Non-chemical Methods Research Articles

A model of flystrike pesticide resistance management on sheep: use of pesticide rotations

Context In some regions of Australia, the Australian sheep blowfly (Lucilia cuprina) is resistant to some of the pesticides used to control flystrike in sheep. Few pesticide groups are available, so it is important to delay or prevent any increase in resistance. Aims This study examined some of the assumptions in a previously developed model of pesticide resistance and tested the use of pesticide rotations as a means of limiting blowfly resistance to pesticides. Methods A model of sheep blowfly pesticide resistance was added to a previous model of sheep blowfly strike, to allow simulation of a range of pesticide management options for control of flystrike in sheep that might avoid increasing pesticide resistance. Key results The model requires some assumptions of settings that are uncertain, but the effects are not sensitive to a wide range of values for these settings. Resistance may not be obvious for some years after a new product is introduced, but once it has been detected, the frequency of resistance genes will increase rapidly if use of the same pesticide continues. The use of different pesticide groups each year is preferable to continuous use of the same product, but this risks losing efficacy of multiple products rather than one product at a time. However, rotations do provide a longer period of good protection from flystrike before all products used in the rotation fail. The number of years of successful protection against flystrike is extended if there is a fitness disadvantage for resistance to the products used. Conclusions The model may be useful for examining interactions between genes for resistance to different pesticides and the effect of non-chemical methods of control of flystrike, to extend the useful life of the current range of pesticides. Implications By the time resistance is detected on a farm, the level of resistance is high and will increase rapidly if the same pesticides continue to be used. Other non-pesticide methods such as breeding sheep for resistance to flystrike may be long-term solutions where resistance has reduced pesticide protection.

Management of Root-Knot Nematode with Non-Chemical Methods for Sustainable Production of Cucumber under Protected Cultivation

The multi-faceted benefits of growing crops under protected cultivation are gradually establishing it as a promising technology for vegetable cultivation in India. However, the adoption of successive cropping patterns in soil-based closed structures is leading to the buildup of soil-borne pathogens and pests, which are becoming a major hindrance to the sustainable production of these crops, particularly in the northern plains. Root-knot nematodes (RKNs) are a critical threat to protected cultivation and farmers are required to contribute a significant amount of time and money for their management. To reduce the overdependence of chemicals, the present study explored the potential of plant-based by-products as amendments for the management of RKN in cucumbers grown under a plastic greenhouse. A pot trial was conducted to assess the efficacy of different plant-based amendments against nematodes in cucumber plants. The pot trial results revealed that the application of mustard cake (MC) and neem cake (NC) at 1 t ha−1 either alone or as a combined application with farmyard manure (FYM) of 2.5 t ha−1 was effective against RKN infestation, reflecting the improved plant growth parameters of cucumber. Based on the results of the pot trials, treatments with plant-based amendments and FYM i.e., T1: MC 1 t ha−1; T2: NC 1 t ha−1; T3: FYM 2.5 t ha−1; T4: MC 1 t ha−1 + NC 1 t ha−1 + FYM 2.5 t ha−1, along with the treated check carbofuran 3 G 2 kg (a.i.) ha−1 (T5) and untreated check (T6), were evaluated in multi-locational field trials. The results revealed that the combined application of MC 1 t ha−1 + NC 1 tha−1 + FYM 2.5 t ha−1 exhibited promising results in decreasing RKN infestation (56–58%) in all of the three RKN-infested polyhouses, with significantly enhanced yields at all of the three locations. Soil organic carbon also increased significantly in the amended plots, indicating improved soil health. The results of the present work hold good promise for the management of RKN in the protected cultivation of cucumber with an environment friendly approach, along with the additional incentives of improved soil health.

Effect of Mint Leaves Powder (Mentha sp.) on Fungi Associated with Sunflower Helianthus annus L. Seeds

Sunflower Helianthus annus is one of the economically significant crops. During poor storage conditions, seed-borne fungi develop. As a result, it is polluted with mycotoxins and its quality is reduced for various uses Chemical and non-chemical methods to control fungal contamination were used. The current study examined the fungi associated with local products seeds and the antifungal activity of mint leaves powder (MLP) on seeds-borne isolates. Alternaria sp., Aspergillus sp., Cladosporium sp., Fusarium sp., Mucor sp., Penicillium sp., Pythium sp., Rhizopus sp., Trichoderma sp., were isolated from untreated seeds by moistened chamber method. Mixing MLP with sunflower seeds decreased the number of fungal isolates. Aspergillus, Mucor, Penicillium, Pythium, and Trichoderma disappear from tested seed samples after month. Also the seed germination% increase after mixing with MLP (not significant), it indicates that the treatment did not affect the embryo's vitality, the significant characteristic for the seeds that will be used for planting.

