Silphium Perfoliatum Research Articles

Towards high-biomass yielding bioenergy crop Silphium perfoliatum L.: phenotypic and genotypic evaluation of five cultivated populations

Cup plant (Silphium perfoliatum L.) represents a promising alternative to silage maize as an energy crop for biogas production. This non-food plant possesses a highly ecological value due to its long blooming period, ability to grow in low-input agriculture and positive influence on soil structure. So far, there have been almost no breeding attempts for the cup plant, and all field experiments showing its high biomass yield were conducted by using only a few cultivated populations of unclear ancestry.Comprehensive assessment of five such populations for their biomass and methane yield parameters revealed substantial genetic variations indicating the possibility of improving these traits through selection and breeding. Higher biomass yield is likely to be achieved by breeding for secondary traits such as plant height, shoot diameter and internode number as well as photoperiod response. For increasing the methane production, reduced lignin or fibre content in the biomass seems to be important.Genetic relationships among the populations were estimated using tunable genotyping by sequencing (tGBS) technology. Genetic structure and phylogeny analyses revealed that all the plants belong to the same gene pool and share a common ancestry. Four out of five populations demonstrate a low genetic differentiation, whereas the fifth one represents a clear example of population stratification. To achieve a successful domestication and breeding of this new high-yielding perennial crop, a broader base of genetic diversity needs to be ensured and complemented by innovative breeding strategies driven by molecular genetic and modern genomics approaches.

Research on thermal disposal of phytoremediation plant waste: Stability of potentially toxic metals (PTMs) and oxidation resistance of biochars

Thermal conversion of phytoremediation plant waste into biochar was performed as a safe approach for organic waste management. In this work, a promising phytoremediation plant―Silphium perfoliatum L. was pyrolyzed for biochar production at 350, 550 and 750 °C. The long-term leaching risk of potentially toxic metals (PTMs) in the derived biochars and the oxidation resistance of the biochars were investigated. The results showed that PTMs in the biochar could transform into more stable and less toxic forms with the elevated pyrolysis temperature. PTMs leaching behavior in the 350 °C biochar was considerably sensitive to the leaching while that in the 750 °C biochar was not affected. The biochar produced at a higher temperature possessed a greater oxidation resistance with little amount of C loss, and the stronger oxidation resistance would prevent the release of metals bound to the organic matter. The findings of this study demonstrated that high-temperature pyrolysis was able to reduce the potential risk of PTMs and ensure carbon stability.

Biomass Production of Monocultures and Mixtures of Cup Plant and Native Grasses on Prime and Marginal Cropland

To date, most candidate systems for producing herbaceous cellulosic biomass have been composed of monocultures of perennial or annual grasses. Ecosystem goods and services provided from these biomass feedstock production systems could be increased dramatically with mixing of one or more forb species that would increase biodiversity and provide habitat for pollinators. Cup plant (Silphium perfoliatum L.) is featured with many desirable characteristics, such as high biomass potential, adaptation to marginal soils, and attractiveness to pollinators, desirable in a dicot species to grow in mixtures with perennial warm-season grasses. The objective of this study was to compare cup plant, switchgrass (Panicum virgatum L.), and prairie cordgrass (Spartina pectinata Link) monocultures to their mixtures for biomass production on prime and poorly drained marginal crop land for two years in both South Dakota and Wisconsin. In Wisconsin, monocultures of prairie cordgrass and cup plant and their mixture produced more biomass (8.1 Mg·ha-1) than the switchgrass monoculture and switchgrass/cup plant mixture (5.3 Mg·ha-1) on both prime and marginal land. While in South Dakota, drought and meristem destruction by the cup plant moth (Eucosma giganteana Riley) caused large reductions in biomass production (1.7 Mg·ha-1) in both years, with the switchgrass/cup plant mixture on marginal land having the highest yield (2.1 Mg·ha-1). Our study showed binary mixtures of cup plant and native warm-season grasses have great potential for increasing biodiversity and other ecosystem goods and services, relative to monocultures, for sustainable biomass feedstock production on poorly drained marginal land in the northcentral USA.

