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This study aimed to evaluate the effect of an arbuscular mycorrhizal fungus (AMF) Glomus mosseae on plant growth, root architecture, and proline metabolism in roots of peach (Prunes persica L.) under non-flooding and flooding conditions. The 12-day flooding dramatically inhibited root colonisation of G. mosseae, but induced a large number of extraradical mycelia. Although the flooding treatment also relatively inhibited growth and root architecture of peach, the mycorrhizal fungal inoculation dramatically increased shoot and root biomass, plant height, stem diameter, number of 1^st- and 2^nd-order lateral roots, root total length (mainly 0-1 cm and > 3 cm long), root surface area, and root volume under flooding. The study also revealed distinctly higher proline accumulation in the roots of mycorrhizal plants than non-mycorrhizal plants under both non-flooding and flooding conditions, accompanied by higher Δ¹-pyrroline-5-carboxylate synthase (P5CS) activity and lower δ-ornithine transaminase and proline dehydrogenase activities. In addition, the PpP5CS1 gene expression was up-regulated by flooding and mycorrhization. This study concluded that mycorrhizal fungi enhanced flooding tolerance of peach through inducing proline accumulation and improving root architecture.

In this experiment, the response of winter oilseed rape cv. SY Alister F1 to diverse foliar fertilization was evaluated. Foliar fertilization with the preparation Insol 5 was applied at the following dates: control (without a foliar fertilizer); autumn; autumn + spring; autumn + twice spring; spring and twice spring. Each variant in which autumn foliar fertilization was carried out contributed to a significant increase in plant density before harvest. In turn, each variant with spring foliar fertilization significantly increased the number of pods per plant compared to the control. Variants with autumn + spring, autumn + twice-spring, and twice-spring foliar fertilization influenced the increase in the soil-plant analysis development index (SPAD), thousand seed weight and protein and fat yield. The leaf area index was the highest after foliar fertilization applied in autumn + in spring or autumn + twice in spring. Foliar fertilization affected a significant increase in seed yield compared to the control. The content of protein and magnesium in seeds was the highest after the fertilizer application in autumn + twice in spring or twice in spring.

The study presents the results of 4-year field trials; their purpose was to assess maize yield in relation to the depth of a mineral two-component (NP) fertiliser application in the soil layer, the type of nitrogen fertiliser (ammonium nitrate and urea) and the date of its application. The yield grain was significantly dependent on changing weather conditions in the growing seasons. Initial fertilisation with two-component NP fertiliser, regardless of the years, significantly affected the grain yield. Row fertilisation with two-component NP fertiliser increases the availability of phosphorus in the acid soil environment, elevating maize grain yield. The efficiency of row NP fertiliser application is determined by the natural soil richness in phosphorus. Maize grain yield depended more on the date of application than the form of nitrogen, and its application before sowing was more effective. The application of ammonium nitrate in the BBCH 15/16 stage significantly reduced the number of production ears per unit area compared to the pre-sowing application of this fertiliser. Deep fertiliser placement under the soil surface can be another tool to alleviate the negative consequences of the increasingly high temperatures and droughts.

Plant species and genotypes differ considerably with respect to the accumulation of mineral elements. This study examined the accumulation of aluminium (Al) in Aegilops and Triticum species with different genomes (AA, BB, BBAA, BBAADD and DD) and correlations between concentration of Al in the grain and features of the spike. Twenty different genotypes were included in three-year field experiments. The examined species and genomes differed significantly in their Al concentration in grain. The highest concentrations of Al were found in the grains of wild diploid Aegilops speltoides (BB genome), and the lowest in tetraploids (BBAA genome). A significant positive correlation was found between the concentration of Al in the grain and spike length, while negative correlations were found between concentration of Al in the grain and the number of grains per spike, grain weight per spike and thousand grains weight. The presence of higher Al content in the individual grains of tetraploid and hexaploid wheat with respect to diploid ancestors suggests that during the increase in ploidity the capacity of plants to uptake Al from soil increased concomitantly with the increase of grain capacity to serve as Al sink.