Suspected rodenticide exposures in humans and domestic animals: Data from inquiries to the Norwegian Poison Information Centre, 2005-2020.

Rodent control is necessary to prevent damage and spread of disease, and the most common pesticides used for urban and rural rodent control are anticoagulant rodenticides. The aim of this present study was to present data on suspected exposure to rodenticides in humans and domestic animals in Norway based on inquiries to the Norwegian Poison Information Centre in the 16-year period from 2005 through 2020. A total of 4235 inquiries regarding suspected exposures to rodenticides were registered in the study period. Of these, 1486 inquiries involved humans and 2749 animals. Second generation anticoagulants were involved in 68% of human exposures and 79% of animal exposures. Dogs were the most frequent species involved in the animal exposures with 93% of the inquiries, while cats were second most frequent involved. Around 50% of the human inquiries concerned children at the age of 0-4 years. Only 2% of the cases were in the age group 10-19 years, while adults comprised 35% of the inquiries. Acute poisonings accounted for almost 100% of the inquiries among both humans and animals. The exposure was accidental in 99% of the animal exposures and in 85% of the human exposures. In humans, only 14 inquiries were regarding occupational related accidents. Misdeed or self-inflicted injury accounted for 15% of the human inquiries and were the cause of 79% of the severe poisonings. Severe poisoning was only assessed in 1% of the cases involving children under 5 years. In contrast, 17% of the inquiries concerning adults (≥20 years) were assessed as severe. Subsequently, to prevent human and animal rodenticide exposure, we urge the use of non-chemical methods such as sanitation, rodent proofing (a form of construction which will impede or prevent rodents access to or from a given space or building) and mechanical traps. Restricting the use of rodenticides to professional pest controllers (or other persons with authorisation), reinforcing high quality education of these persons, and securing compliance of the best codes of practice could be advocated to reduce accidental exposure to rodenticides in humans and animals.

Natural Plant By-Products and Mulching Materials to Suppress Weeds and Improve Sugar Beet (Beta vulgaris L.) Yield and Quality

To reduce the use of herbicides in agriculture, there is an urgent need to look for cost-effective and environmentally friendly non-chemical methods to control weeds in field crops. Plant by-products could be exploited directly as plant residues or indirectly as plant extracts for weed control. Thus, the objective of this study was to evaluate the effectiveness of several plant wastes and extracts in controlling weeds of sugar beet (Beta vulgaris subsp. vulgaris) with enhancing yield and quality. Three weed control groups of twelve practices were examined. The first weed control group included three aqueous extract concentrations (15, 20, and 25%) of Plectranthus amboinicus L. The second weed control group involved six soil mulching plant materials [rice (Oryza sativa L.) straw, wheat (Triticum aestivum L.) hay, peanut (Arachis hypogaea L.) straw, mango (Mangifera indica L.) leaves, flax (Linum usitatissimum L.) meal, and soybean (Glycine max (L.) Merr.) meal], while the third group comprised of desmedipham/ethofumesate/lenacil/phenmedipham (DELP) herbicide 1.5 L ha−1 [desmedipham 70.5 g active ingredient (ai) ha−1 + ethomesufate 112.5 g ai ha−1 + lenacil 40.5 g ai ha−1 + phenmedipham 90 g ai ha−1], hoeing, and unweeded check. During a 2-year field trial (2019/20 and 2020/21), the 12 weed control treatments arranged in a randomized complete block design (RCBD) and replicated three times. Compared to the recommended applications (hoeing and herbicide), reduction averages of both seasons for total weeds biomass were 46.3–54.2%, 37.3–46.4%, and 23.0–34.4% due to rice straw, wheat hay, and mango leaves, respectively. Root and sugar yields of sugar beet divulged the highest values with hoeing in both seasons statistically equaling (P ≥ 0.05) rice straw and wheat hay for root yield and wheat hay for sugar yield in the first season. Except flax meal, all weeded treatments in the first season as well as mango leaves, wheat hay, peanut straw, and hoeing in the second one caused significant (P ≤ 0.05) reductions in sodium content of beet juice. Wheat hay, mango leaves, and hoeing in both seasons, in addition to rice straw, peanut straw, and herbicide in the first season, were the most efficient practices for improving sucrose % and extractable sugar %. Compared to hoeing, reductions in net return were –286.7 and –320.0 ($ ha−1) by percentage of 6.5 and 7.2, due to mulching soil by rice straw and wheat hay, respectively. Recycling the plant by-products such as wheat hay, rice straw, peanut straw, or mango leaves in the form of soil mulch could serve as safe and eco-friendly tools in weed control programs of sugar beet. The beneficial effect of mulching extended to enhance root and sugar yields with low impurities. Since the plant wastes are available in the farm, better revenues will be gained for sugar beet growers. Further investigations related to the use of plant extracts as natural herbicide should be performed to reach acceptable levels for weed control.

