Guide A-340

Revised by Leslie Beck, Mark Marsalis, Brian Schutte, Phillip Lujan, and Leonard Lauriault.
College of Agricultural, Consumer and Environmental Sciences, New Mexico State University

Authors: Respectively, Extension Weed Specialist/Associate Professor, Department of Extension Plant Sciences; Extension Forage Specialist/Professor, Agricultural Science Center at Los Lunas; Associate Professor, Department of Entomology, Plant Pathology, and Weed Science; Extension Plant Pathologist/Assistant Professor, Department of Extension Plant Sciences; Forage Crop Management Scientist/College Professor, Rex E. Kirksey Agricultural Science Center at Tucumcari. All from New Mexico State University.  (Print friendly PDF)

Introduction

Weeds reduce the quality and stand life of desirable plants in pastures and hayfields. Certain weed species are also poisonous to livestock. Therefore, weed management is a crucial component of pasture management.

A well-designed weed management program begins with site preparation since weed control options become limited once the desired pasture species are planted (Figure 1). Good pasture management throughout the life of the pasture is critical for prevention and control of weed infestations.

If weeds are not properly managed during site preparation, weeds will hinder pasture establishment. In established pastures, weeds are often the result of poor management of the pasture species, unless weed infestation is the result of external weed seed introduction (e.g., surface irrigation water or wind). Problems can result from improper species selection, fertilization, irrigation, harvest, or grazing methods and intensity. Well-managed pastures require fewer direct actions to manage weeds because healthy, well-established forage plants are more likely to prevent weed invasions. In some situations, however, herbicides are needed for weed control despite a producer’s best pasture management efforts. In those situations, the quality of pastures can be substantially improved with a well-planned herbicide program.

To be more effective, weed management in permanent grass pastures requires a combination of cultural, mechanical, biological, and chemical tools beginning with site preparation and continuing throughout the life of the pasture.

Figure 1. Yellow foxtail (Setaria pumila) infestation in tall fescue pasture. Photo courtesy of Mark Marsalis.

Weed Identification

Because weed management techniques are often species-specific, the first step in weed management is to correctly identify weeds. Additionally, keeping records of the types of weeds and their movement throughout the field can be a great way to plan more proactive management strategies to increase success, rather than reactive measures, which are often less successful. Weeds can be identified using resources such as weed identification books, websites, phone apps, Cooperative Extension Service publications, Extension personnel, crop consultants and the New Mexico State University Plant Diagnostic Clinic. In order to make sound management decisions, it is important to know the name of a weed, as well as its lifecycle, and reproductive mode and capacity. Keep in mind that common names of plants can vary, or the same name may refer to multiple species. Cross-referencing weeds by their scientific names can help confirm their identities and pinpoint management strategies. Accurate information on the biology and lifecycle of the weeds can help growers apply specific weed management techniques more effectively, based on the susceptibility of the species to different control methods and timings.

Weed Seedbank Management

The reserve of viable weed seeds in soil (hereafter referred to as the “seedbank”) is an important part of the weed community that should be considered in programs for pasture weed management. Seedbanks are problematic because they are sources of weed infestations, and they should be managed to help deplete them rather than replenish them. The goal of weed seedbank management is to lessen the number of weed seeds present in soil, which influences long-term population growth rates of annual weed species, to the efficacy of chemical control tactics, and to the success of cultural and mechanical approaches for weed control.

Weed seedbank depletion relies on two general strategies: 1) increase seedbank losses and 2) reduce seedbank inputs.

Increase seedbank losses

A practical method for targeting buried weed seeds is the “false seedbed” approach, which is a set of successive practices that first stimulates weed seed germination using irrigation and then eliminates subsequent weed seedlings prior to pasture planting using tillage, which prevents the weed’s ability to drop more seed back into the soil. Shallow tillage before irrigation can intensify the effects of false seedbeds on weed seedbanks, especially if multiple false seedbeds are sequentially implemented. However, frequent irrigation and shallow tillage that takes place in repeated false seedbeds may reduce the overall soil health. An alternative to false seedbeds is “stale seedbeds”, which use flame weeding or herbicide application with limited or no soil residual (e.g., glyphosate) to kill weed seedlings prior to seed set and planting of the crop.

