Seed dormancy characteristics in six weed species as affected by after-ripening temperatures and field conditions

Seed dormancy is an important trait that contributes to the survival rate of weeds, helps to avoid the effects of herbicides and protects them against adverse environmental conditions. In order to determine which methods are effective in breaking seed dormancy of invasive weed species (Ambrosia artemisiifolia, Abutilon theophrasti, Xanthium strumarium), an experiment was set up in 2019 in a randomized block design, with three replications in the experimental field of the Institute of Field and Vegetable Crops (Novi Sad). The collected seeds of one population of A. artemisiifolia and A. theophrasti, were cleaned and stored in cold storage at 4°C until testing, while X. strumarium was stored at room temperature. Seed propagation was done in a weed science laboratory, using nine different methods for breaking seed dormancy. The seeds were exposed to different conditions of temperature, light and humidity over a certain period of time (24h or 48h). The dynamics of weed emergence were monitored daily, for a period of 31 days and expressed cumulatively in percentages. Based on the obtained results, the highest percentage of sprouted plants was determined in treatments where the seeds were propagated under light conditions, in water. An appropriate method of propagation can influence the breaking of seed dormancy and emergence in field conditions, which can have practical significance in the research of competitive relations between crops and tested weed species.

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Germination of Amaranthus retroflexus, Portulaca oleracea and other weed species under laboratory, greenhouse, and field conditions

10.31274/rtd-20200617-37 ◽

1965 ◽

Author(s):

Edward Lacaze McWilliams

Keyword(s):

Amaranthus Retroflexus ◽

Portulaca Oleracea ◽

Field Conditions ◽

Weed Species

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Evaluation of Imazethapyr for Weed Control in Leafy Vegetable Crops

Weed Technology ◽

10.1017/s0890037x00039907 ◽

1996 ◽

Vol 10 (2) ◽

pp. 253-257 ◽

Cited By ~ 4

Author(s):

Joan A. Dusky ◽

William M. Stall

Keyword(s):

Regression Analysis ◽

Weed Control ◽

Crop Yield ◽

Relative Sensitivity ◽

Leafy Vegetable ◽

Field Conditions ◽

Vegetable Crops ◽

Weed Species ◽

Common Lambsquarters ◽

Common Purslane

Imazethapyr was evaluated PRE and POST in five lettuce types and chicory under Florida field conditions. The relative sensitivity of leafy crop vigor (most sensitive to most tolerant) to imazethapyr PRE, based on 20% inhibition determined using regression analysis, was as follows: Boston > bibb > crisphead > romaine > leaf > escarole > endive. Leafy crop injury increased as the rate of imazethapyr applied POST increased, with all leafy crops responding in a similar manner. Surfactant addition increased imazethapyr phytotoxicity. Imazethapyr PRE treatments at 0.067 kg ai/ha provided greater than 80% control of livid amaranth, common purslane, flatsedge, and common lambsquarters. Imazethapyr POST at 0.067 kg/ha, with surfactant provided control greater than 85% of all weed species. Greater than 85% spiny amaranth control was provided by imazethapyr POST at 0.017 kg/ha. Use of surfactant with imazethapyr did not improve spiny amaranth control over imazethapyr with no surfactant. POST treatments did not decrease leafy crop yield compared with the hand-weeded check. Imazethapyr applied PRE reduced crop yield compared to the POST treatments and the hand-weeded control.

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Environmental control of seed dormancy, germination and seedling emergence of three weed species

10.31274/rtd-20200716-42 ◽

2003 ◽

Author(s):

Ramon G Leon-Gonzalez

Keyword(s):

Seed Dormancy ◽

Environmental Control ◽

Seedling Emergence ◽

Weed Species

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Utility of Maintained Weed Infestations Under Field Conditions

Weed Science ◽

10.1017/s0043174500079583 ◽

1970 ◽

Vol 18 (2) ◽

pp. 206-214 ◽

Cited By ~ 1

Author(s):

R. P. Upchurch ◽

F. L. Selman ◽

H. L. Webster

Keyword(s):