Multiple resistance mechanisms to penoxsulam in Echinochloa crus-galli from China

Penoxsulam is an important herbicide for the control of Echinochloa crus-galli (L.) P. Beauv. Two resistant populations 17GA (R1) and 16NXB (R2) showed 17- and 3-fold resistance to penoxsulam, respectively. A known resistance mutation of Trp-574-Leu in ALS gene and enhanced rates of penoxsulam metabolism likely involving GST contribute to penoxsulam resistance in R1 population. This population had resistance to the ALS-inhibitors pyribenzoxim and bispyribac‑sodium and the auxin herbicide quinclorac, but was susceptible to ACCase-inhibitors quizalofop-p-ethyl and cyhalofop-butyl. No known mutations in the ALS gene conferring target site resistance to ALS-inhibiting herbicides were presented in R2 population. However, penoxsulam metabolism in R2 plants was about 4-fold greater than in susceptible population 14YC (S0) plants. The enzyme inhibitors piperonyl butoxide, malathion and 4-chloro-7-nitrobenzoxadiazole reversed penoxsulam resistance in this population. GST and P450 enzyme activities and the genes of GST1–1, GST1–2, GST1–3, CYP81A18, CYP81A12, CYP81A21 were increased significantly in R2 population. These results indicate that multiple resistance mechanisms had occurred in E. crus-galli populations in central China and resistance needs to be managed effectively by diverse chemical and non-chemical methods.

Use of Secondary Metabolites of Wood-Decaying Fungi to Reduce Damping off Disease

Phytopathogenic fungi can cause plant diseases that are difficult to control, including mass mortality of some tree species. The Fusarium oxysporum complex (sensu lato) is one of the most dangerous groups of phytopathogenic fungi, causing the death of conifer species, including Pinus sylvestris seedlings in forest and ornamental nurseries. Recently, non-chemical methods of plant protection have become the basis of integrated pest management (IPM) in the European Union (EC Directive). The possibility of protection of pine seedlings against the pathogen F. oxysporum using active substances from wood-destroying fungi commonly found in forests was examined. Methanolic extracts of Fomitopsis pinicola, Ganoderma applanatum, and Trametes versicolor were found to contain substances effective in both prevention and treatment of infected seedlings. G. applanatum and T. versicolor showed particular biological activity in increasing plant resistance. Efficacy, especially of the extract of F. pinicola, increased with concentration. Further field trials are needed to confirm the results obtained in laboratory tests on plant protection.

A Review of Crop Protection Methods against the Twospotted Spider Mite—Tetranychus urticae Koch (Acari: Tetranychidae)—With Special Reference to Alternative Methods

Tetranychus urticae is one of the most important pests of many species of economically important crops, cultivated both under cover and in open ground. Feeding T. urticae reduces the size and quality of the yield. Nowadays, in connection with the popularization of organic farming and the green order policy, non-chemical methods that provide an effective reduction in the harmfulness of this spider mite are sought. The aim of the study is to present the current state of knowledge on methods of reducing the undesirable effects of T. urticae feeding. The paper discusses the main directions of searching for biopesticides against T. urticae and provides a list of natural components on which commercially available products are based. The aspect of using the natural properties of plants, micro- and macro-organisms is presented. The paper also deals with the issue of the spread of spider mites in connection with the observed climate changes.