For false and stale seedbeds to effectively reduce seed banks of problematic weed species, interventions must occur during species-specific periods in which seeds of targeted weed species can germinate. For example, problematic annual weeds, such as spurred anoda (Anoda cristata), morningglory species (Ipomoea spp.), and Wright’s groundcherry (Physalis acutifolia), germinate during June, July, and August in New Mexico. However, annuals such as foxtail and pigweed species often germinate earlier. False and stale seedbed interventions are most effective against such summer annuals if made in the spring and summer before pasture planting.

Reduce seedbank inputs

Foremost in weed seedbank management is to prevent deposits of weed seed in the soil. Seeds can enter soil from many sources, including resident plants, irrigation water, contaminated crop seed, manure-based fertilizers, vehicles, farm machinery, animals, and insects. Eliminating all sources of weed seed entry may not be practical, but there are some actions that can be taken. For example, seedbank deposits from resident weeds can be eliminated by controlling all weeds before they are able to reproduce. Seedbank deposits from contaminated crop seed can be eliminated by seeding pastures with high-quality, weed-free seed. Regularly washing vehicles and machinery when travelling from field to field can also limit seedbank deposits from contaminated equipment.

Although weed seedbank management is generally regarded as a long-term approach for suppressing weeds, preventing large deposits to soil seedbanks can yield tangible results as early as the next growing season. For many annual weed species, a large proportion of a given year’s weed seedlings originates from the seeds produced the previous year; controlling annual weeds before they set seed can therefore reduce the potential weed population the following growing season. Hay production systems are generally more effective than grazing at preventing new weed seed introduction due to the inherent, frequent mowing during the growing season (seedhead removal). However, some livestock (i.e., goats) are quite effective at controlling weeds and will often prefer weed plants over the pasture species but may avoid other weeds that are not palatable or are toxic. Grazing may not prevent total removal of weed seedheads, and plants can become unpalatable as they mature later in the season.

Cultural Methods

Species selection

Planting grass species that are not adapted to the respective environment can lead to encroachment by weeds and shorten the stand life. New Mexico has a wide range of climatic conditions and growing zones due to vast differences in elevation and latitude, and very few species are well adapted throughout the entirety of the state. Therefore, species selection must be based on location. More detailed information about adapted plant species for use in permanent irrigated pastures in New Mexico is provided in NMSU Cooperative Extension Circular 696, Perennial Forage Species for Irrigated Pastures and Hay in New Mexico https://pubs.nmsu.edu/_circulars/CR696/index.html .

Grass species are usually classified based on their lifecycle into cool-season and warm-season species. Cool-season perennial species generally have their highest production in the spring, followed by a summer depression and another period of vigorous growth in the fall. On the other hand, warm-season grasses grow actively from after the last spring frost until a hard freeze in the fall, with peak production in mid-summer. During dormancy, which could be in summer or winter (depending on the lifecycle of the grass), weeds can inhabit the gaps in pastures that would otherwise be covered by stand canopy. This lack of productivity during the dormant season is one disadvantage to monoculture pastures.

If growers decide to use grass mixtures, simple mixtures of no more than three grasses are preferred over more complex mixtures because complex mixtures present several problems. Differences in requirements for cultural practices (harvest timing, fertility, irrigation, etc.), grazing management, and ability to compete for light, water, nutrients, and space make it difficult to maintain multiple healthy and competitive species in the stand. Additionally, animals might selectively graze more palatable species and eliminate them from the stand. Over time, one or two species eventually dominate the stand. In any case, gaps in the stand eventually occur. Consequently, overly complex pre-mixed pasture blends are generally not recommended. A disadvantage for mixed-grass and grass-legume pastures is that a limited number of herbicides may be labeled for safe use; this is particularly true with post-emergence herbicides. Thus, management becomes even more critical to prevent weed infestation from the start.

Seed and plant stock selection

Use high-quality seed or planting stock to improve the chances of obtaining a good stand that can be productive for a long period and competitive against weeds. Read the label and purchase seed with no- or low- percentage of weed seed content to prevent contamination and develop a relatively weed-free stand. Purchasing certified seed or plant variety protected (PVP) seed, while perhaps more expensive, is a good first step toward preventing the addition of weed seed to the field at planting. Long-term weed control costs will almost certainly be more expensive than the additional up-front cost of higher quality, weed-free seed. Additionally, be sure that no noxious or hard-to-control perennial weeds are listed on the label. For more information on seed labels and descriptions, consult NMSU Cooperative Extension Guide A-131, Certified Seed https://pubs.nmsu.edu/_a/A131/index.html .