Use of microorganisms as heavy metal remediators is an effective approach for chromium reduction in plants. Chromium carcinogenicity (Cr⁶⁺) beyond the permissible levels elicits environmental and health problems. To reduce chromium toxicity along with the plant growth improvement, a cost-effective and eco-friendly remediation approach is necessary. In the current study, chromium-resistant bacterial species were evaluated for growth improvement of sunflower. Three auxin-producing bacteria able to tolerate hexavalent chromium, i.e., Sporosarcina saromensis (EI) and two species of Bacillus cereus (AR and 3a) were selected for the proposed study. Growth studies along with auxin synthesis potential of bacterial isolates with and without chromium were conducted. Results revealed a 188% enhancement in plant height under laboratory-grown plants with B. cereus (AR) under 500 mg/L chromium stress (Cr⁶⁺). B. cereus (3a) also showed an 81% increase in leaf number with 400 mg/L chromium stress in laboratory-grown plants. Similarly, 73% increment in the amount of auxin was reported in the case of inoculation with S. saromensis isolate (EI) over respective control treatment. These improvements provide an excellent means of reducing chromium (Cr⁶⁺) in the contaminated soils naturally by stimulating plant growth along with bioremediation potential.

Continuous monocropping can cause the buildup of autotoxins (e.g., phenolic compounds) in the soil, which can alter soil microbial community and inhibit plant growth. However, how different phenolic compounds affect certain soil microbiota is unclear. Here, we studied the response of cucumber rhizosphere Trichoderma spp. community to exogenously applied ferulic and p-coumaric acids by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR techniques. Results showed that ferulic acid, but not p-coumaric acid, increased the Trichoderma spp. abundance, and this increase were positively correlated with ferulic acid concentration. Moreover, ferulic acid changed the community structure, increased the number of DGGE bands, Shannon wiener, and evenness index values, while p-coumaric acid had no effect on all these parameters of Trichoderma spp. community. These results suggest that these two phenolic acids affected Trichoderma spp. differentially at the community level.

Pot experiments were carried out to study the effects of a novel stabilizer of 2,4,6-trimercaptotriazine, trisodium salt, nonahydrate (TMT) on the bioavailability of heavy metals (Cu, Zn, As, Cd and Pb) in soils and heavy metals accumulation in tobacco. The results showed the optimal TMT dosage 200 mL/kg could effectively reduce the bioavailability of heavy metals in soils, and the bioavailability of Cu, Zn, As, Cd and Pb in soils was reduced simultaneously by up to 73.1, 63.2, 48.0, 68.9 and 57.2%, respectively. Application of TMT could significantly decrease Cu, Zn, As, Cd and Pb contents of all parts of tobacco. Furthermore, the contents of available Cu, Zn, As, Cd and Pb in soils were significantly positively correlated with Cu, Zn, As, Cd and Pb contents in upper, middle and lower leaves and stems of tobacco. There were no significant differences among plant height, number of leaves, stem girth, length and width of maximum leaves of tobacco under TMT treatments and that under control (P < 0.05), which showed that the TMT did not promote and inhibit the growth of tobacco.

The aim of the research was to determine the quantitative and qualitative composition of soil-borne fungi in the cultivation of oat, as well as to assess the healthiness of this cereal. The experiment considered spring barley and potato as forecrops, and white mustard or lacy phacelia cultivated after spring barley as catch crops before oat. The population of fungi showing antagonistic effect towards selected fungi pathogenic to cereal was determined. The most fungi (pathogenic and antagonistic) were found in the soil under oat cultivation after spring barley, while the least after potato. The cultivation of oat after spring barley with the use of catch crops significantly influenced a reduction in the number of fungi obtained from the soil. On the other hand, catch crop cultivation increased the share of antagonists in the soil fungus population. Among the species recognised as antagonistic, Clonostachys rosea, Trichoderma viride, T. koningii, and T. harzianum predominated. The introduction of catch crops, especially white mustard, also positively influenced the healthiness of oat. The average disease index for the tested oat cultivars grown after potato and after spring barley with white mustard and lacy phacelia as catch crops was 11.02, 12.78 and 15.90, respectively, whereas after spring barley it was 21.75.