Endophytic Yeasts for the Biocontrol of Phlyctema vagabunda in Apples

Bull’s-eye rot, produced by Phlyctema vagabunda, is an important postharvest disease in apples. Current measures to control infection include synthetic fungicides, in addition to the application of copper hydroxide and potassium phosphite. However, growing public concern regarding fungicide residues in food has generated interest in developing non-chemical alternative control methods; biological control is one of the most promising alternatives. In this research, native endophytic yeasts were isolated and evaluated for the biocontrol of P. vagabunda in apples. The mechanisms of action involved were also determined. Our research found 2 isolates, Vishniacozyma victoriae EPL4.5 and EPL29.5, which exhibited biocontrol activity against P. vagabunda at 20 °C in apples, the incidence of bull’s-eye rot was reduced by 39% and 61%, respectively, and the severity of the disease was decreased by 67% and 70%, respectively, when apples were inoculated with these yeasts 24 h before applying the pathogen. The main mechanisms that could be involved in the observed biocontrol activity are the ability to form biofilms and the production of volatile organic compounds.

Comprehensive comparison of treatments for controlling the large pine weevil (Hylobius abietis) in Central Europe

Adults of the large pine weevil (Hylobius abietis) cause serious damage to coniferous seedlings and are among the most important forest pests in Europe. Seedling protection by chemicals is gradually being restricted or banned for environmental reasons, and non-chemical alternatives are therefore needed. In this 3-year study, we compared the following five treatments for protecting Norway spruce seedlings against H. abietis in the Central European mountains where the weevil is especially abundant: alpha-cypermethrin sprays (the only chemical treatment); coating with sprayed glue (Vermifix); wax coating with C and F types (Norsk Wax); and physical protection with collars. The same block design was set up at a clear-cut site and at a nursery site to compare seedling mortality and wax quality under “wild conditions” with pests and under “ideal conditions” without pests. Repeated application of alpha-cypermethrin was the most effective and least expensive method to protect seedlings against H. abietis. Among the four non-chemical methods, repeated application of glue was the most effective. Because collars were moderately effective but not cost-effective, we do not recommend the use of collars. Wax was inexpensive and environmentally safe but protected seedlings for only 1 year; the newer F type of wax performed better than the C type of wax, and perhaps the F type can be improved. In general we found that seedlings at sites with high numbers of H. abietis require protection for at least 3 years. We conclude by providing an overview of all methods currently available for managing H. abietis in forests.

Inhibition of the spread of Sclerotinia sclerotiorum in aquaponics

Sclerotinia sclerotiorum, which causes white mold, is a widespread pathogen. In 2020, a new host plant of this fungus, the watercress (Nasturtium officinale) was identified in Hungary in an aquaponic system. During the cultivation of watercress S. sclerotiorum was detected on the plant, the fungus caused a 30% yield loss. Fungicides should not be used against fungi in aquaponic systems. Non-chemical methods of integrated pest management should be used. These include biological control (resistant species, predators, pathogens, antagonist microorganisms), manipulation of physical barriers, traps, and the physical environment. In the aquaponic system, the removal of the growing medium (expanded clay aggregate pellets) solved the damage of Sclerotinia sclerotiorum 100%. By removing the expanded clay aggregate pellets, the environmental conditions became unfavorable for the development and further spread of the S. sclerotium fungus.

Peer review of the pesticide risk assessment of the active substance triflusulfuron-methyl.

The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, France, and co‐rapporteur Member State, Denmark, for the pesticide active substance triflusulfuron‐methyl are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of triflusulfuron‐methyl as a herbicide on sugar beet, fodder beet, red beet, chicory and witloof (field uses). The peer review also provided considerations on whether exposure to humans and the environment from the representative uses of triflusulfuron‐methyl can be considered negligible, taking into account the European Commission’s draft guidance on this topic. The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified. An evaluation of data concerning the necessity of triflusulfuron‐methyl as herbicide to control a serious danger to plant health which cannot be contained by other available means, including non‐chemical methods is also presented.