Establishment

Land preparation

Proper land preparation is important for the establishment of an irrigated permanent grass pasture. The best weed control strategy begins with a weed-free seedbed (see Weed Seedbank Management section of this publication) assisted by a uniform stand of pasture plants that can quickly establish ground cover. Controlling existing weed populations that can interfere with establishment of desirable species or become a problem after establishment is the first step in land preparation, especially since rotating to a permanent pasture is a component of a farm-wide weed control program. In flood and furrow irrigation systems, ensuring that land is leveled properly for even distribution of water is important to prevent excessively wet and dry spots in the field, which lead to grass death and open spaces.

Planting

Seeding time is determined largely by the species being sown. Most warm-season species should be planted only after the danger of frost has passed, such as May through early August in much of New Mexico, depending on location (check with local county Cooperative Extension or Natural Resources Conservation Service personnel for local recommendations). This allows sufficient time for the crop to establish a good root system before freezing temperatures occur. Cool-season grasses can be planted in spring or late summer; in New Mexico, however, spring plantings are discouraged mostly due to high irrigation requirements, lack of production during the seeding year, heat stress on young seedlings, and increased weed pressure in the spring and early summer compared with late summer.

Late summer or early autumn seedings need to be planted early enough to allow at least six to eight weeks to become fully established before freezing temperatures. When planting pasture grasses, no-till seeding can be considered in order to reduce the threat of soil erosion during the establishment period, conserve moisture already present in the seedbed and reduce weed seed germination by minimizing soil disturbance.

Completing establishment

Newly seeded pasture grasses should be allowed to reach the early heading stage before grazing or harvesting for the first time. Grazing or harvesting pastures for hay too soon can prevent complete establishment of healthy plants, thus allowing for weed encroachment. More detailed information about establishing adapted plant species for use in permanent irrigated pastures in New Mexico is provided in NMSU Cooperative Extension Circular 695, Forage Selection and Establishment for Irrigated Pastures and Hay in New Mexico https://pubs.nmsu.edu/_circulars/CR695/index.html  and Circular 586, Irrigated Pasture Management in New Mexico, https://pubs.nmsu.edu/_circulars/CR586/index.html .

Irrigation

Irrigation is critical to nearly all moderate- to high-output crop production practices in New Mexico, and improved permanent grass pastures are no exception. As such, irrigation plays a critical role in weed management efforts in permanent pasture systems throughout the state. Proper irrigation is necessary not only for pasture establishment, plant growth, competitiveness, and stand longevity, but also sustainability of the system in terms of water conservation.

Establishing and maintaining a strong, vigorous pasture is the first step in combating weeds and will go a long way toward preventing weed seed germination and competition. Improper irrigation practices can compromise the vigor of the pasture. Over-irrigation can lead to waterlogged soils, weed invasion, nutrient leaching, and wasted resources. Likewise, too few or mistimed irrigations can cause plant stress, inhibiting the desired pasture species’ ability to compete with oftentimes more opportunistic and drought-hardy weeds. It is vital to know the water requirements of the pasture species and when irrigations can be utilized most efficiently during the lifecycle of the plant (i.e., seasonal distribution of growth). In addition, monitoring soil moisture is recommended for proper irrigation scheduling and for preventing waste. This should be done as much as possible; however, matching irrigations with plant demand may be difficult to control when operating within water district allocations, restrictions, and rotating deliveries that are common throughout the state.

Standing water, poor drainage, and excessive soil moisture are conducive to weed invasions into pastures. The anaerobic conditions that result from water ponding facilitate plant disease occurrence and die-off, which create open areas in the pasture for weeds to take over. Oftentimes, the weeds that proliferate in these areas are some of the more problematic weeds for grass pastures, such as foxtails, crabgrass and other grasses, and nutsedge (Figure 1). It is important to know where potentially problematic areas are in the field (slow-draining soil, low areas, restrictive sub-soil layers) and either avoid them completely or take precautions prior to pasture establishment to amend the field for more uniform water flow and infiltration. In fields that will be irrigated through surface methods (e.g., flood and furrow irrigation) where large amounts of water are applied at one time, standing water tends to be more of a problem compared to sprinkler-irrigated systems. As such, prior to planting pastures, laser leveling is recommended for flood irrigation and for fields having greater slopes or sloping in two directions that will be furrow-irrigated; tailwater drainage and/or recovery systems are important.

