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Prevalence of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet & Magne; referred to as A. sterilis hereafter], winter-season weeds, is increasing in the eastern grain region of Australia. Biological attributes of these weeds enable them to survive in a wide range of environments and under different weed infestation levels. The interference of A. fatua and A. sterilis in a wheat (Triticum aestivum L.) crop was examined in southeast Queensland, Australia, through field studies in 2019 and 2020. Different infestation levels (0, 3, 6, 12, 24, and 48 plants m−2) of A. fatua and A. sterilis were evaluated for their potential to cause yield losses in wheat. Based on a three-parameter logarithmic model, the A. fatua and A. sterilis infestation levels corresponding to 50% wheat yield loss were 15 and 16 plants m−2, respectively. The yield reduction was due to a reduced spike number per unit area because of an increased weed infestation level. At the highest weed infestation level (48 plants m−2), A. fatua and A. sterilis produced a maximum of 4,800 and 3,970 seeds m−2, respectively. Avena fatua exhibited lower seed retention (17% to 39%) than A. sterilis (64% to 80%) at wheat harvest, as most of the seeds of A. fatua had shattered at crop maturity. Our results implied that there is a good opportunity for harvest weed seed control if the paddock is infested with A. sterilis. This study suggests that in the absence of an integrated weed management strategy (using both chemical and nonchemical options), a high infestation of these weeds could cause a severe crop yield loss, increase weed seed production, and replenish the weed seedbank in the soil.

Optimum herbicide use is a key factor affecting the success of any integrated weed management strategy. The main objective of the current study was to implement a method based on spectrometer measurements for the in situ evaluation of herbicide efficacy and the detection of potentially herbicide-resistant weeds. Field trials were conducted in Greece between 2018 and 2020 in several durum wheat fields (Triticum durum Desf.). In all trials, the overall effect of herbicide application on the recorded Normalized Difference Vegetation Index (NDVI) values (at 1 and 2 wk after treatment [WAT]) was significant (P ≤ 0.001). For the majority of the surveyed fields, low NDVI values were recorded after 2,4-D application and a mixture of clopyralid + florasulam from 1 WAT, suggesting their increased efficacy. In several cases, the application of pyroxsulam + florasulam resulted in significant NDVI reductions at 2 WAT. As observed at the end of the growing seasons, the herbicides that reduced NDVI resulted in lower weed biomass. Strong correlations were observed between weed aboveground biomass and NDVI (2 WAT). In particular, R2 values were 0.8234 to 0.8649, 0.8453, 0.8595, 0.8149, and 0.8925 for the Aliartos, Thiva, Domokos, Larissa, and Orestiada fields, respectively. The overall effects of herbicide application on wheat grain yield were also significant (P ≤ 0.001). Pot experiments confirmed that the high NDVI values in some cases could be attributed to the presence of herbicide-resistant weeds. For instance, the resistance indices of two accessions of catchweed bedstraw (Galium aparine L.) to mesosulfuron-methyl + iodosulfuron-methyl-sodium ranged between 9.7 and 13.2, whereas one sterile oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet & Magne] accession was 8.8 times more resistant to fenoxaprop-p-ethyl than a susceptible one. The present study is targeted at making a significant contribution toward establishing cause–effect relationships and presenting a useful tool for developing more effective weed management practices in more arable crops and under different soil and climatic conditions.

The combination of herbicides with different modes of action has been adopted not only to improve weed control but also to increase the environmental sustainability of plant-protection products. In this study, we showed a synergistic effect of the auxin herbicide 2,4-D amine with the PSII-inhibiting herbicide metribuzin to control the global grass weed wild oat (Avena sterilis) population and investigated the underlying mechanisms. Pretreatment with 2,4-D amine did not change the foliar absorption of metribuzin but did increase metribuzin translocation to the roots and new leaves, although enhancement of the metribuzin metabolism was also observed. Considering that the expression level of the target site psbA gene is significantly higher in leaves than in roots, increased metribuzin translocation to new leaves is likely the major cause of the observed synergism, even though enhanced metribuzin metabolism may offset the metribuzin efficacy. This is the first report on the synergistic mechanism between 2,4-D amine and metribuzin in weed control.

