The influence of stress factors on the plant can, on the one hand, lead to worse functioning of the plant and loss of its crop, but on the other, it can have a positive effect on the metabolism of compounds with documented biological activity. In this study, the effect of light and drought intensity on photosynthetic activity and physiological status of two barley varieties, as well as the antimicrobial, antioxidant properties and profile of polyphenolic compounds of green barley were analysed. It was shown that under the conditions of water shortage, the KWS Olof variety showed a smaller decrease in CO2 assimilation and transpiration and higher values of these parameters at both light intensities. Only in the KWS Olof variety increased stress as a result of increased light intensity. It has also been shown that both the intensity of radiation and drought-related stress have a significant impact on the profile of polyphenolic compounds from green barley, without a simple relationship between the impact of stress factors on the content of polyphenols. Changes in the profile of polyphenolic compounds augmented the antioxidant and antimicrobial activity of the material. This, in turn, proposes the possibility of reducing the applied doses of herbal material thanks to a greater content of active substances in extracts obtained from the plants used to produce medicinal preparations.

The aim of this study was to characterize extracts from the leaves of Ginkgo biloba L. from selected Slovakian localities in terms of the content of bioactive constituents, antioxidants and their antimicrobial properties. The results indicated that the content of antioxidants was sample-specific, and this specificity was statistically significant. Ginkgo biloba L. from the locality of Košice had the best activity determined by the free radical scavenging activity (DPPH) (1.545 mg Trolox equivalent antioxidant capacity (TEAC)/g fresh matter (FM)) as well as the molybdenum-reducing antioxidant power (35.485 mg TEAC/g FM) methods. The highest content of total polyphenols (2.803 mg gallic acid equivalent (GAE)/g FM) and flavonoids (4.649 μg quercetin equivalent (QE)/g FM) was also detected in this sample. All samples of G. biloba leaf extracts showed significant antimicrobial activity against one or more of the examined bacterial species, and Staphylococcus aureus subsp. aureus CCM 2461 was found to be the most susceptible (minimal inhibition concentration MIC50 and MIC90 values of 64.2 and 72.2 µg/mL, respectively). Based on the results it was concluded that Ginkgo biloba L. extracts can be used as antimicrobial and antioxidant additives. Selected miRNA-based molecular markers were used to examine the environmental adaptability of Ginkgo biloba L. An almost-complete genotype clustering pattern based on locality was determined in the analysis that involved a species-specific gb-miR5261 marker. Morphologically specific exemplar, cv. Ohatsuki, was excluded.

Agriculture is facing the complex challenge of satisfying increasing food demands, despite the current and projected negative impacts of climate change on yields. Increasing crop diversity at a national scale has been suggested as an adaptive measure to better cope with negative climate impacts such as increasing temperatures and drought, but there is little evidence to support this hypothesis at the field scale. Using seven long-term experiments across a wide latitudinal gradient in Europe, we showed that growing multiple crop species in a rotation always provided higher yields for both winter and spring cereals (average +860 and +390 kg ha−1 per year, respectively) compared with a continuous monoculture. In particular, yield gains in diverse rotations were higher in years with high temperatures and scant precipitations, i.e. conditions expected to become more frequent in the future, rendering up to c. 1000 kg ha−1 per year compared to monocultures. Winter cereals yielded more in diverse rotations immediately after initiation of the experiment and kept this advantage constant over time. For spring cereals, the yield gain increased over time since diversification adoption, arriving to a yearly surplus of c. 500 kg ha−1 after 50–60 years with still no sign of plateauing. Diversified rotations emerge as a promising way to adapt temperate cropping systems and contribute to food security under a changing climate. However, novel policies need to be implemented and investments made to give means and opportunities for farmers to adopt diversified crop rotations.

Seed treatments help reduce the pathogen load and thus improve the condition of plants from their earliest developmental stages, but they can have impacts beyond their basic fungicide protection role. In this study, we investigated how seven spring barley seed treatments affected the plants’ physiological state. The tested seed treatments differed significantly in their impacts on the vigor parameters of barley seeds and on the physiological state of seedlings under drought stress and after regeneration. Seed treatments based on substances from the succinate-dehydrogenase-inhibitors (SDHI) group did not cause inhibition of seedling growth and also display by the highest vigor index values. Using the analysis of photosynthesis-related parameters, we showed that seed treatments from the SDHI group provided a superior tolerance of the imposed drought in spring barley than other treatments. In addition to protection against abiotic stress, SDHI treatments also rendered a higher efficiency of photochemical reactions in the treated plants.

The study of the phenology of crops, although quite popular, has limitations, mainly because of frequent changes to crop varieties and management practices. Here, we present data on the phenology and yield of winter rye in western Poland collected between 1957 and 2012 from a long-term field experiment. Data were examined for trends through time and compared to climatological factors using regression analysis. Both annual air temperature and precipitation increased during the study period, equivalent to 2 °C and 186 mm, respectively, over the 52-year period for which met data were available. We detected significant delays in sowing date and recently in emergence, but significant advances were apparent in full flowering date equivalent to 4 days/decade. Yield and plant density experienced a step like change in 1986; yield increasing by ca. 70 % and plant density increasing by ca. 50 %, almost coinciding with a similar change in annual mean temperature, but most likely caused by a changed seed rate and use of herbicides. Future climate change is expected to have a greater impact on this crop, but farmers may be able to adapt to these changes by modifying water regimes, using new machinery and sowing new rye varieties.

No abstract

Abstract:The aim of the presented investigations was to examine changes in the intensity of dehydrogenase and acid phosphatase activities as well as of the dynamics of selected groups of microorganisms in the soil under the cultivation of winter triticale following the application of the following seed dressings: (a.s.) fl utriafol 2.5% + fl udioxonil 2.5% in two doses and (a.s.) carboxin and tiuram. The experiment had a fi eld character. The number of microorganisms (total bacteria, fungi, oligotrophic, copiotrophic and Azotobacter) was determined by the plate method on adequate agar substrates. Activity levels of the selected enzymes were defi ned using the spectrometrical method.The obtained results indicate a change in the dehydrogenase and phoshatase activity in soil depending on the seed dressing applied in the experiment as well as at the date of investigations. The number of microorganisms in the soil underwent fl uctuations depending on the developmental stage of triticale and the applied fungicide. The performed experiment demonstrated that counts of microorganisms in the soil underwent fl uctuations depending on the developmental stage of triticale and the applied fungicide.

Integrated pest management (IPM), a worldwide agricultural strategy, contains methods to control or manage agricultural pests and diseases in a more efficient way, and consequently, to obtain better quality raw materials for food production. The engagement and practice of farmers play a key role in the success of this strategy. Since January 1, 2014, Poland and other European Union countries have been obligated to apply the principles of IPM. This paper shows the results of surveys conducted in 280 randomly selected farms the year before and the year following mandatory IPM implementation. The aim of this study was to gather information about farmers’ knowledge of IPM and the most commonly used plant protection methods. Our results show that law regulations do not significantly change agricultural practice. Among the non-chemical methods farmers most often comply with are: implementing the agrochemical calendar, sowing healthy material, destroying volunteer plants, rotating crop, applying balanced fertilizer, plowing stubble and preventing excess nitrogen. Integrated plant protection is not possible without proper knowledge of diseases. This factor needs improvement in Poland. The average Polish farmer lacks the knowledge about basic cereal diseases such as powdery mildew or brown rust, though larger farm operators tend to be more knowledgeable. The results of this survey demonstrate the necessity to provide informative farmer training campaigns to promote on-farm application of IPM and to improve the knowledge of disease issues.