Viable Weed Seeds Research Articles

СЕМЕННАЯ ПРОДУКТИВНОСТЬ И ЖИЗНЕСПОСОБНОСТЬ СЕМЯН СОРНЫХ РАСТЕНИЙ В РАЗЛИЧНЫХ ТИПАХ ПОЧВ

The results of longterm field experiments on two types of soils (chernozem and kastano-zems) are presented. The indicators of average seed productivity of more than 50 species of weeds growing in these soils are presented. The duration of the viability of seeds planted in a 0–30 cm soil layer, the quality of seeds during their layer-by-layer placement in the soil, on its surface and during storage in a dry warehouse is indicated. It was revealed that early spring and wintering weeds in chernozem soils had the highest seed productivity (more than 50 thousand seeds per plant). It was established that these seeds remained viable in the soil from 3 to 6 years (23 species), more than 6 years (20 species), and less than 3 years (only 3 species). In kastanozems soils, the seed productivity of most weeds decreased by 11–26% compared to chernozems. The loss of seed viability occurred more intensively in kastanozems soils than in chernozem soils. It was established that the lowest viability of seeds on both types of soils was observed during their longterm stay on the soil surface: after 5 years it did not exceed 12–15%, and after 10 years – 2–3%, while in the 0–10 cm layer of chernozem soils, it reached 36 and 18%, respectively, and in kastanozems soils it decreased more strongly and did not exceed 26 and 10%. In the lower soil layers, 10–20 and 20–30 cm, higher viability of weed seeds remained in kastanozems soils.

Substantiation of the weed control system when placing grain production in microzones of the Central Chernozem region

The most important link in modern farming systems is the protection of crops from weeds. Only by taking effective measures to reduce the weediness of crops one can get a high yield of cultivated crops and high-quality products. On a field or plot with high weediness all other agricultural activities aimed at increasing crop yields will be ineffective. When planning for weed control, the grower must give priority to preventive and organizational measures. It is much easier to prevent weeding of agricultural land than to try to weed an already weeded area. Preventive measures include: seed cleaning; preparation of feed for feeding, allowing them to be cleaned of viable weed seeds; preparation of organic fertilizers (manure, composts) before applying them to the fields. An important measure that reduces the weediness of fields is the destruction of weeds on lands adjacent to fields: on unused plots, field edges, roadsides, edges of forest belts. Cleaning of weed seeds from wastes is necessary by means of agricultural machines and vehicles, as well as by means of containers.

PM 3/66 (3) Guidelines for the management of plant health risks of biowaste of plant origin

<scp>PM</scp> 3/66 (3) Guidelines for the management of plant health risks of biowaste of plant origin

Spatial Abundance of Soil Seed Bank in Parthenium Infested Maize Fields in Western Gojjam Zone, Ethiopia

Background The reserve of viable weed seeds present on the soil surface and scattered throughout the soil profile. Objective A glasshouse study was conducted to determine the special abundance of soil seed bank flora in parthenium invaded maize fields in West Gojjam Zone. Methods The soil samples were collected from 90 fields at 0-5 cm, 5-10 cm and 10-15 cm soil depth with 10 cm width. Results A total of 121 weed species belonging to 27 families were found [...]

Long-term impact of zero-till residue management in post-rainy seasons after puddled rice and cropping intensification on weed seedbank, above-ground weed flora and crop productivity

