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The chemical composition of essential oil iso- lated by hydrodistillation from the leaves of Tunisian Eucalyptus erythrocorys Linn. was analyzed by gas chro- matography (GC) and gas chromatography-mass spec- trometry (GC/MS). Fifteen compounds were identified, representing 97 % of total oil, which was found to be rich in oxygenated monoterpenes (66.7 %), particularly in 1,8- cineole (54.8 %). The yield and the physico-chemical properties of oil were determined. The study of antifungal activity revealed that E. erythrocorys essential oil signifi- cantly inhibited the growth of five plant pathogenic fungi especially Bipolaris sorikiniana and Botritys cinerea. Moreover, herbicidal properties of the oil, tested on Sinapis arvensis L. and Phalaris canariensis L. indicated that the E. erythrocorys oil completely inhibited the seed germination at high concentration (1.5 ll/ml), while at low doses (0.25, 0.5, 0.75, 1 ll/ml) the oil acted by decreasing and delaying the germination and inhibiting the seedling growth of all tested weeds.

Comunicación presentada al XVI Congreso de la Sociedad Española de Malherbología, celebrado en la Universidad Pública de Navarra, Pamplona-Iruña, entre los días 25 y 27 de octubre de 2017. La quema de rastrojeras se utilizó para la eliminación de los restos de cosechas de cereal con el objetivo de facilitar las labores de preparación del terreno para el cultivo siguiente y reducir reservorios de plagas, enfermedades y malas hierbas de las parcelas. En 2003 esta práctica quedó prohibida, excepto por razones fitosanitarias, para mantener la materia orgánica en el suelo. En el verano de 2016, después de un incendio en Noain (Navarra), se presentó la posibilidad de evaluar el efecto de la quema sobre la nascencia de malas hierbas en el cultivo siguiente. Se ha comprobado que la quema del rastrojo ha reducido un 45% la densidad de malas hierbas emergidas. Refiriéndose en concreto a las especies de nascencia principalmente otoñal, se ha reducido la densidad de malas hierbas como ballueca Avena sterilis subesp. ludoviciana, vallico Lolium rigidum, verónica Veronica sp., ciape Sinapis arvensis y cebada de ricio del cultivo anterior. Por el contrario amapola Papaver rhoeas aumentó la densidad en las parcelas con rastrojo quemado. The stubble burning was used for the elimination of cereal crop residues in order to facilitate soil preparation for the next crop and to reduce reservoirs of pests, diseases and weeds in plots. In 2003 this practice was prohibited, except for phytosanitary reasons, to keep organic matter in the soil. In the summer of 2016, after a fire in Noain (Navarre), there was an opportunity of evaluating the effect of burning on weed emergence in the next crop. It has been confirmed that stubble burning has reduced weed emergence by 45%. Only considering mainly autumn germinating weed species, it has been reduced the density of Wild oat (Avena sterilis ludoviciana), Rye-grass (Lolium rigidum), Speedwell (Veronica sp), Charlock (Sinapis arvensis) and volunteer Barley of the previous crop. In contrast, Common Poppy (Papaver rhoeas) increased its density in the plots with burnt stubble.

Olfactory ability is an element of fitness in many animals, guiding choices among alternatives such as mating partners or food. Ground beetles (Coleoptera; Carabidae), exhibit preferences for prey, and some species are well-known weed seed predators. We used olfactometer-based bioassays to determine if olfactory stimuli are associated with detection of Brassica napus L., Sinapis arvensis L., and Thlaspi arvense L. seeds by ground beetles characteristic of agroecosystems, and whether behavioural responses to seed odors depended on seed physiological state (imbibed or unimbibed). Imbibed B.napus seeds were preferred over other weed species by two of the three carabid species tested. Only A. littoralis responded significantly to unimbibed seeds of B. napus. Sensitivity to olfactory cues appeared to be highly specific as all carabid species discriminated between the olfactory cues of imbibed brassicaceous weed seeds, but did not discriminate between weed seeds that were unimbibed. Overall, our data suggest that depending on seed physiological state, odours can play an important role in the ability of carabids to find and recognize seeds of particular weed species.

Summary Although we know that alterations in crop density, crop spatial pattern and inclusion of more selective weed control can improve weed suppression for organic growers, it is unknown whether these result in changes to the weed seedbank that increase cropping system profitability over time. Data collected from field trials conducted in 2009 and 2010 in Maine, USA, comparing regional grower practices (Standard) with management that aimed to (i) facilitate better physical weed control through the use of wide row spacing and inter-row cultivation (Wide) or (ii) enhance crop–weed competition through increased seeding rate and narrow inter-row spacing (Narrow HD), were used to construct a matrix population model with an economic sub-model. Using field measurements of grain yield and weed survival and fecundity, we investigated the lasting implications of employing alternative organic spring wheat (Triticum aestivum) production practices on Sinapis arvensis population dynamics. In most scenarios, the model indicated that regional production practices were not sufficient to prevent an increase in the weed seedbank, even with excellent weed control. The two alternative methods, on the other hand, were able to limit weed population growth when initial densities were low or cultivation efficacy was >80%. Due to higher seed costs in the Narrow HD system, net returns were still lower after 10 years of simulation in this system compared with wide rows with cultivation, despite a lower weed seedbank.

Analysis of gene flow between Brassica napus L. and its sexually compatible relatives that could be found in the wild in Slovenia was performed by microsatellite analysis using fifteen selected primer pairs. Genotypes included in the study were obtained from the field survey of sexually compatible relatives of B. napus in natural habitats around Slovenia and from reference collections. Two different wild species of all the presented sexually compatible relatives of B. napus were found in Slovenia, B. rapa and Sinapis arvensis. The reference genotypes included varieties and wild forms from internal collections as marketable seeds or from gene banks. Reference genotypes were represented by the following species and subspecies: B. napus ssp. napobrassica, B. napus ssp. napus, B. nigra, B. oleracea, B. rapa ssp. oleifera, Diplotaxis muralis; D. tenuifolia, Raphanus raphanistrum, R. sativus, R. sativus var. oleiformis, Rapistrum rugosum, S. alba and S. arvensis. Estimation of gene flow described by average number of migrants was 0.72 followed by 0.20 migrants. Due to the observed gene migrations, genetic drift and selection, Hardy-Weinberg equilibrium was not met. The mean number of alleles over all loci was 16.9, the average polymorphic information content was 0.43. We found four highly divergent and polymorphic loci (Na12-C08, Na10-A08, Ni3-G04b and BRMS-050) at statistically significant level (p

The study on weed infestation of root crops in different soils in the protective zone of Roztocze National Park was conducted in the years 1991-1995. As many as 240 phytosociological records, made with the use of Braun-Blanquet method, were taken in potato and sugar beet fields. The number of weed species in sugar beet and potato in the area depended on the soil and type of root crop. In the same environment conditions. the iiuinber of weed species was higher in potato than in sugar beet. The most difficult weed species iii all types of soil were: Chenopodium album, Stellaria media and Convolvulus arvensis. Podsolic soils were highly infested by two acidophylic species: Spergula arvensis and Raphanus raphanistum. Potato in loess soil and brown soil made of loamy sands were highly infested by Echinochloa crus-galli, Equisetum arvense and Galinsoga parviflora. Root crop plantations in brown soils formed from gaizes of granulometric loam texture and limestone soils were infested by: Galium aparine, Sonchus arvensis, Sinapis arvensis and Veronica persica.

Seed shatter of wild oat (Avena fatua L.), green foxtail [Setaria viridis (L.) P. Beauv.], wild mustard (Sinapis arvensis L.), cleavers (Galium spurium L. and G. aparine L.), wild buckwheat (Polygo...

