Winter Oilseed Rape Plants Research Articles

A causal inference and Bayesian optimisation framework for modelling multi-trait relationships-Proof-of-concept using Brassica napus seed yield under controlled conditions.

The improvement of crop yield is a major breeding target and there is a long history of research that has focussed on unravelling the mechanisms and processes that contribute to yield. Quantitative prediction of the interplay between morphological traits, and the effects of these trait-trait relationships on seed production remains, however, a challenge. Consequently, the extent to which crop varieties optimise their morphology for a given environment is largely unknown. This work presents a new combination of existing methodologies by framing crop breeding as an optimisation problem and evaluates the extent to which existing varieties exhibit optimal morphologies under the test conditions. In this proof-of-concept study using spring and winter oilseed rape plants grown under greenhouse conditions, we employ causal inference to model the hierarchically structured effects of 27 morphological yield traits on each other. We perform Bayesian optimisation of seed yield, to identify and quantify the morphologies of ideotype plants, which are expected to be higher yielding than the varieties in the studied panels. Under the tested growth conditions, we find that existing spring varieties occupy the optimal regions of trait-space, but that potentially high yielding strategies are unexplored in extant winter varieties. The same approach can be used to evaluate trait (morphology) space for any environment.

Proline Enhances Resistance and Recovery of Oilseed Rape after a Simulated Prolonged Drought.

This study was carried out to evaluate the effect of exogenous proline on the growth, biochemical responses, and plant recovery of drought-stressed oilseed rape plants after renewed irrigation. The experiment was conducted under controlled laboratory conditions. After 21 days of cultivation, 3-4 leaf stage seedlings were sprayed with proline (1 mM), then subjected to prolonged drought stress for 8 days to achieve a severe water deficit, next, irrigation was resumed and recovery was assessed after 4 days. The results show that exogenous application of proline reduced the drought-induced growth inhibition of seedlings while maintaining relative water content (RWC) and growth parameters closer to those of irrigated plants. Proline had a positive effect on chlorophyll accumulation and membrane permeability while decreasing ethylene, H2O2, and MDA levels. Moreover, after 4 days of recovery, the H2O2 content of the proline-treated plants was significantly lower (2-fold) and the MDA content was close to that of continuously irrigated plants. Thus, all these biochemical reactions influenced plant survival: after drought + proline treatment, the number of surviving plants was two times higher than that of drought-treated plants. The findings show that exogenous proline has antioxidant, osmotic, and growth-promoting properties that improve the drought tolerance of winter oilseed rape plants and is, therefore, beneficial for drought adaptation in oilseed rape.

Chemical Speciation of Trace Elements in Soil Fertilized with Biomass Combustion Ash and Their Accumulation in Winter Oilseed Rape Plants

The impact of fertilization of fly ashes from biomass combustion (BAs) on the changes in the chemical speciation of trace elements (Zn, Cu, Cr, Ni, Pb, Cd) in Gleyic Chernozem soil was analyzed in field-experiment conditions, under cultivation of winter oilseed rape plants. The three-year field experiment was carried out in southeastern Poland (50°3′ N, 22°47′ E). The three-stage sequential extraction procedure developed by the Measurements and Testing Program (BCR) was used for the fractionation of trace elements in BAs and soil. The risk assessment code (RAC) coefficient was used to assess potential soil contamination with trace elements from Bas. The total content of Zn, Cu, Cr, Ni, Pb, and Cd in BAs used in the experiment was 470, 311, 29, 78, 38, and 3.7 mg kg−1, respectively. The present study showed that the application of BAs significantly increased the total concentration of Zn and Cu in the surface layer of the Gleyic Chernozem soil, and did not significantly increase the concentration of Cr, Ni, Pb, and Cd. Generally, using BAs does not significantly change the chemical speciation of trace elements in soil. Regardless of the applied fertilization, residual fraction (F4) was the most abundant, whereas the exchangeable/extractable (F1) fraction and reducible (F2) fraction were present in the smallest amounts. Due to the low share of exchangeable/extractable fraction (F1), the BAs used in the experiment were characterized by a low RAC coefficient; hence, their use as a soil fertilizer is relatively safe for the environment. The BAs fertilization did not cause significant changes in the content of trace elements in the different parts of the winter oilseed rape plants. Due to the relatively high content of trace elements in fly ashes from biomass combustion, an analysis of the content of individual trace element fractions should be carried out to assess their actual impact on the environment. This can help indicate further actions that should be taken to limit their negative environmental impact.