Regulation in weed seed recruitment to soil and its emergence is an ecological approach of weed management for sustainable cropping intensification and land restoration. Intensive tillage operations in rice (Oryza sativa L.) - wheat (Triticum aestivum L.) system is a predominant practice in the South East Asian countries. This practice has emerged as an unsustainable crop management options. Consequently, zero tillage (ZT) in post–rainy seasons after conventional tilled (CT) puddled transplanted rice is being adopted to minimize tillage intensity in system in these regions. However, long–term impact of continuous CT in all seasons versus seasonal ZT (in post–rainy seasons) after puddled transplanted rice with crop residues in cropping system mode on above– and below– ground weed density and diversity is not adequately studied. Hence, we examined four tillage based residue management: (i) conventional tillage in each crop of rotation without residue (CT–CT), (ii) conventional tillage in each crop with incorporated residue (CT–CT + R), (iii) conventional tilled puddled transplanted rice – zero tillage in post–rainy season crops without residue (CT–ZT), (iv) conventional tilled puddled transplanted rice – zero tillage in post–rainy season crops with surface residue mulch (CT–ZT + R) each with three levels of crop rotation: (i) rice – wheat (R–W), (ii) rice – chickpea (Cicer arietinum L.) (R–C), (iii) rice – chickpea – mungbean (Vigna radiata (L.) (R–C–Mb) in split–plot design in Kanpur, India. Zero tillage in post–rainy seasons after conventional tilled rice resulted in 11%, 23%, and 13% lower (P < 0.05) weed seed density than CT–CT at 0–7.5, 7.5–15, and 0–15 cm depth, respectively. However, zero-tilled residue management had 15–19% and 10–14% (P < 0.05) higher above–ground weed density compared with CT–CT. Rice-chickpea-mungbean rotation reduced weed seed density by 6–11%, 4–11%, and 6–8% (P < 0.05) than those of rice-wheat and rice-chickpea across depth. In contrast, rice-chickpea-mungbean had 30–38% higher total above–ground weed density than rest of the crop rotations. Post–rainy seasons zero tillage with and without residues attributed higher weed diversity indices (Shannon and Simpson) compared with conventional tillage in seedbank. Importantly, CT–ZT + R with R–C–Mb (interaction) reduced 24% total viable seed density at 0–15 cm depth than CT–CT with R–W. Further, this system brought about 15% and 62% higher rice seed yield and system productivity over CT–CT with R–W, respectively. Conventional tilled puddled transplanted rice – zero tillage with added residues increased 16% and 33% seed yield of wheat and chickpea compared with CT–CT (P < 0.05), respectively. Thus, it can be concluded that zero tillage in post-rainy seasons after puddled transplanted rice and intensive pulse based cropping (rice-chickpea-mungbean) can minimize viable weed seeds in soil vis–a–vis above–ground weed density over time than conventional tillage and rice-wheat system. The reduced weed density could reduce soil fertility degradation, enhance crop/system productivity, restore soil health and provides opportunity for sustainable cropping intensification in rice ecologies of the Indo-Gangetic plains.

Risk Associated with the Weed Seeds in Imported Grain

The risk of introducing weeds to new areas through grain (cereals, oilseeds and pulses) intended for processing or consumption is considered less than that from seed or plants for planting. However, within the range of end uses for grain, weed risk varies significantly and should not be ignored. There is a need to examine the association of weed seeds with grain commodities throughout the production process from field to final end use, and inspection of representative samples for grain crops commonly imported to India. In the field, weed seed contamination of grain crops is affected by factors such as country of origin, climate, biogeography, production and harvesting practices. As it moves toward export, grain is cleaned at a series of elevators and the effectiveness and degree of cleaning are influenced by grain size, shape and density as well as by grade requirements. In cases where different grain lots are blended, uncertainty may be introduced with respect to the species and numbers of weed seed contaminants. During transport and storage, accidental spills and cross-contamination among conveyances may occur. At the point of import to India, inspection data show that grain shipments contain a variety of weed seeds including seeds of regulated weeds. However, grain cleaning and processing methods tailored to end use at destination also affect the presence and viability of weed seeds. For example, grains that are milled or crushed for human use present a lower risk of introducing weed seeds than grains that undergo minimal or no processing. Risk analysis allows each of these stages to be evaluated in order to characterize the overall risk of introducing weeds with particular commodities, and guide regulatory decisions about trade and plant health.

Thirty‐six years of no‐tillage regime altered weed population dynamics in soybean

AbstractChanges to tillage practices can impact weed species composition and population dynamics in arable fields. The objective of this study was to evaluate and compare the impact of long‐term (36 yr) no‐tillage (NT) and conventional‐tillage (CT) systems on weed species composition, density, seedling emergence, and diversity, in a continuous soybean [Glycine max (L.) Merr.] system in Southeast Texas. Results from 2016 and 2017 observations showed that weed species composition varied between CT and NT, and the total density was greater in NT (14 and 86 plants m–2 for summer and winter annuals, respectively) compared to CT (3 and 45 plants m–2, respectively). Moreover, tall waterhemp [Amaranthus tuberculatus (Moq.) Sauer], prostrate spurge [Chamaesyce humistrata (Engelm. ex Gray) Small], and red sprangletop [Dinebra panicea (Retz.) P.M. Peterson &amp; N. Snow] emergence was delayed in NT compared to CT. Vertical distribution (70‐cm depth) of viable weed seeds in the soil profile was also influenced by tillage regime; greater proportion of weed seeds were present on the soil surface (0–5 cm) in NT (57–80% among different species) compared to CT (38–56%). However, weed diversity indices did not differ between CT and NT. Results indicate that long‐term NT, even with herbicide management, can lead to greater weed densities with a shift towards small‐seeded annual species (common purslane [Portulaca oleraceae L.], parsley‐piert [Aphanes arvensis L.], cutleaf groundcherry [Physalis angulate L.]). Growers transitioning to NT should be cognizant of potential changes to weed population dynamics as a result of altered tillage regime and devise strategies for effective management.

