Growth Of Oilseed Rape Research Articles

Effect of Nitrogen and Sulphur Fertilization on Winter Oilseed Rape Yield

Oilseed rape is one of many crops with high nutritional requirements, particularly for nitrogen (N) and sulphur (S). Both macronutrients affect important physiological plant functions and are essential for the proper growth and development of oilseed rape. The objective of the experiment was to investigate the impact of nitrogen and sulphur fertilization on the yield of the winter oilseed rape cultivar LG Absolut. The experiment was conducted during the 2019/2020, 2020/2021, and 2022/2023 growing seasons on Haplic Cambisol soil formed from loess, with medium levels of mineral nitrogen and sulphur. In the experiment, two nitrogen fertilization treatments (150 and 200 kg ha−1) were compared in combination with three additional sulphur fertilization rates (20, 40, and 60 kg ha−1). The results demonstrated that the effectiveness of N and S fertilization varied between individual years. On average, the highest seed yields were obtained with the application of 200 kg N ha−1 combined with sulphur, regardless of the rate. This was attributed to a significant increase in soil–plant analysis development (SPAD) values, the number of pods per plant, and the thousand-seed weight. The increase in seed yield with the higher nitrogen rate without sulphur ranged from 0.36 to 0.57 t ha−1 compared to the lower rate (control 150 N kg ha−1). Supplementary sulphur fertilization increased seed yield ranging from 0.22 to 0.76 t ha−1. The protein content in the seeds increased, while the fat content decreased, following the application of the higher nitrogen rate. The decrease in fat content was mitigated by higher rates of sulphur. The application of 60 kg S ha−1 yielded similar results of the tested parameters to the lower rates. Therefore, for soils with moderate levels of mineral nitrogen and sulphur, it is recommended to fertilize winter oilseed rape with 200 kg N ha−1 combined with 20 or 40 kg S ha−1.

Determinants of oilseed rape-service plant intercropping performance variability across a farmers’ fields network in Western Switzerland

The intercropping of winter oilseed rape with frost-sensitive service plants can provide a diversity of services including weed control and N supply for oilseed rape. This practice started to be adopted by farmers and has therefore become one of the most popular intercropping in Western Europe. However, in Switzerland, such intercropping leads to contrasting yields. The growth of service plants and the benefits they provide have also been found to be variable. The factors explaining these variabilities remain unclear. Our study aimed to better understand this variability under a temperate climate thanks to the regional agronomic diagnosis framework. In this study, we first investigated the main factors explaining this variability and then aimed to rank them to identify ways to better manage such intercropping systems. A network of 28 farmers’ fields planted with winter oilseed rape intercropped with service plant mixtures was studied. Farmers’ practices were diverse in terms of specific composition of the service plant mixture, pest management, and fertilization. We observed that the growth of oilseed rape and service plants in fall was highly variable. We determined that in late fall, the main drivers of the service plant mixture dry weight were specific composition of the mixture and precipitation. The introduction of buckwheat in the service plant mixture enhanced its late fall biomass. The oilseed rape grain yields ranged from 0.4 to 5.0 t ha−1 and were lower than that of the local reference in 75% of the fields. This was mainly explained by insect pest damage in spring due to a very limited use of insecticide in our field network combined with a lack of alternative pest management strategies. This work provides further elements to investigate the causes leading to the high variability we observed, together with the local observations that will benefit the farmers.

Investigation of the Allelopathic Effect of Two Invasive Plant Species in Rhizotron System.