Lentil(Lens culinaris Medic.) is an important source of protein for humansbeing, forage for animals and nitrogen for soil. Explorator survey wasconducted during the lentil vegetation period of 2018 in Siirt province. Atotal 40 lentil fields were randomly surveyed and the incidence and densitiesof observed weed species were determined at each surveyed point. A total 101weed species belonging to 29 families (2 parasitic, 3 monocotyledoneae and 25dicotyledoneae) were identified during the survey. The most frequently observedweed species were; Sinapis arvensis L. (97.5%), Vicia sativa L. (75%), Papaver rhoeas L. (75%), Avena sterilis subsp. ludoviciana(72.5%), Vaccaria pyramidata Medik (62.5%), Silene conica L. (55%), Vicia narbonensis L. (57.5%) and Silybum marianum (L.) Gaertner (52.5%).Therefore, it is recommended that weed management should be done in lentilproduction areas based on the weed species and their densities in the area., Mercimek(Lens culinaris Medic.) insanlar içinbitkisel protein, hayvanlar için yem, toprak için ise önemli bir azotkaynağıdır. Yabancı otlar mercimek tarımını sınırlandıran unsurların başındagelmektedir. Bu çalışmada, Siirt ili mercimek ekili alanlarda, 2018 yılıvejetasyon döneminde sürvey çalışmaları gerçekleştirilmiştir. Araştırma alanınıtemsil edecek şekilde rastgele toplam 40 mercimek tarlasında örneklemeyapılmıştır. Her örnekleme noktasında yabancı otların tür, rastlanma sıklığı veyoğunlukları belirlenmiştir. Sürvey sonucunda 2’si parazit, 3’ümonocotyledoneae (tek çenekli), 24’ü de dicotyledoneae (çift çenekli) olmak üzere toplam 29 familyaya ait 101yabancı ot türü tespit edilmiştir. İncelenen tarlalarda rastlanma sıklığınagöre en yaygın türlerin; Sinapis arvensis L. (%97.5), Vicia sativa L. (%75), Papaver rhoeas L. (%75), Avena sterilis subsp. ludoviciana (%72.5), Vaccariapyramidata Medik (%62.5), Silene conica L. (%55), Vicia narbonensis L. (%57.5) ve (Silybummarianum (L.) Gaertner (%52.5) olduğu tespit edilmiştir. Çalışma sonuçlarına görebölgede mercimek ekim alanlarında yabancı ot tür ve yoğunlukları dikkate alınarakmücadele yapılması önerilmiştir.

SNP loci linked to the crown rust resistance gene Pc98 were identified by linkage analysis and KASP assays were developed for marker-assisted selection in breeding programs. Crown rust is among the most damaging diseases of oat and is caused by Puccinia coronata var. avenae f. sp. avenae (Urban and Markova) (Pca). Host resistance is the preferred method to prevent crown rust epidemics. Pc98 is a race-specific, seedling crown rust resistance gene obtained from the wild oat Avena sterilis accession CAV 1979 that is effective at all growth stages of oat. Virulence to Pc98 has been very low in the Pca populations that have been tested. The objectives of this study were to develop SNP markers linked to Pc98 for use in marker-assisted selection and to locate Pc98 on the oat consensus map. The Pc98 gene was mapped using F2:3 populations developed from the crosses Pc98/Bingo and Pc98/Kasztan, where Pc98 is a single-gene line carrying Pc98. Both populations were evaluated in seedling inoculation experiments. Pc98 was mapped relative to Kompetitive Allele-Specific PCR SNP markers in both populations, placing Pc98 on the Mrg20 linkage group of the consensus map. Pc98 was bracketed by two SNP markers GMI_ES22_c3052_382_kom399 and GMI_ES14_lrc18344_662_kom398 in the Pc98/Bingo mapping population with genetic distances of 0.9 cM and 0.3 cM, respectively. Pc98 co-segregated with four SNP markers in the Pc98/Kasztan population, and the closest flanking markers were GMI_DS_LB_6017_kom367 and avgbs2_153634.1.59_kom410 with genetic distances of 0.7 cM and 0.3 cM, respectively. Two SNP loci defined a haplotype that accurately predicted Pc98 status in a diverse group of oat germplasm, which will be valuable for marker-assisted selection of Pc98 in breeding of new oat cultivars.