The Effects of Agronomic Management in Different Tillage Systems on the Fall Growth of Winter Oilseed Rape

The article presents the results of a three-year study, which analyzed agronomic management in the production of winter oilseed rape (WOSR) in different tillage systems. The effects of weed control and growth regulation in fall on the number of rosette leaves, epicotyl length, root collar diameter, taproot length, rosette weight, root weight, and the overwintering success of WOSR plants in different tillage systems were determined in the study. A field experiment was conducted at the University’s Agricultural Experiment Station in Bałcyny in north-eastern Poland in three growing seasons (2016/2017–2018/2019). The experiment had a mixed 21 × 32 factorial design with two replications, where one factor was evaluated at two levels, and two factors were evaluated at three levels. The experimental factors were: A—tillage: (A0) strip-till, (A1) low-till, and (A2) conventional tillage; B—weed control: (B0) pre-emergent, (B1) foliar, and (B2) sequential; C—growth regulation: (C0) none and (C1) in fall. Winter oilseed rape plants developed rosettes with the optimal morphometric parameters in the strip-till system. Sequential and foliar application of herbicides decreased the dry matter (DM) content of leaf rosettes (by approx. 18%). The application of the growth regulator in BBCH stages 14–15 increased taproot length by 3%.

The impact of foliar application of biostimulators on the morphological characteristics of the leaf rosette of winter rape plants

The field experiment was caried out in three growing seasons (2013–2016) at the Agricultural Experimental Station – Zawady (52°03'N and 22°33'E) belonging to the University of Natural Sciences and Humanities in Siedlce, Poland. The experiment was set up in a split-plot configuration with three replications. The examined factors were: I – morphotypes of winter oilseed rape: population (Poznaniak), hybrid restored with a semi-dwarf type of growth (PX104), hybrid restored with a traditional type of growth (Konkret); II – four types of biostimulators: 1. control variant, 2. biostimulator Tytanit® (titan), 3. biostimulator Asahi®SL (sodium ortho-nitrophenol, sodium para-nitrophenol, sodium 5-nitroguaiacol), 4. biostimulator Silvit® (active silicon, potassium oxide, boron – form of pure element, zinc – form of pure element). The aim of the study was to evaluate the effect of biostimulators containing various active substances on the morphological characteristics of winter oilseed rape plants in the leaf rosette stage (number of rosette leaves, tap root length, height of the growth cone) and on the fresh and dry mass of the above-ground rosette and the root system of traditional and semi-dwarf winter oilseed rape morphotypes type of growth under changing climatic conditions. The genetic factor significantly influenced the morphological features of plants, marked in autumn by inhibition of vegetation. The population variety Poznaniak developed more rosette leaves, greater length of the tap root, and fresh and dry mass of the rosette and the root system as compared to the restored hybrids. The applied biostimulators significantly influenced plant parameters determined in the fall before the vegetation inhibition. After the use of a biostimulator containing the active substance in the form of sodium o-nitrophenol, sodium para-nitrophenol and sodium 5-nitroguajakol, a significantly higher value of the tested features was obtained compared to the control variant. Regardless of the type of biostimulator used, the height of the growth cone was the same as in the control object. The most favourable parameters of the leaf rosette were obtained in the first and second periods of summer-autumn vegetation and winter dormancy, while in extreme drought conditions during sowing and a fairy dry period of emergence, its weakest features were obtained. Natural growth stimulants are becoming an increasingly common elements of agricultural plant agrotechnics. Their use has a positive effect on the growth and development of plants and increases the resistance of plants to the adverse effects of stress factors.

Altered winter conditions impair plant development and yield in oilseed rape

The demand for agricultural products is expected to increase as a result of population growth, changed diets and demands for bioenergy. At the same time, agricultural yields in many regions are expected to be negatively impacted by climate change. Here we show, how altered winter conditions in combination with an extreme weather event impact reproductive development and yield of oilseed rape ( Brassica napus L.). Winter oilseed rape plants were grown for twelve weeks in climate chambers simulating three winter treatments, control (2–4 °C), shorter winter (6 weeks at 2–4 °C and 6 weeks at 10–12 °C) and warm winter (10–12 °C). During seed maturation, a thunderstorm with heavy winds and rain had a drastic negative effect on yield. We capitalized on this, presenting yields after a combination of altered winter conditions and an extreme weather event. Both warmer and shorter winters reduced the production of flowers and axillary shoots and thereby decreased yield compared with control winter conditions. Both treatments significantly differed from controls, but the effect was particularly strong for the warm winter treatment. The extreme weather event had strong negative effects on yield but effects from the winter treatments remained qualitatively similar. Our findings reveal detrimental effects of altered winter conditions in combination with extreme weather events on the development and production of oilseed rape, which suggests that climate change may have negative consequences for the production of winter crops in many regions of the world.

