Cutleaf Evening Research Articles

Using weed emergence and phenology models to determine critical control windows for winter-grown carinata (Brassica carinata)

AbstractAdoption of the new biofuel crop carinata (Brassica carinata A. Braun) in the southeastern United States will largely hinge on sound agronomic recommendations that can be economically incorporated into and are compatible with existing rotations. Timing of weed control is crucial for yield protection and long-term weed seedbank management, but predictive weed emergence models have not been as widely studied in winter crops for this purpose. In this work, we use observed and predicted emergence of a winter annual weed community to create recommendations for timing weed control according to weed and crop phenology progression. Observed emergence timings for four winter annual weed species in North Carolina were used to validate previously published models developed for winter annual weeds in Florida by accounting for temperature and daylength differences, and this approach explained more than 70% of the variability in observed emergence. Emergence of stinking chamomile (Anthemis cotula L.) and cutleaf evening primrose (Oenothera laciniata Hill.) followed biphasic patterns comparable to wild radish (Raphanus raphanistrum L.), which were predicted with previously published models accounting for 82% and 84% of the variation, respectively. Using the predictive models for weed emergence and carinata growth, critical control windows (CCW) were estimated for Clayton, NC, and Jay, FL, according to different planting dates. The results demonstrated how early planting coincided with the emergence of three competitive winter weeds, but early control could also remove a large proportion of the predicted emergence of these species. The framework for how planting timing will affect winter weed emergence and crop growth will be an instructive decision-making tool to help prepare farmers to manage weeds in carinata, but it could also be useful for weed management planning for other winter crops.

Survey of weed flora and weed management practices in Florida strawberry fields

AbstractA survey of weed flora and basic weed management practices was conducted in commercial strawberry [Fragaria × ananassa (Weston) Duchesne ex Rozier ssp. ananassa] fields in central Florida during the 2019 to 2020 field season. Forty-one fields on 14 farms were surveyed, which represents a total of 907 ha or 23% of the acreage planted to strawberries in Florida. All conventional fields were fumigated, and combinations of chloropicrin and 1,3-dichloropropene were used on 72% of the fumigated acreage. Preemergence or postemergence herbicides were used in row middles on 100% of the conventional acreage, but preemergence herbicides applied under the plastic mulch were only used on 12% of the acreage. A total of 47 weed species were identified during the survey. The five weed species with the highest frequency were goosegrass [Eleusine indica (L.) Gaertn.], cutleaf evening primrose (Oenothera laciniata Hill), Carolina geranium (Geranium carolinianum L.), common ragweed (Ambrosia artemisiifolia L.), and eclipta [Eclipta prostrata (L.) L.] which occurred in 83%, 63%, 58%, 58%, and 46% of all fields surveyed, respectively. The five species with the highest overall relative abundance were E. indica, O. lanciniata, G. carolinium, A. artemisiifolia, and Brazil pusley (Richardia brasiliensis Gomes). The frequency and distribution of E. indica is of particular concern, because populations in strawberry fields are thought to be resistant to paraquat, which is the primary herbicide used for crop termination. Weed density tended to be low overall, which suggests the integrated weed management (IWM) programs adopted by most growers are effective. Mean weed density tended to be similar on conventional and organic fields and unaffected by fumigant applied the year of the survey or the number of years strawberries had been grown consecutively in a field. Weed management research moving forward should focus on the development of IWM programs for E. indica, O. lanciniata, G. carolinium, and A. artemisiifolia.