Ефективність використання дигестату біогазових установок

It has been established that the digestate of biogas plants is a valuable organic fertilizer that is quickly absorbed by plants, contains a complex of macro- and microelements necessary for plant growth, has a high content of readily available nitrogen for plants, has a pH level close to neutral and does not contain viable weed seeds and pathogens. microflora. It is technically difficult to make untreated digestate into the soil, so it is predivided into solid and liquid fractions on separators. A major problem with the commercial use of digestate in Ukraine is the lack of its standardization. When applying digestate to the company's own fields, which owns the biogas plant, the standardization of its quality is not critical. However, the lack of a standard for digestate as a high-quality organic fertilizer significantly limits its use. The needs for digestate were determined to restore soil fertility and fertilize crops in and with a herd of 1,000 cattle (500 heads of dairy cows and 500 heads of young cattle and heifers) and with an arable land area of 1,800 hectares. It is established that only one ton of digestate remains for commercial use after application to the fields, the profit from the sale of which does not significantly affect the profitability of biogas production. The payback period of the biogas plant is 6.4 years and depends on the cost of biogas production. With the commercial use of all digestate produced during the year, the payback period of the biogas plant is reduced to one year and below and does not depend on the cost of biogas production, and the impact of the "green" tariff on the payback period of the biogas plant is leveled.

Integration of Steam with Allyl-isothiocyanate for Soil Disinfestation

Steam has long been used to disinfest greenhouse soils. However, there is increasing interest in expanding the use of steam for in-field soil disinfestation as an alternative to chemical fumigants. Previous studies demonstrated that allyl-isothiocyanate (AITC) reduced viability of weed seeds and plant pathogen propagules, but AITC has a low vapor pressure and is relatively immobile in soil. Heat has been used in the past to enhance the mobility of soil fumigants such as methyl bromide (i.e., “hot gassing”). The effect of steam heat on the mobility of AITC is unknown. The objective of this study was to investigate the potential synergistic effect of steam plus ATIC against weed seeds and a plant pathogen. AITC alone did not reduce the viability of the four weed species and the number of Verticillium dahliae microsclerotia. The steam + AITC treatment reduced the viability of V. dahliae at 12.5 and 18 cm distances by 82% and 88%, respectively, and knotweed and nettle seeds at 70 cm from injection point by 75% and 86%, respectively, from the center of microplots compared with steam alone. The results suggest that AITC and steam have a complementary effect on soilborne pests because steam increases the mobility of AITC.

Herbicide Resistance Management: Recent Developments and Trends.

This review covers recent developments and trends in herbicide-resistant (HR) weed management in agronomic field crops. In countries where input-intensive agriculture is practiced, these developments and trends over the past decade include renewed efforts by the agrichemical industry in herbicide discovery, cultivation of crops with combined (stacked) HR traits, increasing reliance on preemergence vs. postemergence herbicides, breeding for weed-competitive crop cultivars, expansion of harvest weed seed control practices, and advances in site-specific or precision weed management. The unifying framework or strategy underlying these developments and trends is mitigation of viable weed seeds into the soil seed bank and maintaining low weed seed banks to minimize population proliferation, evolution of resistance to additional herbicidal sites of action, and spread. A key question going forward is: how much weed control is enough to consistently achieve the goal of low weed seed banks? The vision for future HR weed management programs must be sustained crop production and profitability with reduced herbicide (particularly glyphosate) dependency.