Changes in the winter oilseed rape microbiome affected by Xanthomonas campestris pv. campestris and biocontrol potential of the indigenous Bacillus and Pseudomonas isolates

Plant pathogenic bacterium Xanthomonas campestris pv. campestris (Xcc) was recently described as a pathogen of winter oilseed rape in Serbia. A metabarcoding approach was used to study bacterial community composition changes in the phyllosphere and rhizosphere of different winter oilseed rape types (lines, cultivars, and hybrids) naturally infected with Xcc. This study also aimed to examine the potential of indigenous Bacillus and Pseudomonas isolates to suppress Xcc. Infection with Xcc leads to depletion of bacterial diversity in the plants' phyllosphere and explicitly decreasing the abundance of genera such as Exiguobacterium, Massilia, and Pantoea with potentially beneficial properties. Strains identified as Bacillus velezensis X5-2, Bacillus megaterium X6-3, and Pseudomonas orientalis X2-1P obtained from oilseed rape phyllosphere were found to be effective against Xcc in vitro and in vivo when applied as a whole-culture and as a cell-free supernatant. The greenhouse in vivo tests on winter oilseed rape plants with three selected biocontrol strains lead to a disease reduction of 82.37% and 72.47% in preventive and curative treatments, respectively. Genetic screening showed potential for the biosynthesis of surfactin, kurstakin, bacillomycin D, and iturin in B. velezensis X5-2, as well as surfactin and kurstakin in B. megaterium X6-3. Gene phcA encoding phenazine-1-carboxylic acid was detected in P. orientalis X2-1P. The chemical composition of ethyl acetate and benzene extracts of three biocontrol strains obtained by GC–MS and HPLC-ESI-qTOF/MS analyses indicates numerous volatile organic compounds (alkenes, benzenes, carboxylic acids, indoles, pyrazines, etc.), lipopeptides, and/or antibiotics, for many of which antimicrobial potential is proven. We assume that this wide range of metabolites is responsible for the exhibited biocontrol activity against Xcc. These results recommend all three biocontrol strains for further studies for use as agents for biocontrol of bacterial blight-like disease caused by Xcc of oilseed rape.

MULTISPECTRAL SHEET DIAGNOSTICS OF TECHNOLOGICAL STRESSES ON WINTER RAPES CROPS

Technological stresses are an urgent challenge for winter crops and in particular rapeseed in industrialproduction and in the mass use of agrochemicals and plant protection products. Effective resuscitationmeasures are possible only in the initial stages of the growing season and require reliable and accessibleinformation about the condition of crops. The purpose of the work is to develop an index based on the resultsof analysis of multispectral images with high spatial resolution, obtained by UAVs for the identificationof technological stresses. During field research on October 30, 2019, it was found that in the affected areas,the plants have an abnormal color of the two lower leaves, namely yellow and red. To identify affectedplants, it was proposed to use an image of the object based on the ratio of several channels simultaneously, which allow to distinguish between affected and healthy plants, soil and leaves of abnormal color. Itis proposed to use the RRL (rape red leaf) indices, which are an indicator of the technological nature ofstress, namely RRLgr, designed exclusively for the optical range and the RRLm index (green — G, red — R,border red — Re and near infrared — NIR). Such indices are convenient for monitoring the condition ofrapeseed crops and automated data processing. It was found that when monitoring rapeseed crops in thegrowing season of 6–8 leaves affected by technological stress, using Slantrange 3p height of 100 m, for the indices RRLgr and RRLm is characterized by abnormal leaf color, which was recorded in 1.5 and 2.1%of the total area of plants on the site, respectively. The use of multispectral analysis makes it possible todifferentiate the identification of technological stresses with different manifestations of impression. Ata standard flight altitude for Slantrange 3p of 100 m with the fixation of anomalous color in 1.5% of thetotal area of winter oilseed rape plants is the basis for the organization of additional ground inspection ofthe identified areas of winter oilseed rape crops.