2,4-D and dicamba removal from the surface of plastic mulch using overhead irrigation: analytical analysis and cucurbit bioassay crop response

AbstractGlyphosate and paraquat are effective preplant burndown herbicide options for multicrop vegetable production that uses plastic mulch, but problematic weeds such as wild radish, cutleaf evening primrose, annual morningglory, or horseweed may not be adequately controlled with these herbicides alone. The herbicides 2,4-D and dicamba could help control these troublesome weeds prior to planting if they can be removed from plastic mulch and thus avoid crop damage. Treatments included 2,4-D (1,065 and 2,130 g ae ha−1) and dicamba (560 and 1,120 g ae ha−1) applied broadcast over plastic mulch a day before transplanting. Just before transplanting, treatments received either 0.76 cm of water via overhead irrigation or no irrigation. Plastic mulch samples were collected at application and planting to determine herbicide presence using analytical techniques, and cantaloupe and zucchini squash were subsequently transplanted on the plastic beds. Analytical ultra-high performance liquid chromatography revealed that 88% to 99% of the initial herbicide concentration was present at crop planting when irrigation was not implemented. At most, a 1/50 rate of dicamba and a 1/500 rate of 2,4-D was present at planting when overhead irrigation was applied prior to transplanting. Maximum cantaloupe and squash injury from 2,4-D with irrigation was 10% and did not influence plant growth, biomass, or yield. For dicamba with overhead irrigation, cantaloupe injury was 35%, vine lengths were reduced by 24%, and maturity was delayed, whereas squash injury ranged from 9% to 12%, with no influence on growth or yield. Without irrigation to wash herbicides from the mulch prior to planting, 60% to 100% injury of both crops occurred with both herbicides. Zucchini squash was more tolerant to dicamba than cantaloupe. Results demonstrated that 2,4-D can be adequately removed from the surface of plastic mulch with irrigation, whereas a single irrigation event was not sufficient to remove dicamba.

Hairy buttercup (Ranunculus sardous) and cutleaf evening primrose (Oenothera laciniata) control using halauxifen-methyl based programs in Mississippi and Oklahoma winter wheat

AbstractHairy buttercup and cutleaf evening primrose are winter annual weeds that have become more problematic for winter wheat growers in the southern Great Plains and the midsouthern United States in recent years. Little research exists on which to base recommendations for controlling hairy buttercup in wheat, and little research has been published on cutleaf evening primrose control in recent years. With growing concerns of increased herbicide resistance among winter annual weeds, incorporating new herbicide sites of action has become necessary. The objective of this study was to assess halauxifen-methyl as a novel herbicide to control these two problematic winter annual broadleaf weeds in winter wheat in Mississippi and Oklahoma. Studies were conducted across four site-years in Mississippi and one site-year in Oklahoma comparing 15 herbicide programs with and without halauxifen-methyl. Hairy buttercup and cutleaf evening-primrose control was the greatest when a synthetic auxin was combined with an acetolactate synthase–inhibiting herbicide. Treatments including halauxifen-methyl resulted in the greatest control of hairy buttercup, whereas a synthetic auxin herbicide plus chlorsulfuron and metsulfuron resulted in the greatest control of cutleaf evening primrose. Halauxifen-methyl is an effective addition for control of winter annual broadleaf weeds like hairy buttercup and cutleaf evening primrose in winter wheat.

Comparison of 2,4-D, dicamba and halauxifen-methyl alone or in combination with glyphosate for preplant weed control

AbstractA field study was conducted in 2017 and 2018 to determine foliar efficacy of halauxifen-methyl, 2,4-D, or dicamba applied alone and in combination with glyphosate at preplant burndown timing. Experiments were conducted near Painter, VA; Rocky Mount, NC; Jackson, NC; and Gates, NC. Control of horseweed, henbit, purple deadnettle, cutleaf evening primrose, curly dock, purple cudweed, and common chickweed were evaluated. Halauxifen-methyl applied at 5 g ae ha−1 controlled small and large horseweed 89% and 79%, respectively, and was similar to control by dicamba applied at 280 g ae ha−1. Both rates of 2,4-D—533 g ae ha−1(low rate [LR]) or 1,066 g ae ha−1 (high rate [HR])—were less effective than halauxifen-methyl and dicamba for controlling horseweed. Halauxifen-methyl was the only auxin herbicide to control henbit (90%) and purple deadnettle (99%). Cutleaf evening primrose was controlled 74% to 85%, 51%, and 4% by 2,4-D, dicamba, and halauxifen-methyl, respectively. Dicamba and 2,4-D controlled curly dock 59% to 70% and were more effective than halauxifen-methyl (5%). Auxin herbicides applied alone controlled purple cudweed and common chickweed 21% or less. With the exception of cutleaf evening primrose (35%) and curly dock (37%), glyphosate alone provided 95% or greater control of all weeds evaluated. These experiments demonstrate halauxifen-methyl effectively (≥79%) controls horseweed, henbit, and purple deadnettle, whereas common chickweed, curly dock, cutleaf evening primrose, and purple cudweed control by the herbicide is inadequate (≤7%).