Summer annual grassy weeds are shallow-rooted and are particularly favored by frequent irrigations, standing water, and wet soils. In contrast, perennial pasture grasses have extensive root systems and can extract water from depths of three to four feet.

Ensuring that water is available at these depths will help plants survive dry spells and summer heat better than frequent shallow watering alone and will increase pasture competitiveness. If water is available early in the growing season, deep irrigations that fill more of the soil profile may be beneficial before the onset of summer, particularly if winter precipitation is low. Also, it is important to know the drought and heat tolerance of the grasses being grown. Cool-season species, such as tall fescue and orchardgrass, are more sensitive to drought and high temperatures than warm season grasses such as bermudagrass. It is especially important that cool-season pastures be adequately irrigated during the hot summer months to avoid weakened plants and open spaces in the field. Maintaining an appropriate stubble height (i.e., 3–4 inches minimum) to promote the health of pasture plants will also help protect them from heat damage. Applying irrigation only when plant growth is dense enough will reduce competition from weed seedlings since the dense pasture cover prevents the exposure of bare ground to sunlight.

Fertilization

Similar to irrigation, proper soil fertility and a balance of essential plant nutrients are critical to pasture health and competitiveness. A soil test is necessary to determine plant needs and should be conducted before planting the pasture and periodically throughout each growing season.

Fertilization is not a remedy for pasture mismanagement caused by overgrazing or poor irrigation practices. Fertilizer applications to abused pastures with weak stands will only benefit the weeds that can utilize excessive nitrogen. As with irrigation, applying fertilizer only when the pasture canopy shades bare ground will minimize competition from weed seedlings.

Nitrogen (N) will likely be the most limiting nutrient in grass-based pasture systems. However, phosphorus (P) also can often be insufficiently available in the high-pH soils common in New Mexico. Most pasture grasses have a high N requirement and respond very favorably to N fertilizers. In general, response to P fertilizers is less predictable due to high soil pH; nevertheless, P fertilizer should be available to plants over the life of the stand. Consequently, P fertility should be raised to recommended levels based on initial soil testing and monitored every couple of years for availability. Then, P may be surface applied annually based on recommendations from the most recent soil test.

Timing of fertilizer applications is critical and should be such that the desirable pasture species benefit from the nutrient(s) applied and not the weeds. For example, if N fertilizer is applied to a bermudagrass pasture too early in the spring and much ahead of green-up, early emerging weeds will be able to take advantage of the N before the bermudagrass, and intense competition from the weeds may ensue. During pasture establishment, it is generally better to delay N applications until after the planted grass is growing well and can utilize it before the weeds. Producers should be familiar enough with their pasture species to know the most beneficial time to apply fertilizer for maximum return (i.e., match N application to greatest potential uptake). Cool-season species like tall fescue have a high N demand in the spring and again in the fall, whereas bermudagrass has its greatest demand only in summer. It is better to apply fertilizers in split applications throughout the year to match plant demand rather than one large N application at the beginning of the season. These split applications generally coincide with a regular cutting or 30-day grazing schedules. Nitrogen is highly mobile in the soil, and applications during periods of pasture dormancy or slow growth will only benefit opportunistic weeds and/or be leached from the rooting zone with heavy irrigations or rainfall.

Applying N to cool-season grass pastures when soil moisture is adequate to prevent stress and then following the N application with an irrigation in lieu of anticipated precipitation, especially in late fall, will increase productivity the following spring. This will also likely promote root growth going into winter for better competition against winter weeds and a healthier stand the next spring. If warm-season pastures are overseeded with a cool-season annual grass (e.g., cereal rye, ryegrass), nitrogen should be applied to promote growth from late autumn through spring.

Manures

While manure applications to crops and pastures can be beneficial as a source of organic matter and nutrients, be aware that manures can also be a source of weed seeds. Both grass and broadleaf weed seeds can survive the digestive systems of different classes of livestock. For example, seeds from pigweeds, lambsquarters, foxtails, and various mustards have all been found in dairy manures. The level of weed seed in the manure is a function of several factors: class of livestock, feed/pasture consumed, time since feeding, collection site, composting, etc. In general, composted manure contains fewer viable weed seeds, but composting will not eliminate all viable seed. Using previously composted manure or storing the manure on-site for a few months is recommended before application. Fields where manure has been applied should be monitored closely for the presence of both regionally common weeds and new weeds not previously found on the farm. Timely weed control should follow any new emergence from manured fields, especially if exotic, non-native weed species are found.