Урожайність насіння ріпака озимого за оптимізації окремих елементів технології вирощування

The results of researches of influence of ways of application of growth regulator "Vermiyodis" and sowing norms on productivity of winter rape of Cheremosh and hybrid Mercedes are covered. The study was performed during 2017-2020 on sod-podzolic soils of the experimental field of the Carpathian State Agricultural Research Station of the Institute of Agriculture of the Carpathian region of NAAS Taking into account the yield, it was found that the pre-sowing treatment of winter rapeseed Cheremosh with growth regulator "Vermiyodis" at a dose of 5 l / ha on average for 2017-2020 at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.60 t / ha or 0.26 t / ha more than control, for sowing rates 0.8 million / ha of similar seeds - 3.92 t / ha or 0.21 t / ha more than control, for sowing rates 1.0 million / ha of similar seeds - 3.46 t / ha or 0.23 t / ha more than control. With a single spraying of winter oilseed rape plants during the growing season with the growth regulator "Vermiyodis" at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.62 t / ha or 0.28 t / ha more control, with at the sowing rate of 0.8 million / ha of similar seeds, the yield was 3.94 t / ha or 0.33 t / ha more than the control, at the sowing rate of 1.0 million / ha of similar seeds, the yield was 3.48 t / ha or 0.25 t / ha more than control. In the variants where pre-sowing treatment of rapeseed seeds of winter hybrid Mercedes with growth regulator "Vermiyodis" at a dose of 5 l / t and during the growing season was carried out a single spraying of plants with growth regulator "Vermiyodis" at a dose of 4 l / ha at seeding rates of 0.6 million / ha similar seeds yield was 3.73 t / ha or 0.39 t / ha more than control, at sowing rates of 0.8 million / ha of similar seeds - 4.07 t / ha or 0.46 t / ha more than control, at sowing rates of 1.0 million / ha of similar seeds - 3.62 t / ha or 0.39 t / ha more than control. Double spraying of rapeseed plants of the winter hybrid Mercedes during the growing season of plants with the growth regulator "Vermiyodis" at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds, the yield was 3.82 t / ha or 0.48 t / ha more control, for sowing rates of 0.8 million / ha of similar seeds - 4.15 t / ha or 0.54 t / ha more than control, for sowing rates of 1.0 million / ha of similar seeds - 3.68 t / ha or 0.45 t / ha more than control. In the variants where pre-sowing treatment of Cheremosh winter rape seeds with Vermiyodis growth regulator was carried out at a dose of 5 l / t and during the growing season, plants were sprayed with Vermiyodis growth regulator at a dose of 4 l / ha at sowing rates of 0.6 million / ha of similar seeds. yield was 3.91 t / ha or 0.57 t / ha more than control, for sowing rates of 0.8 million / ha of similar seeds - 4.24 t / ha or 0.63 t / ha more than control, for norms sowing 1.0 million / ha of similar seeds - 3.77 t / ha or 0.50 t / ha more than control.

EFFECT OF SOWING METHOD AND N APPLICATION ON SEED YIELD AND N USE EFFICIENCY OFWINTER OILSEED RAPE

In the conditions of the Right-Bank Forest-Steppe, the cultivation of winter rapeseed crops after winter wheat usually leads to a delay in sowing the latter and deterioration of autumn plant development. Based on data from a field experiment conducted in 2016/2017, 2017/2018 and 2018/2019, the aim of this study was to investigate how sowing delay affects seed yield, nitrogen uptake by seeds and significant efficiency of nitrogen use by winter rape plants; to check the ability of autumn and spring application of nitrogen fertilizers to compensate for the negative impact of delays in sowing crops; and estimate the minimum autumn development for optimal seed yield. To solve the set tasks, a combination of four sowing dates (from the first week of August to the third week of September) and four autumn nitrogen applications (0, 30, 60 and 90 kg / ha per year) was fixed. In each of these 16 variants, nitrogen application was performed 5 times in the spring (0/0, 40/40, 80/80, 120/120, 140/140 kg / ha, etc.) in order to estimate the individual nitrogen reaction curves. Nitrogen accumulation by aboveground mass of plants in autumn, seed yield and nitrogen uptake by seeds were determined. It was found that sowing the crop after mid-September significantly reduced yields. Application of nitrogen fertilizers in autumn in the amount of at least 30 kg / ha per year increased the yield and absorption of nitrogen seeds without any significant interaction with the sowing period and spring application of nitrogen fertilizers. Increasing the dose of spring fertilizer application to 130 kg / ha increased seed yield. Nitrogen utilization efficiency decreased with increasing application rate when winter oilseed rape plants used nitrogen applied in the fall to a lesser extent than in the spring. In order to achieve high yields, it was necessary for the above-ground mass of plants to absorb nitrogen at the level of at least 10-15 kg / ha at the end of the autumn vegetation. From an ecological point of view, the optimal autumn development of plants should be achieved by choosing an adequate sowing date, rather than using additional nitrogen in autumn.