Yabancı otlar, kültür bitkileriyle bitki besin maddeleri, ışık, su ve yer için rekabet ederek ürün kayıplarına sebep olmaktadırlar. Yabani yulaf (Avena sterilis L.) tahıllarda yüksek oranda verim kaybına yol açan bir yabancı ottur. Organik tarımın önem kazanmasıyla yabancı otlarla biyolojik mücadele artmıştır. Bu çalışmada, kontrollü koşullarda yetiştirilen A. sterilis fidelerine, bir karayosunu türü olan Plagiomnium undulatum ekstraktları uygulanmıştır. Gelişen fidelerde fotosentetik pigment miktarı, prolin konsantrasyonu, toplam protein miktarı ve antioksidan enzim aktivitesi analizleri yapılmıştır. Negatif kontrollerine oranla klorofil ve protein miktarlarındaki azalmalara, prolin konsantrasyonu ve katalaz enzim aktivitesindeki artışlara ait veriler P. undulatum’un yabani yulaf üzerinde allelopatik etkiye sahip olduğunu kanıtlamakta, yapılacak ilave çalışmalarla yabancı ot kontrolünde kullanılabilecek alternatif bir yol olabileceğini düşündürmektedir.

Weeds compete with crop plants for plant nutrients, light, water and space, causing crop losses. Wild oat (Avena sterilisL.) is a weed that causes high yield loss in cereals. As organic agriculture gained importance, biological control of weeds increased. In this study, extracts of Plagiomnium undulatum, a moss species,were applied to A. sterilis seedlings grown under controlled conditions. Photosynthetic pigment amount, proline concentration, total protein amount and antioxidant enzyme activities were analyzed in developing seedlings. The data of the decrease in chlorophyll andprote in amounts, increase in proline concentration and catalase enzyme activity compared to negative controls prove that P. undulatumhas an allelopathic effect on wild oats, suggestingthat it may be an alternative way for weed controlwith additional studies.

Herbicide resistance can affect seed germination and the optimal conditions required for seed germination, which in turn may impose a fitness cost in resistant populations. Winter wild oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet and Magne] is a serious weed in cereal fields. In this study, the molecular basis of resistance to an ACCase herbicide, clodinafop-propargyl, in four A. ludoviciana biotypes was assessed. Germination differences between susceptible (S) and ACCase-resistant biotypes (WR1, WR2, WR3, WR4) and the effect of Isoleucine-1781-Leucine mutation on germination were also investigated through germination models. The results indicated that WR1 and WR4 were very highly resistant (RI &gt, 214.22) to clodinafop-propargyl-contained Isoleucine to Leucine amino acid substitution. However, Isoleucine-1781-Leucine mutation was not detected in other very highly resistant biotypes. Germination studies indicated that resistant biotypes (in particular WR1 and WR4) had higher base water potentials than the susceptible one. This shows that resistant biotypes need more soil water to initiate their germination. However, the hydrotime constant for germination was higher in resistant biotypes than in the susceptible one in most cases, showing faster germination in susceptible biotypes. ACCase-resistant biotypes containing the Isoleucine-1781-Leucine mutation had lower seed weight but used more seed reserve to produce seedlings. Hence, integrated management practices such as stale seedbed and implementing it at the right time could be used to take advantage of the differential soil water requirement and relatively late germination characteristics of ACCase-resistant biotypes.

Crown rust, caused by Puccinia coronata f. sp. avenae, is one of the most destructive fungal diseases of oat worldwide. Growing disease-resistant oat cultivars is the preferred method of preventing the spread of rust and potential epidemics. The object of the study was Pc50-5, a race-specific seedling crown rust resistant gene, highly effective at all growth stages, selected from the differential line Pc50 (Avena sterilis L. CW 486-1 × Pendek). A comparison of crown rust reaction as well as an allelism test showed the distinctiveness of Pc50-5, whereas the proportions of phenotypes in segregating populations derived from a cross with two crown rust-susceptible Polish oat cultivars, Kasztan × Pc50-5 and Bingo × Pc50-5, confirmed monogenic inheritance of the gene, indicating its usefulness in oat breeding programs. Effective gene introgression depends on reliable gene identification in the early stages of plant development, thus, the aim of the study was to develop molecular markers that are tightly linked to Pc50-5. Segregating populations of Kasztan × Pc50-5 were genotyped using DArTseq technology based on next-generation Illumina short-read sequencing. Markers associated with Pc50-5 were located on chromosome 6A of the current version of the oat reference genome (Avena sativa OT3098 v2, PepsiCo) in the region between 434,234,214 and 440,149,046 bp and subsequently converted to PCR-based SCAR (sequence-characterized amplified region) markers. Furthermore, 5426978_SCAR and 24031809_SCAR co-segregated with the Pc50-5 resistance allele and were mapped to the partial linkage group at 0.6 and 4.0 cM, respectively. The co-dominant 58163643_SCAR marker was the best diagnostic and it was located closest to Pc50-5 at 0.1 cM. The newly discovered, very strong monogenic crown rust resistance may be useful for oat improvement. DArTseq sequences converted into specific PCR markers will be a valuable tool for marker-assisted selection in breeding programs.