Impact of Acetic Acid Concentration, Application Volume, and Adjuvants on Weed Control Efficacy

Acetic acid (CH3COOH) is produced naturally through anaerobic fermentation (vinegar) or synthesized through various industrial chemical methods. The primary components of vinegar are water and acetic acid. Acetic acid can destroy cell membranes, which then can result in plant tissue desiccation and plant death. Therefore, vinegar has the potential as a natural contact herbicide for the control of weeds in organically produced crops. Additional information is needed to determine the influence of acetic acid concentration, application volume, and adjuvants on weed control. Typically, household vinegar contains 5% acetic acid and greater acetic acid concentrations are available commercially. Field research was conducted in southeast Oklahoma (Lane, OK) to determine the effect of acetic acid concentrations, application volumes, and adjuvants on weed control efficacy. The factorial experimental design included three acetic acid concentrations (0, 5 and 20%), two sprayer application volumes (187 and 935 L/ha), three adjuvants (none, orange oil, and canola oil), and one weedy-check. The experiment was repeated twice. Visual weed cover and control ratings were collected 4 days after treatment. The experiment had very high weed densities with multiple grass and broadleaf weed species. The weedy check average weed cover percentages were 98% total weeds, 53% grass, 44% broadleaf weeds, 52% large crabgrass (Digitaria sanguinalis (L.), 25% carpetweed (Mollugo verticillata L.), and 14% cutleaf evening primrose (Oenothera laciniata Hill). Total weed control ranged from 0% control (no acetic acid) to 74% control (20% acetic acid, 935 L/ha, & canola oil). Acetic acid was more effective in controlling broadleaf weeds than in controlling grasses. Optimum total grass and crabgrass weed control occurred with 20% acetic acid applied at 935 L/ha, resulting in weed control that ranged from 44% to 63%. Broadleaf weed control was 84% or greater for plots receiving either 10% acetic acid applied at 935 L/ha or 20% acetic acid applied at 187 or 935 L/ha. In addition, 5% acetic acid applied at 187 L/ha provided good cutleaf evening primrose control (77% to 90%). When averaged across application volumes (187 and 935 L/ha) and adjuvants (none, orange oil, and canola oil), weed control increased for all species as acetic acid concentrations increased from 5% to 20%. When averaged across acetic acid concentrations and adjuvants, weed control increased as application volumes increased from 187 to 935 L/ha. Individual comparisons among adjuvants within acetic acid concentrations and application volumes showed little or no advantage to adding either orange oil or canola oil to vinegar spray solutions.