Four field experiments were carried out from 2011 to 2014 in order to evaluate the effects of foramsulfuron, applied at the recommended (60.8 g a.i./ha ) and reduced doses (1/3 and 2/3), on the efficacy against several of the most important weeds in maize. For each “year-weed” combination, dose-response curves were applied to estimate the dose of foramsulfuron required to obtain 90% and 95% weed control (ED 90 and ED 95 ). Foramsulfuron phytotoxicity on maize and crop yield were assessed. Foramsulfuron at 1/3 of the recommended dose (20.3 g a.i./ha) provided 95% efficacy against redroot pigweed ( Amaranthus retroflexus L.), green foxtail ( Setaria viridis (L.) Beauv.), wild mustard ( Sinapis arvensis L.) and black nightshade ( Solanum nigrum L.). Velvetleaf ( Abutilon theophrasti Medik.) , common lambsquarters ( Chenopodium album L.) and barnyardgrass ( Echinochloa crus-galli (L.) Beauv.) were satisfactorily controlled (95% weed efficacy) with ED 95 ranged from 20 to 50 g/ha of foramsulfuron (about from 1/3 to 5/6 of the recommended dose) depending on growth stage. The recommended dose was effective against pale smartweed ( Polygonum lapathifolium L.) at 2-4 true leaves (12-14 BBCH scale), but this dose did not kill plants larger than 2-4 true leaves. The ranking among weed species based on their susceptibility to foramsulfuron was: redroot pigweed = green foxtail = wild mustard = black nightshade > velvetleaf = common lambsquarters = barnyardgrass > pale smartweed. Dose of foramsulfuron can be reduced below recommended dose depending on weed species and growth stage. Foramsulfuron showed a good crop selectivity and had no negative effect on maize yield.

Çalışma, 2012-2013 yıllarında Çanakkale ilinde Domates güvesi [Tuta absoluta (Meyrick 1917) (Lepidoptera: Gelechiidae)]’nin konukçuları ve bulaşma oranını belirlemek amacıyla yürütülmüştür. Araştırma, zararlının konukçusu olabilecek kültür bitkilerinde 10 gün ve kültür alanları dışındaki yabancı otlar üzerinde ise 10-15 gün arayla survey yapılarak gerçekleşmiştir. Örnekleme yapılan tüm ilçelerde T. absoluta’nın varlığı tespit edilmiş olup, zararlının değişik biyolojik dönemleri ile domates alanlarının %88 oranında bulaşık olduğu belirlenmiştir. Domates dışında T. absoluta’nınvarlığı Capsicum annuum L. (%2.7) ve Solanum melongena L.’da (%5.8) kaydedilirken; Nicotiana tabacum, Phaseolus vulgaris ve Solanum muricatum’da zararlıya rastlanılmamıştır. Yabancıotlarda ise Solanum nigrum L. (%4.8), Convolvulus arvensis L. (%1.6), Sinapis arvensis L. (%1.6) ve Sonchus oleraceus L. (%1.6) üzerinde zararlı tespit edilmiştir. S. arvensis ve S. oleraceus ilk kayıttır., The study was conducted to determine the hosts and infestation rate of tomato leafminer [Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae)] in 2012-2013 in Çanakkale province. Research was conducted by examining cultivated plants at 10 day intervals and weeds at 10-15 days intervals from uncultivated fields to determine possible hosts of the pest. The pest was determined in all surveyed tomato fields and an infestation rate of 88% was found with different life stages of T. absoluta. Other than tomato, presence of T. absoluta on Capsicum annuum L. (2,7%) and Solanum melongena L. (5,8%) was found but it wasn’t found on Nicotiana tabacum, Phaseolus vulgaris and Solanum muricatum. The pest was also found on weeds such as Solanum nigrum L., Convolvulus arvensis L., Sinapis arvensis L. and Sonchus oleraceus L.. S. arvensis and S. oleraceus are first records as hosts

Rate-response experiments with nine putative resistant wild mustard (Sinapis arvensis) populations from Greece showed cross-resistance to tribenuron and imazamox. The calculated GR50 values [herbicide rate (gaiha-1) required for 50% reduction of fresh weight] of the nine resistant (R) populations ranged from 51.8 to 555.6gaitribenuronha-1 and from 66.3 to 900.4gaiimazamoxha-1. Regarding the susceptible population, GR50 value was not estimated for tribenuron as its lower treatment reduced fresh weight by >95%, whereas the respective value for imazamox was 0.5gaiha-1. Gene sequencing of als revealed that a point mutation at Trp574 position, leading to amino acid substitution by Leu in the ALS enzyme was present and the likely cause of resistance. The in vitro activity of the ALS enzyme indicated I50 values (herbicide concentration required for 50% reduction of the ALS activity) ranging from 19.11 to 217.45μM for tribenuron, whereas the respective value for the S population was 1.17μM. All populations were susceptible to MCPA at the recommended rate. These results strongly support that cross-resistance of 9 S. arvensis populations was due a point mutation of the als gene, which resulted in a less sensitive ALS enzyme.

BACKGROUND: Wild mustard seed is similar in size and shape to canola seed and can be separated by pneumatic means if the aerodynamic properties of these two materials are well known. The objective of this study was evaluation of the aerodynamic properties of canola and wild mustard seeds as a function of moisture content from 5% to 20% (w.b). RESULTS: The results showed that the terminal velocity of canola seeds increased, following a polynomial relationship from 5.401 to 6.566 m s −1 , as the moisture content increased from 5% to 20%. Over this same moisture content range the terminal velocityofwildmustardseedsvariedfrom4.276to5.433ms −1 .Thedragcoefficientofcanolaandwildmustardseedsdecreased linearly from 1.062 to 0.646 and from 1.432 to 0.928, respectively, as moisture content increased from 5% to 20%. Analysis of variance showed that there was a significant difference between the terminal velocity and drag coefficient of canola and wild mustard seed at a 1% probability level. CONCLUSION: The results suggest that aerodynamic separation of wild mustard seed from canola is possible. Moisture content had a significant effect on the terminal velocity and drag coefficient of seeds. c � 2012 Society of Chemical Industry

Though adjuvants are abundant in almost every pesticide solution, their mode of action is still not completely clear. Studies on their way through the cuticle are quite difficult due to a lack of radiolabelled surfactants. In this study we want to present the results of an experiment conducted to evaluate the mode of action of an ethoxylated soybean oil (ESBO) adjuvant. To evaluate the route of ESBO through the cuticle it was labelled with fluorescein and applied to one leaf of different test species (Abutilon theophrasti, Sinapis arvensis and Beta vulgaris). Treated leaves were harvested and rinsed with either deionised water, methanol/water or chloroform. The fluorescein content of washed leaves and the solution in which they were washed were analysed with High-Performance Liquid Chromatography (HPLC) coupled with an UV detector. Results lead to the assumption that ESBO passed through the cuticle. If this holds true, ESBO was able to reach the underlying cell tissue where it might have been metabolised or even translocated to other plant parts. Though a lot of research has to be conducted on the mechanism and mode of action of adjuvants, this study gives an approach to investigate the behavior of foliar applied adjuvants.

Weeds are a significant part of the pests limiting crop production. Currently, chemical herbicides are widely used for weed control. Environment pollution and the rise of resistant strains highlight the need for new herbicides. Nep1 is a natural bio-herbicide protein which is an effective necrosis stimulant in dicotyledonous weeds. In this study, the cDNA encoding nep1 was isolated form Fusarium oxysporum, cloned and overexpressed in Escherichia coli. The Nep1 inclusion body was purified and refolded. For biological assay, the recombinant Nep1 was applied on Sinapis arvensis, as a chemical herbicide-resistant weed, and on Nicotiana tabacum, as a model plant. Our results show a significant necrosis on the leaves of S. arvensis and N. tabacum after spraying 50 μg/ml of the recombinant protein.

