Rape Crops Research Articles

Combination of the degrading bacterium Bacillus cereus MZ-1 and corn straw biochar enhanced the removal of imazethapyr from water solutions

Long residual herbicide imazethapyr has caused a serious threat to subsequent sensitive crop plants and ecological security. Efficient immobilized microorganism technology offers a sustainable solution for remediating pesticides contamination. In this study, three corn straw biochars produced at 300℃, 500℃, and 700℃ were used as carriers to immobilize the imazethapyr degrading strain Bacillus cereus MZ-1, aiming to efficiently remove imazethapyr from the water environment. Response surface methodology was employed to optimize the best immobilization conditions based on the efficiency of imazethapyr removal. The results indicate that the biochar produced at 500 ℃ was the most effective carrier for immobilization, despite having a lower imazethapyr removal capacity compared to the biochar produced at 700 ℃. Additionally, the optimal strain addition amount was a suspension of strain MZ-1 (OD600=1) in a 3.5-fold biochar solution, and the best immobilized time was 18 h. The prepared immobilized MZ-1 achieved a maximum imazethapyr removal efficiency of 79.85 %. Moreover, the immobilized MZ-1 demonstrated enhanced detoxification efficacy against imazethapyr-induced harm in sensitive oilseed rape crops, surpassing the effects of using MZ-1 or biochar alone. Results of this work suggests biochar immobilized degradation strain MZ-1 is a highly effective in-situ remediation strategy for bioremediation of imazethapyr contamination.

Image Segmentation-Based Oilseed Rape Row Detection for Infield Navigation of Agri-Robot

The segmentation and extraction of oilseed rape crop rows are crucial steps in visual navigation line extraction. Agricultural autonomous navigation robots face challenges in path recognition in field environments due to factors such as complex crop backgrounds and varying light intensities, resulting in poor segmentation and slow detection of navigation lines in oilseed rape crops. Therefore, this paper proposes VC-UNet, a lightweight semantic segmentation model that enhances the U-Net model. Specifically, VGG16 replaces the original backbone feature extraction network of U-Net, Convolutional Block Attention Module (CBAM) are integrated at the upsampling stage to enhance focus on segmentation targets. Furthermore, channel pruning of network convolution layers is employed to optimize and accelerate the model. The crop row trapezoidal ROI regions are delineated using end-to-end vertical projection methods with serialized region thresholds. Then, the centerline of oilseed rape crop rows is fitted using the least squares method. Experimental results demonstrate an average accuracy of 94.11% for the model and an image processing speed of 24.47 fps/s. After transfer learning for soybean and maize crop rows, the average accuracy reaches 91.57%, indicating strong model robustness. The average yaw angle deviation of navigation line extraction is 3.76°, with a pixel average offset of 6.13 pixels. Single image transmission time is 0.009 s, ensuring real-time detection of navigation lines. This study provides upper-level technical support for the deployment of agricultural robots in field trials.

Temperature and time of season are the predominant drivers of cabbage stem flea beetle, Psylliodes chrysocephala, arrival at oilseed rape crops

Cabbage stem flea beetle (CSFB) is an economically important pest of oilseed rape crops responsible for substantial yield losses in recent years, particularly since the restrictions on neonicotinoid seed treatment use came into force in 2013. To effectively time sowing dates and target control measures, it is crucial that accurate estimates of when migratory adult CSFB will arrive at the crop can be made. A Bayesian hierarchical model was fitted to data from 19 sites containing adult CSFB traps over a period of three years to characterise the relationship between the day of year, temperature, rainfall, wind speed and solar radiation on beetle counts and to understand their relative importance. Day of the year was identified as the main driver of migration and temperature was the predominant environmental driver of CSFB migration. A hot day (based on the range of observed temperatures over the trapping window) resulted in approximately 300% of the expected CSFB migration relative to an average day during peak migration. The second most important environmental driver of migration was wind speed, but this resulted in a relatively negligible increase of approximately 15% from an average day to a still day. These findings suggest that efforts to predict timing of adult CSFB migration should focus on understanding how the phenology of CSFB and temperature interact to drive the timing of migration.