A key question in plant invasion biology is why invasive plants are more competitive in their introduced habitat than in their native habitat. Studies show that invasive species exhibit allelopathy, influencing other plants by releasing chemicals. Research on allelopathy uses in vitro tests, investigating effects on seed germination and seedling development. Although soil plays a role in modifying allelopathic effects, observations with soil are rare and almost nothing is known about the root development of test plants developing in soil and the effects of allelopathic compounds on root architecture. Our study evaluates the allelopathic effects of false indigo-bush (Amorpha fruticosa L.) and common milkweed (Asclepias syriaca L.) on oilseed rape growth as a model plant. The rhizotron system was used to study the effect of morphology and root architecture. Leaf-soil mixtures at 0.5%, 1%, and 5% concentrations were used. Shoot and root development was strongly inhibited at 5%. But there was no difference between the allelopathy of the two species, and the application of lower concentrations did not show any effect, demonstrating that soil has a significant modifying effect on their allelopathy. Our results highlight that the development of roots growing in the soil is also worth investigating in connection with allelopathy, which can strengthen the ecological importance of allelochemicals during successful invasions.

Highly stable and antifungal properties on the oilseed rape of Cu3(MoO4)2(OH)2 nanoflakes prepared by simple aqueous precipitation

In the last few decades, nanoparticles have been a prominent topic in various fields, particularly in agriculture, due to their unique physicochemical properties. Herein, molybdenum copper lindgrenite Cu3(MoO4)2(OH)2 (CM) nanoflakes (NFs) are synthesized by a one-step reaction involving α-MoO3 and CuCO3⋅Cu(OH)2⋅xH2O solution at low temperature for large scale industrial production and developed as an effective antifungal agent for the oilseed rape. This synthetic method demonstrates great potential for industrial applications. Infrared spectroscopy and X-ray diffraction (XRD) results reveal that CM samples exhibit a pure monoclinic structure. TG and DSC results show the thermal stable properties. It can undergo a phase transition form copper molybdate (Cu3Mo2O9) at about 300 °C. Then Cu3Mo2O9 nanoparticles decompose into at CuO and MoO3 at 791 °C. The morphology of CM powder is mainly composed of uniformly distributed parallelogram-shaped nanoflakes with an average thickness of about 30 nm. Moreover, the binding energy of CM NFs is measured to be 2.8 eV. To assess the antifungal properties of these materials, both laboratory and outdoor experiments are conducted. In the pour plate test, the minimum inhibitory concentration (MIC) of CM NFs against Sclerotinia sclerotiorum (S. sclerotiorum) is determined to be 100 ppm, and the zone of inhibiting S. sclerotiorum is 14 mm. When the concentration is above 100 nm, the change rate of the hyphae circle slows down a little and begins to decrease until to 200 ppm. According to the aforementioned findings, the antifungal effects of a nano CM NFs solution are assessed at different concentrations (0 ppm (clear water), 40 ppm, and 80 ppm) on the growth of oilseed rape in an outdoor setting. The results indicate that the application of CM NFs led to significant inhibition of S. sclerotiorum. Specifically, when the nano CM solution was sprayed once at the initial flowering stage at a concentration of 80 ppm, S. sclerotiorum growth was inhibited by approximately 34%. Similarly, when the solution was sprayed once at the initial flowering stage and once at the rape pod stage, using a concentration of 40 ppm, a similar level of inhibition was achieved. These outcomes show that CM NFs possess the ability to bind with more metal ions due to their larger specific surface area. Additionally, their semiconductor physical properties enable the generation of reactive oxygen species (ROS). Therefore, CM NFs hold great potential for widespread application in antifungal products.

Optimizing oilseed rape growth: Exploring the effect of foliar biostimulants on the interplay among metabolism, phenology, and yield.