Seed predation can be exploited as a mean of natural weed control. Field experiments were conducted in 2007 in four barely fields in Mashhad, NE of Iran to determine the effects of seed covering tissues, seed distribution patterns and interactions between seed density and background seed density on postdispersal seed predation. Five weed species (Avena ludoviciana, Hordeum spontaneum, Sinapis arvensis, Rumex obtusifolius and Rapistrum rugosum), three seed densities (50, 100 and 150 seed dish-1), two background seed densities (with and without), three distribution patterns (random, even, and aggregate), and two level of seed covering tissues (with and without) were arrange in a factorial randomized complete block design. Seed covering tissues had significant negative effect on predation and the most its effect was observed for H. spontaneum. Seed predation was also affected by seed distribution patterns. The highest and lowest seed predations of all species were observed from aggregate and random treatments respectively. The interaction between density and background seed density affected seed predation. Results show that seed predation can play an important role in decreasing the weed seeds on the soil surface and thus, in soil seed bank. Therefore, seed predation could be considered as a control technique in integrated weed management.

In Denmark, several political initiatives have been taken to reduce use of pesticides and fertilizer in order to avoid unwanted side effect of the increasing cropping intensification. Based on two nation wide surveys we investigate flora changes and discuss the changes in relation to biodiversity, crop yield, agricultural management and climate. Our assumption is that the surveys are representative for the country. We present frequency analyses of 90 species recorded in 157 fields surveyed in 1987–89, and in 167 fields surveyed in 2001–04. Based on 4910 circular sample plots in unsprayed areas, we studied flora changes in four crops and showed that the frequency of many weed species have increased. Particularly some winter annual species (e.g. Veronica arvensis L. and Viola arvensis Murray), grass weeds ( Poa annua L., Apera spica-venti (L.) P. Beauv.) and nitrophileous species (e.g. Capsella bursa-pastoris (L.) Medik, Cirsium arvense (L. Scop.) , Galium aparine L., Fallopia convolvulus (L.) A. Lowe, Tripleurospermum inodorum (L.) Sch. Bip.) have been favoured. Some weeds have declined in some crops but increased in other crops (e.g. Chenopodium album L., Geranium pusillum L.), while only a few species declined in one crop without increasing in other crops (e.g. Elytrigia repens (L.) Desv. ex Nevski; Sinapis arvensis L). Our data indicate that continuously increasing productivity (increasing yields) seems to be possible simultaneously with enhancing the frequency of the wild flora in arable crops.

The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Tunisian Pinus pinea Linn. was analyzed by GC and GC/MS. Sixty-six compounds were identified, representing 98.5% of total oil, which was found to be rich in monoterpene hydrocarbons (73.1%) particularly limonene (54.1%), α-pinene (7.7%), and β-pinene (3.4%). The yield and the physico-chemical properties were determined. Results of the antifungal activity study by in vitro contact assay showed that P. pinea oil significantly inhibited the growth of ten plant pathogenic fungi. Moreover, herbicidal properties of the oil, tested on Sinapis arvensis L., Lolium rigidum Gaud., and Raphanus raphanistrum L., indicated that the oil completely inhibited the seed germination at a high concentration, while at low doses the oil acted by decreasing and delaying the germination and inhibiting the seedling growth of all tested weeds unlike the commercial herbicide. Our results showed that P. pinea essential oil could be valorized as bioproduct for biocontrol of weeds and fungal plant diseases.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; To determine to what extent wild species related to crops might serve as refuges for insect pests and their natural enemies, we compared the performance of the aphid Myzus persicae and its endoparasitoid Diaeretiella rapae on one cultivar of Brassica napus and Brassica oleracea, two wild species Brassica nigra and Sinapis arvensis, and one cultivar of Solanum lycopersicum. These species differ in traits associated with plant defences that may have an impact on the herbivore and its parasitoid. In contrast to our initial hypothesis, aphid population growth rate was significantly smaller on B. napus than on the other Brassicaceae species. Similarly, the performance of the parasitoid was affected by the host plant on which the aphid was feeding. However, aphid and parasitoid performance was not correlated. Thus, in temporally changing landscapes, pests and natural enemies may utilize crops and wild-related host species with contrasting impacts on their fitness.

Onion thrips, Thrips tabaci Lindeman, is a key foliage-feeding pest of onion worldwide and the principal vector of a serious onion pathogen, Iris yellow spot virus (IYSV). Long-term management of T. tabaci and IYSV will require an understanding of T. tabaci ecology and IYSV epidemiology in onion ecosystems. This study focused on identifying winter-annual, biennial and perennial weed species that host both T. tabaci and IYSV. Unlike summer-annual weeds, weeds with these habits survive overwinter and could serve as a green bridge for IYSV to survive between onion-growing seasons. T. tabaci larvae and adults were sampled every two weeks from 69 weed species in five areas located adjacent to onion fields in western New York in 2008 and 2009. Twenty-five of the 69 weed species were identified as hosts for T. tabaci larvae and populations were highest on the Brassicaceous weeds, Barbarea vulgaris Ait. f., Sinapis arvensis L., and Thalspi arvense L. None of these species are hosts for IYSV. Four of the 25 weed species were hosts for both T. tabaci larval populations and IYSV: common burdock, Arctium minus Bernh., dandelion, Taraxacum officinale G.H. Weber ex Wiggers, curly dock, Rumex crispus L., and chicory, Cichorium intybus L. Of these four weed species, T. officinale and A. minus may play an important role in the epidemiology of IYSV in New York onion fields because they may survive between onion-growing seasons, they are relatively abundant in the landscape, and they support relatively high densities of T. tabaci.

The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved plant growth with 45% and reduced metal uptake by over 70% in comparison to untreated soil. Reductions in availability as estimated by BaCl2-extractable metals reached up to 90% for Zn and 65% for Cd as compared to unamended soil. These reductions were associated with lower shoot and root metal contents. Shoot Zn content was reduced from 1,369 microg g(-1) in plants grown on untreated soil to 377 microg g(-1) when grown on cyclonic ash amended soil while Cd decreased from 267 to 44 microg g(-1) in steel shots amended soil. Superphosphate addition had no ameliorating effect. On the contrary, it increased BaCl2-extractable amounts of Zn. Considering all parameters we determined, steel shots, cyclonic ash and silifertil are the most promising for remediating metal contaminated soil in the tropics. Further studies evaluating impacts, cost-effectiveness and durability of effects will be conducted.

The diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) is an important pest of cultivated brassicaceous crops worldwide. The host plant preferences, developmental biology and survival and longevity of P. xylostella are relatively well understood on commercial crop species; however, its relationship with brassicaceous weeds is poorly known. Sinapis arvensis L., Erysimum cheiranthoides L. and Capsella bursa-pastoris (L.) Medicus are among the most common brassicaceous weeds worldwide and can serve as important bridge hosts of P. xylostella. In this study, preference and performance of P. xylostella were compared on these weed species. In free-choice situations, females deposited 5.5 and 18.8 times more eggs on S. arvensis than on E. cheiranthoides and C. bursa-pastoris, respectively. Survival from neonate to pupa and from pupa to adult was highest on S. arvensis and E. cheiranthoides and lowest on C. bursa-pastoris. Development was fastest, foliage consumption was greatest, pupae and silk cocoons were heaviest, adult body masses and longevities were highest and forewings were largest for both females and males when reared as larvae on S. arvensis. Realized fecundity of new generation adults was highest for individuals reared on S. arvensis compared to those reared on E. cheiranthoides or C. bursa-pastoris. Relative growth rates of pupae and adults were highest on S. arvensis, suggesting that this plant species is a high-quality host for P. xylostella compared with other species tested. Potential impacts of these wild brassicaceous species on P. xylostella populations are discussed.