Wild oat (Avena sterilis) is a very common annual plant species. Successful seed dispersion support its wide distribution in Africa, Asia and Europe. The seed dispersal units are made of two elongated stiff awns that are attached to a pointy compartment containing two seeds. The awns bend and twist with changes in humidity, pushing the seeds along and into the soil. The present work reveals the material structure of the awns, and models their functionality as two-link robotic arms. Based on nano-to-micro structure analyses the bending and twisting hygroscopic movements are explained. The coordinated movements of two sister awns attached to one dispersal unit were followed. Our work shows that sister awns intersect typically twice every wetting-drying cycle. Once the awns cross each other, epidermal silica hairs are suggested to lock subsequent movements, resulting in stress accumulation. Sudden release of the interlocked awns induces jumps of the dispersal unit and changes in its movement direction. Our findings propose a new role to epidermis silica hairs and a new facet of wild oat seed dispersion. Reversible jumping mechanism in multiple-awn seed dispersal units may serve as a blueprint for reversibly jumping robotic systems. Statement of significance The seed dispersal unit of wild oats carries two elongated stiff awns covered by unidirectional silica hairs. The awns bend and twist with changes in humidity, pushing the seed capsule along and into the ground. We studied structures constructing the movement mechanism and modeled the awn as a two-link robotic arm. We show that sister awns, attached to the same seed capsule, intersect twice every drying cycle. Once the awns cross each other, the epidermal silica hairs are suggested to lock any subsequent movements, causing stress accumulation. Sudden release of the interlocked awns may cause the dispersal unit to jump and change its direction. Our findings suggest a new role to silica hairs and a new dispersal mechanism in multiple-awn seed dispersal units.

A field study was conducted to evaluate the compatibility of herbicide tank mixtures in winter wheat (Triticum aestivum L.) Sagittario cv. in 2017-2019. Weed Index (VI) and Crop Injury (CI) of three mixtures prominent was recorded with mesosulfuron-methyl plus 2.4-D ethylhexyl ester + florasulam (5.8% and 1.5%) followed by pyroxsulam + florasulam + cloquintocet-mexyl plus 2.4-D dimethylamine salt (6.3% and 1.6%), and mesosulfuron-methyl + iodosulfuron-methyl-sodium plus bromoxynil + MCPA (7.1% and 0.0%), respectively. Weed Control Efficiency (WCE) was maximum with mesosulfuron-methyl + mefenpyr-diethyl plus 2.4-D ethylhexyl ester + florasulam so, Cirsium arvense (90%) heavily damaged; Avena fatua (98%), Avena sterilis (94%), and Papaver rhoeas (96%), Sinapis arvensis (95%) very heavy damaged (severe chlorosis and/or dead leaves); Galium aparine, Phalaris brachystachys, and Ranunculus arvensis were completely killed (100%, dead). Consequently, mesosulfuron-methyl + mefenpyr-diethyl plus 2.4-D ethylhexyl ester + florasulam herbicide mixture is recommended to provide weed control efficiency and wheat production safely. The compatibility of herbicides is necessary for sustainable weed management as it leads to reduced input costs, to prevent economic losses and to less pollution of the ecological environment. In addition, the conditions may require that the herbicides be applied with fungicides, insecticides or foliar fertilizers, and growers wish to know the safety of these mixtures. Therefore, studies on the compatibility of chemicals used in agriculture were considered to be needed.