Biomass Production of Cup Plant (<i>Silphium perfoliatum</i> L.) in Response to Variation in Plant Population Density in the North Central USA

The North American genus Silphium is receiving global attention for its potential in the development of new food, forage, and industrial crops, including cellulosic biomass for biofuel. Little is known about the effect of plant population density on biomass production in large, coarse perennial forbs. Our objective was to evaluate the effect of variation in plant density on biomass production and stand morphology of cup plant (Silphium perfoliatum L.). Plant population densities of 17,000, 34,000, and 68,000 plants ha-1 were evaluated for biomass production in a single-harvest per annum system for three years at Brookings, SD and Arlington, WI. Biomass increased linearly by 43% between the low and high density at Brookings; whereas, at Arlington, response to variation in plant density was year dependent. Shoots plant-1 was inversely related to plant density with linear regression explaining >95% of the variation. Our results strongly suggested that further studies of effects of plant population density on biomass production in cup plant should include evaluation of, in addition to, densities higher than 68,000 plants ha-1.

Skład chemiczny i właściwości biologiczne rożnika przerośniętego (Silphium perfoliatum L.)

A cup plant (Silphium perfoliatum L.) is a poorly-known crop in the country. It came to Europe from North America in the 18th century. It can be propagated by dividing rhizomes or by sowing seeds. This plant is undemanding in terms of alimentary requirements and resistant to cold and pests. Due to the high content of nutrients and the yield of green mass a cup plant is used for fodder purposes. A cup plant contains numerous secondary metabolites, such as phenolic acids, flavonoids, terpenes, essential oil, tannins, vitamins and mineral components. It is characterized by antioxidant, antibacterial, antifungal, cytostatic and immunosuppressive activity. Research on laboratory animals indicates that the cup plant accelerates wound healing and indicate hypolipemic and estrogenic activity. Numerous reports confirm, that this plant also has a strengthening, diuretic, anti-inflammatory, antihemorrhagic and spasmolytic activity. In addition, it is used in the healing diseases of the liver and spleen, and also heals gastric and duodenal ulcers.

Новые перспективные кормовые культуры для условий Архангельской области

Нетрадиционные кормовые культуры, к которым относятся многие виды растений, представляют значительную ценность, так как отличаются высокой урожайностью, хорошими кормовыми качествами, обладают высоким адаптивным потенциалом и сочетают его со значительной экологической пластичностью. Представлены результаты изучения нетрадиционных и малораспространенных кормовых культур на юге Архангельской области. Объектом исследования, проведенного в 2015 – 2017 гг., являлись многолетние кормовые культуры различных ботанических семейств: Sida hermaphrodita, Silphium perfoliatum L., Serratula coronata. Дана сравнительная оценка малораспространенным кормовым культурам. В течение вегетационного периода проводили фенологические наблюдения за ростом и развитием растений, урожайностью зеленой массы. По комплексу хозяйственно ценных признаков выделены культуры, характеризующиеся высоким потенциалом кормовой продуктивности, устойчивые к засухе, полеганию, вредителям и пораженности болезнями. Урожайность зеленой массы у сильфии пронзеннолистной в среднем составила 45,2 т/га, содержание сухого вещества — 12,1 %, переваримого протеина – 62,0 г, сахара — 88,6 г, вегетационный период — 85 дней; у серпухи венценосной — соответственно 29,4 т/га, 18,4 %, 66,9 и 111,4 г, 54 дня; у сиды многолетней — соответственно 15,3 т/га, 18,4 %, 57,2 и 92,2 г, 58 дней. Данные культуры рекомендованы для использования в сельскохозяйственном производстве. Предшественниками этих культур могут быть озимые и яровые зерновые, а также пропашные культуры.