Tillage Practices Effect on Root Distribution and Variation of Soil CO2 Emission under Different Cropping Strategies

Conservation soil management strategies, particularly no-tillage and cropping strategies, have become an effective and widely adopted practice that has a direct influence on root parameters and mitigation of greenhouse gasses. However, the effect of different tillage and cropping strategies on root growth in field conditions is rarely studied. The study aimed to quantify and characterise the relationship between root network development and CO2 emission and how these parameters are affected by different cropping and tillage strategies. Five different crop rotations were tested, with or without the inclusion of catch crops (CC), by growing them in the soil where different tillage practices were applied. Selected cropping strategies differed among themselves in terms of the frequency of CC grown per rotation. The data revealed that in NT treatments, the CO2 emission (both autotrophic and heterotrophic simultaneously) was 25% higher than in CT. The cropping strategies were identified as an important factor influencing CO2 emissions. An increase in CO2 emission varied between 30 and 35% depending on the share of legume and CC inclusion. The frequency of CC grown per rotation has had an effect on the rate of CO2 emission. The cropping strategy when CC was grown every year showed the lowest amount of CO2 (by 26%), while in other cropping strategies, when CC was grown once or twice per rotation, significantly higher CO2 emissions were observed. Root growth and their development were significantly affected (p < 0.05) by soil depth and cropping strategies concerning root length and root volume changes. The inclusion of CC into the rotations led towards a decrease in root volume (by 21%). Root length (R2 = 0.45; p < 0.05) and root volume (R2 = 0.82; p < 0.05) had a significant impact on soil CO2 emissions. The results collected from 2021 to 2023 experiments indicated that cropping strategies and CC management areas are important tools not only for the improvement of root parameters but also for understanding how they affect CO2 emissions. The main message for stakeholders is that the cropping strategies diversification with the inclusion of CC every year in a winter oil-seed rape, spring wheat and pea crop rotation (R/W/P + CC) had demonstrated the possibilities to reduce CO2 emission and improve the root network parameters as compared to the monoculture strategy.

Multiple cropping effectively increases soil bacterial diversity, community abundance and soil fertility of paddy fields

BackgroundCrop diversification is considered as an imperative approach for synchronizing the plant nutrient demands and soil nutrient availability. Taking two or more crops from the same field in one year is considered as multiple cropping. It improves the diversity and abundance of soil microbes, thereby improving the growth and yield of crops. Therefore, the present study was conducted to explore the effects of different multiple winter cropping on soil microbial communities in paddy fields. In this study, eight rice cropping patterns from two multiple cropping systems with three different winter crops, including Chinese milk vetch (CMV), rape, and wheat were selected. The effects of different multiple winter cropping on soil microbial abundance, community structure, and diversity in paddy fields were studied by 16 S rRNA high-throughput sequencing and real-time fluorescence quantitative polymerase chain reaction (PCR).ResultsThe results showed that different multiple winter cropping increased the operational taxonomic units (OTUs), species richness, and community richness index of the bacterial community in 0 ~ 20 cm soil layer. Moreover, soil physical and chemical properties of different multiple cropping patterns also affected the diversity and abundance of microbial bacterial communities. The multiple cropping increased soil potassium and nitrogen content, which significantly affected the diversity and abundance of bacterial communities, and it also increased the overall paddy yield. Moreover, different winter cropping changed the population distribution of microorganisms, and Proteobacteria, Acidobacteria, Nitrospira, and Chloroflexi were identified as the most dominant groups. Multiple winter cropping, especially rape-early rice-late rice (TR) andChinese milk vetch- early rice-late rice (TC) enhanced the abundance of Proteobacteria, Acidobacteria, and Actinobacteria and decreased the relative abundance of Verrucomicrobia and Euryarchaeota.ConclusionIn conclusion, winter cropping of Chinese milk vetch and rape were beneficial to improve the soil fertility, bacteria diversity, abundance and rice yield.

The Influence of Nitrogen and Sulfur Fertilization on Oil Quality and Seed Meal in Different Genotypes of Winter Oilseed Rape (Brassica napus L.)