​Effect of Legume and Cereal Mulches on Weed Dynamics and Potato Yield

Background: Non-chemical management methods, including cover crops, has an essential role in diminishing weed infestations and reducing the use of herbicides. Methods: To evaluate the suppressive effects of four cover crop options on weed populations, a field experiment was conducted in factorial randomized bock design with three replications at Ardabil Agricultural and Natural Resources Research Station, Ardabil, Iran, in 2016. The treatments consisted of legumes and cereal cover crop as one factor (Control, Rye, Common vetch, Grass pea and Hungarian vetch) and crop management strategies as a second factor [forage use (FU) and land cover use (LCU)]. Result: Grass pea sown as fodder use strategy recorded the highest fresh and dry weight of weeds significantly. The greatest potato yield production was observed in Rye and Hungarian vetch plots, approximately 5000 kg ha-1 in both FU and land LCU strategies. Generally, it seems that Rye and Hungarian vetch could be acceptable options to use in potato production as cover crops.

Reduction in use of herbicides by combining aqueous extract of grass pea for weed management and yield of wheat

Nowadays, the increasing costs in the agricultural sector, increasing public concern about the widespread use of herbicides and the development non-chemical methods of weed control programs are alerting management. In this regard, an experiment was conducted to evaluate the effect of aqueous extract of grass pea residues on weed management and crop performance of wheat. The experiment was comprised of three varieties of wheat viz., BARI Gom-30, BARI Gom-31, BARI Gom-32 and six different levels of treatments such as no weeding, recommended dose of herbicide, aqueous extraction of grass pea, 90% recommended dose + aqueous extraction of grass pea,80% recommended dose + aqueous extraction of grass pea, 70% recommended dose +aqueous extraction of grass pea, 60% recommended dose + aqueous extraction of grass pea. The experiment was laid out in a randomized complete block design with three replications. Weed population, weed dry weight and weed control efficacy were significantly influenced by aqueous extract of grass pea crop residues and varieties. The highest numbers of tillers hill-1, numbers of grains spike-1, 1000 grain weight and grain yield were observed where recommended dose of herbicide was used followed by the application of 90% recommended dose +aqueous extraction of grass pea. BARI Gom-31along with 90% recommended dose +aqueous extraction of grass pea produced the highest grain and straw yield among the treatment combination. Therefore, aqueous extract of grass pea crop residues might be used as an alternative way for weed management in effective and sustainable crop production.

Drug and pesticide usage for sea lice treatment in salmon aquaculture sites in a Canadian province from 2016 to 2019

We used 4 years of publicly available data (2016–2019) on chemical usage at salmon sites with information on production, stocking, locations and environmental conditions to explore patterns of anti-sea lice treatments in a Canadian province. Results show that sequential chemical treatments are prevalent, emamectin benzoate (EMB) with azamethiphos being the most used combination with a decrease in ivermectin usage. Relatively high rates of usage of EMB per fish biomass may point to potential lice resistance patterns with information needed on mechanisms and local populations. Lower or no chemical usage at some sites indicate less sea lice infestations likely influenced by localized site conditions (coves), and a lessened need for medication due to the usage of cleaner fish and possibly other non-chemical methods (not documented in this report). The year/climate influenced chemical input only in sites with higher treatment levels likely due to effects on sea lice growth and reproduction. Observed differences between years are warmer surface temperature in the fall, a higher freshwater input in spring, and stronger wind conditions for 2017 and 2018 with more medication usage for these two years. The lack of significant effect of site distances calculated in zones of influence based on 24 h potential connectivity patterns highlight the need to refine the resolution of hydrodynamic processes.

Target-site cross-resistance to ALS inhibitors in johnsongrass originating from Greek cornfields

AbstractFive johnsongrass populations collected from corn grown in northern Greece were studied to elucidate the levels and mechanisms of resistance to acetolactate synthase (ALS)- and acetyl-CoA carboxylase (ACCase)-inhibiting herbicides. Whole-plant response assays indicated that two populations were highly cross-resistant to all ALS inhibitors tested (foramsulfuron, nicosulfuron, rimsulfuron, and imazamox) but were effectively controlled by the recommended rate of the ACCase-inhibiting herbicides propaquizafop and clethodim. TheALSgene sequence revealed a point mutation that resulted in the substitution of Trp574 by Leu in the ALS enzyme, suggesting that the resistance mechanism is target-site mediated. These findings highlight a serious threat against the sustainable use of the ALS-inhibiting herbicides in controlling johnsongrass and other grass weeds in cornfields, suggesting rotational use of herbicides with different modes of action, along with the use of nonchemical methods, for viable Johnsongrass management.