Biochemical methane potential (BMP) of six perennial energy crops cultivated at three different locations in W-Germany

To mitigate the effects of climate change, the emission of greenhouse gases (GHG) should be reduced. In the near future, an increased use of biomass for energy production will be prescribed by law in the European Union (EU) to achieve the target of emission reduction. One possibility to use biomass energetically is its transformation into biogas. The most widely grown crop for this purpose is maize. Although, the increased use of maize as biogas feedstock, due to generous subsidies, is linked to several ecological and (socio)economic problems. The most important are soil erosion, depletion and compaction, high demand and subsequent leaching of fertilizers/biocides, heavy workload, and competition for land between food and energy production. In contrast, the use of second-generation perennial energy crops (PECs) as biogas feedstock can be an auspicious approach to improve the environmental footprint of biomass production. Therefore, we evaluated and compared the biochemical methane potential (BMP) of five different perennial species (cup plant, virginia mallow, tall wheatgrass, giant knotweed, reed canary grass) and a wild plant mix (composite of 25 in parts perennial plants) on three different sites in West-Germany. In terms of methane production per area, tall wheatgrass and reed canary grass exceeded the productivity of maize under favorable conditions. Hence, we recommend both species as biogas feedstock for Central Europe or comparable climates. Additionally, other species might be suitable for biomethanation from an overall perspective, to enhance (agro)biodiversity in rural areas.

Cup-plant potential for biogas production compared to reference maize in relation to the balance needs of nutrients and some microelements for their cultivation

The study was focused on the assessment of cup-plant (Silphium perfoliatum L.) as a potential feedstock for biogas production in comparison to reference maize related to the balance needs of nutrients and some microelements for their cultivation, especially with use of digestate for fertilization. Field experiments were carried out in areas of the Czech Republic with less favorable conditions for the cultivation of maize. Obtained results confirmed that cup-plant can be considered a promising novel crop for biogas production due to high yields of biomass (12–18 t/ha DM) and methane (3600–4250 Nm3/ha) competing with reference maize grown under the same soil and climatic conditions. The biochemical analyses characterizing the feed value of phytomass were conclusively better with maize than cup-plant. This corresponds with specific methane yields, which is about 5–10% higher in maize (269–319 Nm3/t VS) than in cup-plant (254–298 Nm3/t VS). On the basis of chemical analyses of tested crops, the uptake of basic nutrients (N, P, K, Ca, Mg and S) and selected trace elements (microelements B, Fe, Mn, Co, Cu, Mo, Ni and Zn) was determined. Then, using the element contents and average yields, it was possible to calculate the annual removal of each element from the field with cup-plant and reference maize as the basis value for the evaluation of compensatory fertilization needs. With respect to the cultivation of tested crops for biogas production, the possibilities of their compensatory fertilization were evaluated using digestate from biogas plants. The uptake of different nutrients and microelements on tested crops was verified. The experiment showed that cup-plant has higher requirements on all tested nutrients, except N, and microelements, except Cu and Zn. In the case of nutrients, the highest uptake differences between cup-plant and maize were at B (about 11× higher), followed by Mg (3.5×) and K (1.8×). In the case of microelements, the highest uptake differences were B at (about 9× higher), followed by Co (5×), Fe, and Mn (2×). Therefore, increasing yields of cup-plant after using these nutrients and microelements for compensative fertilizing can be expected. For the mixture of maize and cup-plant (1:1 of VS weight), the higher specific methane yield was obtained (292 Nm3/t VS). It was more than expected of the average value (286 Nm3/t VS). It cannot be explained by the improvement in the feed value of cup-plant and maize mixture, but a possible explanation could be the positive synergistic effect of cup-plant due to the better supply with biologically active essential nutrients and microelements. In any case, this phenomenon deserves more detailed research in the future.