Adequate nitrogen (N) and sulfur (S) fertilization of oilseed rape crops is necessary to obtain good-quality oil and post-extraction rapeseed meal. The aim of this study was to determine the effect of different doses of N fertilization (100, 160 and 220 kg ha−1) and S (0, 30, 60 and 90 kg ha−1) on the value of seeds of three winter oilseed rape genotypes. Two winter oilseed rape genotypes obtained by mutagenesis (cultivar Polka and breeding genotype PN440) were characterized by changed fatty acid profile. The cultivar Polka, type HO (high oleic), had a high content of oleic acid (C18:1, 78.0%) and the breeding genotype PN440, type HOLL (high-oleic and low-linolenic), had a high content of oleic acid (C18:1, 75.0%) and a low content of linolenic acid (C18:3, 3.0%). We also used the canola type of winter oilseed rape cultivar, Monolit. The analysed winter oilseed rape genotypes responded similarly to the N and S fertilization factors with regard to the content of crude fat and total protein in the seeds and the composition of fatty acids in the oil. N fertilization increased the content of glucosinolates (GLS-alkenyl, indole and total) in seeds, whereas S application decreased the content of saturated fatty acids (stearic acid-C18:0) in oil and increased the content of alkenyl and total glucosinolates (GLSs) in seeds. A significant interaction between N and S was observed for crude-fat and total-protein content. This study suggests that ensuring an adequate supply of both nitrogen and sulfur in the soil is essential for optimizing meal and oil quality in different types of winter oilseed rape cultivars. Proper management of these nutrients can lead to improved oil content and overall crop performance.

ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ МИНЕРАЛЬНОГО УДОБРЕНИЯ С МИКРОЭЛЕМЕНТАМИ БИОЧАР-АГРО МАРКИ ТЕХНИЧЕСКИЕ НА ЯРОВОМ РАПСЕ

The research was carried out in order to study the effectiveness of mineral fertilizer with microelements of Biochar-Agro Technical grade on spring rape crops on gray forest soils of the Republic of Tatarstan. Field experiments were conducted in 2023 on the basis of Agrobiotechnopark LLC (Narmonka village, Laishevsky Municipal District of the Republic of Tatarstan), laboratory analyses were carried out at the Center for Agroecological Research of the Kazan State Agrarian University. According to the research results, it was found that the application of Biochar-Agro fertilizer of the Technical brand contributed to an increase in the safety of plants for harvesting by 0.8 % compared with the control variant. In addition, the studied complex fertilizer contributed to an increase in the duration of the growing season of spring rapeseed. In the 10.0 kg/ha variant, the growing season was increased by 6 days. The height of the plants increases from 116.6 cm at the control, to 123.4 cm in the last version of the experiment, which is 6.8 centimeters higher than the control. In the variant Background NPK + Biochar-Agro brand: Technical (seed application, 10.0 kg /ha), the number of weeds per 1 m2 was 8.2 pcs., which is less than the control variant by 3.2 w. or 31.7 %. The maximum number of productive branches (5.5 pcs./plant) was formed on the variant of the near-sowing application of Biochar-Agro fertilizer of the Technical brand 10.0 kg/ha. The increase in the actual yield of spring rapeseed from the application of the studied preparation ranged from 0.23 to 0.49 t /ha, depending on the rate of application of Biochar-Agro brand fertilizers: Technical.

Novel indices reveal that pollinator exposure to pesticides varies across biological compartments and crop surroundings

Declines in insect pollinators have been linked to a range of causative factors such as disease, loss of habitats, the quality and availability of food, and exposure to pesticides. Here, we analysed an extensive dataset generated from pesticide screening of foraging insects, pollen-nectar stores/beebread, pollen and ingested nectar across three species of bees collected at 128 European sites set in two types of crop. In this paper, we aimed to (i) derive a new index to summarise key aspects of complex pesticide exposure data and (ii) understand the links between pesticide exposures depicted by the different matrices, bee species and apple orchards versus oilseed rape crops. We found that summary indices were highly correlated with the number of pesticides detected in the related matrix but not with which pesticides were present. Matrices collected from apple orchards generally contained a higher number of pesticides (7.6 pesticides per site) than matrices from sites collected from oilseed rape crops (3.5 pesticides), with fungicides being highly represented in apple crops. A greater number of pesticides were found in pollen-nectar stores/beebread and pollen matrices compared with nectar and bee body matrices. Our results show that for a complete assessment of pollinator pesticide exposure, it is necessary to consider several different exposure routes and multiple species of bees across different agricultural systems.