The current agricultural system is in search of new strategies to achieve a more sustainable production while keeping or even increasing crop yield and quality. In this scenario, the application of biostimulants constitutes a potent solution. In the current study, the impact of a blue-green microalgal extract (MB) and a pig tissue hydrolysate (PTH) on rapeseed plants' development was characterized. Obtained results revealed a positive effect on yield parameters of plants treated with MB and, especially, PTH; this was associated to an improvement on the photosynthetic performance. Moreover, this study remarked the effects of biostimulants on plant phenology through their pivotal role in modulating developmental processes. More specifically, proteomic, metabolomic, and hormone content analyses revealed distinct alterations associated with the acceleration of phenology induced by biostimulant application. Additionally, some antioxidant enzymes and stress-related compounds were up-regulated upon MB and PTH treatments, indicating enhanced plant defense mechanisms in response to accelerated phenological transitions. Such findings highlight the intricate interplay between biostimulants and plant physiology, wherein biostimulants orchestrate rapid developmental changes, ultimately influencing growth dynamics. Altogether, the current study reveals that the application of both MB and PTH biostimulants promoted rapeseed plant phenology and productivity associated with an improvement in the photosynthetic machinery while boosting other physiological and molecular mechanisms.

Improved chlorophyll fluorescence, photosynthetic rate, and plant growth of Brassica napus L. after co‐application of biochar and phosphorus fertilizer in acidic soil

AbstractAimsBiochar has been used as an amendment to improve soil fertility and increase crop yield. A pot trial and incubation experiment were conducted to evaluate the effects of combined biochar and phosphate fertilizer applications on changes in soil physiochemical properties, photosynthetic parameters, and plant growth of Brassica napus L. in acidic soil.MethodsBiochar (B) was applied at rates (B0: 0%, B1: 2%, and B2: 4% w/w) to the soil, while phosphorus (P) as KH2PO4 was added at P0: 0 mg kg–1 soil, P1: 100 mg kg–1 soil, and P2: 150 mg kg–1 soil. Non‐amended soil served as the control (Ck).ResultsThe study found that the maximum photochemical quantum yield of photosystem II (Fv/Fm) and non‐photochemical quenching were affected by biochar and P fertilizer treatments. The Fv/Fm was significantly lower in the Ck while the highest in B2P1. Compared to the Ck treatment, the electron transport rate and photosynthetic rate were significantly increased under the application of biochar with P fertilizer. Additionally, malondialdehyde content declined by 68.9% when biochar was added with P fertilizer treatments. Furthermore, the plant P content and plant growth parameters were significantly increased. Biochar with and without P fertilizer treatments increased soil pH significantly, compared to the application of P fertilizer alone. Water‐soluble P decreased with incubation time, while Al‐P decreased significantly by 69.9% and 76.4% under B1 and B2 treatments, respectively, compared to CK.ConclusionThe findings revealed a positive effect of the combined application of biochar with phosphate fertilizer on the growth of oilseed rape in acidic soil.

Removal of chromate in aqueous solutions by termite nests and reduction chromate accumulation in Brassica chinensis L.

Chromate [Cr(VI)] is a highly toxic heavy metal element, representing one of the most prevalent sources of wastewater contamination. It poses a significant threat to human health and food safety. Therefore, effective treatment before discharging wastewater is of paramount importance. In this study, termite nests (Coptotermes formosanus and Odontotermes formosanus), as natural biomass materials, were used to adsorb Cr(VI) ions in wastewater as a strategy to reduce environmental pollution and minimize poisoning by Cr. Structural and morphological characterizations were performed using scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. Batch adsorption experiments were conducted to evaluate the influence of termite nest dosage, coexisting ions, and pH. To gain further insight, detailed studies on adsorption kinetics, adsorption isotherms, and adsorption thermodynamics were undertaken. The results indicate that under acidic pH conditions, both termite nests exhibit the highest adsorption capacity for Cr(VI), with an optimal adsorbent dosage of 10 g/L. The maximum adsorption capacities of C. formosanus nest and O. formosanus nest for Cr(VI) were found to be 48.52 mg/g and 35.99 mg/g, respectively. Thermodynamic studies confirmed the spontaneous and endothermic nature of the adsorption process. In the rapeseed cultivation experiment, the growth status of Brassica chinensis L. post-adsorption treatment was markedly improved compared to the untreated group. Additionally, the concentration of Cr(VI) in the plants was significantly reduced. This demonstrates both the inhibitory effect of Cr(VI) on the growth of oilseed rape and the effectiveness of water remediation techniques. In addition, both types of termite nests can be effectively reused by 0.1 mol/L HCl. To the best of our knowledge, this is the first report of adsorption removal of Cr(VI) by C. formosanus nest and O. formosanus nest. Compared to traditional natural biomass adsorbents, termite nests exhibit a relatively higher adsorption capacity for Cr(VI). The results of this study demonstrate that subterranean termite nests can efficiently remove Cr(VI) from wastewater, offering the potential for a cost-effective and reusable bioremediation agent with the advantages of ease of operation.