Vermessung und Sortierung von Saatkörnern der Durchwachsenen Silphie zur Optimierung der Bestandesetablierung

By using cup plant ( Silphium perfoliatum L.), which is native to North America, as bio­gas substrate, there is an economically interesting alternative or supplement to the predominantly used substrate maize. Due to its ecological advantages, it also contributes to the increase of biodiversity in the agricultural landscape. In order to establish an efficient crop stand with a long useful life of more than 10 years, a precise distribution of the seeds is necessary. The seeds are characterized by a strong heterogeneity in size and shape within a seed batch which negatively affects the quality of singling. The aim of the experiments was to quantify the size and geometry of seeds from different batches. In this context, seeds were measured and divided into fractions by using a self generated scheme and procedural analyses. In addition to optimize the singling by increasing the homogeneity, the study supports also the potential for improving the quality of commercially available seeds

The Yield of Silphium Perfoliatum L. Depending on the Conditions of Cultivation

Abstract The article presents the results of two-year studies on the influence of the method of sowing and the level of nitrogen application on the yield of seeds of Silphium perfoliatum L. − a new fodder crop for the conditions of Belarus. Silphium is precious for the nutritive value of green mass. According to the literature sources, dry matter contains 16-28% of protein, more than 60% of nitrogen-free extractives, 13-23% of sugars, high content of mineral substances, a small amount of fiber, adequate calcium and phosphorus, carotene, vitamin C. Mineral composition of Silphium contains 17.6% of dry matter, including 152.3 mg·kg−1 of ash. Macro elements: calcium – 18.1, phosphorus − 2.55, manganese – 4.48, potassium – 24.03, sodium – 0.40, sulphur – 0.40 mg· kg−1 of mg· kg−1 of dry matter. The mass of 1000 seeds was from 23.7 to 25.5 g. The seed germination was good and varied from 75% to 84%. It has been established that the best way to sow the Silphium is planting seedlings according to the 70x30 scheme. This option ensured the yield of seeds of 3.6 and 3.7 c/ha. The applying of increased doses of nitrogen fertilizers N90 and N120 and sowing seeds ensured the yield of seeds ranging from 3,6 to 3,9 c·ha−1.

Soil quality indicator response to land‐use change from annual to perennial bioenergy cropping systems in Germany

AbstractProduction of biomass feedstock for methanation in Europe has focused on silages of maize and cereals. As ecological awareness has increased in the last several years, more attention is being focused on perennial energy crops (PECs). Studies of specific PECs have shown that their cultivation may enhance agrobiodiversity and increase soil organic carbon stocks while simultaneously providing valuable feedstock for methanation. This study was designed to compare soil quality indicators under annual energy crops (AECs), PECs and permanent grassland (PGL) on the landscape level in south‐western Germany. At a total 25 study sites, covering a wide range of parent materials, the cropping systems were found adjacent to each other. Stands were commercially managed, and PECs included different species such as the Cup Plant, Tall Wheatgrass, Giant Knotweed, Miscanthus, Virginia Mallow and Reed Canary Grass. Soil sampling was carried out for the upper 20 cm of soil. Several soil quality indicators, including soil organic carbon (Corg), soil microbial biomass (Cmic), and aggregate stability, showed that PECs were intermediate between AEC and PGL systems. At landscape level, mean Corg content for (on average) 6.1‐year‐old stands of PEC was 22.37 (±7.53) g kg−1, compared to 19.23 (±8.08) and 32.08 (±10.11) for AEC and PGL. Cmic contents were higher in PECs (356 ± 241 μg C g−1) compared to AECs (291 ± 145) but significantly lower than under PGL (753 ± 417). The aggregate stability increased by almost 65% in PECs compared to AEC but was still 57% lower than in PGL. Indicator differences among cropping systems were more pronounced when inherent differences in the parent material were accounted for in the comparisons. Overall, these results suggest that the cultivation of PECs has positive effects on soil quality indicators. Thus, PECs may offer potential to make the production of biomass feedstock more sustainable.