Deacclimation of Winter Oilseed Rape—Insight into Physiological Changes

Climate changes, which result in the occurrence of periods with relatively high temperatures during the winter, can lead to the deacclimation of cold-hardened plants and cause problems with their winter survival. The aim of these studies was to investigate the physiological changes (photosynthesis and water relations including aquaporin expression) that accompany deacclimation process in the economically important winter oilseed rape plants. The effect of deacclimation on frost tolerance was also estimated for two tested cultivars: semi-dwarf and plants of a normal height. After cold acclimation at 4 °C (compared to the unacclimated control) the typical changes that accompany cold acclimation such as an increase in the content of water-soluble sugars or a lower water content in the leaves, which lead to an increased frost tolerance, were observed. Deacclimation partially or completely reversed these changes, which resulted in a decreased frost tolerance that was accompanied by a decrease in the content of sugars and an increase of the osmotic potential. The chemical composition of the leaves, which was measured using FT-Raman spectroscopy also clearly confirmed the metabolic differences between the cold-acclimated and deacclimated plants. The plants were significantly different in regard to the content of the various pigments as well as fatty acids and polysaccharides. The phenomenon of a deacclimation-induced decrease in aquaporin PIP1 accumulation, which was accompanied by unchanged PIP1 transcript accumulation, will be discussed in the aspects of the water relations and decreased frost tolerance in deacclimated plants.

ОСОБЛИВОСТІ ПЕРЕЗИМІВЛІ РІПАКА ОЗИМОГО ЗА РІЗНИХ НОРМ ВИСІВУ ТА ЗАСТОСУВАННЯ РЕГУЛЯТОРА РОСТУ

Висвітлено результати виконаних протягом 2017-2020 років досліджень впливу регулятора росту «Вермийодіс» і норм висіву на перезимівлю рослин ріпака озимого сорту Черемош та гібриду Мерседес на дернових опідзолених ґрунтах дослідного поля Прикарпатської державної сільськогосподарської дослідної станції ІСГ Карпатського регіону НААН. Дослідженнями встановлено, що на варіантах де не проводили допосівне оброблення насіння ріпаку озимого сорту Черемош, в середньому за роки досліджень, за норми висіву 0,6 млн/га загибель рослин під час перезимівлі становила 4,7-5,7 шт/м2 або 9,5-10,8 %, за норми висіву 0,8 млн/га схожих насінин – 5,7-6,2 шт/м2 або 8,5-9,3 %, за норми висіву 1,0 млн/га схожих насінин – 8,7-9,3 шт/м2 або 10,1-10,9 %. На варіантах де проводили допосівне оброблення насіння регулятором «Вермийодіс» в дозі 5 л/т за норми висіву 0,8 млн/га загибель рослин становила 4,6-5,6 %, що на 2,8-3,0% менше порівняно до норми висіву 1,0 млн/га схожих насінин. На варіантах, де проводилося допосівне оброблення насіння ріпаку озимого гібрида Мерседес регулятором росту «Вермийодіс» 5 л/т відсоток загиблих рослин становив за норми висіву 0,6 млн/га схожих насінин 4,8-5,6 %, за норми висіву 0,8 млн/га – 6,1-7,3 %, за норми висіву 1,0 млн/га схожих насінин 8,1-8,6 %, що значно менше контролю і варіантів, де не проводили допосівне оброблення насіння регулятором росту «Вермийодіс». Дослідженнями встановлено, що найкраща перезимівля, в середньому за роки досліджень, була у сорту ріпака озимого гібриду Мерседес за норми висіву 0,6 млн/га схожих насінин, у сорту Черемош за норми висіву 0,8 млн/га схожих насінин за допосівного оброблення насіння.

Фотосинтетична продуктивність рослин ріпака озимого залежно від норм висіву та застосування регулятора росту «Вермийодіс»