Microbial biostimulant counteracts negative effects of herbicides on oilseed rape growth

Use of herbicides in agriculture aids enormously the weed control. However, these products may also negatively affect both ecosystem and human health. As such the aim of this study was to analyze the effects of a herbicide containing the active substances clopyralid and picloram on the growth of oilseed rape cv. ‘Visby’ and to investigate the possibilities of using biologically active, environmentally friendly microbial biostimulants to accelerate plant growth and eliminate the adverse effects of herbicides. Biometrical parameters (aboveground plant height, dry plant weight) as well as biochemical markers (hydrogen peroxide production, total polyphenols concentration, antioxidant activity, lipid peroxidation level, photosynthetic pigments chlorophyll a, chlorophyll b and their ratio, carotenoids) were measured. The study showed that the herbicide containing clopyralid + picloram at doses recommended by the manufacturer showed a negative effect on oilseed rape growth. Microbial biostimulant “NaturGel” used prior to herbicide alleviated the damage of herbicide, moreover increased growth and development processes of tested plants, through serving as an activator of the non-enzymatic defence system. Thus, microbial biostimulant “NaturGel” is used to solve the problems of reducing herbicide use and increasing oilseed rape yields. Partially replacing herbicides with the microbial biostimulant “NaturGel”, strengthens crop vitality, increases competitiveness with weeds, improves yield quality, and the sustainability of agricultural land use. This knowledge can be used to provide practical guidance for farmers to reduce the use of herbicides in agro-ecosystems and make a step-by-step transition towards organic farming, while it may also serve as information on side-effects of commonly used herbicides at recommended doses.

Waste sulfur from biogas desulphurization: a supplement of Brassica napus L. nutrition

The content of sulfur in soils has been declining. Possible option to supply sulfur into the soil can be utilization of waste sulfur from biogas production. Two pot experiments with identical treatments were established to examine the effect of waste sulfur from biogas plant applied solely and in mixture with other nutrients on the growth and yield of oilseed rape. The included treatments were control, waste elemental sulfur (S), S + boron (B), S + B + humic substances (HS), S + B + HS + ammonium sulfate (AS), S + B + HS + ammonium nitrate (AN). The results from the first experiment showed significant increase in N-tester values and aboveground biomass after the treatments with S enhanced with both mineral fertilizers compared to any other treatments. The content of N and S in plants was also higher after these treatments. This was confirmed by second experiment. The seed yield was highest after the same treatments. The result from both experiments proved, that reutilization of waste S can be an interesting option. The application of sole waste S is a viable possibility. However, the mixture of sulfur with AS and AN is a more optimal alternative. Such combination could lead to better N use efficiency due to the co-application of N and S and also presents an interesting compromise to an overall lower consumption of mineral fertilizers (especially N) while adding more sulfur to the soil, especially in mixture with AS. This treatment resulted in the highest seed yield and production of oil in comparison with any other treatment.

Effects of Sodium Selenite on the Rhizosphere Environment, Growth, and Physiological Traits of Oilseed Rape (Brassica napus L.)