The appropriate selection of various traits in valuable plants is very important for modern plant breeding. Effective resistance to fungal diseases, such as powdery mildew, is an example of such a trait in oats. Marker-assisted selection is an important tool that reduces the time and cost of selection. The aims of the present study were the identification of dominant DArTseq markers associated with a new resistance gene, annotated as Pm11 and derived from Avena sterilis genotype CN113536, and the subsequent conversion of these markers into a PCR-based assay. Among the obtained 30,620 silicoDArT markers, 202 markers were highly associated with resistance in the analysed population. Of these, 71 were selected for potential conversion: 42 specific to resistant and 29 to susceptible individuals. Finally, 40 silicoDArT markers were suitable for primer design. From this pool, five markers, 3 for resistant and 2 for susceptible plants, were selected for product amplification in the expected groups. The developed method, based on 2 selection markers, provides certain identification of resistant and susceptible homozygotes. Also, the use of these markers allowed the determination of heterozygotes in the analysed population. Selected silicoDArT markers were also used for chromosomal localization of new resistance genes. Five out of 71 segregating silicoDArT markers for the Pm11 gene were found on the available consensus genetic map of oat. Five markers were placed on linkage groups corresponding to Mrg12 on the Avena sativa consensus map.

The bioeconomic models developed in Weed Science consider the effect of a species on the crop. Bioeconomic models accounting for species interactions within the weed community might represent more realistic approximation to the economic outcome of weed control options in Mediterranean cereal crops. A bioeconomic model, based in community dynamics, competition and economic submodels, was developed and used to investigate the long-term agronomic, economic and environmental consequences of using herbicide-based strategies for the control of winter wild oats (Avena sterilis) and rigid ryegrass (Lolium rigidum) in winter wheat. The results of simulations indicated that different winner strategies can be postulated depending on selection criterion. Based on purely economic outcome, the best strategy was the application of half-dose herbicide to both species whereas if the goal is to achieve a long-term economically viable and environmental friendly decision making, then the strategy chosen would be the one based on a full-dose herbicide application for the control of L. rigidum and half-dose for control of A. sterilis. The sensitivity of the model to variation in economic and competition parameters was checked. The most sensitive model parameters were the potential yield and the wheat price. Bioeconomic models offer practical guidance regarding the possibilities and limitations of various strategic approaches for weed control., This work has been partially funded by FEDER (European Regional Development Funds) and the Spanish Ministry of Economy and Competitiveness funds (Projects AGL2015-63130-R).

Crown rust is the most widespread and damaging disease of oat (Avena species). Genetic resistance to the pathogen is the preferred method for crop protection but widespread deployment of limited numbers of major effect genes has promoted the rapid emergence and spread of pathogen races that are able to overcome these genes. Combining genes with even partial resistance may help develop durable cultivars that are less vulnerable to changes in pathogen virulence. Partial resistance is expected to be relatively common in populations of wild species where constant pathogen pressure encourages diversity in host resistance mechanisms, but it may be discarded in conventional screens for major gene resistance. Here, we used a detached leaf assay to detect resistance to the crown rust pathogen, Puccinia coronata Cda. f. sp. avenae, in previously uncharacterized collections of the hexaploid wild oat relative A. sterilis made by the Polish National Centre for Plant Genetic Resources. Many of the accessions were collected in Morocco, the center of diversity for the Avena genus. The detached leaf assessment allowed individual plants to be challenged with multiple pathotypes and their responses compared with 34 known differentials. Broad-spectrum resistance was identified within accession PL 51855, which behaved as a single major locus on crossing to three cultivars. The locus provided resistance to over 50 rust pathotypes, a greater range than seen for any of the known host resistance (Pc) genes. Strong resistance was identified in other accessions, and heterogeneity in response within accessions was common. Several accessions show multiple partial resistance responses that may be of value for developing durable resistance in cultivars. Because the sources of resistance in all but two differential lines were collected outside of Morocco, resistance in all accessions tested here are potentially novel. This study demonstrates that diversity within A. sterilis accessions collected in Morocco could be a very valuable source of resistance to crown rust, and it provides new germplasm for use in resistance breeding programs. Detached leaf assessment provides a valuable first step in the identification of promising candidates in complex gene bank accessions.

Whole-plant response experiments in pots and field experiments over two years were conducted to study the resistance levels and chemical control options of sterile oat (Avena sterilis L.) in typica...