Growth Stage Affects Response of Selected Weed Species to Flaming

Propane flaming could be an alternative tool for PRE control or suppression of early-emerging weeds in organic and conventional crops. The objective of this study was to test the tolerance of selected early-season weeds to broadcast flaming in no-till systems. Four winter annuals (tansy mustard, henbit, cutleaf evening primrose, and field pennycress), one summer annual (common lambsquarters), and one perennial (dandelion) species were included in the study. Except for dandelion, the response to propane flaming was evaluated at two growth stages. Flaming treatments were applied using an all-terrain-vehicle-mounted flamer moving 4.8 km h−1, and propane pressure was adjusted to deliver doses of 0 (nonflamed control), 22, 34, 48, 67, and 90 kg ha−1. The response of each species to propane doses was described by log-logistic models based on visual ratings of weed control and dry matter reduction. Response to broadcast flaming varied among species and growth stages. Common lambsquarters, tansy mustard, and henbit were more susceptible to flaming than cutleaf evening primrose, field pennycress, and dandelion. On the basis of visual ratings, propane doses between 54 and 62 kg ha−1 effectively controlled (90% control) common lambsquarters at the early growth stage (five-leaf), tansy mustard at both growth stages (nine-leaf and flowering), and henbit (flowering). However, a higher propane dose (> 80 kg ha−1) was necessary to obtain 90% control of common lambsquarters in later growth stage (11-leaf) and early growth stage of henbit (nine-leaf). Cutleaf evening primrose, field pennycress, and dandelion exhibited higher levels of tolerance to broadcast flaming. A 90% control of these species was not achieved even with the highest propane dose (90 kg ha−1) utilized in the study. Results of this study indicate that a single application of broadcast flaming can be an effective tool for controlling tansy mustard, henbit, and common lambsquarters and temporary suppression of cutleaf evening primrose, field pennycress, and dandelion.

Winter and Early-Spring Survey of Thrips Vectors and Host Plants of Tomato Spotted Wilt Tospovirus in and near a Flue-Cured Tobacco Farmscape

The tobacco thrips, Frankliniella fusca (Hinds), is an economic pest of flue-cured tobacco because it vectors tomato spotted wilt tospovirus. Other species of thrips are also vectors of spotted wilt in tobacco, including the western flower thrips, F. occidentalis (Pergande). This study examined the presence of thrips species on alternate plant hosts associated with the tobacco farmscape and surrounding area. Weed hosts were sampled from December through April from 1998 through 2001 to assess which plants provide suitable refuge and nutrients for thrips survival, reproduction, and spotted wilt infection. Thrips were identified to species and confirmed as potential vectors of spotted wilt by using ELISA to test for the presence of a non-structural tomato spotted wilt virus protein. Wild radish (Raphanus raphanistrum L.), broomsedge (Andropogon virginicus L.), and narrowleaf vetch (Vicia sativa L. subsp. nigra (L.) Ehrh.) are common late-winter weeds in the farmscape that harbor spotted wilt vectors. Cutleaf evening primrose, Oenethera laciniata Hill, and volunteer soybean, Glycine max(L.) Merrill, also were hosts of spotted wilt vectors in the tobacco farmscape. Numerous other weed hosts were present in the tobacco farmscape but either had no thrips collected from them or thrips were not confirmed as potential spotted wilt vectors from these host plants. Several other plants near the tobacco farmscape also were infected with spotted wilt, and three of these host plants, common chickweed (Stellaria media (L.) Cyrillo), carrot (Daucus carota L.), and flowering dogwood (Cornus florida L.) had confirmed vectors (ELISA) collected from them. Henbit (Lamium amplexicaule L.), wild radish, cutleaf evening primrose, narrowleaf vetch, carrot, curly dock (Rumex crispus L.), red sorrel (Rumex acetosella L.), and common chickweed were confirmed as positive plant hosts in this study for spotted wilt using ELISA. Frankliniella fusca appears to be the most abundant thrips vector on these alternate plant hosts and is the predominate thrips species collected on the flue-cured tobacco, Nicotiana tabacum L. However, F. occidentalis, Haplothrips graminis Hood, and Chirothrips spp. also were confirmed in this study to be potential vectors in the tobacco farmscape. Weed hosts in the farmscape appear to be influential as refuge and nutrients for vectors and an innoculant source of tomato spotted wilt virus in the flue-cured tobacco farmscape.

