2,4-D amine plus surfactant or a mixture of Beacon plus Banvel. After corn harvest, spot spray any remaining infestations with Roundup or a mixture of 1 pint per acre of 2,4-D amine plus 0.5 pint per acre of Banvel plus surfactant. See Roundup label for suggested application rates. Alternatively, Roundup can be applied preharvest in cotton; see 2002 Cotton Information, AG-417, for details. Roundup applied in the row middles of cotton using a hooded sprayer also is an option.

Bermudagrass

Two applications of Poast, Poast Plus, or Select in combination with good crop competition usually will provide adequate to good control of bermudagrass. Strive for good control in rotational crops. In corn, incorporate Sutan+ or Eradicane. In cotton, apply Roundup, Assure II, Fusilade DX, Poast, Poast Plus, or Select postemergence.