Evaluation of New Harvesting Methods to Reduce Weeds on Arable Fields and Collect a New Feedstock

During harvesting, grain, straw, and chaff with weed seeds are separated. The chaff is returned to the fields, resulting in weed problems in the subsequent crops. We estimated the fraction of weed seeds a combine harvester could potentially harvest and used various methods to collect the chaff and treat it with heat to kill weed seeds or reduce weed seed germination. Chaff with weed seeds was placed on top of the straw and afterwards baled with the straw as a method to remove weed seeds from the field. We exposed chaff with weed seeds to exhaust gas with various temperatures and durations to study whether this heating method could be used to reduce the input of viable weed seeds to the soil during harvesting. By collecting the shed weed seeds during the growing season, we estimated that a combine harvester could potentially harvest 41%, 11%, and 100% of the seeds produced in the growing season by Bromus hordeaceus, Cirsium arvense, and Galium aparine, respectively. When the chaff was placed on top of the straw, 45% of the weed seeds stayed in the chaff fraction on top of the straw swath after one day, 35% got into the straw swath, and 20% past through the swath to the ground. Therefore, baling straw with chaff placed on the top only had a limited effect on reducing weed seed infestation. The study showed that thermal weed seed control during harvesting could potentially be applicable and incorporated in an integrated weed management approach.

Conditions of development of weeds, pests and diseases in crops of monoculture of hemp, depending on fertilizer

The article presents the results of studies of the conditions for the development of weeds, pests and diseases in the sowing of hemp monoculture. It was found that hemp is well adapted for growing for a long time in one field, providing a high yield of hemp production. It is recommended to grow a monoculture on fiber (harvesting in the phase of flowering plants). This makes it possible to avoid the ripening of seeds of the bulk of weeds and the main periods of harmfulness of pests and diseases. Differences in the degree of weediness of the field were revealed depending on the form and dose of fertilizers. In areas fertilized with manure, there are more weeds than in areas with introduced fertilizers. The large contamination of the fertilized areas is a consequence of the introduction of viable weed seeds together with manure, which is not properly harvested and stored in field shoulders. With an increase in the dose of manure, the number of weeds increases, and an increase in the dose of mineral fertilizers with which weed seeds are not introduced, on the contrary, decreases as a result of an increase in the height of the stalk and its foliage. This is clearly confirmed by the fact that during the period from 3-4 pairs of leaves and to the phase of flowering plants, a large number of weeds die. Indicated on agrotechnical methods of weed, pest and disease control when growing hemp monoculture.

Exploiting Waste Heat from Combine Harvesters to Damage Harvested Weed Seeds and Reduce Weed Infestation

Weeds are mainly controlled with herbicides in intensive crop production, but this has resulted in increasing problems with herbicide-resistant weeds and public concerns about the unwanted side-effects of herbicide use. Therefore, there is a need for new alternative methods to reduce weed problems. One way to reduce weed infestation could be to collect or kill weed seeds produced in the growing season. Crop and weeds are harvested simultaneously with the combine harvester, but most of the weed seeds are returned with the chaff to the field creating new problems in future growing seasons. During the harvesting process, the harvester produces heat. Under normal harvest conditions, the exhaust gas temperature measured directly behind the turbocharger of the engine of a combine harvester may reach between 400 °C and 480 °C depending of the size of the engine. These high temperatures indicate that there is a potential for developing a system which perhaps could be utilized to kill or damage the weeds seeds. We investigate how much heat is needed to damage weed seeds significantly and focuses on the germination patterns over time in response to these treatments. We investigated if heat treatment of weed seeds could kill the seeds or reduce seed vigour or kill the seeds before they are returned to the field. The aim is to avoid harvested viable weed seeds being added to the soil seed bank. During the threshing and cleaning process in the combine harvester, most weed seeds and chaff are separated from the crop grains. After this separation, we imagine that the weed seeds could be exposed to a high temperature before they are returned to the field. Seeds of nine common weed species were treated with temperatures of 50 °C, 100 °C, 150 °C, 200 °C, and 250 °C for 0, 2, 5, 10, and 20 s, respectively. Afterwards, the seeds were germinated for fourteen days. Seeds were differently affected by the heat treatments. We found that 50 °C and 100 °C was insufficient to harm the seeds of all species significantly at all durations. Heating with a temperature of 50 °C and 100 °C showed a slight tendency to break the dormancy of Alopecurus myosuroides Huds. and Papaver rhoeas L., but the results were not statistically significant. Seeds treated with 150 °C gave varying results depending on the duration and the weed species. The germination of A. myosuroides was significantly repressed when seeds were exposed to 250 °C for 5 s. Most species were significantly damaged when they were exposed to 250 °C for more than 10 s. Our results showed that there is a potential to explore how the waste heat energy produced by combine harvesters can be exploited to either kill or reduce the vigour of weed seeds before they are returned to the field with the chaff.