Soil Aggregation and Carbon and Nitrogen Pools under Rhizoma Peanut and Perennial Weeds

Roots of rhizoma peanut [(Arachis glabrata Benth.), a warm-season perennial legume forage] and perennial weeds may influence soil aggregation and associated C and N pools. We compared aggregate-size distribution and concentrations of organic C and N, NH4–N, NO3–N, potential C and N mineralization (PCM and PNM), microbial biomass C and N (MBC and MBN), and particulate organic C and N (POC and PON) in whole-soil and aggregates under 10-yr-old rhizoma peanut and perennial weeds [dominated by henbit (Lamium amplexicaule L.) and cut-leaf evening primrose (Oenothera laciniata Hill)]. Field plots were established on a Norfolk loamy fine sand in April 1991 in central Georgia. While soil aggregation and associated C and N pools were not influenced by treatments, whole-soil NH4–N and PON at the 0- to 15-cm, PCM at the 30- to 90-cm, and MBC at the 0- to 30-cm depth were 28 to 100% greater under peanut than under weeds. Under both treatments, the amount of soil present in the 4.75- to 2.00-mm aggregate-size class and mean-weight diameter of aggregates were 21 to 47% greater at 15- to 60- than at 0- to 15-cm, indicating improved aggregation in the subsurface compared with the surface soil. At 0 to 15 cm, concentrations of organic C and N, MBC, MBN, POC, and PON were greater in the <0.25-mm than in the 4.75- to 0.50-mm size class. At 0 to 30 cm, NO3–N was greater in the 4.75- to 0.85-mm than in the 0.50- to 0.25-mm size class. Although treatments did not influence soil organic C and N levels, rhizoma peanut may increase microbial activities and labile N pools compared with perennial weeds. Rhizoma peanut and perennial weeds may improve aggregation in the subsurface compared with the surface soil and C and N pools in aggregates <0.25 mm in diameter.

Allelopathy of Bermudagrass, Tall Fescue, Redroot Pigweed, and Cutleaf Evening Primrose on Pecan

Two studies were conducted to determine if selected grass and dicot species had an allelopathic interaction with pecan (Carya illinoinensis Wangenh. C. Koch). Leachate from pots with established grasses or dicots was used to irrigate container-grown pecan trees. Leachates from bermudagrass [Cynodon dactylon (L.) Pers.], tall fescue (Festuca arundinacea Shreb. cv. Kentucky 31), redroot pigweed (Amaranthus retroflexus L.), and cutleaf evening primrose (Oenothera laciniata Hill) reduced leaf area and leaf dry weight about 20% compared to the controls. Bermudagrass, tall fescue, and primrose leachate decreased pecan root weight 17%, trunk weight 22%, and total tree dry weight 19% compared to the control. In a second study, trees were 10% shorter than the control when irrigated with bermudagrass or pigweed leachate.

Cutleaf Evening Primrose and Palmer Amaranth Reduce Growth of Nonbearing Pecan Trees

Growth of `Apache' pecan [Carya illinoinensis (Wangenh.) K. Koch] seedlings was evaluated for 3 years when grown in a 11.2-m2 weed-free area or when various combinations of one or two plants of cutleaf evening primrose (Oenothera laciniata Hill), a cool-season species, or Palmer amaranth (Amaranthus palmeri S. Wats.), a warm-season species, were grown 30 cm from the tree, with the rest of the 11.2-m2 area weed-free. Either weed species alone suppressed tree growth compared to the weed-free control. A temporal succession of primrose followed by amaranth reduced growth most. After 3 years, two plants of primrose followed in succession by two of amaranth caused a 79% reduction in cumulative current-season's growth.

Bacterial Streak and Bulb Rot of Sweet Onion: II. Epiphytic Survival of Pseudomonas viridiflava in Association with Multiple Weed Hosts.

A semiselective agar medium (T-5) was used to sample environment and plant material as a habitat for Pseudomonas viridiflava. Soil, irrigation water, soybean foliage, and foliage from various weeds in an onion-growing area were assayed over a 5-year period. P. viridiflava was recovered only as an epiphytic resident from weed species that included cutleaf evening primrose, dandelion, common fumitory, purple cudweed, spiny sowthistle, Virginia pepperweed, and wild radish. The bacterium apparently overseasons in association with these weeds, because its presence was detected prior to, as well as during, the onion-growing season. Preliminary tests indicated that weed control may suppress bacterial streak and bulb rot levels.