This study was conducted to improve our understanding of how earthworms and microorganisms interact in the decomposition of litter of low quality (high C : N ratio) grown under elevated atmospheric [CO2]. A microcosm approach was used to investigate the influence of endogeic earthworm (Aporrectodea caliginosa Savigny) activity on the decomposition of senescent Charlock mustard (Sinapis arvensis L.) litter produced under ambient and elevated [CO2]. Earthworms and microorganisms were exposed to litter which had changed in quality (C : N ratio) while growing under elevated [CO2]. After 50 d of incubation in microcosms, C mineralization (CO2 production) in the treatment with elevated-[CO2] litter was significantly lower in comparison to the ambient-[CO2] litter treatment. The input of Charlock mustard litter into the soil generally induced N immobilization and reduced N2O-emission rates from soil. Earthworm activity enhanced CO2 production, but there was no relationship to litter quality. Although earthworm biomass was not affected by the lower quality of the elevated-[CO2] litter, soil microbial biomass (Cmic, Nmic) was significantly decreased. Earthworms reduced Cmic and fungal biomass, the latter only in treatments without litter. Our study clearly showed that A. caliginosa used the litter grown under different [CO2] independent of its quality and that their effect on the litter-decomposition process was also independent of litter quality. Soil microorganisms were shown to negatively react to small changes in Charlock mustard litter quality; therefore we expect that microbially mediated C and N cycling may change under future atmospheric [CO2].

Conservative agriculture includes a range of management strategies with low energy inputs such as no-tillage, minimum tillage, and low application of fertilizers. Weed flora in arable fields is strictly affected by agronomic practices such as tillage and fertilization management. This study was conducted seven years after the beginning of a long-term&mdash, durum wheat&ndash, faba bean&mdash, rotation. It analyzes the combined effects on the soil seed bank of three different tillage systems (conservative, reduced, and conventional tillage) and two levels of nitrogen fertilization. The effects were investigated both using stepwise discriminant analysis and analysis of variance in order to find statistical differences among main factors and their interactions. The seed bank of Conyza canadensis, Papaver rhoeas, Solanum nigrum, Fallopia convolvulus, and Fumaria officinalis was higher in conservative or reduced tillage plots. The magnitude of the response to nitrogen supply varied among weed species. Conyza canadensis seemed to be favored by low nitrogen supply, whereas Sinapis arvensis by higher doses of nitrogen. Anagallis arvensis showed the lowest seed bank in conventionally tilled plots, without distinction of nitrogen supply. The results suggest that different tillage systems and, to a lesser extent, different nitrogen supply, produce changes in the seed bank size and composition, along the soil profile.

The current study aimed to evaluate the negative allelopathic effect of Eucalyptus citriodora essential oil on some of the most noxious weeds in Algeria (Sinapis arvensis, Sonchus oleraceus, Xanthium strumarium and Avena fatua). Gas chromatography-flame ionization detector (GC-FID) and GC/mass spectrometry (MS) were used to define the chemical composition of the oil. Citronellal (64.7%) and citronellol (10.9%) were the major essential oil compounds. Three concentrations of the oil were used for laboratory (0.01, 0.02 and 0.03%) and greenhouse (1, 2 and 3%) experiments. Seed germination and seedling's growth were drastically reduced in response to the oil concentrations where at 0.01 and 0.02% the oil drastically affects the seed germination of the tested weeds and at 0.03% the oil suppresses completely the germination of S. arvensis. The oil also exhibited strong allelopathic effect on the 3 - 4 leaf-stage plants 1 and 6 days after treatment. A completely death of S. arvensis, S. oleraceus and A. fatua and severe injuries on X. strumarium appeared at 3% of the oil. Chlorophyll content and membrane integrity were significantly affected after treatment of the plant weeds representing a severe reduction in total chlorophyll and cell membrane disruption. The study concludes that E. citriodora essential oil might has the potential use as bioherbicide and can constitute an alternative process of weed control.

In order to investigate the effect of trifluralin, pronamide, haloxyfop-p methyl, propaquizafop and isoxaben on weed control and oilseed rape yield, a two year field experiment was conducted at Darab, Iran, during 2004–2005 and 2005–2006 growing seasons. Herbicides reduced weed biomass compared with the weedy check. In 2004–2005, at 16 WAP (weeks after planting), application of trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha and trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha provided best control (80%) of wild mustard (Sinapis arvensis L.), compared to other treatments. At 8 and 16 WAP, wild mustard control decreased to 47 and 42%, respectively, when trifluralin was applied alone at 1400 g a.i./ha. In 2005–2006 at 16 WAP, maximum reduction in wild mustard biomass (82%) was achieved with trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha. In both years, all herbicide treatments controlled fumitory (Fumaria officinalis L.) 64–96%. In 2004–2005, at 16 WAP, wild oat (Avena fatua L.) biomass reduction by trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha was 95%. In 2005–2006, at 8 and 16 WAP, minimum biomass reduction of wild oat (37–53%) was observed with trifluralin at 1200 and 1400 g a.i./ha. In both years, at 8 and 16 WAP, the most effective herbicide treatments were trifluralin plus propaquizafop plus isoxaben and trifluralin plus haloxyfop-p methyl plus isoxaben regardless of the dose applied and provided maximum reduction in total weed biomass (77–89%) compared to other treatments. Results of both years showed that all herbicide treatments increased oilseed rape grain yield as compared with the weedy check but percentage of oil was not affected by various herbicide treatments. Maximum grain yield was obtained with trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha.

بذر خردل وحشی مانند سایر بذور علف‌های هرز پس از جمع‌آوری دچار تغییراتی در پتانسیل جوانه‌زنی می‌گردد. در این پژوهش، تاثیر دمای محل نگهداری بذر پس از جدا شدن آن از گیاه مادر (18- ، 3+ و دمای اتاق: 22-25 درجه سلسیوس) بر جوانه‌زنی آن بررسی گردید. بذور خردل وحشی از چهار منطقه (استان‌های فارس، آذربایجان غربی، خوزستان و مازندران) جمع‌آوری شدند و پس از 3، 6، 9، 12و15 ماه انبارسازی در دماهای مذکور جوانه زنی آن‌ها درون ژرمیناتور مورد بررسی قرار گرفت. همچنین میانگین زمان جوانه‌زنی در شرایط دمایی مختلف طی گذشت 6، 12 و 18 ماه برای بذور به دست آمد.