To find out exactly how sowing density and sowing pattern affect soybean grain yield, quality and its components in non-traditional soybean growing regions, such as Germany, two field trials have been conducted at two locations in Bavaria in 2016 and 2017. The experiments were carried out with four sowing densities (30, 50, 70, 90 seeds/m²) and four cultivars from different maturity groups (Viola 000, Lissabon 000, ES Mentor 00, Orion 00) as randomized complete block design with four replicates. Almost all evaluated traits varied significantly depending on year × location. There was no interaction between the main factors (cultivar × sowing density). The results revealed that grain yield and height of the first pod increased with increase of sowing density. The number of pods per plant and branching decreased with increasing sowing density. At higher sowing densities at flowering leaf area index was significantly higher than at lower sowing densities. The cv. ES Mentor (00) with 70 seeds/m² has proved to be a suitable cultivar in terms of yield and quality in southern Germany (> 3.6 t/ha grain yield and 40% protein).

Considering the improvement of acacia species growth in arid and semi-arid environment, a pot experiment was conducted to evaluate the role of arbuscular mycorrhizal fungi (AMF); Funneliformis mosseae (syn. Glomus mosseae), Rhizophagus intraradices (syn. Glomus intraradices) and Claroideoglomus etunicatum (syn. Glomus etunicatum) on growth and drought tolerance of Acacia seyal Del. seedlings under drought cycles (7, 14, 21 and 28 days). AMF-inoculated seedlings showed a clear colonisation percentage (36-68%). AMF treatment significantly improved seedlings shoot and root growth under all drought cycles compared to non-AMF control seedlings. Moreover, AMF treatment enhanced seedlings drought resistance by increasing root surface area (root length increased by 483.76% and root tips number increased by 1 463.94% under 28 days of drought cycle), there was a strong linear relation between proline accumulation, AMF and drought stress (proline content decreased in treated seedlings by 31.3% and 14.3% and increased by 97.5% and 80.4% in untreated seedlings under drought cycles of 21 and 28 days, respectively). In conclusion, the AMF inoculation improved growth and enhanced drought tolerance of A. seyal seedlings and can be used as a natural biostimulator for acacias seedlings establishment in arid areas.

Maintaining a strong antioxidant system is essential for preventing drought or waterlogging stresses damage in potato tubers. In the two-year pot experiment, the effect of long-term drought and waterlogging stresses on the content of phenolic acids, ascorbic acid, and antioxidant activity in potato tubers and relative water content of four cultivars was evaluated. Drought stress significantly (P < 0.05) decreased relative water content (RWC) in the leaves of all genotypes. The evaluation of the relationship between phenolic acid content and the level of plant stress expressed as RWC showed a negative correlation between RWC and most phenolic acids, but these correlations were not statistically significant, with the exception of l-tyrosine. A significant positive correlation was found between total and individual phenolic acid content and antioxidant activity (R = 0.657), confirming the main responsibility for the increase of antioxidant activity. The average tuber yield and weight as well as their average number correlated negatively with total phenolic acids. Drought stress decreased l-ascorbic acid content by reduction of biosynthesis, and its content was positively correlated with decreased RWC, tubers yield, weight, and number. The increase of phenolic antioxidants in potato under stress conditions can be a distinctive marker of cultivar resistance against abiotic stresses.