Mechanical/Biological Methods

Grazing

In grass pastures, grazing should be initiated when the pastures are established and grasses are 6 to 12 inches tall, depending on plant species (bunch-type or upright species should be taller than creeping types). When cool-season grasses fall below 3 to 4 inches tall, there may not be enough leaf material to promote regrowth, eventually leading to weak, noncompetitive plants and possibly bare ground exposed to sunlight, all of which allow for weed invasion. Not grazing intensively enough may allow any weeds that might be grazed to produce seed. In some cases, co-grazing different species of animals is beneficial for maximizing forage utilization and weed control, especially brush and some weeds that are less palatable to cattle. In pastures with heavy weed infestations that are being avoided by cattle, one sheep or goat can be added for each beef animal unit without affecting beef production per acre. For more details, see NMSU Cooperative Extension Circular 586, Irrigated Pasture Management in New Mexico https://pubs.nmsu.edu/_circulars/CR586/index.html .

Mowing

Timely mowing (clipping) of pastures not only optimizes forage production but can also help reduce weed pressure in pastures. Many annual weeds can be effectively suppressed/controlled and, more importantly, their seed production can be prevented by clipping off flowers. Care should be taken to not delay/inhibit regrowth of the desirable plants by cutting them too short. It is important to set the mower at the correct height, which could vary depending on the grass species present. Information on how a particular grass species grows and regrows could help with setting the optimal height. Dragging the pasture with a chain harrow after clipping will scatter the clippings, speed the breakdown of manure from grazing animals, and help prevent standing piles that can kill forage plants and leave dead spots in the field.

Harvesting the crop through hay or grazing when the field is too wet can lead to compacted areas or can damage and weaken plants making them less competitive, thereby giving weeds an advantage in highly trafficked areas. Compacted soils restrict root growth, take in water more slowly, and are poorly aerated. To the greatest extent possible, animals or equipment should be withheld from the pasture after irrigation or rain events until soils are dry enough to avoid compaction. In general, this is not as much of a concern in sandy soils as it is in finer-textured soils. For more on soil compaction, see NMSU Cooperative Extension Circular 672, Understanding and Managing Soil Compaction in Agricultural Fields (https://pubs.nmsu.edu/_circulars/CR672/).

Burning

Burning pastures is a common practice in some areas of New Mexico. This is done on both warm- and cool-season grasses. In either, burning during the dormant period can control existing annual weeds and possibly help eliminate seed and reduce viability of some annual weeds. Burning is also effective for removing senesced plant material from the previous year that reduces forage quality and may allow for earlier spring green-up and nutrient recycling. Burning after pasture grasses have initiated spring growth will cause harm and may lead to plant death. Growers should be aware that cool-season pastures will break dormancy much earlier than warm-season grasses. In some regions of the state and under warm climatic conditions, cool-season grasses may not go completely dormant in winter. Caution should be taken when burning in winter, especially because of low precipitation and high winds in many areas of New Mexico and since many native species and forested lands in surrounding areas will also be dormant and dry, which can increase the possibility of wildfire.

Chemical Methods

Even if all recommended cultural and mechanical/biological control measures are followed, chemical control may still be necessary. Herbicides utilize various functional groups (active ingredients) to impede the growth and development of weeds. A list of currently registered herbicides for permanent grass pastures and hayfields in New Mexico, along with some information regarding their use, is provided in Table 1. Successful chemical weed control requires the application of the correct type and quantity of herbicide(s) uniformly over the target area. This makes the application of herbicides a precision operation. Proper sprayer calibration is therefore very important since rates that are too high may injure the pasture grasses, and rates that are too low may not provide effective weed control, which contributes to herbicide-resistant weeds. It is also important to use the chemicals at a time when the pasture grasses are at their maximum tolerance and the weeds are at their maximum susceptibility to injury. Several herbicides are registered for use in permanent warm- and cool-season grass pastures in New Mexico (Tables 1 and 2); however, many herbicides are species-specific and must match the appropriate growth stage of the grasses according to the label or injury may result. Very few herbicides are labeled for use during grass establishment, and it is not uncommon to experience significant flushes in annual weeds during the first growing season, especially early in the year (i.e., late-summer planting previous year). However, if an adequate stand of grass has emerged and is healthy, planted grasses will eventually outcompete these weeds later in the growing season (e.g., after first cut) and in subsequent years (Figure 2). In mixed-grass pastures, care must be taken to select the herbicides that are labeled for use on all species in the pasture to prevent injuries to desirable species. Again, this is a significant limiting factor for grass-legume mixtures.