Soil selenium (Se) speciation characteristics and their influence on the Se enrichment pattern and physiological characteristics of oilseed rape are poorly understood. We investigated dynamic changes in rhizosphere soil physicochemical properties, Se uptake and partitioning, biomass, and physiological indices in oilseed rape under five exogenous Se condition levels (0, 1.0, 2.5, 5.0, and 10.0 mg kg−1 Se in sodium selenite) using soil cultivation experiments. The rhizosphere pH and dissolved organic carbon in the soil solution were higher than those of the non-rhizosphere soil solution. The total Se, water-soluble Se, exchangeable Se, and organic Se contents in soils, as well as rapeseed root/leaf Se contents, significantly increased with increasing exogenous Se. Under 2.5 mg kg−1 Se, the biomass of rapeseed roots and leaves increased at the sixth week (82% and 58%) and eighth week (48% and 32%), respectively, reaching the highest level. Applications of 5.0 mg kg−1 Se at 6 and 8 weeks significantly increased the glutathione peroxidase activity (49%/82%), and decreased malondialdehyde content (23%/39%). Canonical correlation and ridge regression analyses showed that Se in the rapeseed roots/leaves significantly and positively correlated with water-soluble Se, exchangeable Se, and organic Se in rhizosphere soil. Overall, moderate-concentration Se soil application benefited oilseed rape growth (optimum = 2.5 mg kg−1 Se). Our findings reveal the response of oilseed rape to soil Se application based on plant growth and physiological traits, rhizospheric soil solution properties, and Se speciation transformation.

Effective strategies for reclamation of saline-alkali soil and response mechanisms of the soil-plant system

The combination of amendments has emerged as a potential strategy to efficiently alleviate salt stress in saline-alkali soil. However, knowledge regarding how to optimize the proportion of different amendment materials, comprehensively assess the contribution of each component, and clarify the response mechanisms of the amendment-saline-alkali soil-plant system is incomplete. Based on this, we conducted a pot experiment to evaluate the improvement effect of the combined application of different amendment materials at varying levels and the contribution of the amendment components to alleviating salt stress. Overall, T6 exhibited the most significant improvement effect on the physicochemical and biological properties of the saline-alkali soil and promoted the growth of oilseed rape, with the levels of 2.0 % phosphogypsum, 2.0 % humic acid, 0.25 % bentonite, and 0.03 % sodium carboxymethyl cellulose. Compared with the control group, the EC decreased by 1.51 % to 33.49 %, the soil salt content dropped by 11.40 % to 35.46 %, and the soil soluble Na + concentration significantly declined by 39.47 % to 63.20 %. Additionally, the soil nutrient content and soil microbial community structure were enhanced in treatment groups. Meanwhile, amendments alleviated salt stress in the oilseed rape plant by activating anti-oxidative enzymes and osmoregulatory substances such as soluble sugar and proline, thus improving their ability to remove reactive oxygen species (ROS). The anti-oxidative enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were significantly increased, with an increase of 10.68 % (SOD, T2) ∼207.31 % (CAT, T6) compared to the control group. The structural equation modeling (SEM) analysis and simulation experiments indicated that the amendment components synergically promoted the amelioration effect on salt stress, and effectively improved soil properties, which affected the response of oilseed rape to soil environment. This research paper provides the relevant reference for the combined application of different amendment materials for soil reclamation.

Endophytic Beauveria bassiana induces biosynthesis of flavonoids in oilseed rape following both seed inoculation and natural colonization.