The influence of a non-ionic surfactant (20% isodecyl alcohol ethoxylate plus 0.7% silicone surfactants), an anionic surfactant (25.5% alkylethersulfate sodium salt), and a vegetable oil (95% natural rapeseed oil with 5% compound emulsifiers) on the performance and rainfastness of a new commercial formulation of tribenuron-methyl was assessed on four broad-leaved weeds:wild mustard (Sinapis arvensis),scentless mayweed (Tripleurospermum inodorum),common poppy (Papaver rhoeas), and common lambsquarters (Chenopodium album). In one experiment, six doses of tribenuron-methyl alone or in a mixture with each of the three adjuvants were applied to each weed species at two different leaf stages. In another experiment, the plants of T. inodorum were sprayed and subsequently subjected to 3 mm of rain at 1, 2, and 4 h after treatment (HAT). The activity of tribenuron-methyl was significantly enhanced by all the adjuvants on all the weed species and only minor differences were observed among the tested adjuvants.The impact of the adjuvants varied among the weed species and growth stages.The highest response to the inclusion of adjuvants in the spray liquid was found at the late growth stage and on C.album,followed by P.rhoeas and T.inodorum,while S.arvensis was less responsive to the adjuvants.All the adjuvants significantly improved the rainfastness of tribenuron-methyl on T. inodorum, with differences among the adjuvants being more pronounced when rain occurred shortly after herbicide application.The effect of the vegetable oil on tribenuronmethyl’s rainfastness was significantly lower than that of the surfactants with rain at 1 HAT, while no significant differences among the three adjuvants were observed when rain occurred at 2 and 4 HAT.

International audience; Vegetation cover may affect weed seed predation by modifying the habitat quality for predatory organisms. Post-dispersal weed seed predation was measured by placing ‘seed cards’ in two perennial crops (alfalfa, cocksfoot) with and without crop cutting and in plots with bare soil. Each treatment was repeated four times in a randomized complete block design. Vegetation cover was measured by canopy light interception. Predation trials lasted two weeks and were repeated three times. Seed predation rates varied among three weed species (highest for Viola arvensis, intermediate for Alopecurus myosuroides, lowest for Sinapis arvensis). Vertebrate exclusion cages (12 mm × 12 mm openings) strongly reduced seed predation rates. Positive relationships were observed between vegetation cover and seed predation rates by both vertebrates and invertebrates for all weed species and trials, except when overall predation rates were very low. Predation rates were highest in uncut alfalfa, lowest on bare soil, but 16–64% of this variation could equally be explained by vegetation cover. The factorial design indicated that cutting had a stronger impact than crop species (legume or grass). Results suggest that weed seed predation may be enhanced by maintaining a high and temporally extended vegetation cover.

Low inputs in nitrogen may affect canola (Brassica napus L.) competitiveness and allelopathic potential as well as grain and oil yields. A 2-yr study was conducted to assess nitrogen supply effect on the ability of four canola hybrids to compete with corn poppy (Papaver rhoeas L.) as well as its effect on canola seed and oil yields. Phytotoxic potential of canola hybrids on germination and growth of winter wild oat (Avena sterilis spp. ludoviciana L.), corn poppy, and wild mustard (Sinapis arvensis L.) was also determined using a perlite-based bioassay. At canola blossom, corn poppy plant number in nitrogen-treated plots was 23% less than that in the nitrogen-untreated ones. Canola seed and oil yield was reduced 18.6 and 23.7%, respectively, by the competition of 100 corn poppy plants m –2 , with ‘Elan’ and ‘Titan’ the most productive hybrids. Nitrogen supply did not increase in all cases the competitive ability or the seed and oil yields. In the laboratory, germination of the winter weeds was completely inhibited by the greatest extract concentration (5 g 100 mL –1 ) of all hybrids. Nitrogen supply did not affect, in most cases, the phytotoxicity of canola hybrids, while phytotoxicity did not signifi cantly differ among hybrids. Conclusively, the hybrids Elan and Titan, cultivated without any herbicide or nitrogen fertilizer, could be viable as a shortterm alternative crop system for canola seed and oil production, especially in organic or low-input fi elds infested by corn poppy.

Stolcova J. (2009): Feeding preferences of Phyllotreta herbivores to winter rape and chosen weeds. Plant Protect. Sci., 45: 156–160. In model experiments with leaf disks from Brassica napus L. subsp. napus and thlaspi arvense L. and Sinapis arvensis L. in spring periods (May–June) of 2006–2007 feeding preferences of Phyllotreta herbivores to the above-mentioned crop and two common weeds were investigated. In seedlings of identical ontogenetic stages insignificantly higher feeding injuries were recorded in B. napus. Between the two monitored weeds insignificantly higher herbivory was found in S. arvensis compared to t. arvense. In a comparison of older crop and younger weeds and vice versa, flea beetles significantly preferred the four-leaf seedling stage to the cotyledon seedling stage irrespective of the monitored plant species. Though generally in feeding preference of flea beetles a general drift B. napus > S. arvensis > t. arvensis was recorded, the sequence of leaves also played its role under conditions of this experiment.

An allo-cytoplasmic male sterile line, which was developed through somatic hybridization between Brassica napus and Sinapis arvensis (thus designated as Nsa CMS line), possesses high potential for hybrid production of rapeseed. In order to select for restorer lines, fertile plants derived from the same somatic hybridization combination were self-pollinated and testcrossed with the parental Nsa CMS line for six generations. A novel disomic alien addition line, B. napus-S. arvensis, has been successfully developed. GISH analysis showed that it contains one pair of chromosomes from S. arvensis and 19 pairs from B. napus, and retains stable and regular mitotic and meiotic processes. The addition line displays very strong restoration ability to Nsa CMS line, high resistance to Sclerotinia sclerotiorum and a low incidence of pod shattering. Because the addition line shares these very important agricultural characters, it is a valuable restorer to Nsa CMS line, and is named NR1 here (Nsa restorer no. 1).

Surfactants can improve postemergence herbicide efficacy and reduce the amount of herbicide required to obtain weed control. The effect of surfactants on the efficacy of herbicides is complicated and depends on the interaction among the plant, surfactant, and herbicide. The effects of surfactants on the efficacy of clodinafop-propargyl and/or tribenuron-methyl on wild oat (Avena ludoviciana) and wild mustard (Sinapis arvensis) under greenhouse conditions were investigated. In addition, the surface tension of aqueous solutions of the surfactants and surfactants + herbicides was determined. Significantly lower surface tension values were obtained with the aqueous solutions of citofrigate (Citogate plus Frigate) alone and with the herbicides used in this study. The citofrigate surfactant lead to the greatest enhancement of clodinafop-propargyl and/or tribenuron-methyl efficacy and the effect was species-dependent. The efficacy of clodinafop-propargyl and/or tribenuron-methyl in the presence of surfactants in controlling wild oat was higher than for wild mustard. The foliar activity of the tested herbicides rose with increasing surfactant concentrations. The tank mixture of clodinafop-propargyl and tribenuron-methyl showed a synergistic effect in controlling wild oat and wild mustard. The synergistic effect in controlling wild mustard was greater than for wild oat.

Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)‐docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)‐octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)‐octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm^2 s^−1 (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively. Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity, as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751 and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production.

In order to evaluate the competitive ability (CA) of canola cultivars against wild mustard, two experiments were conducted at the Gorgan Institute in Iran during the 2005–2007 cropping seasons. The experimental factors were canola cultivars (1st year: Zarfam, Option500, Hayola330, Hayola401, Talayh, RGS003 and Sarigol; 2nd year: Zarfam, Hayola330, RGS003 and Option500) and weed density (1st year: control and 30 plants m −2 ; 2nd year: control, 4, 8 and 16 plants m −2 ). The result of the first year of experiment indicated that the grain yield and competitive indices differed significantly between the cultivars. Cultivar Zarfam showed a high ability to withstand competition (AWC = 47%), high competitive indices (CI = 1.79 and CI 2 = 10 1.83) and low grain yield in the weed-free plots (1729 kg ha −1 ). The cultivar Option500, a less competitive cultivar had the lowest ability to withstand competition (AWC = 4%) and the lowest competitive indices (CI = 0.09 and CI 2 = 0.11) amongst the cultivars. However, the cultivar Option500 showed more grain yield in the weed-free plots (2333 kg ha −1 ) than cultivar Zarfam. In the second year of the experiment, the result of the yield loss models showed that the lowest and highest yield loss belonged to cultivars Zarfam and Option500 (50 and 95% respectively). A comparison of different empirical models revealed that the empirical yield loss model based on weed relative leaf area was more reliable for predicting canola yield loss according to a high coefficient of determination ( R 2 = 0.99). The relative damage coefficient ( q ) of the weed relative leaf area model showed that wild mustard was more competitive than canola ( q > 1).