Photosynthesis is the most important biochemical process of plant life, as a result of which they absorb the energy of solar radiation and with its help synthesize organic matter from inorganic substances. The purpose of the research is to establish the influence of the growth regulator "Vermiyodis" and seeding rates on the photosynthetic productivity of winter oilseed rape plants and the Mercedes hybrid in the conditions of the Western Forest-Steppe. The study was performed during 2017-2020 in the research field of the Precarpathian State Agricultural Research Station of the Institute of Agriculture of the Carpathian region of NAAS on sod podzolic soils. The results of researches of photosynthetic productivity of winter oil seed rape plants and Cheremos hybrid at different sowing rates and application of growth regulator "Vermiyodis" are highlighted. It was found that pre-sowing treatment of rapeseed of winter variety Cheremosh with growth regulator Vermiyodis (5 l / t) and single or double spraying during the growing season with the same drug at seeding rates of 0.6; 0.8; 1.0 million / ha of similar seeds during the entire growing season had a significant impact on the formation of the assimilation surface. The area of leaves increased depending on the phase of plant development. At the beginning of the growing season, it grew slowly, reached its maximum during the budding-flowering period and began to decrease. In the variant of pre-sowing treatment of winter rapeseed Cheremosh with growth regulator "Vermiyodis" at a dose of 5 l / ha on average over the years of research at sowing rates of 0.8 million / ha of similar seeds in the stalk phase, the increase in leaf area to control was 3.5 thousand m2 / ha, in the budding phase - 6.3 thousand m2 / ha, in the flowering phase - 9.4 thousand m2 / ha. Determination of the leaf area of rapeseed plants of the winter hybrid Mercedes showed that all methods of application of the growth regulator Vermiyodis in all phases of growth and development of plants depending on seeding rates provided an increase in the leaf surface of plants of winter rapeseed. The largest leaf surface was observed in the stalk phase of 14.1 thousand m2 / ha or 2.3 thousand m2 / ha more control, in the budding phase 22.5 thousand m2 / ha or 5.9 thousand m2 / ha more control and in the flowering phase 43.7 thousand m2 / ha or 7.0 thousand m2 / ha more control was on the option, which carried out pre-sowing treatment of seeds with growth regulator "Vermiyodis" at a dose of 5 l / t and double spraying of rapeseed plants winter hybrid Mercedes growth regulator "Vermiyodis" at 4 l / ha at sowing rates of 0.6 million / ha of similar seeds. Studies have shown that in the variants where pre-sowing treatment of seeds with Vermiyodis growth regulator (5 l / t) and double spraying of winter oilseed rape plants during the growing season was used, the photosynthetic potential in the germination-wax ripening phase was 2 million million in winter rapeseed.6 million67. days / ha, which is 0.407 million m2 days / ha more than the sowing rate 0.8 million / ha, the Mercedes hybrid - 2.612 million m2 days / ha, which is 0.364 million m2 days / ha more than the sowing rate 0.6 million / ha of similar seeds. It was found that the highest net productivity of winter oil seed rape plants was 8.68 g / m2 per day or 1.46 g / m2 per day more than the control over sowing rates of 0.8 million / ha of similar seeds and 8.58 g / m2 per day in the hybrid Mercedes, which is 1.44 g / m2 per day at the sowing rate of 0.6 million / ha of similar seeds was on the option, which carried out pre-sowing treatment of seeds (5 l / t) and double spraying with growth regulator "Vermiyodis" at a dose 4l / ha during the growing season. It was found that the largest accumulation of dry matter in winter rapeseed crops Cheremosh in the budding phase is 2.98 t / ha or 0.38 t / ha more control, in the flowering phase 4.67 t / ha or 0.77 t / ha more control, in the phase of wax ripeness 8.22 t / ha or 1.36 t / ha more control, was on the option, which carried out pre-sowing treatment of seeds with growth regulator "Vermiyodis" (5 l / t) and carried out double spraying of rapeseed plants winter during the growing season growth regulator "Vermiyodis" - 4l / ha from sowing rate of 0.8 million / ha.

Is leaf age a predictor for cold tolerance in winter oilseed rape plants?

In the present study, low temperature-dependent physiological changes were investigated through photosynthetic activity and some endogenous mechanisms in two winter oilseed rape cultivars (Brassica napus L. ssp. oleifera cvv. Eurol and Hansen) on the basis of leaf age. Chlorophyll fluorescence measurements demonstrated that low temperature caused decreased photosynthetic activity in both cultivars. However, photosynthetic apparatus in the young leaves of Hansen is more tolerant to low temperature as demonstrated by lower F0 (minimum fluorescence yield) and 1-qp (excitation pressure of photosystem II), higher Fm (maximum fluorescence yield), Fv/Fm and non-photochemical quenching (NPQ) compared with Eurol. In addition, young leaves of Hansen represented marked increase in some antioxidant enzyme activities (superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR)) during cold exposure. In the young leaves of Eurol, however, APX and GR activity was decreased by low temperature, indicating lower efficiency of ascorbate-glutathione cycle. Lower antioxidant activity in the young leaves of Eurol may be responsible for increased malondialdehyde (MDA), H2O2 and membrane damage and decreased chlorophyll content as a result of oxidative damage during cold exposure. In the cold-stressed mature leaves, both cultivars represented similar antioxidant capacities and photosynthetic efficiency. As a consequence, coordinated increase in SOD, APX and GR activities, increased capacity to keep quinone A (QA) in an oxidised state (as indicated by lower 1-qp) and accumulation of soluble sugar and proline could be mainly attributed to higher level of tolerance of the young leaves of Hansen to low temperature when compared with Eurol.