Detection of Tomato Spotted Wilt Virus in Tobacco Thrips (Thysanoptera: Thripidae) Overwintering in Harvested Peanut Fields

Volunteer and transplanted peanut, Arachis hypogaea L., and cutleaf evening primrose, Oenothera laciniata Hill, were sampled for thrips, Frankliniella spp., from November 1990 to April 1991 in seven fields in southwestern Georgia that had been planted with peanut during 1990. Thrips and roots from these plants were assayed for presence of tomato spotted wilt virus with enzyme-linked immunosorbent assay. Totals of 1,414 brachypterous and 2,360 macropterous tobacco thrips, Frankliniella fusca (Hinds), 218 western flower thrips, Frankliniella occidentalis (Pergande), and 8,590 Frankliniella spp. larvae were assayed during the study. The virus was repeatedly detected in adult tobacco thrips and thrips larvae collected from three fields. Virus incidence ranged from 0 to 6.2% in brachypterous adults, 0 to 10.0% in macropterous adults, and 0 to 0.9% in thrips larvae, depending on field and sample date. Tomato spotted wilt virus also was detected in two adult western flower thrips. The virus was detected in only 2 of 816 volunteer peanut roots and in none of 374 cutleaf evening primrose roots assayed during March and April. Implications for overwintering by tomato spotted wilt virus are discussed.

Indole-Acetic Acid and the Ethylene Precursor, Acc, in the Cotton Fleahopper (Hemiptera: Miridae) and Their Role in Cotton Square Abscission

Indole-acetic acid (IAA) was present in laboratory-reared nymphal and adult cotton fleahoppers, Pseudatomoscelis seriatus (Reuter). The ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), occurred in nymphal and adult cotton fleahoppers reared in the laboratory and in nymphs collected from the host plants croton, Croton capitatus Michaux; horsemint, Monarda punctata L.; and cutleaf evening primrose, Oenothera laciniata Hill. Cotton fleahopper eggs did not contain ACC. IAA and ACC, when injected into cotton shoot tips at concentrations occurring in cotton fleahoppers, induced ethylene production to levels higher than in controls but lower than in terminals infested with cotton fleahoppers. Thus the IAA and ACC in cotton fleahoppers may contribute partially to the mechanism by which cotton fleahoppers promote ethylene-mediated abscission of cotton flower buds.

Forage Quality of Selected Cool-Season Weed Species

Forage quality was determined at vegetative, flowering, and fruiting stages for nine cool-season weed species and four cultivated forages. When compared at the vegetative stage of maturity, Carolina geranium (Geranium carolinianumL. # GERCA), Virginia pepperweed (Lepidium virginicumL. # LEPVI), Virginia wildrye (Elymus virginicusL. # ELYVI), wild oats (Avena fatuaL. # AVEFA), cheat (Bromus secalinusL. # BROSE), and little barley (Hordeum pusillumNutt. # HORPU) had high nutritive quality as indicated by in vitro dry-matter digestibility (IVDMD) values equal or superior to rye (Secale cerealeL.), tall fescue (Festuca arundinaceaSchreb.), and ladino clover (Trifolium repensL.). Cutleaf evening primrose (Oenothera laciniataHill # OEOLA) and curly dock (Rumex crispusL. # RUMCR) had lower IVDMD values than the cultivated forages and all weed species except wild oats. However, the rate of decline in IVDMD as plants matured was generally greater for the weed species compared to cultivated forage plants. All weed and cultivated forage species had adequate levels of Ca and K for livestock. Nearly all weed and cultivated forage species had suboptimum levels of P for high-producing ruminant animals; Carolina geranium and cutleaf evening primrose had high Ca:P ratios, which can cause metabolic disorders. Carolina geranium, Virginia wildrye, wild oats, cheat, little barley, and all the cultivated forage species had inadequate levels of Mg and could be considered “tetany prone”. Most of the forbs had high Mg concentrations.