Biochar-based fertiliser (BF) is beneficial to improve yield and quality, but the effect of BF on open field tomato remains unclear, especially in karst mountainous areas. The objective of this study was to identify the application effect and optimum application rate of BF. A field experiment was carried out in Southwestern China from 2019 to 2020 to study the effects of different application amounts of BF on the yield, quality, nutrients accumulation and fertiliser utilisation of open field tomatoes. The results showed that compared with the traditional fertilisation practice, BF can significantly increase the yield of open field tomato by 5-9% (2019) and 12-23% (2020), and significantly reduce nitrate content and increase vitamin C content of fruits. Meanwhile, nutrient accumulations, agronomic efficiency, and recovery efficiency of BF treatments were all significantly improved. In conclusion, the BF rate of 2 326 kg/ha improves yield and fertiliser utilisation in open-field tomatoes and could be recommended for tomato production in karst mountainous areas.

The effect of simultaneous intercropping of winter wheat (Triticum aestivum L.) with different legumes of faba bean (Vicia faba L.), pea (Pisum sativum L.), and purple clover (Trifolium incarnatum L.) on selected production and qualitative parameters of wheat was evaluated in field trials conducted both in organic and conventional cropping systems, in comparison with pure sown wheat. Wheat intercropped with legumes achieved higher grain yield compared to pure sown wheat for an average of two years. However, in organic cultivation, the positive effect of intercropping on wheat yields was more pronounced. In addition, a strong influence of the year was noted. In 2021, in the organic cropping system, the most yielding intercropped wheat (especially with pea and bean) achieved 114-117% higher yields compared to pure sown wheat (in the previous year of 2020, it was usually only about 102-106%). In the conventional cropping system, the effect of intercropping on wheat yield was significantly weaker, and in 2021, wheat intercropped with legumes reached even lower yields than pure sown wheat in some cases. In terms of sowing methods (both in organic and conventional cropping systems), mixed sowing with individual legumes significantly exceeded the yields of wheat grown with legumes in separate, alternating rows. As regards quality parameters, wheat intercropped with legumes reached in comparison with pure sown wheat usually had higher crude protein content in wheat grain dry matter and higher values of Zeleny sedimentation.

Insect pollination is one of the most important ecosystem services. Pollinator communities are rarely studied across years and crops in the same location. The aim of this study was to investigate the pollinator community structure on five different fruit crops, as well as the activity of different pollinator groups during the day and their temperature preferences. Pollinator activity was observed across two years on apple trees and blueberry, strawberry, blackcurrant and raspberry bushes. Pollinator community structure varied by plant and year. Honeybees were the most numerous pollinators on all plants except blueberry bushes (39-95% of visits). Bumblebee numbers were high on blackcurrant (up to 28%) and blueberry bushes (up to 61%). Solitary bees visited all plants except blueberries. Honeybees, solitary bees, and hoverflies were most active in the middle of the day, while bumblebees became active earlier in the morning and remained active later in the evening. Pollinators also differed greatly in their temperature preferences. This knowledge gained is necessary for less harmful pesticide application management and the development of more sustainable agriculture to maintain pollinator diversity and thus reliable pollination in extreme weather conditions.

To assess the response of two safflower genotypes to auxin foliar application under late-season drought stress using a factorial split-plot experiment with the randomised complete block design, a two-year experiment (2016-2017 and 2017-2018) was conducted in Iran. The watering regime as specified in two levels including, regular irrigation and drought stress in main plots and two safflower genotypes and auxin foliar application in two levels including non-foliar application (control) and auxin foliar application at a concentration of 30 ppm were categorised in subplots. Drought stress at the seed filling stage reduced the safflower seed and oil yield. Moreover, a significant drought-induced decrease in linoleic acid, palmitic acid and behenic acid content, as well as an increase in oleic acids, was observed in two safflower genotypes. Among two safflower genotypes, the early maturing genotype less affected by drought and Goldasht had higher seed yield than the Padideh by 814 kg/ha, respectively. Auxin foliar application alleviates the adverse effects of drought, which led to an 18% increase in seed yield and components. However, the auxin application had no effect on the safflower seed oil content but palmitic acid content was affected by auxin foliar application. Generally, safflower along with auxin application can be recommended to develop safflower cultivation in semi-arid areas.