Design and Synthesis of Novel Diphenyl Ether Carboxamide Derivatives To Control the Phytopathogenic Fungus Sclerotinia sclerotiorum.

Sclerotinia stem rot (SSR) caused by the phytopathogenic fungus Sclerotinia sclerotiorum has led to serious losses in the yields of oilseed rape and other crops every year. Here, we designed and synthesized a series of carboxamide derivatives containing a diphenyl ether skeleton by adopting the scaffold splicing strategy. From the results of the mycelium growth inhibition experiment, inhibition rates of compounds 4j and 4i showed more than 80% to control S. sclerotiorum at a dose of 50 μg/mL, which is close to that of the positive control (flubeneteram, 95%). Then, the results of a structure-activity relationship study showed that the benzyl scaffold was very important for antifungal activity and that introducing a halogen atom on the benzyl ring would improve antifungal activity. Furthermore, the results of an in vitro activity test suggested that these novel compounds can inhibit the activity of succinate dehydrogenase (SDH), and the binding mode of 4j with SDH was basically similar to that of the flutolanil derivative. Morphological observation of mycelium revealed that compound 4j could cause a damage on the mycelial morphology and cell structure of S. sclerotiorum, resulting in inhibition of the growth of mycelia. Furthermore, in vivo antifungal activity assessment of 4j displayed a good control of S. sclerotiorum (>97%) with a result similar to that of the positive control at a concentration of 200 mg/L. Thus, the diphenyl ether carboxamide skeleton is a new starting point for the discovery of new SDH inhibitors and is worthy of further development.

INFLUENCE OF HERBICIDE TREATMENT ON YIELD SPRING RAPE IN THE FARMS OF THE MAGZHAN ZHUMABAYEV DISTRICT OF THE NORTH KAZAKHSTAN REGION

The research work is devoted to the study of the effect of herbicide treatment on the yield of spring rapeseed in the farms of the Magzhan Zhumabayev district of the North Kazakhstan region. Field experiments were conducted to study the effect of herbicides on weed vegetation and the yield of spring rapeseed oil seeds. The timing of sowing spring rapeseed is the end of May. The species composition of the weed vegetation of rapeseed agrophytocenosis was determined. The most common weeds in spring rapeseed crops are tilted schiritsa, common shepherd's bag, white mar, field osot, creeping wheatgrass. The type of clogging of crops is root-sprout-annual. The soil of the experimental field is a complex of leached and ordinary chernozems. The objects of the study were selected herbicides "Simba" and "Hacker". These drugs are aimed at combating annual and perennial weeds. They have a systemic effect, are absorbed by the leaves, transferred to the point of growth, roots and rhizomes and easily move around the plant, disrupting cell division and stopping its growth. The drug Simba has a high efficiency in the fight against monocotyledonous weeds in spring rape crops, the average efficiency for 28 days was 28.9%. Hacker herbicide is effective for controlling dicotyledonous juvenile and perennial weeds, providing an average efficiency of 40% in 28 days. Among the processing options, the most optimal from the point of view of crop quality was the treatment with Hacker preparation in compliance with the recommended consumption rate. The quality of the crop in this variant is close to the harvest with manual weeding and differs by only 3-5%.

THE CONTROL OF WEEDS PRESENT IN THE RAPE CROP FROM NARDI FUNDULEA

This paper present the results obtained at National Agricultural Research and Development Institute Fundulea, during 2020-2022, according to the herbicide treatments: : Galera Super (40 g/l aminopyralid +240 g/l clopyralid+80 g/l picloram), Galera Super (40 g/l aminopyralid +240 g/l clopyralid+80 g/l picloram), Korveto (5g/l halauxifen-metil+ 120g/l clopyralid), postemergently (rape, BBCH 12-13 in autumn) and postemergently (rape, BBCH 33-39 in spring) applied for the weeds controlling from the rape crop. The main objective of this work focused on the study of the selectivity and effectiveness of the application of herbicide treatments to combat the weeds present in the rape crop.The herbicides must be correlated with the infestation degree of weed, the spectrum and dominance of weeds, the time of application, the technical potential for efficacy, the local climatic conditions.