Black rot, caused by Xanthomonas campestris pv. campestris (Pam.) Dawson (Xcc), is a serious disease of vegetable crucifers worldwide. The USDA NC-7 and NE-9 regional PI stations maintain vegetable, mustard, and oilseed crucifers, of which 4084 accessions were available for testing, representing 23 genera and 125 species. These accessions were evaluated for resistance to black rot after wound inoculation with race 1 of the pathogen. Accessions that were symptomless for race 1 of Xcc were replanted and inoculated with race 4 of the pathogen to identify accessions with resistance to both races. Symptomless responses were observed in 362 accessions of the mustard species (Brassica juncea, Brassica carinata, and Brassica nigra), in particular, B. juncea for which 353 of the 389 accessions tested were symptomless. Resistance was identified in five accessions of B. carinata out of 63 evaluated (PI 193460, PI 193959, PI 194254, PI 280230, PI 633077) determined by repeated symptomless responses after inoculation and four accessions of B. nigra from the 83 evaluated (PI 197401, A 25399, A 25401, PI 458981). Five accessions of Brassica rapa (PI 633154, A9285, PI 340208, PI 597831, PI 173847) were identified, which represent promising new sources of resistance to Xcc. Incomplete resistance was identified in an accession of Eruca sativa (PI 633207), an accession of Lepidium spp. (PI 633265), an accession of Sinapis arvensis (PI 296079), and two accessions of B. napus (PI 469733 and PI 469828). These identified accessions represent germplasm that can be used in breeding for resistance to Xcc in vegetable crucifers through interspecific crossing.

In previous experiments, the pollen of Helianthus L. was labelled with radioactive phosphorus. The measurements of the radioactive pollen and ovule samples were made with a Geiger-Muller counter. The number of pollen contents per ovule was determined by dividing the radioactivity of the ovule sample by the radioactivity per pollen grain plus the number of ovules. This was possible since evidence was obtained that all radioactive phosphorus left the pollen grain and entered the ovule, and that the florets within the whorl are often equivalent. In the present experiments, polyspermy in charlock (Sinapis arvensis L.) was studied. Flowers were pollinated with pollen from single stamens that were labelled with P-32. The activity per pollen grain, as well as the activity per ovule (or seed), was determined by means of an anticoincidence arrangement for low-level beta radiation. A high frequency of polyspermy, and of wide varying degree, was found in the experimental material. The highest number found was about 33 contents of pollen grains per ovule. With a certain significance, it was demonstrated that the values of the number of contents of pollen grains per ovule coincide with the uneven numbers and an interval of 4 in the integer series. The number of pollen contents per ovule is to a great extent dependent on the location of both the female and male flowers on the plant. The events comprising the fertilization process extended over a period of about 3 weeks. Some evidence was obtained that pollen grains showing high valency incorporate larger amounts of phosphorus.

Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), a common insect pest in Europe and a new invasive pest in North America, causes severe damage to cruciferous crops. In the United States, C. nasturtii was first reported in western New York in 2004. From 2005 to 2007, field surveys were conducted in western New York to investigate the occurrence of C. nasturtii in weeds that might serve as a reservoir for this pest. The results indicate that 12 cruciferous weed species were found in and around commercial vegetable crucifer plantings, and C. nasturtii emergence was detected from most of them. The number of C. nasturtii that emerged from the weeds was low and varied by species, year, and the timing of sampling. Peak emergence from weeds in fallow fields occurred in June. Nonchoice tests in the laboratory showed that significantly fewer larvae were found on cruciferous weeds than on cauliflower plants, although C. nasturtii could lay eggs on the weeds. When weeds and cauliflower plants were simultaneously exposed to C. nasturtii adults for egg laying (choice tests), 97.3% of the C. nasturtii larvae were found on the cauliflower plants 8 d after oviposition, 2.7% on Sinapis arvensis L., and none on the other five weed species tested. Our results suggest that cruciferous weeds can serve as alternative host plants of C. nasturtii but are less suitable than cauliflower. A method of detecting C. nasturtii on weeds and control of C. nasturtii through weed management are discussed.

Levels of sinalbin (4-hydroxybenzylglucosinolate) and 28 other glucosinolates were determined in leaves and roots of 20 species that were either phylogenetically close to Sinapis alba, Sinapis arvensis, or Sinapis pubescens (tribe Brassiceae, Brassicaceae), or were expected to contain arylalkyl nitrilase activity. Comparison with a molecular phylogenetic tree based on ITS DNA sequences identified two separate occurrences of sinalbin. The first in a group of species related to S. alba (including members of the genera Coincya and Kremeriella); and the second in S. arvensis, nested among sinalbin deficient species. Significant 4-hydroxyphenylacetonitrile degrading enzyme activity was found in both S. alba and S. arvensis, but in S. alba the major product was the corresponding carboxylic acid, while in S. arvensis the major product was the amide. Both investigated enzyme activities, nitrilase and nitrile hydratase, were specific, accepting only certain arylacetonitriles such as 4-hydroxy and 4-methoxyphenylacetonitrile. Only the S. alba enzyme required an oxygen in para position of the substrate, as found in sinalbin. Indole-3-acetonitrile, arylcyanides, and arylpropionitriles were poor substrates. The nitrilase activity of S. alba was quantitatively comparable to that reported in the monocot Sorghum bicolor (believed to be involved in cyanogenic glycoside metabolism). Glucosinolates derived from methionine were found in all Sinapis clades. Glucosinolate patterns suggested a complex evolution of glucosinolates in the investigated species, with several apparent examples of abrupt changes in glucosinolate profiles including chain length variation and appearance of glucosinolates derived from branched-chain amino acids. NMR data for desulfated homosinalbin, 9-methylsulphonylnonylglucosinolate, 3-methylpentylglucosinolate and related glucosinolates are reported, and a facultative connection between sinalbin and specific nitrilases is suggested.

A study of the penetration of 3:5-dinitro-0-cresol from spray solutions or suspensions into leaves of Sinapis arvensis L. shows that entry through the stomata is unimportant. Lethal amounts may enter from aqueous solution by simple diffusion of the undissociated phenol through the epidermis, which behaves as a homogeneous lipide membrane. The effect of the structure of the epidermal surface on the rate of diffusion is discussed. Lethal amounts may also enter Sinapis from a dry surface deposit by gaseous diffusion through the stomata or by diffusive penetration of the epidermis following sublimation. Movement of the substance within a plant is slight and appears to be mainly by diffusion. The selective action of 3:5-dinitro-0-cresol as a weed-killer is discussed in the light of these results.

Plants of wild species Sinapis arvensis L . — (wild mustard) with severe mosaic symptoms were established all around different farm crops in Sofia valley and even in the Sofia suburbs in 2006. Two viruses were identified by ELISA method (DAS-ELISA) and by the indicator method. Those were the virus of the genus Caulimovirus , family Caulimoviridae — Cauliflower mosaic virus (CaMV) and a virus of the genus Potyvirus , family Potyviridae — Turnip mosaic virus (TuMV). Both viruses were found in wild mustard plants, often in mixed infection. Turnip yellow mosaic virus (TYMV) wasn’t determined in wild mustard plants. CaMV was identified by the infection of its diagnostic indicator species Brassica oleracea var. botrytis (cv. Snowball) — cauliflower. Besides cauliflower, TuMV was also identified in cabbage — Brassica oleracea var. capitata, cv. Balkan, Chenopodium amaranticolor, Chenopodium quinoa and tobacco plants — Nicotiana rustica and Nicotiana tabacum , cv. Samsun. The economically important crop oilseed r...