Molecular mapping of crown rust resistance genes is important to effectively utilize these genes and improve breeding efficiency through marker-assisted selection. Pc45 is a major race-specific crown rust resistance gene initially identified in the wild hexaploid oat Avena sterilis in the early 1970s. This gene was transferred to cultivated oat (Avena sativa) and has been used as a differential for identification of crown rust races since 1974. Previous research identified an association between virulence to Pc45 and PcKM, a crown rust resistance gene in the varieties ‘Kame’ and ‘Morton’. This study was undertaken to reveal the relationship between Pc45 and PcKM. Pc45 was studied in the crosses ‘AC Morgan’/Pc45 and ‘Kasztan’/Pc45, where Pc45 is the differential line carrying Pc45. F2 progenies and F2:3 families of both populations were inoculated with the crown rust isolate CR258 (race NTGG) and single gene segregation ratios were observed. SNP markers for PcKM were tested on these populations and linkage maps were generated. In addition, 17 newly developed SNP markers identified from genotyping-by-sequencing (GBS) data were mapped in these two populations, plus another three populations segregating for Pc45 or PcKM. Pc45 and PcKM mapped to the same location of Mrg08 (chromosome 12D) of the oat chromosome-anchored consensus map. These results strongly suggest that Pc45 and PcKM are the same resistance gene, but allelism (i.e., functionally different alleles of the same gene) or tight linkage (i.e., two tightly linked genes) cannot be ruled out based on the present data.

The purpose of this study is to determine the allelopathic effects of extracts obtained by using liquid nitrogen from the plant of Antep radish (Raphanus sa-tivus L.) and little radish (Raphanus sativus L. var. radikula) on germination and seedling growth of sterile oats. The experiments were carried out in six groups with root, stem and root stem mixed extracts of radish plants (Antep and little radish). A novel method that we developed based on the principle of liquid nitrogen crushing was used for extraction. According to this method, Antep radish and little radish plant parts were frozen with liquid nitrogen aid and then crushed to powder. These powders obtained were stored at ？20？C for nine months until the experiments were established. The aqueous solutions prepared at specific concentrations (0%, 1%, 2%, 4%, 8%, 16%) from the ob-tained radish powders were applied as 5 ml to per each petri dishes contain 10 seeds on Whatman No: 1 double layer filter paper. Experiments were carried out in six replicates for each concentration. The prepared petri dishes were kept in the incubator at 15？C for 15 days. At the end of the experimental period, the number of germination of the seeds of sterile wild oat plant was evaluated by measuring the length of seedling root and stem. As a result, as the concentra-tion of allelopathic solutions increased in all experimental groups, the number of germination and root and stem lengths of sterile wild oats decreased. Alt-hough allelopathic effects in all three experimental groups were observed in terms of germination number and seedling lengths, the most significant effects were observed in the results of Antep radish root experiments. In this experi-ment group, the inhibition rate of root and stem length of weed seeds at a con-centration of 16% were 86% and 82%, respectively, when compared to the control. In addition, the germination number was reduced by 74.36% in the seeds at the highest concentration compared to the control. As a result of the study, it was determined that samples of radish plant crushed with liquid nitro-gen were stored for a long time and showed high allelopathic effect on sterile wild oats plant.

Departamento de ​Protección Vegetal (INIA), Winter wild oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet & Magne; referred to as A. sterilis here] is one of the major weed species of the Avena genus, given its high competitive ability to infest cereal crops worldwide, with special concern in Spain. A nine-location field experiment was established across Spain where a total of 400 A. sterilis seeds per location were sowed in four replicates in autumn 2016 to monitor the emergence during two growing seasons in dryland conditions. The data were used to test the prediction ability of previously published thermal (TT) and hydrothermal time (HTT) models and to develop new models, if required. Overall, the average percentage of emergence was 30% during the first season and 21% during the second season. In both seasons, the main emergence flush occurred between November and February. According to the phenological stage, A. sterilis achieved the tillering earlier in southern sites, between November 25 and the end of December, compared with northern sites, where this stage was reached at the end of January. The newly developed model described the emergence with precision, using three cardinal temperatures to estimate the TT. The three cardinal points were established at-1.0, 5.8, and 18.0 C for base (T b), optimum (T o), and ceiling temperature (T c), while the base water potential (Ψb) was established at-0.2 MPa for the HTT estimation. This study contributes to improving prediction of the emergence of A. sterilis and provides knowledge for decision support systems (DSS) for the control of this weed., We would like to thank first the funding institutions, Cátedra Adama and the Spanish Weed Science Society (SEMh), with special mention of Cátedra Adama, which financed the article publishing charges. Also, JT acknowledges support from the Spanish Ministry of Science, Innovation and Universities (grant Ramon y Cajal RYC2018-023866-I). We also want to thank the students and the technicians that have helped with the fieldwork for this experiment in different sites, without whose help data collection would have been more difficult., 12 Pág.