In field experiments over three vegetation periods (2010-2012) we studied impact of the CULTAN (controlled uptake long term ammonium nutrition) method on yield and yield parameters of kernel maize. The field experiments were conducted at three sites with different soil-climatic conditions. CULTAN treatments were fertilized once with the total amount of nitrogen using an injection machine (at the canopy height of 20 cm) and compared to conventional fertilization with calcium ammonium nitrate application at pre-sowing preparations. In all treatments the amount of nitrogen was the same, 140 kg N/ha. In 2010 at Humpolec site, CULTAN urea ammonium nitrate + inhibitor of nitrification treatment gave by 20.5% higher number of ears compared to CULTAN urea ammonium nitrate treatment. In 2011 at Ivanovice all CULTAN treatments reached statistically significantly higher number of kernels per ear. The higher 1000 kernel weight at CULTAN treatments was observed in 2012 at the Ivanovice site; a statistically significant difference between conventional and CULTAN urea ammonium nitrate + inhibitor of nitrification treatment was observed. Fertilization of maize with nitrogen using the CULTAN method under the conditions of the Czech Republic provides the same yield certainty as the conventional surface application and the CULTAN method of fertilization increases the yield certainty at delayed sowing. Harvest index was statistically significantly influenced by year, fertilization treatment and site.

The aim of our three consecutive years (2017-2019) field trial was to obtain information as to the effect of weather conditions of the actual year as well as to assess the impact of some technological parameters such as fertilisation, the choice on the hybrid type on the yield parameters, phytosanitary conditions and mycotoxin contamination of maize. According to our results, the climatic characteristics of the years, the examined hybrid characters (FAO 310 and 490) and the fact of N-fertilisation had significant effects on yield parameters and grain moisture content. The additional N-supply did not affect the development or severity of stem rot in any of the hybrid effects. In this respect, the year effect appeared to be the decisive factor since much higher stem rot values were recorded in the plots of the longer growing season hybrids. Among the mycotoxins examined, only zearalenone and fumonisin found in the harvest were significantly influenced by the effect of the year, the length of the growing season as well as nutrient replenishment. It can be stated that the applied technological parameters have a major effect on the expression of this toxin load in maize. Dry maize stocks that have lost their water in the vegetation are predisposing factors for toxin accumulation. N-content of soil and that of plants can play a different role in mycotoxin accumulation in maize plants.

The production of summer maize is greatly affected by nitrogen (N) sources through regulating root growth and distribution. Four N treatments in the field experiment were designed as UAN (urea ammonium nitrate solution was applied under traditional side-dressing method), urea (urea was applied under traditional side-dressing method), UWFI (UAN was applied underwater and fertiliser integration technology) and CK (no N applied). The results showed that the root length density, surface area density and volume of DH605 (mid-late hybrid) and DH518 (mid-early hybrid) under UWFI were higher than other treatments, especially in shallow layers. The root absorption area of each soil layer under N application treatments varied with the growth stage. The grain yield and the accumulations of N, P and K in the shoots showed the trend of UWFI > UAN > urea > CK. Compared with UAN and urea, the nitrogen agronomic efficiency of UWFI treatment increased by 40.5~78.6%, and the nitrogen partial factor productivity increased by 4.75~7.61%. Consequently, rational application of UAN would improve root traits, nutrient uptake and utilisation, and yield of summer maize.