Impact of newly introduced perennial bioenergy crops on soil quality parameters at three different locations in W‐Germany

AbstractThe land areas used for bioenergy crop cultivation are increasing across Europe. For several years now, various perennial crops have been cultivated, including Miscanthus, switchgrass and reed canary grass, and the newly introduced cup plant, giant knotweed, tall wheatgrass, virginia mallow, and wild plant mixtures. We investigated the impact that many of these perennial bioenergy crops (PECs) have on the soil organic C and N pools, microbial properties, and earthworm activity at three different study sites in W‐Germany with varying soil conditions after an experimental period of five years. Silage maize (Zea maize) in rotation with green rye (Cecale cereale) or Triticale was used for comparison (= annual energy crops; AEC). The overall intention of this study was to gain insights into the future trends of soil quality with changes in land‐use towards bioenergy production. Our results emphasized that in general, soil quality was improved through the cultivation of perennials. For example, after five years of investigation, the mean soil organic carbon contents increased, on average, by 1–2% at two of the three study sites, the soil microbial biomass increased from 13% (virginia mallow) to 27% (tall wheatgrass) (p < 0.05) compared to AEC treatment and the mean earthworm activity (cast production) was significantly improved in PECs compared to AEC. These trends were mainly found in silty to loamy soils, but the results were slightly different in sandy soils and dry climate conditions. We suggest that this might be traced back to unfavourable growing conditions for perennial crops during the first years of establishment. To our knowledge, this is the first comprehensive field investigation of the impact of these newly introduced perennial crops on soil quality indicators that considers various site‐ and soil‐specific growth conditions.

Extraction optimization and influences of drying methods on antioxidant activities of polysaccharide from cup plant (Silphium perfoliatum L.).

Response surface methodology (RSM) was used to investigate the extraction condition of polysaccharide from cup plant (Silphium perfoliatum L.) (named CPP). Water to raw material ratio (10–30 mL/g), extraction time (40–80 min) and extraction temperature (60–100°C) were set as the 3 independent variables, and their effects on the extraction yield of CPP were measured. In addition, the effects of drying methods including hot air drying (HD), vacuum drying (VD) and freeze drying (FD) on the antioxidant activities of CPP were evaluated. The results showed that the optimal condition to extract CPP was: water to raw material ratio (15 mL/g), extraction time (61 min), and extraction temperature (97°C), a maximum CPP yield of 6.49% was obtained under this condition. CPP drying with FD method showed stronger reducing power (0.943 at 6 mg/mL) and radical scavenging capacities against DPPH radical (75.71% at 1.2 mg/mL) and ABTS radical (98.06 at 1.6 mg/mL) than CPP drying with HD and VD methods. Therefore, freeze drying served as a good method for keeping the antioxidant activities of polysaccharide from cup plant. The polysaccharide from cup plant has potential to use as a natural antioxidant.

Bestimmung der Korngeometrie der Durchwachsenen Silphie als Voraussetzung für die Einzelkornsaat

In search of economically and ecologically interesting alternatives and additions to maize, currently the predominantly used biogas substrate, cup plant (Silphium perfoliatum L.) has been found as a promising plant species. The perennial composite, which is located in North America, can be established by modified conventional seeders. Due to a long flowering period and different geographic origins of the plant material, seeds of different sizes and shapes can be found in the seed batch, which makes a precise singling of the seeds difficult. For the quantification of the geometric parameters the seeds were recorded and measured. The results of these researches were used to optimize the seeding in precision seeders.