Wild oat, Avena sterilis L. is a stout broad-leaved annual grass resembling cultivated oats in general appearance. In this study, we sequenced the complete chloroplast (cp) genome sequence of A. sterilis for the first time to investigate their phylogenetic relationship in the family Poaceae. The complete cp genome sequence is 135,887 bp in length with 38.5% overall GC content and exhibits a typical quadripartite structure comprising one pair of inverted repeats (21,603 bp) separated by a small single-copy region (12,575 bp) and a large single-copy region (80,106). The cp genome encodes 111 unique genes, 76 of which are protein-coding genes, four rRNA genes, 30 tRNA genes, and 18 duplicated genes in the inverted repeat region. The phylogenetic analysis indicated A. sterilis closely clustered with the cultivated oat, A. sativa L.

This review is updated from Beckie et al. (2012a) and Bajwa et al. (2017). Avena fatua and Avena sterilis are problematic grass weeds with widespread global distributions. Both species can persist in the seed bank for approximately 5 years; however, emergence timing may differ both spatially and temporally. Both species are highly selfing. Herbicidal control of A. fatua and A sterilis is primarily reliant on acetyl-CoA carboxylase and acetolactate synthase inhibitors; however, herbicide resistance has evolved in both species to these modes of action. Both species can cause significant yield losses in a number of field crops, which together with their herbicide resistance profiles, increases the importance of integrated weed management strategies and tactics.

The dead husk is a vital component of the dispersal unit whose biochemical properties can be modified following exposure to drought. This might affect seed performance and fate, soil properties and consequently plant biodiversity. We investigated the effects of extreme drought on the dispersal unit (DU) properties of winter wild oat (Avena sterilis L.) in the Mediterranean ecosystems focusing on a commonly ignored component of the DU, namely the dead floral bracts (husk). DUs were collected from a climate change experimental research station in the Judean Hills, Israel, simulating extreme drought and from two additional sites differing in the rainfall amounts. Our results showed that drought conditions significantly affected A. sterilis reproductive traits displaying reduced DUs and caryopses weights. The husk contributes profoundly to seed performance showing that germination from the intact DUs or the intact florets 1 was higher, faster and more homogenous compared to naked caryopses; no effect of drought on germination properties was observed. The husk stored hundreds of proteins that retain enzymatic activity and multiple metabolites including phytohormones. Changes in rainfall amounts affected the composition and levels of proteins and other metabolites accumulated in the husk, with a notable effect on abscisic acid (ABA). The husk of both control and drought plants released upon hydration substances that selectively inhibited other species seed germination as well as substances that promoted microbial growth. Our data showed that the dead husk represents a functional component of the DU that have been evolved to nurture the embryo and to ensure its success in its unique habitat. Furthermore, drought conditions can modify husk biochemical properties, which in turn might affect seed performance and fate, soil microbiota and soil fertility and consequently plant species diversity.

The best source of crown rust resistance genes (Pc) in genus Avena is a wild hexaploid A. sterilis L. In this study, accessions of A. sterilis gathered from European and North American gene banks, originated from 21 countries were evaluated at the seedling stage for crown rust reaction using the host–pathogen test and two Puccinia coronata f. sp. avenae isolates. Of the 45 oat accessions analyzed, 12 were resistant to one crown rust race (3.2). Resistance to both pathotypes used in the study was observed in two of the accessions, first of which was collected in Libya (AVE 2532) and second in Portugal (CN 26036). Further research is required to evaluate the genetic background of the discovered resistance, however, obtained results provide a valuable first step in the identification of new promising crown rust resistance sources.