Cultivation of oilseed rape Brassica napus is pesticide-intensive, and alternative plant protection strategies are needed because both pesticide resistance and legislation narrow the range of effective chemical pesticides. The entomopathogenic fungus Beauveria bassiana is used as a biocontrol agent against various insect pests, but little is known about its endophytic potential and role in plant protection for oilseed rape. First, we studied whether B. bassiana can establish as an endophyte in oilseed rape, following seed inoculation. To evaluate the plant protection potential of endophytic B. bassiana on oilseed rape, we next examined its ability to induce plant metabolite biosynthesis. In another experiment, we tested the effect of seed inoculation on seedling survival in a semi-field experiment. Beauveria bassiana endophytically colonized oilseed rape following seed inoculation, and, in addition, natural colonization was also recorded. Maximum colonization rate was 40%, and generally increased with inoculation time. Seed inoculation did not affect the germination probability or growth of oilseed rape, but B. bassiana inoculated seeds germinated more slowly compared to controls. Endophytic colonization of B. bassiana induced biosynthesis of several flavonoids in oilseed rape leaves under controlled conditions. In the experiment conducted in semi-field conditions, inoculated seedlings had slightly higher mortality compared to control seedlings. Beauveria bassiana showed endophytic potential on oilseed rape via both natural colonization and seed inoculation, and it induced the biosynthesis of flavonoids. However, its use as an endophyte for plant protection against pests or pathogens for oilseed rape remains unclear. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Adjustment of the Structure of the Simplest Amino Acid Present in Nature-Glycine, toward More Environmentally Friendly Ionic Forms of Phenoxypropionate-Based Herbicides.

The use of chemicals for various purposes in agriculture has numerous consequences, such as the contamination of ecosystems. Thus, nowadays it is perceived that their development should adhere to the principles of green chemistry elaborated by Paul Anastas. Consequently, to create more environment-friendly herbicides, we elaborated a 'green' synthesis method of a series of ionic liquids (ILs) containing cations derived from glycine. The appropriately modified cations were combined with an anion from the group of phenoxy acids, commonly known as 2,4-DP. The products were obtained with high yields, and subsequently, their properties, such as density, viscosity and solubility, were thoroughly examined to elucidate existing structure-property relationships. All ILs were liquids at room temperature, which enabled the elimination of some serious issues associated with solid active forms, such as the polymorphism or precipitation of an active ingredient from spray solution. Additionally, the synthesized compounds were tested under greenhouse conditions, which allowed an assessment of their effectiveness in regulating the growth of oilseed rape, selected as a model dicotyledonous plant. The product comprising a dodecyl chain exhibited the greatest reduction in the fresh weight of plants, significantly surpassing not only a commercially used reference herbicide but also the potassium salt of 2,4-DP.

Monitoring Growth Status of Winter Oilseed Rape by NDVI and NDYI Derived from UAV-Based Red–Green–Blue Imagery

The current study aimed to evaluate the potential of the normalized difference vegetation index (NDVI), and the normalized difference yellowness index (NDYI) derived from red–green–blue (RGB) imaging to monitor the growth status of winter oilseed rape from seeding to the ripening stage. Subsequently, collected values were used to evaluate their correlations with the yield of oilseed rape. Field trials with three seed densities and three nitrogen rates were conducted for two years in Salzdahlum, Germany. The images were rapidly taken by an unmanned aerial vehicle carrying a Micasense Altum multi-spectral camera at 25 m altitudes. The NDVI and NDYI values for each plot were calculated from the reflectance at RGB and near-infrared (NIR) bands’ wavelengths pictured in a reconstructed and segmented ortho-mosaic. The findings support the potential of phenotyping data derived from NDVI and NDYI time series for precise oilseed rape phenological monitoring with all growth stages, such as the seedling stage and crop growth before winter, the formation of side shoots and stem elongation after winter, the flowering stage, maturity, ripening, and senescence stages according to the crop calendar. However, in comparing the correlation results between NDVI and NDYI with the final yield, the NDVI values turn out to be more reliable than the NDYI for the real-time remote sensing monitoring of winter oilseed rape growth in the whole season in the study area. In contrast, the correlation between NDYI and the yield revealed that the NDYI value is more suitable for monitoring oilseed rape genotypes during flowering stages.

Biogas slurry increases the reproductive growth of oilseed rape by decreasing root exudation rates at bolting and flowering stages

Biogas slurry increases the reproductive growth of oilseed rape by decreasing root exudation rates at bolting and flowering stages

Effects of tetracycline on the secondary metabolites and nutritional value of oilseed rape (Brassica napus L.).