Chenopodium Album ◽

Amaranthus Retroflexus ◽

Ambrosia Artemisiifolia ◽

Field Conditions ◽

Moderate Degree ◽

Weed Species ◽

Common Ragweed ◽

Common Lambsquarters ◽

Dimethyl Urea ◽

Polygonum Pensylvanicum

Relatively pure stands of eight weed species were maintained under field conditions on a Goldsboro loamy sand at Lewiston, North Carolina, for all or part of a 6-year period. Herbicides evaluated as preemergence surface treatments for these species were 2-sec-butyl-4,6-dinitrophenol (dinoseb), isopropyl m-chlorocarbanilate (chloropropham), 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (diuron), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), and 3-amino-2,5-dichlorobenzoic acid (amiben). S-ethyl dipropylthiocarbamate (EPTC) and a,a,a-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) were evaluated as preemergence incorporated treatments. The first four herbicides were evaluated in 1961, 1964, and 1966 while the last three were evaluated in 1962, 1963, and 1965. A series of rates was used for each chemical with three replications. With the exception of diuron which failed to control goosegrass (Eleusine indica (L.) Gaertn.), all of the herbicides provided at least a moderate degree of control of goosegrass, smooth crabgrass (Digitaria ischaemum (Schreb.) Muhl.), and redroot pigweed (Amaranthus retroflexus L.) at the respective typical field use rates. In general, trifluralin and amiben gave the best grass control and dinoseb the poorest. None of the herbicides effectively controlled common cocklebur (Xanthium pensylvanicum Wallr.) or ivyleaf morningglory (Ipomoea hederacea (L.) Jacq.). Trifluralin and EPTC did not control Pennsylvania smartweed (Polygonum pensylvanicum L.), common ragweed (Ambrosia artemisiifolia L.), and common lambsquarters (Chenopodium album L.). Chloropropham was ineffective on common ragweed. Simazine, chloropropham, and amiben controlled Pennsylvania smartweed while diuron, simazine, dinoseb, and amiben were especially effective on common lambsquarters. Distinctive patterns of nematode infestations were observed as a function of weed species.

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Seed Dormancy and Seed Morphology Related to Weed Susceptibility to Biofumigation

Weed Science ◽

10.1017/wsc.2017.66 ◽

2017 ◽

Vol 66 (2) ◽

pp. 199-214 ◽

Cited By ~ 6

Author(s):

Maxime Lefebvre ◽

Maryse L. Leblanc ◽

Alan K. Watson

Keyword(s):

Seed Dormancy ◽

Weed Management ◽

Relative Weight ◽

Indian Mustard ◽

Petri Dish ◽

Seed Morphology ◽

Weed Species ◽

Common Ragweed ◽

Common Lambsquarters ◽

Wild Carrot

Biofumigation is practiced to control soilborne pests and weeds in agronomic fields. The objectives of this research were to assess the dose response of weed seeds to Indian mustard biofumigation and associate responses to seed dormancy state, initial dormancy, and seed parameters. A petri dish biofumigation methodology was developed to expose seeds of common lambsquarters, bird vetch, wild carrot, common ragweed, green foxtail, velvetleaf, hairy galinsoga, and red clover to allelochemicals produced after rehydrating 0 (control), 1.94, 2.90, 5.81, 11.61, and 17.41 mg cm−2of dried mustard powder. Weed species expressed specific dose responses, estimated ED50, LD50, and maximal mortality. Hairy galinsoga and wild carrot were consistently the most affected by biofumigation, with maximal mortality reaching 97% and 95%, ED50values for germination were 1.91 and 2.68 mg cm−2, and LD50values were 3.31 and 3.69 mg cm−2of dried mustard tissue, respectively. Initial dormancy was assessed by germination and tetrazolium tests. Seed parameters such as testa thickness, relative weight of the testa, and seed size were measured directly by manual dissection, weighing seed structures, and stereomicroscopic imaging software measurements. Linear regression analyses revealed initial dormancy to be positively related to ED50and LD50values with a significant interaction with seed surface and seed width, respectively. Exposure to 5.81 mg cm−2of dried mustard powder increased common ragweed seed mortality for after-ripened seeds by 293% and by 58% for primary dormant seeds compared with untreated seeds. Mortality of common lambsquarters secondary and primary dormant seeds increased by 730% and 106%, respectively, and for wild carrot by 1,193 and 156%, respectively. Results underline the potential to incorporate biofumigation into weed management programs for repression of susceptible weed species.

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Different strategies for breaking physical seed dormancy in field conditions in two fruit morphs of Vachellia caven (Fabaceae)

Seed Science Research ◽

10.1017/s096025851800003x ◽

2018 ◽

Vol 28 (1) ◽

pp. 8-15 ◽

Cited By ~ 1

Author(s):

Ana E. Ferreras ◽

Paula I. Marcora ◽

M. Paula Venier ◽

Guillermo Funes

Keyword(s):