The weed species in the common barley (Hordeum vulgare L.) fields in the Diyarbakir were observed with this study. For this purpose, 50 quadrats of 1m by 1m (1 m-2) were randomly placed and examined at each study site. In every set of the quadrat, frequency and density were observed throughout the cropping season of 2015-2016. During the course of field study 72 weed species belonging to 21 families, 13 grasses, 59 broadleaves were recorded. The common families were Asteraceae and Poaceae in the common barley fields. The encounter frequency of weeds was determined by observing 80% wild mustard (Sinapis arvensis L., 80%), animated oat (Avena sterilis L., 63%), common wild oat (Avena fatua L., 54%), corn buttercup (Ranunculus arvensis L., 54%), corn poppy (Papaver rhoeas L., 52%), creeping thistle (Cirsium arvense (L.) Scop., 51%), volunteer lentils (Lens culinaris Medik., 51%). Wild mustard, which had the highest frequency was also the densest weed species (5.18 plant m-2), and other species such as animated oat (4.33 plant m-2), creeping thistle (1.77 plant m-2), common wild oat (1.72 plant m-2), corn buttercup (1.47 plant m-2), cleavers (1.38 plant m-2), corn poppy (1.22 plant m-2), volunteer lentils (1.07 plant m-2) were important species at all the observed fields. It was observed that the great infestation was shown by broadleaf weeds due to the lack of effective weed control in the barley areas.

Different techniques have been devised to detect herbicide resistance in weeds, and the overall aim from this study was to compare four different assay techniques for evaluating acetolactate synthase (ALS)-inhibiting herbicide resistance in sterile wild oat (Avena sterilis L.). A resistant sterile wild oat population (R) was collected from the wheat field in Kozan, Adana province, Turkey. The susceptible (S) population was collected from the border of the same field. Effects of different doses of mesosulfuron-methyl + iodosulfuron-methyl- -sodium and pyroxsulam + cloquintocet-mexyl were assessed in agar based (seed and seedling) assay, Petri dish with seeds, and whole plant pot assay. In the agar based assays, the level of resistance was evaluated by measuring coleoptile and hypocotyl lengths, and survival of seedlings. Plant height and shoot dry weight were measured in the Petri dish and whole plant pot assays, respectively. Results from the dose response analyses showed that both the R and S populations were extremely sensitive to mesosulfuron-methyl + iodosulfuron in the seedling bioassay. The resistance indices (RI’s) of the R biotype treated with mesosulfuron-methyl + iodosulfuron in the agar based seed, Petri dish, and whole plant assays were 2.29, 2.63 and 4.18, respectively. The resistance indices of the R biotype treated with pyroxsulam + cloquintocet-mexyl was 3.41, 5.05 and 2.82 in the agar based seed, Petri dish, and whole plant pot assays, respectively. The agar based seed assays and Petri dish assay provided feasible, accurate, rapid, and cost effective opportunities to identify resistance in sterile wild oat.

We estimated the risk of selecting for herbicide resistance in 101 weed species known to occur in wheat and barley crops on farms in New Zealand. A protocol was used that accounts for both the risk that different herbicides will select for resistance and each weed's propensity to develop herbicide resistance based on the number of cases worldwide. To provide context we documented current herbicide use patterns. Most weeds (55) were low-risk, 30 were medium-risk and 16 high-risk. The top ten scored weeds were Echinochloa crus-galli, Poa annua, Lolium multiflorum, Erigeron sumatrensis, Raphanus raphanistrum, Lolium perenne, Erigeron bonariensis, Avena fatua, Avena sterilis and Digitaria sanguinalis. Seven out of ten high-risk weeds were grasses. The most used herbicides were synthetic auxins, an enolpyruvylshikimate-phosphate synthase inhibitor, acetolactate synthase (ALS) inhibitors, carotenoid biosynthesis inhibitors, and long-chain fatty acid inhibitors. ALS-inhibitors were assessed as posing the greatest risk for more species than other modes-of-action. Despite pre-emergence herbicides being known to delay resistance, New Zealand farmers only applied flufenacet and terbuthlazine with high frequency. Based on our analysis, surveys for herbicide-resistant species should focus on the high-risk species we identified. Farmer extension efforts in New Zealand should address resistance evolution in cropping weeds.

AvenaNET and VallicoNET are web-based DSS developed for Lolium rigidum (ryegrass) and Avena sterilis spp. ludoviciana (winter wild oat) control in Spanish dryland cereals. This chapter describes the rationale, structure and evaluation of these DSS. Both systems present a common structure that contains an interface, a database and a bioeconomic model. The interface has been kept as simple as possible, and it requires simple agronomic, biological and economic data. The databases store information on the available herbicides for the control of A. sterilis and L. rigidum. The bioeconomic model contains a detailed life cycle structure including integrated management strategies, weed-crop competition and economic submodels. Both DSS followed an evaluation process consisting of the verification of the functions contained in the system, its ergonomics and the evaluation in field conditions. The validation results revealed that the performance of both systems was satisfactory.