The effect of soil selenate application to two different soils (Phaeozem and Cambisol) on biomass yield and selenium (Se) uptake by spring wheat (Triticum aestivum L.) was investigated in a pot experiment. Additionally, organic amendment (fugate, i.e. liquid by-product from the biogas plant) was applied to assess (i) the effect of organic matter on the bioavailability of Se and (ii) the fugate (containing 2.3 mg/kg of Se) as a potential source of Se for plants. Selenium was applied at two levels: 6.4 µg/kg (Se1) and 32 µg/kg (Se2) of soil. The efficiency of biofortification and the distribution of selenium within individual plant compartments were assessed in this case. The highest Se contents in the grain were achieved in the treatments receiving NPK fertiliser together with selenate, 455 µg/kg (Se1) and 2 721 µg/kg (Se2) when wheat was planted in Phaeozem. Fugate in co-application with selenate significantly reduced Se content in wheat plants as compared to treatments enriched solely with selenate. The lower Se contents in the wheat plants growing in Phaeozem were due to the biodilution effect, whereas in Cambisol, the decrease in wheat Se uptake was not clearly driven by a particular factor.

This study investigated the influence of soil undergoing different crop rotations on the CH₄, CO₂ emissions, and decomposition of rice straw. The studied soil undergoing crop rotation systems were rice-rice-rice (SR) and baby corn-rice-mungbean (SB). Two main microcosm set-ups: anaerobic (SR-AN, SB-AN) and aerobic (SR-AE, SB-AE) conditions. Litter bags containing rice stems were inserted into the soil and recollected at different time points for chemical analysing and the gas sampling was collected to measure the CO₂ and CH₄ emissions. The results indicated that the total carbon (TC) decreased around 30%, and the TC removal in anaerobic was significantly higher than in aerobic conditions. The residue cellulose content varied in a range from 68.2% to 78.6%, while the hemicellulose content varied from 57.4% to 69.3% at day 50 after incorporation. There were no significant differences in the total nitrogen removal, cellulose, hemicellulose, and lignin contents among the microcosm set-ups. CO₂ emission increased in all the microcosm set-ups with the treatments without rice straw (CTSR, CTSB) in both aerobic and anaerobic conditions. CH₄ release in the SR-AN treatments did not differ significantly compared with the SB-AN treatments. This study confirmed that the decomposition of rice straw residues is faster in the anaerobic paddy soil condition compared to the aerobic crop rotation condition.

With the need to obtain new methods to protect seed material from Ditylenchus dipsaci (Kühn, 1857) nematodes, a study was conducted to evaluate the nematicidal effects of several plants' essential oils on the mortality of D. dipsaci. Tests were performed under in vitro conditions; a concentration of 2 000 ppm was tested, nematodes were added into diluted oils, and numbers of living/dead nematodes were scored after 4 and 24 h. The results show a significant effect of several plant essential oils on D. dipsaci mortality, with the highest efficacy found for oil from Cinnamomum cassia ((L.) J. Presl), with 100% mortality observed even after 4 h.

Improved soil properties are commonly reported benefits of adding biochar to agriculture soils. To investigate the range of biochar's effects on soil chemical properties (e.g., soil pH, electrical conductivity (EC), cation exchange capacity (CEC), soil organic carbon (SOC), soil total carbon (TC), and soil carbon-nitrogen ratio (C:N ratio)) in response to varied experimental conditions, a meta-analysis was conducted on previously published results. The results showed that the effect of biochar on soil chemical properties varied depending on management conditions, soil properties, biochar pyrolysis conditions, and biochar properties. The effect size (Hedges'd) of the biochar was greatest for SOC (0.50), the C:N ratio of soil (0.44), soil pH (0.39), TC (0.35), EC (0.21), and CEC (0.20). Among the various factors examined by aggregated boosted tree analysis, the effects of biochar on soil chemical properties were largely explained by the biochar application rate, initial soil pH, and soil sand content. In conclusion, our study suggests that improving soil chemical properties by adding biochar not only requires consideration of biochar application rates and chemical properties but also the local soil environmental factors, especially soil initial pH and sand content of the soil, should be considered.