Secondary metabolism, which helps a plant cope with external stress, is sensitive to environmental changes and plays a prominent role in maintaining plant health. However, few studies of the effects of tetracycline on the relationships between secondary metabolism and plant stress responses have been performed. Here, secondary metabolism, nutritional value, and oxidative stress responses in oilseed rape (Brassica napus L.) exposed to tetracycline for 14days were investigated. Tetracycline inhibited growth and biomass accumulation and decreased the chlorophyll content. The sinapine, phenol, and flavonoid contents were 118.46%, 99.67%, and 93.07% higher, respectively, but the carotenoid content was 76.47% lower in plants exposed to 8mg/L tetracycline than the control plants. Tetracycline affected the nutritional value of oilseed rape. Tetracycline decreased the dietary fiber, soluble sugar contents, and microelement (Fe, Mn, and Zn) contents. The antioxidant system also responded strongly to tetracycline. The catalase and peroxidase activities were increased and the superoxide dismutase activity was decreased by tetracycline. Tetracycline caused oxidative damage and secondary metabolite disturbances and adversely affected oilseed rape growth and quality. The results provide a new perspective on the effects of tetracycline on plants in relation to secondary metabolites and improve our understanding involved in the toxicity of tetracycline.

The effect of pollination on the growth and reproduction of oilseed rape (Brassica napus)

Phenotypic plasticity is an organism's ability to alter its development and life history in response to environmental conditions. In plants, biotic and abiotic factors drive the distribution of resources between growth and reproductive traits. One such biotic factor is pollination. Studies show that wind and insect pollination enhance oilseed rape (Brassica napus) yield. However, the impact of pollination on resource allocation towards growth and reproduction is less understood. We conducted a controlled experiment to assess the effect of pollination on growth and functional reproductive traits. We compared two simulated supplementary pollen deposition methods (representing wind and insect pollination) alongside a non-supplementary control. Pollinated plants allocated resources towards growth and reproduction similarly, irrespective of deposition method. Plants receiving no supplementary pollination produced fewer seeds, allocating resources to growth, more prolific and persistent flowering, and heavier seeds. Pollinated plants had a reduced flowering period and were shorter, indicating resources were allocated to seed production rather than growth or the production of additional flowers. This allocation of resources from growth and flowering metrics can increase yield directly through increased seed production and indirectly through shorter plants and a reduced flowering period with seeds that mature earlier (agronomically beneficial traits).Wind and insect pollination can enhance and stabilise oilseed rape yield under various environmental conditions by acting in complementary ways. Since pollination limits yield in oilseed rape, it must be considered an input that can be actively managed. Successful management of pollination services requires growers to detect pollination deficits. Inadequately pollinated oilseed rape plants exhibit apparent morphological changes (e.g. taller plants that flower for longer), acting as an early warning to growers. Equipping growers with this knowledge provides them with a means of detecting deficits and thus enables them to take positive action to restore pollination services by introducing honeybees or enhancing wild pollinators.

Consortium of plant growth-promoting rhizobacteria enhances oilseed rape (Brassica napus L.) growth under normal and saline conditions.

A preparation development, which stimulates plant growth under normal and saline conditions, and protects against fungal infections, would increase crop yields and reduce damage in agriculture. This study was conducted using bacterial isolates from rape rhizosphere as a plant growth promoter and an alternative to chemical fertilizers. Three from fifty bacterial isolates: B14 (Pseudomonas sp.), B16 (Sphingobacterium sp.), and B19 (Microbacterium sp.) showed the best in vitro plant growth-promoting (PGP) characteristics. B14 strain had the best antifungal activity against phytopathogens inhibiting growth of B. cinerea, C. acutatum, and P. lingam. Moreover, B14, B16 and B19 isolates coded for several genes involved in PGP activities, aimed at improving nutrient availability, resistance to abiotic stress, and fungal pathogen suppression. Microbial consortium (B14, B16, and B19) had the best effect on rape growth, significantly increasing number of live leaves, compared to the untreated control and single inoculant treatments. Moreover, the consortium induced significant increase in shoots length and chlorophyll content in comparison to Pseudomonas sp. B14 and Microbacterium sp. B19. The consortium also induced plants tolerance to salt stress. The genomic information as well as the observed traits, and beneficial attributes towards rape, make the rhizobacterial consortium an ideal candidate for further development as biofertilizers.