SOIL MINIMUM TILLAGE SYSTEM IMPACT UPON ARIDITY HINDERED LAND IN TELEORMAN COUNTY

Two land bodies in Teleorman County were characterized in order to identify aridity affected areas. The country's agricultural and edaphic potential were taken into account on one hand, and the negative consequences determined by years long application of classical technology which contributes in the long run to the enhancement of degradation processes of fine textured soils through compaction, cleaving, and waterlogging on the other. In the Traian Administration and Territorial Unit (ATU) a pronounced soils settlement process was noted due to ploughing execution at the same depth and equipment passage on the soil in inappropriate conditions. In the Mavrodin ATU the soils have a high clay content which favors soil compaction and waterproofing raising issues of air capacity. Rape crop output was 3,700 kg/ha on the Calcic Chernozem of the Traian ATU, and 3,000 kg/ha on the Mavrodin Chromic Luvisol in the same soil works system. These soils suitability for soil minimum tillage is low due to specific intrinsically characteristics. Preserving soil covered with vegetation for an as long as possible period is recommended.

Short-term effects of brassica cover crops on soil quality indicators in organic production in high tunnels

The use of cover crops is aimed at sustaining soil health and productivity in the context of agricultural intensification and accompanying soil degradation. While cover crops have been extensively studied in field production systems, limited research has been conducted concerning their application in high-tunnel vegetable production. This study aimed to assess the effects of turnip (Brassica napus subsp. napobrassica (L.) Jafri) and swede Brassica rapa subsp. Rapifera Metzg) cover crops (CCs) on soil physicochemical and biological properties in an organic high tunnel system in southern Poland in 2017–2019. The planting sequence was as follows: winter cover crops/pumpkin/romaine lettuce/broad bean/chilli pepper. Soil analyses included measurements of bulk density, water capacity, soil aggregation, soil organic carbon (SOC), available soil nutrients, as well as microbial abundance and diversity. Rape crops produced a higher aboveground dry biomass (4.11 t ha−1) than swede (2.85 t ha−1), and the N content in their biomass was 101 kg N ha−1 and 75 kg N ha−1, respectively. The results presented that CC residue significantly contributed to soil organic carbon stock, retention of plant-available nitrogen, and improvement of soil physical properties, especially wet aggregate stability. Soils with the highest SOC concentrations were associated with the highest bacterial and fungal abundance. The most significant number of mesophilic bacteria was detected in the soil where turnip was grown as a cover crop (7.6 × 107 cfu g−1 DM soil). Moreover, a higher abundance of the tested nitrogen cycle bacteria was found in the soils after CC cultivation compared to the control soils, particularly bacteria reducing NH4 +-N and NO₃⁻-N. These findings highlight the importance of cover crop management practices in high tunnels, as they influence the composition of the total bacterial community and the abundance of N-cycling microbial guilds.

Using Remote Sensing Vegetation Indices for the Discrimination and Monitoring of Agricultural Crops: A Critical Review

The agricultural sector is currently confronting multifaceted challenges such as an increased food demand, slow adoption of sustainable farming, a need for climate-resilient food systems, resource inequity, and the protection of small-scale farmers’ practices. These issues are integral to food security and environmental health. Remote sensing technologies can assist precision agriculture in effectively addressing these complex problems by providing farmers with high-resolution lenses. The use of vegetation indices (VIs) is an essential component of remote sensing, which combines the variability of spectral reflectance value (derived from remote sensing data) with the growth stage of crops. A wide array of VIs can be used to classify the crops and evaluate their state and health. However, precisely this high number leads to difficulty in selecting the best VI and their combination for specific objectives. Without thorough documentation and analysis of appropriate VIs, users might find it difficult to use remote sensing data or obtain results with very low accuracy. Thus, the objective of this review is to conduct a critical analysis of the existing state of the art on the effective use of VIs for the discrimination and monitoring of several important agricultural crops (wheat, corn, sunflower, soybean, rape, potatoes, and forage crops), grasslands and meadows. This data could be highly useful for all the stakeholders involved in agricultural activities. The current review has shown that VIs appear to be suitable for mapping and monitoring agricultural crops, forage crops, meadows and pastures. Sentinel-1 and Sentinel-2 data were the most utilized sources, while some of the frequently used VIs were EVI, LAI, NDVI, GNDVI, PSRI, and SAVI. In most of the studies, an array of VIs needed to be employed to achieve a good discrimination of crops or prediction of yields. The main challenges in using VIs are related to the variation of the spectral characteristics during the vegetation period and to the similarities of the spectral signatures of various crops and semi-natural meadows. Thus, further studies are needed to establish appropriate models for the use of satellite data that would prove to have greater accuracy and provide more relevant information for the efficient monitoring of agricultural crops.