Exploitation of the Antibacterial Properties of Photoactivated Curcumin as 'Green' Tool for Food Preservation.

In the search for non-chemical and green methods to counteract the bacterial contamination of foods, the use of natural substances with antimicrobial properties and light irradiation at proper light waves has been extensively investigated. In particular, the combination of both techniques, called photodynamic inactivation (PDI), is based on the fact that some natural substances act as photosensitizers, i.e., produce bioactive effects under irradiation. Notably, curcumin is a potent natural antibacterial and effective photosensitizer that is able to induce photodynamic activation in the visible light range (specifically for blue light). Some practical applications have been investigated with particular reference to food preservation from bacterial contaminants.

A Review of Chemical Weed Control Practices in Christmas Tree Production in the United States

Christmas trees are sensitive to weed competition, especially during establishment. In initial stages of the tree crop, weeds can utilize available soil moisture and trees may succumb to drought stress. In later stages, weeds can even interfere with production practices. Non-chemical weed control methods alone may not provide effective weed control. Chemical weed management strategies involve the use of preemergence and postemergence herbicides at the right timing and application rates. There are many herbicides that are used in Christmas tree production in the United States, and each has specific application guidelines and weed control spectra. Moreover, crop trees vary in tolerance by species and tree age. Growers need to be careful while applying herbicides as many of these chemicals can cause injury to Christmas trees. Repeated application of herbicides with the same mechanism of action has resulted in development of herbicide resistance among several weed species. Managing herbicide resistance has now become an important issue. More research is required on identifying and managing herbicide resistance among weed species in Christmas tree production. Future research needs to focus on herbicide and mulch combinations, herbicide rotations, and tank mixing different herbicides with different mechanisms of actions and how these affect Christmas tree varieties.

Knowledge of eggplant farmers on the proper use of pesticides in Khartoum State, Sudan

The knowledge of eggplant farmers on the proper use of pesticides was evaluated in Khartoum State. Questionnaire was distributed to farmers in North Nile Farms (NN), East Nile Farms (ENF), and West Nile Farms (WNF) to solicit information. Interviews and questionnaires revealed that there is a limited level of awareness among farmers. The majority (94%) of farmers did not abide by recommended disposal procedures, they only damage and bury the containers inside the farms. The majority of farmers (66%) were not aware of the safety period for any given product. The excessive use of pesticides in eggplant production and reliance only on pesticides as a pest management strategy calls for the implementation of IPM programs integrating the use of environmentally soft chemicals with other non-chemical control methods to manage pests and diseases. Safety periods should be carefully watched to reduce the level of residues in eggplant fruits below the acceptable level and to ensure sustainable and safe production.

Flooding depths and burial effects on seedling emergence of five California weedy rice (Oryza sativa spontanea) accessions

AbstractWeedy rice (Oryza sativa f. spontanea Roshev.) has recently become a significant botanical pest in California rice (Oryza sativa L.) production systems. The conspecificity of this pest with cultivated rice negates the use of selective herbicides, rendering the development of nonchemical methods a necessary component of creating management strategies for this weed. Experiments were conducted to determine the emergence and early growth responses of O. sativa spontanea to flooding soil and burial conditions. Treatment combinations of four flooding depths (0, 5, 10, and 15 cm) and four burial depths (1.3, 2.5, 5, and 10 cm) were applied to test the emergence of five O. sativa spontanea accessions as well as ‘M-206’, a commonly used rice cultivar in California, for comparison. Results revealed that burial depth had a significant effect on seedling emergence. A 43% to 91% decrease in emergence between seedlings buried at 1.3 and 2.5 cm depending on the flooding depth and accession and an absence of emergence from seedlings buried at or below 5 cm were observed. Flooding depth did not affect emergence, but there was a significant interaction between burial and flooding treatments. There was no significant difference between total O. sativa spontanea emergence from the soil and water surfaces regardless of burial or flooding depths, implying that once the various accessions have emerged from the soil they will also emerge from the floodwater. Most accessions had similar total emergence compared with M-206 cultivated rice but produced more dry weight than M-206 when planted at 1.3 cm in the soil. The results of this experiment can be used to inform stakeholders of the flooding conditions necessary as well as soil burial depths that will promote or inhibit the emergence of California O. sativa spontanea accessions from the weed seedbank.