The Effect of Autumn Foliar Fertilization on the Yield and Quality of Winter Oilseed Rape Seeds

This paper presents the results of a 3-year field experiment conducted in north-eastern (NE) Poland to determine the influence of the autumn application of foliar macronutrient and micronutrient fertilizers (control, one application in BBCH (Biologische Bundesanstalt, Bundessortenamt and Chemische Industrie) stage 16 (six leaves unfolded)), two applications in BBCH stages 14 (four leaves unfolded), and 16 (six leaves unfolded) on the growth and development of winter oilseed rape plants, nutrient accumulation, overwintering success, yield components, yield, nutritional value (crude fat content, fatty acid concentrations), and feed value (total protein content, concentrations of acid detergent fiber and neutral detergent fiber, quantitative and qualitative composition of glucosinolates) of seeds. When applied in BBCH stages 14 and 16, foliar fertilizers stimulated the development of leaf rosettes, increased the accumulation of minerals in aerial rosette parts (N, K, and Mg) and roots (K, Cu, Mn, and Fe), and contributed to the overwintering success of winter oilseed rape plants (by 8–11%). The application of foliar macronutrient and micronutrient fertilizers in autumn increased seed yield (by 0.25 Mg ha−1), contributed to a significant increase in the crude fat content of seeds (by 1.3–7.4 g kg−1 dry matter (DM), increased the content of oleic acid, decreased the concentration of linoleic acid, and increased the content of glucosinolates, mostly the alkenyl fraction with antinutritional properties.

Impact of winter oilseed rape nutritional status during vegetative growth on yield

The nutritional status of winter oilseed rape (WOSR) during its vegetative period is crucial for plant growth and can be used for the seed yield prediction. This hypothesis was verified based on the data from long-term field experiments. The experiment consisted of four potassium (K) treatments based on the progressive K supply potential to plants from soil and fertilizer and two magnesium treatments (–Mg, +Mg) conducted in 2013–2015. The content of nutrients (N<sub>tot</sub>, P, K, Mg, Ca, Fe, Mn, Zn, Cu) was determined at the rosette stage (BBCH 30) for leaves and separately for leaves and stems in the late stage of inflorescence growth (BBCH 57–59). The low K content appeared as the key limiting nutrient in WOSR plants in the rosette stage due to the insufficient soil fertility level, depended even more on weather conditions. This negative K nutritional trait persisted through the whole vegetative WOSR growth. Its detection was possible, because stems were included in the diagnostic procedure. The most reliable prognosis of WOSR yield was conducted based on the nutritional status of stems in the late stage of the inflorescence development.

Contrasting Patterns of Colonization with Verticillium longisporum in Winter- and Spring-Type Oilseed Rape (Brassica napus) in the Field and Greenhouse and the Role of Soil Temperature

Oilseed rape, an important source of vegetable plant oil, is threatened by Verticillium longisporum, a soil-borne vascular fungal pathogen so far occurring in oilseed rape growing regions in Europe and Canada. Despite intensive research into V. longisporum in the last decades in controlled conditions, basic knowledge is still lacking about the time course of infection, temporal pattern of colonization, and disease development on field-grown plants. In this study, colonization of roots, stem bases, and stems with V. longisporum was followed by real-time PCR from the seedling until mature plant stages in 2-year field experiments with microsclerotia-infested plots and either spring-type or autumn-sown (winter-type) oilseed rape cultivars. The temporal pattern of plant colonization differed between greenhouse and field-grown oilseed rape and between spring- and winter-type plants in the field. Within 28 to 35 days, a continuous systemic colonization with V. longisporum was detected in roots and shoots of young plants in the greenhouse associated with significant stunting. In contrast, real-time PCR analysis of V. longisporum in field-grown winter oilseed rape plants displayed a strongly discontinuous colonization pattern with low fungal growth in roots during juvenile growth stages until flowering, whereas in spring oilseed rape, no root colonization was observed until early flowering stages. Hence, stem colonization with the pathogen required 6 months in winter oilseed rape and 1 month in spring oilseed rape from the time of initial root infection. The different patterns of stem colonization were related to soil temperature. Average soil temperatures in 5-cm depth during 7 days before sampling time points from 2 years of field experiments displayed a significant relationship with fungal colonization in the root. A climate chamber inoculation trial with soil temperature levels that varied from 6 to 18°C revealed a threshold temperature of >12°C in the soil to enable root invasion. This soil condition is reached in winter-type oilseed rape in the field in Germany either until the eight-leaf stage in early autumn or after pod stage in spring, whereas in spring-sown oilseed rape early root infection is delayed owing to the cool conditions during juvenile growth stages. The delay of stem colonization in field-grown oilseed rape may explain the lack of stunting as observed in the greenhouse and the previously reported inconsistent effects of V. longisporum on yield levels and seed quality, which were confirmed in this study.

