scholarly journals Burial Environment Drives Seed Mortality of Kochia (Bassia scoparia), Wild Oat (Avena fatua), and Volunteer Canola (Brassica napus) Irrespective of Crop Species

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1961
Author(s):  
Charles M. Geddes
Keyword(s):  
Brassica Napus ◽  
Avena Fatua ◽  
Wild Oat ◽  
Population Demography ◽  
Weed Seed ◽  
Brassica Napus L ◽  
Crop Species ◽  
Seed Survival ◽  
Weed Population ◽  
Seed Mortality

Models of weed population demography are critical to understanding the long-term viability of management strategies. The driving factors of weed seedbank persistence are often underrepresented in demographic models due to the cumbersome nature of seedbank research. Simplification of weed seedbank dynamics may induce substantial error in model simulations. A soil bioassay was conducted to determine whether growth of different crop species, including wheat (Triticum aestivum L.), canola (Brassica napus L.), and field pea (Pisum sativum L.), differentially impact seed mortality of kochia [Bassia scoparia (L.) A.J. Scott], wild oat (Avena fatua L.), and volunteer canola in seven burial environments in western Canada. Weed seed survival after the 7 week burial period varied widely among burial environments (from 8% to 88% when averaged among weed and crop species), whereas growth of the different crop species had negligible impact on seedbank persistence. Among environments, wild oat seed survived the greatest (79%), followed by kochia (20%), and volunteer canola (6%). Weed seed survival was associated with soil physical properties (texture) and seed microsite characteristics (temperature), but not crop species or soil chemical properties. Overall, these data support the need for greater integration of soil and environmental parameters into models of weed population demography.

Influence of chaff and chaff lines on weed seed survival and seedling emergence in Australian cropping systems

2020 ◽  
pp. 1-22
Author(s):  
Michael J. Walsh ◽  
Annie E. Rayner ◽  
Annie Rutledge ◽  
John C. Broster
Keyword(s):  
Cropping Systems ◽  
Seedling Emergence ◽  
Field Studies ◽  
Wild Oat ◽  
Weed Seed ◽  
Weed Species ◽  
Environment Effect ◽  
Seed Survival ◽  
Cropping Seasons ◽  
Rigid Ryegrass

Abstract Chaff lining and chaff tramlining are harvest weed seed control (HWSC) systems that involve the concentration of weed seed containing chaff material into narrow (20 to 30 cm) rows between or on the harvester wheel tracks during harvest. These lines of chaff are left intact in the fields through subsequent cropping seasons in the assumption that the chaff environment is unfavourable for weed seed survival. The chaff row environment effect on weed seed survival was examined in field studies, while chaff response studies determined the influence of increasing amounts of chaff on weed seedling emergence. The objectives of these studies were to determine 1) the influence of chaff lines on the summer-autumn seed survival of selected weed species; and 2) the influence of chaff type and amount on rigid ryegrass seedling emergence. There was frequently no difference (P>0.05) in survival of seed of four weed species (rigid ryegrass, wild oat, annual sowthistle and turnip weed) when these seed were placed beneath or beside chaff lines. There was one instance where wild oat seed survival was increased (P<0.05) when seed were placed beneath compared to beside a chaff line. The pot studies determined that increasing amounts of chaff consistently resulted in decreasing numbers of rigid ryegrass seedlings emerging through chaff material. The suppression of emergence broadly followed a linear relationship where there was approximately a 2.0% reduction in emergence with every 1.0 t ha-1 increase in chaff material. This relationship was consistent across wheat, barley, canola and lupin chaff types, indicating that the physical presence of the chaff was more important than chaff type. These studies indicated that chaff lines may not affect the over summer-autumn survival of the contained weed seeds but the subsequent emergence of weed seedlings will be restricted by high amounts of chaff (>40 t ha-1).