The effects of the co-application of molybdenum (Mo) and zinc (Zn) on winter wheat grain yield, leaf photosynthetic efficiency, and antioxidant activity were investigated using pot culture experiments with sandy soil. Four treatments were investigated, including a control (CK), 0.15 mg Mo/kg soil (Mo), 1 mg Zn/kg soil (Zn), and 0.15 mg Mo/kg + 1 mg Zn/kg soil (Mo + Zn). The results showed that the soil application of Mo and Mo + Zn increased the winter wheat grain yield, spike number, and thousand kernel weight, coupled with significant enhancement in nitrate reductase activity, chlorophyll a and chlorophyll a + b contents, as well as the photosynthetic rate of the leaves, which were also positively correlated with grain yield. Furthermore, the co-utilization of Zn and Mo + Zn significantly increased the activities of superoxide dismutase, catalase, and peroxidase in the leaves. The overall results indicate that the co-application of Mo and Zn can increase winter wheat grain yield by improving the leaf photosynthetic efficiency and antioxidant ability.

The study presents the results of field experiments, the aim of which was to assess the yield of maize cultivars with different genetic profiles depending on the method of soil preparation for sowing and the method of NP fertilizer application. The yield and water content in the grain were significantly dependent on changing weather conditions in the growing seasons. Sowing maize into the soil cultivated traditionally (autumn ploughing), stay-green type cultivars and row fertilization positively influenced maize yielding. The stay-green cultivar yielded at a higher level compared to the fast maturing cultivar, the difference being significant in the year characterized by unfavourable distribution (deficit) of precipitation in the growing season. The stay-green cultivar reacted favourably to the localized application of NP fertilizer, the clear result of which was the increase in grain yield. Direct maize sowing significantly reduced the number of production ears per surface area unit and the number of grains on the ear. Selection of the stay-green cultivar and row fertilization with NP fertilizer improved this condition.

The aim of the study was to evaluate the glomalins content (total glomalin (TG), easily extractable glomalin (EEG) and glomalin-related soil proteins (GRSP)) in the soil under winter wheat from different crop production systems. The experiment involved four different cultivation systems: organic, integrated (INT), conventional (CON), monoculture-conventional (MON). The highest content of TG and GRSP proteins were observed in organic system. A strong positive correlation was observed between the total number of glomalins and dehydrogenase activity and organic matter. A strong correlation between TG and GRSP content was observed (r = 0.93) as well as between EEG and GRSP (r = 0.79). The highest yields of winter wheat were observed in CON (9.12 t/ha) and INT (9.04 t/ha) systems, while the lowest in monoculture (4.47 t/ha).

The results of 81 different crop management practices in spring barley grown in small-plot field trials on fertile soils in central Moravia were assessed during 2014-2016 with the aim to achieve the highest gross margin (GM - calculated as the difference between revenues and direct costs). GM was most affected by protein content in the grain below 12% corresponding to malting quality. Analyses identified greater determination level of non-linear relationships between stand structure elements and the content of nitrogen substances in the grain. This indicates that the probability of obtaining high quality malting barley is increased when a high level of sinks (number of grains/m²) corresponding to availability of sources, mainly water, is formed by optimal plant density (300-400/m²) and balanced combination of both structural elements of crop stand, i.e. - number of spikes per plant (2-4) and number of grains per spike (18-26). In case that the high level of sinks will be formed predominantly by one element, the risk of higher protein content in grain increases. This constitutes the requirement of early sowing and uniform, synchronized tillering and efficient use of nitrogen fertilizers.

The cultivation of plants under the covers made of synthetic polymers brings many benefits, however, it is associated with the need to utilize or recycle these materials after the period of their use. Such problems are not caused by the covers made of natural polymers. The aim of the study carried out in the years 2013-2014 was to determine an effect of covers made of biopolymers and synthetic polymers on thermal conditions and potato yield. Field study was carried out under sandy loam and silty clay loam soils conditions. The temperature of silty clay loam soil under the covers was on average by 2.9°C higher than in the unprotected area, whereas sandy loam soil had the temperature higher by 2.5°C under biodegradable foil and by 2.7°C under standard foil. Temperature increase under non-woven fabrics was lower than under foils. The highest increase in marketable tuber yield after 40 days from emergence and in full maturity of potato plants was found after at application of standard non-woven fabric P17 (7.2 and 7.4 t/ha, respectively) and the lowest, i.e., 3.0 and 3.4 t/ha, respectively, under biodegradable foil. Cover type had no effect on the number of tubers formed on the first harvest date, whereas a significantly higher number of tubers was recorded in the full maturity of plants in the year characterized by a longer growing period of potato under non-woven P17 on sandy loam soil, and under biodegradable foil on silty clay loam soil conditions. A significant influence of cover on the average tuber weight on the first harvest date was found only on sandy loam soil under non-woven fabrics in 2013, as compared to full maturity of plants under biodegradable covers on sandy loam soil in 2013 and on silty clay loam soil under all covers in 2014.