Stale seedbed technique for weed control negatively impacts the indigenous AM fungal population

Among weed control tools available to organic farmers are a variety of stale seedbed techniques. Stale seedbed methods create a surface layer of soil depleted in viable weed seeds through repetitive cycles of seed germination followed by cultivation to uproot and kill those seedlings. Two experiments were conducted to examine the impact of two stale seedbed techniques, roto-tilling and spading (each at two frequencies), upon the native AM fungal communities in organically farmed high P soils. Weed biomass, propagule densities of the indigenous AM fungal communities, development of mycorrhizas in roots of transplanted leek (Allium porrum L.) seedlings, and impact of AM fungus inoculation upon growth and yield were measured for repetitively cultivated vs. control planting beds. Stale seedbed treatments had significant negative impact upon total weed biomass the first month after planting the leek seedlings. Control beds, cultivated only just before planting, had significantly greater AM fungus propagule density than soils roto-tilled (Pr > F = 0.0004) or spaded (Pr > F = 0.0008) at 2–4 week intervals. Early season development of mycorrhizas in transplanted seedlings was greater in the control beds than in repetitively cultivated beds, e.g. 6% vs. 1% of root length colonized (Pr > F = 0.0001) two weeks after transplanting in Exp II. Even though the stale seedbed techniques had negative impacts upon the indigenous AM fungal populations, there was no measurable impact on crop yield in the high P soils used here. Nevertheless, farmers may want to consider use of AM fungus inoculation of vegetable seedlings transplanted into stale seedbed-treated fields low in plant available P.

A Soil Probe System to Evaluate Weed Seed Survival in Soil Disinfestation Trials

Weed seed viability is an important parameter to assess the efficacy of soil disinfestation methods like fumigation and steam. In field experiments, seed samples are commonly placed in permeable bags and buried at several depths in soil before the application of soil disinfestation treatments. The seed samples are recovered several days to weeks after treatment and then seed viability is determined in the laboratory. The process of sample installation and recovery is time consuming and may expose personnel to hazardous conditions such as heat or fumigants. Described is a custom soil probe system, developed to simplify installation and recovery of weed seeds from soil. Each soil probe is capable of holding weed seed samples at three different depths up to 30 cm. The following hypothesis was tested: viability of weed seeds is similarly affected by soil disinfestation treatments whether the seeds were contained in the soil probe system or seed bag assays. Two different soil disinfestation trials were conducted: (1) a repeated micro-plot study (USDA Salinas, 1 m-2), using steam as a soil disinfestation treatment and (2) a field study in a commercial strawberry field with 1,3-dicloropropene plus chloropicrin (Pic-Clor 60) as soil disinfestation method. In both studies, seed viability of burning nettle, common knotweed, and common purslane (tetrazolium assay) and germination rates of yellow nutsedge tubers were assessed. Results indicate that the soil probe system can be used as an alternative to the seed bag assay to assess weed control efficacy of described soil disinfestation methods.

Effect of Temperature and Retention Time in Cattle Slurry on Weed Seed Viability

Effect of Temperature and Retention Time in Cattle Slurry on Weed Seed Viability

Can winter cover crops influence weed density and diversity in a reduced tillage vegetable system?

Weeds are a major constraint for organic crop production. Previous research has found that cover crops in reduced tillage systems can provide weed interference, subsequently reducing inputs and improving crop yield. However, questions remain about effects of cover crop species identity and cover crop biomass on weed suppression and crop yield. This four-year study investigated how winter cover crops grown alone or in mixture influenced weed presence and crop yield in a reduced tillage organic vegetable system. Treatments were barley (Hordeum vulgare L.), crimson clover (Trifolium incarnatum L.), mixed barley + crimson clover, and a no-cover crop control. Plots were flail-mowed and strip-tilled prior to planting main crops (2011 and 2012: broccoli Brassica oleracea L.; 2013 and 2014: crookneck squash Cucurbita pepo L.). We measured density, diversity, and community composition of weeds and viable weed seeds, changes in weed percent cover within growing seasons, and crop yield. We found that the presence of barley, crimson clover, or barley + crimson clover reduced weed density by 50% relative to the control. Cover crop biomass negatively influenced weed density and weed seed diversity, and positively influenced squash yield. Weed percent cover within growing seasons did not respond differentially to cover crop treatment. Cover crop treatment and cover crop biomass had no influence on weed or weed seed community composition. These results suggest that reduced tillage winter cover crops in mixture or monoculture can similarly suppress weeds and improve yield, primarily due to biomass effects.