Site-specific wild oat (Avena fatua L.) management

2012 ◽  
Vol 92 (5) ◽  
pp. 923-931 ◽  
Author(s):  
H. J. Beckie ◽  
S. Shirriff
Keyword(s):  
Specific Treatment ◽  
Triticum Aestivum L ◽  
Avena Fatua ◽  
Slope Position ◽  
Wild Oat ◽  
Herbicide Application ◽  
Brassica Napus L ◽  
Site Specific ◽  
Lower Slope ◽  
Upper Slope

Beckie, H. J. and Shirriff, S. 2012. Site-specific wild oat ( Avena fatua L.) management. Can. J. Plant Sci. 92: 923–931. Variation in soil properties, such as soil moisture, across a hummocky landscape may influence wild oat emergence and growth. To evaluate wild oat emergence, growth, and management according to landscape position, a study was conducted from 2006 to 2010 in a hummocky field in the semiarid Moist Mixed Grassland ecoregion of Saskatchewan. The hypothesis tested was that wild oat emergence and growth would be greater in lower than upper slope positions under normal or dry early growing season conditions. Three herbicide treatments were imposed on the same plots each year of a 2-yr canola (Brassica napus L.) – wheat (Triticum aestivum L.) sequence: (1) nontreated (weedy) control; (2) herbicide application to upper and lower slope positions (i.e., full or blanket application); and (3) herbicide application to lower slope position only. Slope position affected crop and weed densities before in-crop herbicide application in years with dry spring growing conditions. Site-specific wild oat herbicide application in hummocky fields in semiarid regions may be justified based on results of wild oat control averaged across slope position. In year 2 of the crop sequence (wheat), overall (i.e., lower and upper slope) wild oat control based on density, biomass, and dockage (i.e., seed return) was similar between site-specific and full herbicide treatment in 2 of 3 yr. Because economic thresholds have not been widely adopted by growers in managing wild oat, site-specific treatment in years when conditions warrant may be an appropriate compromise between no application and blanket herbicide application.

scholarly journals Genetic Diversity in Commercial Rapeseed (Brassica napus L.) Varieties from Turkey as Revealed by RAPD

2013 ◽  
Vol 5 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Özlem ÖZBEK ◽  
Betül Uçar GIDIK
Keyword(s):  
Genetic Diversity ◽  
Brassica Napus ◽  
Dna Analysis ◽  
Diversity Index ◽  
Principal Component ◽  
Brassica Napus L ◽  
Binary Matrix ◽  
Crop Species ◽  
Commercial Crop ◽  
The Mean

In cultivated commercial crop species, genetic diversity tends to decrease because of the extensive breeding processes. Therefore, germplasm of commercial crop species, such as Brassica napus L. should be evaluated and the genotypes, which have higher genetic diversity index, should be addressed as potential parental cross materials in breeding programs. In this study, the genetic diversity was analysed by using randomly amplified polymorphic DNA analysis (RAPD) technique in nine Turkish commercial rapeseed varieties. The RAPD primers (10-mer oligonucleotides) produced 51 scorable loci, 31 loci of which were polymorphic (60.78%) and 20 loci (39.22%) were monomorphic The RAPD bands were scored as binary matrix data and were analysed using POPGENE version 1.32. At locus level, the values of genetic diversity within population (Hs) and total (HT) were 0.15 and 0.19 respectively. The genetic differentiation (GST) and the gene flow (Nm) values between the populations were 0.20 and 2.05 respectively. The mean number of alleles (na), the mean number of effective alleles (nae), and the mean value of genetic diversity (He) were 2.00, 1.26, and 0.19 respectively. According to Pearson’s correlation, multiple regression and principal component analyses, eco-geographical conditions in combination had significant effect on genetic indices of commercial B. napus L. varieties were discussed.

Influence of tillage, vertical seed distribution, and pyroxasulfone application timing and rate on control of wild oat (Avena fatua L.)