Seed Dormancy ◽

Environmental Conditions ◽

Environmental Variables ◽

Environmental Heterogeneity ◽

Environmental Changes ◽

Gradual Increase ◽

Field Conditions ◽

Fruit Morphology ◽

Physical Dormancy ◽

And Coping

AbstractDifferences in fruit morphology among or within species might indicate differences in other regenerative traits, such as seed dormancy and germination. In species with physical dormancy (PY), environmental conditions are suggested to be responsible for dormancy break in field. Seeds of Vachellia caven have PY. This species exhibits two fruit morphs highly represented in Córdoba forests, Argentina: one is dehiscent and the other is indehiscent. In this study we performed a burial experiment with the aim to determine if the differences in V. caven fruit morphology were related to different patterns of PY break of their seeds in field conditions. We related these patterns to (1) environmental conditions that could influence the loss of PY, and (2) histological features of the lens zone. Seeds of both morphs exhibited dormancy break within 14 months of the start of the experiment, but with different patterns. The dehiscent morph showed an abrupt percentage of seeds that broke dormancy 14 months after the beginning of the experiment, probably after undergoing environmental changes similar to those suggested by the two-stage softening model. The indehiscent morph showed a gradual increase in seeds that broke dormancy, not clearly related to any of the environmental variables studied. No differences in seed coat structure of the lens zone were observed between morphs. The existence of both morphs could confer the species with higher possibilities of establishing and coping with environmental heterogeneity. Those characteristics contribute to the understanding of the success of this species in open and disturbed environments.

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Investigation of Potential Seed Dormancy Mechanisms in American Burnweed (Erechtites hieraciifolius) Seeds from Wild Blueberry (Vaccinium angustifolium) fields

Weed Science ◽

10.1017/wsc.2016.21 ◽

2017 ◽

Vol 65 (2) ◽

pp. 256-265

Author(s):

Scott N. White ◽

Linshan Zhang ◽

Kris Pruski

Keyword(s):

Seed Dormancy ◽

Seed Treatment ◽

Potassium Nitrate ◽

Weed Species ◽

Cold Temperatures ◽

Breaking Dormancy ◽

Physiological Dormancy ◽

Series Of Experiments ◽

Favorable Conditions ◽

Wild Blueberry

American burnweed is an increasingly common annual weed in wild blueberry fields in Atlantic Canada and Maine. Knowledge of seed dormancy characteristics and potential for this species to form persistent seedbanks in wild blueberry soils, however, is lacking. A series of experiments were therefore conducted to investigate potential mechanisms regulating American burnweed seed dormancy in wild blueberry fields. Seeds were dormant at maturity and did not germinate in dark or light under warm conditions. Cold moist stratification (CMS) at 4 C for 90 d followed by exposure to warm conditions (22/15 C day/night) and light caused >90% germination, and germination was generally maximized following 80 d CMS. Exogenous potassium nitrate applied as a 5% solution did not stimulate germination, but nearly all seeds (>95%) germinated following treatment with 200, 400, 600, or 800 ppm (w/v) gibberellic acid (GA3) solution. Physical removal of the seed coat or seed exposure to short durations of dry heat did not increase germination. Seed exposure to 1 s of direct flame increased germination, but germination was low relative to germination following CMS and treatment with GA3. Based on these results, we conclude that American burnweed seeds in wild blueberry fields exhibit non–deep physiological dormancy that is most readily broken by CMS and light or seed treatment with GA3. Seeds will likely be exposed to favorable conditions for breaking dormancy (cold temperatures and light) in wild blueberry fields due to lack of tillage and seed burial, indicating high potential for this weed species to proliferate in wild blueberry fields if not properly managed.

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Hybridization and backcrossing between transgenic oilseed rape and two related weed species under field conditions

Environmental Biosafety Research ◽

10.1051/ebr:2004007 ◽

2004 ◽

Vol 3 (2) ◽

pp. 73-81 ◽

Cited By ~ 45

Author(s):

Matthew D. Halfhill ◽

Bin Zhu ◽

Suzanne I. Warwick ◽

Paul L. Raymer ◽

Reginald J. Millwood ◽

...

Keyword(s):

Oilseed Rape ◽

Field Conditions ◽

Weed Species ◽

Transgenic Oilseed Rape

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Germination Techniques for Common Lambsquarters (Chenopodium album) and Pennsylvania Smartweed (Polygonum pensylvanicum)

Weed Technology ◽

10.1614/wt-05-091r.1 ◽

2006 ◽

Vol 20 (2) ◽

pp. 530-534 ◽

Cited By ~ 7

Author(s):

Shawn M. Hock ◽

Stevan Z. Knezevic ◽

Chris L. Petersen ◽

John Eastin ◽

Alex R. Martin

Keyword(s):

Seed Germination ◽

Seed Dormancy ◽

Chenopodium Album ◽

Solid Matrix ◽

Cold Stratification ◽

Weed Species ◽

Laboratory Bioassay ◽

Common Lambsquarters ◽

Polygonum Pensylvanicum ◽

Germination Techniques

A laboratory bioassay was conducted to describe the effects of cold stratification and solid matrix priming (SMP®) on the germination response of common lambsquarters and Pennsylvania smartweed seeds. Treating seeds of common lambsquarters with a combination of cold stratification and SMP resulted in 78% germination compared with 13% in control seeds. Analogous treatments of Pennsylvania smartweed seeds resulted in 22% germination compared with 1% for control. Improved germination of common lambsquarters and Pennsylvania smartweed seeds suggested that the combination of cold stratification and SMP treatments have potential for improving seed germination in other weed species that exhibit high levels of seed dormancy.

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