In order to estimate the introgressive hybridisation propensity (IHP) between genetically modified (GM) oilseed rape (Brassica napus) and certain of its cross-compatible wild/weedy relatives at the landscape level, a conceptual approach was developed. A gene flow index was established enclosing the successive steps to successfully achieve introgressive hybridisation: wild/weedy relatives and oilseed rape should co-occur, have overlapping flowering periods, be compatible, produce viable and fertile progeny, and the transgenes should persist in natural/weedy populations. Each step was described and scored, resulting in an IHP value for each cross-compatible oilseed rape wild/weedy relative. The gene flow index revealed that Brassica rapa has the highest introgressive hybridisation propensity (IHP value = 11.5), followed by Hirschfeldia incana and Raphanus raphanistrum (IHP = 6.7), Brassica juncea (IHP = 5.1), Diplotaxis tenuifolia and Sinapis arvensis (IHP = 4.5) in Flanders. Based on the IHP values, monitoring priorities can be defined within the pool of cross-compatible wild/weedy oilseed rape relatives. Moreover, the developed approach enables to select areas where case-specific monitoring of GM oilseed rape could be done in order to detect potential adverse effects on cross-compatible wild/weedy relatives resulting from vertical gene flow. The implementation of the proposed oilseed rape-wild relative gene flow index revealed that the survey design of existing botanical survey networks does not suit general surveillance needs of GM crops in Belgium. The encountered hurdles to implement the gene flow index and proposals to acquire the missing data are discussed.

Esta Tesis trata de conocer el papel del cultivo de la remolacha azucarera como sumidero de CO2 cuantificando, por una parte, la absorción de dicho gas de efecto invernadero y dilucidando, por otra, si este proceso de asimilación está determinado ontogénicamente o si bien está influenciado por condiciones ambientales. Una vez demostrado que el factor localización (clima, suelo y campaña) es determinante e identificada la influencia de radiación y temperatura, se plantea la necesidad de, a través de un escenario de cambio climático del AR5 de IPCC y el modelo de simulación de cultivos Aquacrop de FAO, conocer los posibles futuros comportamientos y tendencias del cultivo. Todo ello y junto al uso de índices de vegetación RGB (existentes y dos nuevos propuestos), como herramientas para la detección de cambios críticos en el cultivo que afecten a su capacidad como sumidero, se genera el conocimiento necesario para ulteriores medidas de adaptación., Departamento de Ingeniería Agrícola y Forestal

To explore the phylogenetic relationship, genome donor, and evolutionary history of the polyploid mustard (Brassica juncea) from China, eighty-one sequences of the chalcone synthase gene (Chs) were analyzed in 43 individuals, including 34 B. juncea, 2 B. rapa, 1 B. nigra, 2 B. oleracea, 1 B. napus, 1 B. carinata, and 2 Raphanus sativus. A maximum likelihood analysis showed that sequences from B. juncea were separated into two well-supported groups in accordance with the A and B genomes, whereas the traditional phenotypic classification of B. juncea was not wholly supported by the molecular results. The SplitsTree analysis recognized four distinct groups of Brassicaceae, and the median-joining network analysis recognized four distinct haplotypes of Chs. The estimates of Tajima's D, Fu and Li's D, and Fu and Li's F statistic for the Chs gene in the B genome were negative, while those in the A genome were significant. The results indicated that 1) the Chs sequences revealed a high level of sequence variation in Chinese mustard, 2) both tree and reticulate evolutions existed, and artificial selection played an important role in the evolution of Chinese mustard, 3) the original parental species of Chinese mustard are B. rapa var. sinapis arvensis and B. nigra (derived from China), 4) nucleotide variation in the B genome was higher than that in the A genome, and 5) cultivated mustard evolved from wild mustard, and China is one of the primary origins of B. juncea.

Experience of insect herbivores and their natural enemies in the natal habitat is considered to affect their likelihood of accepting a similar habitat or plant/host during dispersal. Growing phenology of food plants and the number of generations in the insects further determines lability of insect behavioural responses at eclosion. We studied the effect of rearing history on oviposition preference in a multivoltine herbivore (Pieris brassicae), and foraging behaviour in the endoparasitoid wasp (Cotesia glomerata) a specialist enemy of P. brassicae. Different generations of the insects are obligatorily associated with different plants in the Brassicaceae, e.g., Brassica rapa, Brassica nigra and Sinapis arvensis, exhibiting different seasonal phenologies in The Netherlands. Food plant preference of adults was examined when the insects had been reared on each of the three plant species for one generation. Rearing history only marginally affected oviposition preference of P. brassicae butterflies, but they never preferred the plant on which they had been reared. C. glomerata had a clear preference for host-infested B. rapa plants, irrespective of rearing history. Higher levels of the glucosinolate breakdown product 3-butenyl isothiocyanate in the headspace of B. rapa plants could explain enhanced attractiveness. Our results reveal the potential importance of flexible plant choice for female multivoltine insects in nature.

Bu çalışma, Niğde ili ve İlçeleri patates ekim alanlarında sorun olan yabancı ot türlerinin yoğunluklarını ve rastlanma sıklıklarını belirlemek amacıyla 2016 yılında yürütülmüştür. Sürvey çalışmaları Niğde Merkez ve İlçelerinde (Altunhisar, Bor, Çamardı, Çiftlik, Ulukışla) 180 tarlada Mayıs-Temmuz aylarında gerçekleştirilmiştir. Yapılan sürvey çalışması sonucunda, 21 farklı familyaya ait 60 farklı yabancı ot türü tespit edilmiştir. Survey yapılan tarlalardaki m2'deki yoğunluklara göre en fazla sorun olan tür 4,24 bitki/m2 yoğunluk ile Kırmızı köklü tilki kuyruğu (Amaranthus retroflexus L.) olmuştur. Bu türü 2,81 bitki/m2 ile Sirken (Chenopodium album L.), 2,67 bitki/m2 ile Melez horozibiği (A. hybridus L.), 1,46 bitki/m2 ile Siyah it üzümü (Solanum nigrum L.), 1,45 bitki/m2 ile Yabani hardal (Sinapis arvensis L.), 1,45 bitki/m2 ile Tarla sarmaşığı (Convolvulus arvensis L.) ve 1,32 bitki/m2 ile Darıcan [Echinochloa crus-galli (L.)] izlemiştir. Rastlanma sıklığına göre ise %68 Sirken (C. album), %65 Kırmızı köklü tilki kuyruğu (A. retroflexus), %42 Tarla sarmaşığı (C. arvensis), %25 Melez horozibiği (A. hybridus L.), %24 Yabani hardal (S. arvensis), %19 Yatık horoz ibiği (A. blitoides L.), %15 Siyah it üzümü (S. nigrum ), %13 Kekre (Acroptilon repens L.), %12 Domuz pıtrağı (Xanthium strumarium L.) olarak belirlenmiştir., This study was carried out to determine the distribution and density of weed species which are problem on potato fields at around Niğde Province in 2016 year. Survey studies were made in potato cultivation field in Niğde center and its district (Altunhisar, Bor, Çamardı, Çiftlik, Ulukışla) between May and July on 180 potato fields. As a result of survey, 60 different weed species from 21 families were identified. The weed species with higher infestation rate and density according to average number of weeds m were found in this study as follows: Red pigweed (Amaranthus retroflexus L.,) with the density of 4.24 plants/m2. Followed by 2.81 plants/m2 with white goosefoot (Chenopodium album L), 2.67 plants/m2 with lying amaranth (Amaranthus hybridus L.), 1.46 plants/m2 with black nightshade (Solanum nigrum L.), 1.45 plants/m2 with white mustard (Sinapis arvensis L.), with field bindweed 1.45 plants/m2 with field bindweed (Convolvulus arvensis L.), 1.32 plants/m2 of barnyard grass (Echinochloa crus-galli). Weeds which are important in terms of frequency of occurrence is white goosefoot by 68%, red pigweed by 65%, field bindweed by 42%, lying amaranth by 25%, field mustard by 24%, mat amaranth by 19%, black nightshade by 15%, Russian knapweed by 13%, rough cocklebur by 12% were determined.