2018 ◽  
Vol 98 (3) ◽  
pp. 601-608 ◽  
Author(s):  
Amy R. Mangin ◽  
Linda M. Hall ◽  
Jeff J. Schoenau ◽  
Hugh J. Beckie
Keyword(s):  
Avena Fatua ◽  
Vertical Position ◽  
Wild Oat ◽  
Weed Seed ◽  
Application Timing ◽  
Herbicide Resistant ◽  
Oat Seeds ◽  
Tillage System ◽  
Seed Distribution ◽  
Oat Biomass

Tillage and new herbicide options may be necessary for the control of herbicide-resistant wild oat. The efficacy of soil-applied herbicides such as pyroxasulfone can be influenced by edaphic factors and weed seed recruitment depth, which varies with tillage system. We investigated the effect of tillage and pyroxasulfone rate when applied in the fall and spring on wild oat biomass at three locations in Alberta in 2014–2015. The vertical position of wild oat seeds, with and without tillage, was examined at each site. Wild oat biomass was greater in untilled plots compared with plots with fall tillage at all locations. In two out of three locations, pyroxasulfone efficacy was superior when applied in the fall compared with spring, possibly influenced by low spring rainfall. A single tillage pass at the Edmonton and Kinsella locations did not affect wild oat seed distribution, but there was an increase in seeds present in the surface layer in the untilled treatment at Lacombe. Tillage, used in combination with soil-applied herbicides, may be an option to achieve acceptable control of herbicide-resistant wild oat.

Comparison of the crop species Brassica napus and wild B. rapa: characteristics relevant for building up a persistent seed bank in the soil

2013 ◽  
Vol 23 (3) ◽  
pp. 169-179 ◽  
Author(s):  
Tom J. de Jong ◽  
Maria Tudela Isanta ◽  
Elze Hesse
Keyword(s):  
Brassica Napus ◽  
Seed Bank ◽  
Low Temperatures ◽  
Crop Species ◽  
Seed Survival ◽  
Primary Dormancy ◽  
Aliphatic Glucosinolates ◽  
Seed Characters ◽  
Persistent Seed Bank ◽  
Important Character

AbstractCan seed characters be used for predicting the presence of a persistent seed bank in the field? We address this question using ten cultivars of the crop Brassica napus, ten feral B. napus accessions originating from seeds collected in the field and nine accessions of the closely related ruderal species Brassica rapa. When buried for a year in the field, seeds of the wild B. rapa displayed, as expected, much higher survival fractions than those of domesticated B. napus at two different locations in The Netherlands. Compared to B. napus, B. rapa produces relatively small seeds with high levels of aliphatic glucosinolates and a thick seed coat. However, within each species none of these characters correlated with seed survival in the soil. At low temperatures, B. rapa seeds had lower and more variable germination fractions than those of B. napus; a small fraction (4.6%) of the B. rapa seeds showed primary dormancy. Rather surprisingly, B. napus displayed genetic differences in germination at low temperature, and germination fractions at 5°C correlated negatively with seed survival in the soil. Our comparisons between and within the two species suggest that foregoing germination at low temperatures is an important character for developing a persistent seed bank. We discuss our results in light of environmental risk assessment of genetically modified B. napus.

Functionally diverse flax-based rotations improve wild oat (Avena fatua) and cleavers (Galium spurium) management

Weed Science ◽  
2022 ◽  
pp. 1-37
Author(s):  
Dilshan Benaragama ◽  
William E. May ◽  
Robert H. Gulden ◽  
Christian J. Willenborg
Keyword(s):  
Crop Rotation ◽  
Life Cycles ◽  
Avena Fatua ◽  
Crop Rotations ◽  
Cereal Crops ◽  
Western Canada ◽  
Wild Oat ◽  
Crop Species ◽  
Winter Cereal ◽  
Galium Spurium