Accelerating Silphium Domestication: An Opportunity to Develop New Crop Ideotypes and Breeding Strategies Informed by Multiple Disciplines

Silphium perfoliatum L. (cup plant, silphie) and S. integrifolium Michx. (rosinweed, silflower) are in the same subfamily and tribe as sunflower (Helianthus annuus L.). Silphium perfoliatum has been grown in many countries as a forage or bioenergy crop with forage quality approaching that of alfalfa (Medicago sativa L.) and biomass yield close to maize (Zea mays L.) in some environments. Silphium integrifolium has large seeds with taste and oil quality similar to traditional oilseed sunflower. Silphium species are all long‐lived, diploid perennials. Crops from this genus could improve the yield stability, soil, and biodiversity of agricultural landscapes because, in their wild state, they are deep rooted and support a wide diversity of pollinators. In contrast with premodern domestication, de novo domestication should be intentional and scientific. We have the luxury and obligation at this moment in history to expand the domestication ideotype from food and energy production to include (i) crop‐driven ecosystem services important for sustainability, (ii) genetic diversity to enable breeding progress for centuries, (iii) natural adaptations and microbiome associations conferring resource use efficiency and stress tolerance, and (iv) improving domestication theory itself by monitoring genetic and ecophysiological changes from predomestication baselines. Achieving these goals rapidly will require the use of next‐generation sequencing for marker development and an international, interdisciplinary team committed to collaboration and strategic planning.

Radiation use efficiency, chemical composition, and methane yield of biogas crops under rainfed and irrigated conditions

For biomethane production, the cup plant (Silphium perfoliatum L.) is considered a promising alternative substrate to silage maize (Zea mays L.) due to its high biomass potential and associated ecological and environmental benefits. It has also been suggested to grow cup plant on less productive soils because of its presumed drought tolerance, but robust information on the impact of water shortage on biomass growth and substrate quality of cup plant is rare. Therefore, this study assesses the effects of soil water availability on the chemical composition and specific methane yield (SMY) of cup plant. Furthermore above-ground dry matter yield (DMY) was analysed as a function of intercepted photosynthetic active radiation (PAR) and radiation use efficiency (RUE). Data were collected in a two-year field experiment under rainfed and irrigated conditions with cup plant, maize, and lucerne-grass (Medicago sativa L., Festuca pratensis Huds., Phleum pratense L.). The cup plant revealed a slight decrease of −6% in the SMY in response to water shortage (less than 50% of plant available water capacity). The average SMY of cup plant [306 l (kg volatile solids (VS))−1] was lower than that of maize [362 l (kg VS)−1] and lucerne-grass [334 l (kg VS)−1]. The mean drought-related reduction of the methane hectare yield (MHY) was significantly greater for cup plant (−40%) than for maize (−17%) and lucerne-grass (−13%). The DMY reduction in rainfed cup plant was mainly attributed to a more severe decrease in RUE (−29%) than for maize (−16%) and lucerne-grass (−12%). Under water stress, the mean cup plant RUE (1.3 g MJ−1) was significantly lower than that of maize (2.9 g MJ−1) and lucerne-grass (1.4 g MJ−1). Compared to RUE, the reduced PAR interception was less meaningful for DMY in rainfed crops. Hence, the cup plant is not suitable for growing on drought prone lands due to its high water demand required to produce reasonably high MHYs.

A new species of Acanthocaudus Smith (Braconidae: Aphidiinae), with a key to species and new host and distribution records for aphidiines associated with Silphium perfoliatum L. (Asterales: Asteraceae).

A new species, Acanthocaudus bicolor Kula (Braconidae: Aphidiinae), from the Nearctic Region is described and differentiated from all other species of Acanthocaudus Smith. Acanthocaudus schlingeri Muesebeck, 1958 is synonymized with Acanthocaudus tissoti (Smith, 1944). A key to the species of Acanthocaudus is provided. The following aphidiines are reported as parasitoids of aphids on Silphium perfoliatum L. (cup plant) for the first time: Aphidius (Aphidius) ohioensis ex Uroleucon (Uroleucon) cf. rudbeckiae (Fitch), Aphidius (Aphidius) polygonaphis (Fitch) ex Uroleucon sp., Praon pequodorum Viereck ex undetermined aphids, and Praon simulans (Provancher) ex undetermined aphids. Aphidius (A.) ohioensis and P. simulans are reported from Indiana and South Dakota for the first time. Acanthocaudus tissoti and P. pequodorum are reported from Indiana for the first time.