Potential for Seed Transmission of Verticillium longisporum in Oilseed Rape (Brassica napus).

Verticillium longisporum is a soilborne vascular fungal pathogen that has spread throughout the European oilseed rape cultivation area since the 1980s and was detected in canola fields in Canada in 2014. In a series of greenhouse and field inoculation experiments using V. longisporum-resistant and susceptible cultivars of winter and spring types of oilseed rape, the present study investigated the potential of V. longisporum dissemination by seeds of Brassica napus. Greenhouse inoculation studies with a DsRed-labeled isolate of V. longisporum confirmed the systemic growth of the pathogen from roots to seeds. Further monitoring of plant colonization in the greenhouse with a species-specific real-time polymerase chain reaction assay verified the pathogen growth from roots to stem bases, pods, and seeds in root-inoculated plants. The frequency of recovery of viable colonies of V. longisporum from seeds harvested from greenhouse-grown inoculated plants ranged from 0.08 to 13.3%. The frequency of seed transmission in the greenhouse differed in oilseed rape cultivars varying in susceptibility to V. longisporum. Subsequent studies on transmission of the disease into the offspring revealed that only 1.7 to 2.3% of plants showed disease symptoms as confirmed by the formation of microsclerotia in the stems. Results from field-grown plants differed from the greenhouse studies. The degree of seed transmission in the field was dependent on the crop type. Although only low concentrations of DNA of V. longisporum were detectable in seeds harvested from severely infected winter oilseed rape, significantly greater concentrations of fungal DNA were found in seeds of spring-type oilseed rape, at similar soil conditions and inoculum densities. Correspondingly, plating seeds that were harvested from infected plants on agar yielded viable V. longisporum colonies only from seeds of the spring-type but not of the winter-type plants. Lack of seed infection in the winter-type crop was confirmed in two seasons. Equally, none of the offspring grown from seeds from severely diseased winter oilseed rape plants developed symptoms of Verticillium stem striping. The results suggest that the rate of seed transmission of V. longisporum depends on the degree of plant colonization, which is significantly faster under greenhouse than field conditions and in a spring-sown crop compared with an autumn-sown oilseed rape crop. According to our studies, disease transmission by seeds from European winter oilseed rape production cannot be confirmed.

Improvement of cold tolerance of winter oilseed rape by exogenous amino acids

Research was carried out at the Experimental Station of Aleksandras Stulginskis University on Calc(ar)i-Endohypogleyic Luvisol (LVg-n-w-cc) during 2014–2017. The effect of exogenous amino acids on the cold tolerance of the linear cultivar ‘Cult’ of winter oilseed rape (Brassica napus L. spp. oleifera biennis Metzg.) was studied. In autumn the plants were sprayed with L-proline and L-glutamic acid one or two times. The biometric parameters of winter oilseed rape prepared for wintering, the amount of endogenous proline and over-wintering of plants were evaluated. It was determined that exogenous L-proline and L-glutamic acid stimulated the growth of green mass of the winter rape surface, accumulation of dry matter and increase of the root neck diameter in the autumn period. The investigated concentrations of L-proline and L-glutamic acid stimulated a more intensive synthesis of endogenous proline in winter oilseed rape plants during the preparation for wintering. The highest percentage of over-wintering has been determined in the variants where in the autumn plants were sprayed two times with 30 mM l–1 L-proline or 1.5 M l–1 L-glutamic acid.

The effect of the type of preparation on the deposit of copper while spraying the winter oilseed rape

The aim of the research was to determine the copper deposit volume on winter oilseed rape in three development phase (according to the BBCH scale: 12, 14 and 16). The experiment was performed in triplicate at the spraying speed of 0.86 m s-1. Two working fluids were used: foliar fertilizer Mikrovit Copper 80 and a nanocopper preparation, at the dose of 160 g Cu ha-1. The deposition treatment of the plants was conducted in the spraying chamber ‘Aporo1’ at two pressures (0.20 and 0.28 MPa), using two different types of flat fan nozzles. The dried rape plants were mineralized, and then, in order to determine the deposit, the Cu element concentration was measured using the spectrometer. The largest deposit of copper was obtained using the foliar fertilizer Mikrovit Copper 80 and using a double flat fan nozzle DF 120-02. The statistical analysis of the results of the study showed a significant effect of the type of liquid used on the value of copper deposit on winter oilseed rape plants.