The following terms describe the timings at which herbicides may be applied for improved success. Unless otherwise specified, they refer to the stage of development of the weeds as well as the desired pastures species to limit injury. All label instructions and precautions must be followed carefully. Many times, an herbicide’s poor performance or nonperformance can be traced to improper use and failure to follow label directions.

Pre-emergence herbicides are generally applied to the soil prior to weed emergence for residual weed control and many don’t control emerged weeds. However, some herbicides, such as diuron (Direx 4L) and imazapic (Plateau), have post-emergence activity that can control small seedlings of certain weed species as well as provide residual weed control.

Post-emergence herbicides, such as clopyralid (Clean Slate), 2,4-D (2,4-D Amine-4), glyphosate (Roundup PowerMAX), imazapyr (Polaris), and carfentrazone-ethyl (Aim EC), are all applied after weed emergence. However, the timing of application could vary depending on the herbicide (see Table 1 for more detail on each herbicide).

Tank Mixing

Tank mixing herbicides may provide broader weed control, and several premixed herbicides are available on the market (Table 2). Depending on the present weed species and their stage of development, tank mixing herbicides might be beneficial in pasture weed management. For example, Prowl H2O may be tank-mixed with post-emergence herbicides labeled for use in bermudagrass and other perennial warm-season grasses to not only control germinating weed seeds but also emerged weeds. However, it is important to follow the label directions when tank mixing because some herbicides may not be compatible with each other. If such herbicides are mixed, the efficacy of one or both chemicals in the mixture can be reduced or injury to grass species may occur.

Pasture Renovation

Pasture renovation is renewing a pasture by introducing desired forage species into existing plant stands, and is occasionally required, especially when weeds dominate pastures and cause low yields of low-quality forage. The specific weed problem and cause of infestation determine the degree of renovation necessary. When all desirable species have perished and only weeds are present, or if weeds are not manageable with herbicides or multispecies grazing, total renovation and reseeding of the entire field or the affected portion are usually required.

If the stand has merely thinned and existing weeds can be controlled with herbicides, the pasture can be renovated by interseeding with desirable species using no-till seeding. For bermudagrass and other rhizomatous species, extensive tillage at the surface with a light nitrogen application and irrigation can promote growth into thin areas. For cool-season bunch grasses such as tall fescue, tillage is not recommended prior to interseeding as significant crown damage can occur. In either case, growers should follow proper agronomic procedures to avoid the possibility of stand failure of the new seeding (see NMSU Cooperative Extension Circular 695, Forage Selection and Establishment for Irrigated Pastures and Hay in New Mexico, available at https://pubs.nmsu.edu/_circulars/CR695/index.html).

Figure 2a and 2b. Annual winter weeds infesting cool-season grass pasture/hay field planted in late summer (left) and clean pasture the year after planting following two hay cuttings (right). No herbicides were applied. Photos courtesy of Mark Marsalis.

Brand names appearing in publications are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. Persons using such products assume responsibility for their use in accordance with current label directions of the manufacturer.

The pesticide recommendations in this publication are provided only as a guide. The authors and New Mexico State University assume no liability resulting from their use. Please be aware that pesticide labels and registration can change at any time; by law, it is the applicator's responsibility to use pesticides ONLY according to the directions on the current label. Use pesticides selectively and carefully and follow recommended procedures for the safe storage and disposal of surplus pesticides and containers.

Original authors: Jamshid Ashigh, Leonard Lauriault, Mark Marsalis, Brian Schutte, and Carry Hamilton.

Leslie Beck  is the Extension Weed Specialist at New Mexico State University. Her research program focuses on integrated weed management systems in landscape, horticultural, and agronomic crops. Her Extension work provides the citizens of New Mexico with accurate, applicable, and effective weed identification and management strategies in multiple cropping systems.

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