Dynamic of nematode communities in energy plant cropping systems

The perennial cropping system of the cup plant (Silphium perfoliatum) might counteract major drawbacks of intensively managed annual biomass production systems due to a long-term reduction of agricultural management. In this context, the ecological value of the cup plant was assessed for free-living soil nematodes to reveal changes in soil biodiversity and functions associated with cultivation period length. For this purpose, cup plant fields from a chronosequence were sampled in two consecutive years and compared to energy maize production systems. Nematodes were identified on a family level and assigned to feeding guilds. General and nematode-specific diversity indices, as well as multivariate redundancy analysis were used to assess changes in community structure. General mixed-effects modeling and multi model averaging were applied to reveal the influence of cultivation period length and environmental factors on nematode assemblages. Major changes were found in almost all trophic groups. In the long-term, abundances of herbivores, fungivores and carnivores increased along with total nematode abundance. Bacterivores remained almost unchanged, but decreased in dominance. Old cup plant fields (8+ years) showed mass occurrences of Helicotylenchus spp.. In cup plant fields, facilitation of fungal decomposer channels and top-down regulation within the nematode food web could improve soil fertility and soil quality. However, long-term dynamic of the nematode community was not indicative of succession and remained characteristic for agroecosystems, hence positive effects are presumably restricted to conversion of farmed land.

The Application of Mycorrhizal Fungi and Organic Fertilisers in Horticultural Potting Soils to Improve Water Use Efficiency of Crops

In recent years, the addition of microorganisms such as Plant Growth-Promoting Bacteria (PGPB) and mycorrhiza are becoming more popular, both in research as well as in practical use. While inoculants are usually not necessary for plants cultivated outdoors on biologically active soil, they can be useful on sterile substrates, newly created artificial landscapes, and also in soils that have been managed using non-selective sterilization methods, such as fumigation. In a multi-year lysimeter experiment, we investigated the influence of a commercial mycorrhizal inoculum on water use efficiency and biomass production of maize (Zea mays), sunflower (Helianthus annuus), sweet clover (Melilotus officinalis), sweet sorghum (Sorghum bicolor), cup-plant (Silphium perfoliatum) and tall wheatgrass (Elymus elongatus subsp. ponticus cv. Szarvasi-1) when exposed to high or low ground-water levels. Results showed that all plants benefited from the mycorrhizal association. Mycorrhizal-inoculated plants were more successful in terms of dry matter production and water use than the non-mycorrhizal plants. The source of the mycorrhiza—autochthonous or introduced—made no significant difference. The results indicate that inoculation with mycorrhiza and promotion of the naturally abundant mycorrhiza in agricultural production systems can significantly contribute to a sustainable production of crops. Effects depended on plant species, cultivar, soil type, ground-water level and the mycotrophy of the individual crop species.

Peculiarities of growing Silphium perfoliatum L. in conditions of radioactive contamination of Ukrainian Polissya

The results of the cultivation Silphium perfoliatum L. studies on withdrawn agricultural lands and contaminated lands as a feed crop are given. The positive effect for plant growth regulators such as Emistim C and Rehoplant to yield Silphium perfoliatum L. was established. It has been shown Silphium perfoliatum L. productivityas fodder crop in the conditions of second zone of obligatory resettlement village Khrys tynivka Narodychi district, Zhytomyr region. It has been established that in the taken samples of plants from the studied area, radiation safety level was not exceeded for specific activity of cesium-137 in the studied crop. Analyzing the data, we can conclude that Silphium perfoliatum L. growing in the contaminated areas can be recommended as a valuable nutritious crop. Growing Silphium perfoliatum L. as fodder and bioenergy crop requires further studies and development of new adaptive technologies for the Polissia and foreststeppe of Ukraine.