The habitus of oilseed rape and its yield component values can be strongly affected by the structure of its stand. Field experiments took place in Central Bohemia in years 2013-2015 aiming at determining the influence of row-spacing (12.5, 25, 35 and 45 cm) on the yield components. Chosen parameters (the number of plants per unit area, the number of pods per plant, the number of seeds per pod and yield) were evaluated at the monitored stands (30 seeds/m² sowing rate, cv. DK Exquisite). The study confirmed the statistical significance of the influence of row-spacing on some winter oilseed rape yield components. Widening of the row-spacing has led to a decrease in the number of pods per plant and the number of plants per unit area and an increase in the number of seeds per pod parameter. 1000 seed weight was not affected. This study did not confirm a positive effect of sowing oilseed rape in rows wider than 12.5 cm. Therefore, such an agronomical decision cannot be recommended as a way to achieve higher seed yield.

The effect of nitrogen fertilization and microbial preparations on yielding and development of potato tuber yield components were assessed in field experiments conducted under soil conditions of Luvic Chernozem. The factors of the experiment were nitrogen fertilization levels: 0, 60, 120 and 180 kg N/ha and the following preparations: BactoFil B10, effective microorganisms and UG_max soil fertilizer. Nitrogen fertilization caused a significant increase in marketable yield of potato tubers. Yield increments on individual fertilizer treatments ranged from 66% to 140%. An evident effect of this factor was also visible regarding the yield components values. Increase in the number of main stems per 1 m² under the influence of growing nitrogen doses occurred from the fertilization level 120 kg N/ha, whereas the number of tubers per 1 stem increased only to the level of 60 kg N/ha. Each nitrogen dose applied within the range to 180 kg N/ha caused a marked increase in an average tuber weight. Conducted investigations demonstrated an unfavourable effect of microbial preparations on the marketable crop yield of tubers and formation of yield components. On the objects where microbial preparations were applied, the marketable yield was lower by 1.5 to 2.3 t/ha than in the control. Analysis of linear regression revealed occurrence of significant dependencies between the total tuber yield and the values of individual yield components. The relationships were the most visible for an average tuber weight formation as evidenced by the value of coefficient of determination (R² = 0.983).

This study aimed at investigating the effect of ontogenetic and diurnal variability on yield and quality criteria of Mentha piperita. The research was conducted in the Ordu province of Turkey for two years. The trial was established in a randomised complete block design with 3 replications according to factorial regulations. Four different harvesting periods (budding, first flowering, 50% flowering, 100% flowering) and three harvesting hours (9:00 a.m., 1:00 p.m., 5:00 p.m.) were evaluated. A significant difference was determined between the trial years in all characters examined: plant height 55.9-69.0 cm, fresh herb yield 3 236-16 438 kg/ha, drug-herb yield 1 748-2 862 kg/ha, fresh leaf yield 3 477-4 506 kg/ha, drug leaf yield 968-1 253 kg/ha, essential oil ratio 2.0-2.5% and essential oil yield that varied between 19-28 L/ha. The highest yields were obtained at the beginning of flowering in drug leaf yield and 100% flowering period for all other characteristics. Diurnal variability was statistically significant only in the rate of essential oil, and the highest rate occurred in the 9:00 a.m. harvest.