This experiment was conducted in order to determine if Persian clover (Trifolium resupinatum) and Berseem clover (Trifolium alexandrium) contained water-soluble and methanol-soluble constituents that could affect the seedling growth of four test species; namely, Amaranthus retroflexus, Convolvulus arvensis (field bindweed), Secale cereale, and Sinapis arvensis (wild mustard). The above-ground tissues of the Persian and Berseem clover plants were collected during the vegetative growth stage and oven-dried. Three concentrations of aqueous and methanolic extracts were used at full-strength (33.3 g L−1), half-strength (16.7 g L−1), and quarter-strength (8.3 g L−1). Distilled water was used as the control. The weed seeds were placed in Petri dishes containing the legume extract or distilled water (control). The seedling growth of the weed species declined with the increasing concentration of the clover extracts. Wild mustard exhibited the highest sensitivity to both the legume extracts. Compared to the aqueous extract, the methanolic extract caused a greater decline in the seedling growth of the weeds. Berseem clover was the stronger inhibitor of the weed seedling growth, as compared to Persian clover. Therefore, the amounts of allelochemicals present might differ in these two clover species. Field bindweed showed the least sensitivity to both the legume extracts. Field bindweed showed more tolerance to the allelochemicals produced by the clover species.

Field experiments were conducted from 2003 to 2005 in Ontario to determine if reduced rates of imazethapyr (< 75 g a.i. ha-1) tank-mixed with dimethenamid applied preemergence (PRE) can be used as a feasible weed management strategy for broad-spectrum weed control in white and kidney beans (Phaseolus vulgaris L.). There was no injury in white or kidney bean with the imazethapyr plus dimethenamid tank-mix treatments evaluated. The rate of imazethapyr required to provide adequate control of green foxtail [Setaria viridis (L.) P. Beauv.], lamb’s-quarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), wild mustard (Sinapis arvensis L.), and redroot pigweed (Amaranthus retroflexus L.) tended to be reduced when tankmixed with dimethenamid at 1000 g ha-1. There was no adverse effect on the yield of white and kidney beans at the highest rate (75 g a.i. ha-1) of imazethapyr evaluated. Although both herbicides are considered reduced risk, the environmental impact of imazethapyr (75 g a.i. ha-1) was seven times less than that of dimethenamid (1000 g a.i. ha-1). The addition of reduced rates of imazethapyr to dimethenamid did not significantly increase environmental impact (EI) vs. dimethenamid alone. Profit margins were greater when dimethenamid was tank-mixed with imazethapyr than for applications of imazethapyr alone. Across all treatments, profit margins were maximized at an imazethapyr rate of 60 g a.i. ha-1 for white bean and an imazethapyr rate of between 60 and 75 g a.i. ha-1 for kidney bean. However, the profit-maximizing rates of imazethapyr tended to be higher for treatments without dimethenamid than for treatments where dimethenamid was tank-mixed with imazethapyr. Key words: Dimethenamid, environmental impact quotient (EIQ), imazethapyr, Montcalm, OAC Thunder, Phaseolus vulgaris L., profit margin

Three field trials were conducted over a 3-year period (2003, 2004 and 2005) near Exeter, Ontario to determine if dimethenamid tank-mixed with reduced doses of imazathapyr applied preplant incorporated (PPI) can be used as an efficacious, environmentally acceptable, and economically feasible weed management strategy for broad spectrum weed control in white and kidney beans. There was no additional injury in white or kidney beans with the imazethapyr plus dimethenamid tank-mix treatments evaluated. Based on regression analysis, the dose of imazethapyr required to provide a minimum of 95% control of Amaranthus retroflexus , Ambrosia artemesiifolia , Chenopodium album , Sinapis arvensis , and Setaria viridis was reduced significantly when tank-mixed with dimethenamid (1000 g ha −1 ). There was no adverse effect on the yield of white and kidney beans with any of the herbicides evaluated. The low application dose of imazethapyr compared to dimethenamid (75 vs. 1000 g ai ha −1 , respectively) resulted in an environmental impact (EI) of imazethapyr that was seven-times less than dimethenamid. The application of dimethenamid at 1000 g ai ha −1 or imazethapyr at 15 g ai ha −1 produced the lowest profit margins. Application of higher doses of imazethapyr alone and tank-mixing dimethenamid with imazethapyr increased the profit margins for both white and kidney beans. Based on these results, dimethenamid tank-mixed with reduced doses of imazathapyr applied PPI results in acceptable weed control, crop yield and net returns with an acceptable minimal increase in environmental impact.

Fertilization may affect the relative competitive ability of weeds and crops if the growth response to fertilizer differs among species. Greenhouse studies were conducted to evaluate the relative biomass yield response of 19 weed species and the crops canola (Brassica napus L.) and spring wheat (Triticum aestivum L.) to potassium (K) and sulphur (S) fertilization. Seven weed species showed a significant increase in biomass production at 6 wk with K fertilization, but biomass production of canola and wheat did not increase with K addition. Sulphur fertilizer increased the biomass production of canola, flixweed (Descurainia sophia L.) and wild mustard (Sinapis arvensis L.), three of the four Cruciferae species evaluated, as well as that of hairy nightshade (Solanum sarrachoides Sendtner), round-leaved mallow (Malva pusilla Sm.) and stork’s-bill [Erodium cirutarium (L.) L’Her. Ex. Ait.]. Sulphur fertilizer did not increase the biomass production of spring wheat or of any grass weed species. The data from the greenhouse study support the concept that fertilization may shift the relative competition between a crop and the weed population if the weeds are more responsive than the crop to the type of fertilizer applied. However, this concept should be tested under field conditions. Key words: Integrated weed management, sulphur, potassium

The genetic basis for auxinic herbicide resistance of a wild mustard biotype is unknown, although the physiological basis of its resistance is well characterized. Since the auxinic herbicide-resistant (R) biotype and normally susceptible (S) wild mustard plants are genetically diverse, development of completely homozygous R and S lines is a prerequisite for isolation and subsequent characterization of the resistance gene. Completely homozygous lines can be produced using either in vitro microspore culture or by conventional breeding methods (i.e., several generations of selfing); the former being a less time consuming method. With this in mind, microspore culture was used to produce homozygous wild mustard plants. However, despite altering many variables, only a few cotyledonary stage embryos and haploid plantlets could be produced. Upon transfer to soil only one doubled haploid plant established. This plant was self-sterile, cross compatible and resistant to auxinic herbicides. This is the first report describing production of a microspore-derived doubled haploid of wild mustard. However, because only one R doubled haploid plant could be produced, conventional breeding methods (i.e., repeated selfing) will be required for production of both R and S wild mustard plants that are completely homozygous.