Melatonin enhanced oilseed rape growth and mitigated Cd stress risk: A novel trial for reducing Cd accumulation by bioenergy crops

Melatonin (M) is a pleiotropic molecule that improves plant growth and increases heavy metal tolerance. The role of M for improving plant growth and tolerance under cadmium (Cd) stress, and mitigation of Cd-induced toxicity has not yet been sufficiently examined. Therefore, here we conducted a glasshouse experiment to explore the influence of various M dosages on Cd detoxification and stress-tolerance responses of Brassica napus under high Cd content (30 mg kg−1). The effects of M on the modulation of Cd tolerance in B. napus plants have been investigated using various growth attributes, Cd accumulation and tolerance indices, and secondary metabolic parameters. We found that Cd stress inhibited root growth (by 11.9%) as well as triggered reactive oxygen species accumulation (by 31.2%) and MDA levels (by 18.7%); however, exogenous M substantially alleviated the adverse effect of oxidative stress by decreasing levels of H2O2 (by 38.7%), MDA (by 13.8%) and EL (by 1.8%) in the Cd-stressed plants, as compared to the M-untreated plants (control). Interestingly, exogenous M reduced Cd accumulation in roots (∼48.2–58.3-fold), stem (∼2.9–5.0-fold) and leaves (∼4.7–6.6-fold) compared to control plants, which might be due to an M-induced defense and/or detoxification response involving a battery of antioxidants. Overall, addition of the exogenous M to the Cd-stressed plants profoundly enhanced Cd tolerance in B. napus relative to control plants. These results suggested the biostimulatory role (at the physiological and molecular level) of M in improving growth, Cd tolerance, and Cd detoxification in B. napus, which indicate the potentiality of M for green remediation of Cd contaminated soils. This green trial would provide a reference for producing renewable bioenergy crops under Cd stress in contaminated soils. However, these recommendations should be verified under field conditions and the potential mechanisms for the interaction between Cd and M should be explicitly explored.

Drought-protective effects of nutrient seed treatments during early growth of oilseed rape

Crop production is increasingly affected by water limitation even in temperate climates due to a rising frequency of drought periods, related with global change. The stress-protective nutrients, discussed as a mitigation strategy, were investigated for their potential drought-protective effects of nutrient seed treatments, based on Ca, K, Fe, Zn, Mn on early growth of oilseed rape (OSR). Responses were observed in five OSR hybrids under greenhouse conditions on two soils with contrasting properties (sandy-loam pH 5.6 vs. silty-loam pH 6.9) in two independent pot experiments. A 7-days drought period with reduced soil moisture level (40% soil water-holding capacity. WHC) inhibited shoot and root growth and caused irreversible wilting and leaf necrosis (27-46% of total leaf area) particularly on the sandy-loam with lower WHC, depending on the investigated genotype. Nutrient seed treatment increased shoot (10-15%) and particularly root growth (14-23%) as well as nutrient accumulation, but also reduced the proportion of irreversibly damaged leaves to 17-21%, with the largest effect in strongly drought-affected genotypes under the challenging conditions on the sandy-loam soil. Analysis of physiological stress indicators revealed increased accumulation of phenolics (23-28%), antioxidants (14-47%) and higher activities of ascorbate peroxidase (APX) (23-87%) in the leaf tissue, counteracting drought-induced oxidative stress. Moreover, APX activity was positively related with root length (R20.8953), suggesting a protective effect on drought-induced oxidative IAA degradation with inhibitory effects on root growth. Increased levels of absisic, jasmonic and salicylic acids during drought stress recovery point to stress priming effects, strengthening the natural adaptive responses to water limitation.