The INRAE Biological Resource Center ‘BrACySol’: a French centre of valuable genetic resources to address major issues faced by potato and oilseed rape crops

The INRAE Biological Resource Center ‘BrACySol’: a French centre of valuable genetic resources to address major issues faced by potato and oilseed rape crops

The effect of vermicompost and K+amino on the winter rape growth

Vermicompost contains a high concentration of macro- and micronutrients, vitamins, growth hormones, enzymes such as proteases, amylases, lipases, cellulases, and chitinases, as well as immobilized microflora. Vermicompost improves plant germination, growth, biomass, and yield. K+amino is a biologically active liquid soil amendment that is suitable for organic gardens of all types. It is a 100 % veganic growth- and health-promoting liquid microbial inoculant for all plant types, particularly fast-growing crops like vegetables, fruits, and blooms. The purpose of investigation was to look the effect of vermicompost and k+amino on the winter rape germination and growth. Methods: There were six treatments: 1. A rape (means a rape crop in Aru Agricultural Ltd. soil), 2. A rape+YaraBela AXAN 0.3g per pot, 3. A rape+vermicompost 7.9 g per pot in the soil+the vermiextract is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 1:30, 33 ml extract per 1 L water, 4. A rape+vermicompost 7.9 g per pot in the soil, 5. A rape+vermiextract is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 1:30, 33 ml extract per 1 L water, 6. A rape+K+Amino biostimulator is sprayed on the plants 1 week after sowing, 2 weeks after sowing, both treatments 5 ml K+Amino per 1 L water. Results: Rape plants were elongated in treatment with YaraBela AXAN. Stem diameter was largest in K+Amino treatment. Root length was lowest in treatment with vermicompst extract (soil was too moisty and compacted). Conclusions: Vermicompost tended to improve plant growth, while stem diameter was largely increased by using k+amino fertilizer. It turns out both actually are good sources of mineral nutrients and also different enzymes and microbes, which help plants grow

Use of an unmanned aerial vehicle for monitoring and prediction of oilseed rape crop performance.

The flowering stage of oilseed rape (Brassica napus L.) is of vital interest in precision agriculture. It has been shown that data describing the flower production of oilseed rape (OSR), at stage 3, in spring can be used to predict seed yield at harvest. Traditional field-based techniques for assessing OSR flowers are based on a visual assessment which is subjective and time consuming. However, a high throughput phenotyping technique, using an unmanned aerial vehicle (UAV) with multispectral image (MSI) camera, was used to investigate the growth stages of OSR (in terms of crop height) and to quantify its flower production. A simplified approach using a normalised difference yellowness index (NDYI) was coupled with an iso-cluster classification method to quantify the number of OSR flower pixels and incorporate the data into an OSR seed yield estimation. The estimated OSR seed yield showed strong correlation with the actual OSR seed yield (R2 = 0.86), as determined using in-situ sensors mounted on the combine harvester. Also, using our approach allowed the variation in crop height to be assessed across all growing stages; the maximum crop height of 1.35 m OSR was observed at the flowering stage. This methodology is proposed for effectively predicting seed yield 3 months prior to harvesting.

The Brassica napus boron deficient inflorescence transcriptome resembles a wounding and infection response.