Abstract Wild oat (Avena fatua L.) and false cleavers (Galium spurium) are currently a challenge to manage in less competitive crops such as flax (Linum usitatissimum L.). Increasing the functional diversity in crop rotations can be an option to improve weed management. Nonetheless, this strategy is not tested in flax in Western Canada. A 5-yr (2015-2019) crop rotation study was carried at three locations in western Canada to determine the effect of diverse flax-based crop rotations with differences in crop species, crop life cycles, harvesting time and reduced herbicides on managing A. fatua and G. spurium. The perennial rotation (flax-alfalfa (Medicago sativa L.)-alfalfa-alfalfa-flax) under reduced herbicide use was found to be the most consistent cropping system, providing similar A. fatua and G. spurium control to the conventional annual flax crop rotation[flax-barley (Hordium vulgare L.)-flax-oat (Avena sativa L.)-flax] with standard herbicides. At Carman, this alfalfa rotation provided even better weed control (80% A. fatua, 75% G. spurium) than the conventional rotation. Furthermore, a greater A. fatua control was identified compared to conventional rotation where two consecutive winter cereal crops were grown successfully in rotation (flax-barley-winter triticale (x Triticosecale ex A. Camus)-winter wheat (Triticum aestivum L.)-flax), greater A. fatua control was observed compared to the conventional crop rotation under standard herbicides. Incorporation of silage oat crops did not show consistent management benefits compared to the perennial alfalfa rotation but were generally similar to the conventional rotation with standard herbicides. The results showed that perennial alfalfa in the rotation minimized G. spurium and A. fatua in flax cropping systems, followed by rotations with two consecutive winter cereal crops.

Response of wild oat (Avena fatua) to residual and non-residual herbicides in canola (Brassica napus) in western Canada

2002 ◽  
Vol 82 (4) ◽  
pp. 797-802 ◽  
Author(s):  
H. J. Beckie ◽  
F. A. Holm
Keyword(s):  
Brassica Napus ◽  
Selection Pressure ◽  
Residual Activity ◽  
Triticum Aestivum L ◽  
Avena Fatua ◽  
Western Canada ◽  
Wild Oat ◽  
Response Curves ◽  
Rate Interaction ◽  
Residual Herbicide

It has been stated that soil residual herbicides, by controlling successive flushes of weeds, increase effective kill (efficacy) over the growing season, and thus impose a higher selection pressure for resistance in weeds than non-residual herbicides. To investigate this issue, the responses of wild oat to increasing rates of residual and non-residual herbicides in canola and wild oat recruitment in the following year were examined in a field study conducted in Saskatchewan, Canada, from 1997 to 2000. The rate-response curves of the wild oat variables indicated that efficacy of the soil residual herbicides, ethalfluralin and triallate, and of the non-residual herbicide, glufosinate, was generally lower than that of imazamox/imazethapyr (residual), sethoxydim, and glyphosate (non-residual). Emergence of wild oat in spring wheat (Triticum aestivum L.) grown in the following year did not differ among herbicides applied in the preceding crop year, nor was there a significant herbicide by rate interaction. The results suggest that the soil residual activity o f these herbicides does not strongly influence selection pressure, estimated by reduction in wild oat seed return in canola. Key words: Brassica napus, Avena fatua, selection pressure, herbicide resistance

Competitive ability of hybrid and open-pollinated canola (Brassica napus) with wild oat (Avena fatua)

2002 ◽  
Vol 82 (2) ◽  
pp. 473-480 ◽  
Author(s):  
E. Zand ◽  
H. J. Beckie
Keyword(s):  
Brassica Napus ◽  
Weed Management ◽  
Plant Density ◽  
Management Program ◽  
Avena Fatua ◽  
Integrated Weed Management ◽  
Wild Oat ◽  
Replacement Series ◽  
Weed Interference ◽  
High Plant Density

The competitiveness of three hybrid and three open-pollinated canola cultivars against two wild oat populations was determined under controlled environment conditions at two plant densities and five canola:wild oat ratios (100:0, 75:25, 50:50, 25:75, 0:100). Analysis of replacement series and derivation of relative crowding coefficients (RCC), based on shoot dry weight or leaf area, indicated that hybrid canola cultivars were twice as competitive than open-pollinated cultivars when weed interference was relatively high (i.e., high plant density and vigorous wild oat growth). Little difference in competitiveness among cultivar types was apparent when weed interference was lower. The results of this study suggest that hybrid canola cultivars may be best suited for use in an integrated weed management program, particularly for farmers of organic or low input cropping systems. Key words: Hybrid canola, Brassica napus, Avena fatua, replacement series, competition

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