Meat waste as feedstock for home composting: Effects on the process and quality of compost

Home composting is a powerful tool, which is spreading in different parts of the world, to reduce the generation of municipal waste. However, there is debate concerning the appropriateness, in terms of domestic hygiene and safety, of keeping a composter bin in the household deputed to kitchen waste of animal origin, such as meat or fish scraps and pet droppings. The purpose of our work was to study how the addition of meat scraps to household waste influences the composting process and the quality of the final compost obtained. We compared four raw material mixtures, characterized by a different combination of vegetable and meat waste and different ratios of woody bulking agent. Changes in temperature, mass and volume, phenotypic microbial diversity (by Biolog™) and organic matter humification were determined during the process. At the end of the experiment, the four composts were weighed and characterized by physicochemical analysis. In addition, the presence of viable weed seeds was investigated and a germination bioassay was carried out to determine the level of phytotoxicity. Finally, the levels of pathogens (Escherichia coli and Salmonella spp.) were also determined in the final compost.Here we show that the presence of meat waste as raw feedstock for composting in bins can improve the activity of the process, the physicochemical characteristics and maturity of the compost obtained, without significantly affecting its salinity, pH and phytotoxicity. Pathogen levels were low, showing that they can be controlled by an intensive management and proper handling of the composter bins.

Late-Season Weed Management to Stop Viable Weed Seed Production

Integrated weed management (IWM) for agronomic and vegetable production systems utilizes all available options to effectively manage weeds. Late-season weed control measures are often needed to improve crop harvest and stop additions to the weed seed bank. Eliminating the production of viable weed seeds is one of the key IWM practices. The objective of this research was to determine how termination method and timing influence viable weed seed production of late-season weed infestations. Research was conducted in Delaware, Michigan, and New York over a 2-yr period. The weeds studied included: common lambsquarters, common ragweed, giant foxtail, jimsonweed, and velvetleaf. Three termination methods were imposed: cutting at the plant base (simulating hand hoeing), chopping (simulating mowing), and applying glyphosate. The three termination timings were flowering, immature seeds present, and mature seeds present. Following termination, plants were stored in the field in mesh bags until mid-Fall when seeds were counted and tested for viability. Termination timing influenced viable seed development; however, termination method did not. Common ragweed and giant foxtail produced viable seeds when terminated at the time of flowering. All species produced some viable seed when immature seeds were present at the time of termination. The time of viable seed formation varied based on species and site-year, ranging from plants terminated the day of flowering to 1,337 growing degree d after flowering (base 10, 0 to 57 calendar d). Viable seed production was reduced by 64 to 100% when common lambsquarters, giant foxtail, jimsonweed, and velvetleaf were terminated with immature seeds present, compared to when plants were terminated with some mature seeds present. Our results suggest that terminating common lambsquarters, common ragweed, and giant foxtail prior to flowering, and velvetleaf and jimsonweed less than 2 and 3 wk after flowering, respectively, greatly reduces weed seed bank inputs.

Effect of Dry Heat, Direct Flame, and Straw Burning on Seed Germination of Weed Species Found in Lowbush Blueberry Fields

Experiments were conducted to determine the effects of dry heat, direct flame, and straw burning on germination of several weed species from lowbush blueberry fields. Dry heat experiments were designed as factorial arrangements of temperature (100, 200, and 300 C in experiment 1 and room temperature, 100, 200, and 300 C in experiment 2) and exposure time (0, 5, 10, 20, 40, and 80 s in experiment 1 and 2, 5, 10, and 20 s in experiment 2) to determine the exposure time required to reduce germination for each temperature. Susceptibility to dry heat varied across species tested, but germination of spreading dogbane, meadow salsify, fireweed, and hair fescue seeds collected from lowbush blueberry fields in Nova Scotia, Canada generally declined exponentially as a function of duration of heat exposure at the temperatures tested. Germination decreased more rapidly at higher temperatures in all species, although the duration of heat exposure required to reduce germination by 50 and 90% varied across temperatures and species. Exposure of seeds to direct flame rapidly reduced germination, with less than 1 s of exposure required to reduce seed germination of witchgrass, spreading dogbane, and meadow salsify by &gt; 90%. Straw burning did not consistently reduce germination of hair fescue or winter bentgrass, indicating that a surface burn occurring above weed seeds may not be consistently effective at reducing seed viability. These results provide important estimates of the temperature and exposure times required to reduce viability of weed seeds in lowbush blueberry fields and suggest that thermal technologies that expose weed seeds to direct flame will be the most consistent in reducing seed viability.