Oilseed rape and other crops of Brassica napus have a high demand for boron (B). Boron deficiencies result in the inhibition of root growth, and eventually premature flower abortion. Understanding the genetic mechanisms underlying flower abortion in B-limiting conditions could provide the basis to enhance B-efficiency and prevent B-deficiency-related yield losses. In this study, we assessed transcriptomic responses to B-deficiency in diverse inflorescence tissues at multiple time points of soil-grown plants that were phenotypically unaffected by B-deficiency until early flowering. Whilst transcript levels of known B transporters were higher in B-deficient samples, these remained remarkably stable as the duration of B-deficiency increased. Meanwhile, GO-term enrichment analysis indicated a growing response resembling that of a pathogen or pest attack, escalating to a huge transcriptome response in shoot heads at mid-flowering. Grouping differentially expressed genes within this tissue into MapMan functional bins indicated enrichment of genes related to wounding, jasmonic acid and WRKY transcription factors. Individual candidate genes for controlling the "flowering-without-seed-setting" phenotype from within MapMan biotic stress bins include those of the metacaspase family, which have been implicated in orchestrating programmed cell death. Overall temporal expression patterns observed here imply a dynamic response to B-deficiency, first increasing expression of B transporters before recruiting various biotic stress-related pathways to coordinate targeted cell death, likely in response to as yet unidentified B-deficiency induced damage-associated molecular patterns (DAMPs). This response indicates new pathways to target and dissect to control B-deficiency-induced flower abortion and to develop more B-efficient crops.

Significance of Direct and Indirect Impacts of Temperature Increase Driven by Climate Change on Threat to Oilseed Rape Posed by Sclerotinia sclerotiorum.

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, threatens oilseed rape (Brassica napus) crops internationally. The development of this disease is strongly controlled by the weather, which is why global climate change is likely to influence its spread and impact. Climate change may affect the pathogen directly or indirectly via the host plant. This study investigates the potential impact of climate warming on Sclerotinia stem rot severity in oilseed rape in Poland. The aim of this investigation was to assess the relationship between the direct impact (DI) and indirect impact (II) of climate change on disease severity using the 4.5 and 8.5 representative concentration pathways (RCPs). Under the RCP4.5 scenario, nearly 60% of the simulations performed for 16 regions in four periods (2020-2039, 2040-2059, 2060-2079, 2080-2099) showed reductions in disease severity in comparison to those conducted for 1986-2005, while under RCP 8.5, this reduction was generated for nearly 90% of the cases. The effect of the RCP scenario on clustering the regions according to the value of Sclerotinia stem rot severity was also investigated. The simulations revealed that, for all periods, the lowest disease severities are expected for Zachodniopomorskie and Pomorskie. The results obtained also show the superior effects of the II over the DI on Sclerotinia stem rot severity in the future. Under the RCP4.5 scenario, the rate of IIs was greater than that of DIs for 10 regions, while under RCP8.5, this relationship was registered for 16 regions. These outcomes result from the acceleration of the oilseed rape flowering period triggered by expected temperature increases. The novelty of this study lies in a detailed analysis of the relationships between the DI and II of climate change, expressed numerically, for 16 regions in Poland. The obtained results highlight the role of the indirect impact in shaping disease severity and indicate that it should be incorporated into assessment methods of climate change effects alongside the direct impact.

The structure of plant–pollinator networks is affected by crop type in a highly intensive agricultural landscape

In agricultural landscapes, bipartite networks formed by pollinators and the flowers they forage on, are characterised by the presence of honeybees (Apis mellifera) or crop plants. These managed species can affect the structural properties of these networks because of spatial and temporal variation in the availability of resources, and competition for these resources; for example, crop plants such as oilseed rape and sunflower produce a large number of flowers during a short blooming period. Here, we examined the structure of plant–pollinator networks in an intensive agricultural landscape, the Zone Atelier Plaine & Val de Sèvre (West of France). We compiled a six-year monitoring dataset of plant–pollinator interactions, sampling by sweep-nets along transects in the main six crop types (811 fields in total). To describe networks, we computed six metrics: connectance, nodes number, modularity, specialisation and a nestedness measure. We found that the degree distribution (number of partners per species in the network) fitted better to Fisher’s log-series rather than Power law. Strong differences between crops were observed in nestedness and specialisation, even when accounting for the effect of sample size: in oilseed rape, networks were much more nested and much less specialised than in sunflower. In addition, the link ‘honeybee–crop flower’ differed between the two mass-flowering crops. Honeybees and sunflowers appeared as specialist species in sunflower crops, interacting strongly and almost exclusively with each other, whereas they are usually considered highly generalist species. Indeed, sunflower pollination may be almost entirely driven by honeybees, conversely to oilseed rape crops, where the presence of wild bees and other insects tended to produce a more diversified network.