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SuMMARyThis paper discusses possibilities for pyrethrum Chrysanthemum cinerariaefolium (Trevir.) Vis. production in southern regions of Slovakia, with an emphasis on target marketing, management constraints and further research. Pyrethrum is not a traditional crop in Slovakia but prospects have opened up for its cultivation. The high yields and quality of some suitable pyrethrum ecotypes provide the grounds for effective field production under favorable conditions. Pyrethrum yielding 1.275 t of dried flowers per hectare and having at least 1.5% pyrethrum content can be a profitable and highly lucrative crop with an economic result ranging from 413 to 1071 € per ha. A SWOT analysis revealed that pyrethrum production in Slovakia could take a course of an offensive strategy. However, intensive production of this commodity needs further development. Prospects for this non-traditional crop in Slovakia are also promising in terms of development of farming systems in which plant protection products of botanical origin would be welcome. Improved processing and stabilization of extract would further increase the possibilities.

A field trial with Miscanthus sinensis Anderss. was performed in Vysoká nad Uhom (average yearly temperature: 9.0°C, yearly precipitation: 584 mm) on Haplic fluvisol (WRB 2006) during 2006-2009. The average dry matter (DM) yield of the above- ground phytomass was 25.63 t/ha/year (excluding establish- ment year when yield was 4.81 t/ha) and had an increasing trend according to production years (14.13, 26.14 and 36.63 t/ha). We achieved in developing a trial stand in the third year of production when the field coverage of 10 thousand rhizomes being planted per hectare was over 80%; however, it can be used as a denser spacing for the earlier performance of stand with full production capability, which means plantation of 12-13 thousand plants per hectare. The average lower heating value of the organic sample of phytomass, as received (LHV) was 15.56 MJ/kg, and according to the trial years were 15.09; 15.80; 15.70; and 15.80 MJ/kg. The amount of total energy value of the produced phytomass per unit area (energy yield) was 1,284.989 GJ/ha, and 72.583, 223.254, 410.398, 578.754 GJ/ha, respectively, in the trial years. The energy yield was exclusively affected (r = 0.999), and the caloric value (LHV) was affected by phytomass yield (r = 0.739). Obtained emission characteristics and the concentration of selected volatiles, and remaining ash, ash content 3.46%, total water 10.65%, carbon 42.49%, hydrogen 5.20%, total sulphur 0.12%, nitrogen 0.55%, silicone 1.17% and chlorine 0.16% have supported the environmentally friendly introduction of Chinese silvergrass, as the energy crop is desirable for the targeted agroecological conditions of Slovakia.

The yield potential of switchgrass was verified by testing seven cultivars in a small-scale experiment carried out from 2018 to 2022 on Gleyic Fluvisol under Central European conditions. The treatments are as follows: pre-sowing (i/HA) soil humic preparation Humac AGRO (based on leonardite) with an ameliorative dose of 1000.0 kg ha−1 or (ii/NPK) basic nutrition with a dose of 220.0 kg ha−1 NPK; an annual dose of 70 kg ha−1 N was applied to both treatments (HA, NPK) and compared to (iii/UC) untreated control. A dry matter (DM) yield of 9.02 t ha−1 was achieved in the total average, which varied from 0.05 t ha−1 to 60.64 t ha−1. The yield was affected mainly by years (F-ratio 106.64), then by nutrition (F-ratio 79.03), followed by cultivars (F-ratio 56.87), and finally by replications (F-ratio 0.00). Switchgrass productivity increased according to the utility year; however, the driest year (2020—388 mm, 2021—372 mm, and 2022—288 mm) changed the order of the three full utility years (12.44, 19.13, and 7.73 t ha−1 DM, respectively). HA gives the highest DM yield of 13.69 t ha−1 on average with values of 9.19 and 4.19 for NPK and UC, respectively. The cultivars order was EG 1101 ˃ BO Master ˃ EG 1102 ˃ Kanlow ˃ Alamo ˃ Carthage ˃ NJ Ecotype (21.15, 12.48, 8.14, 7.70, 6.34, 4.47, and 2.89 t ha−1 DM when ranking average yield or 60.64, 45.20, 29.92, 29.15, 17.87, 9.86, and 5.93 t ha−1 DM when ranking maximal yields).

Milk thistle Silybum marianum (L.) Gaertn. is one of the most researched medicinal plants, but at the same time it belongs to crops with wide industry potential whose growth requirements for marginal agroecological conditions or the response to agronomic interventions has not yet been sufficiently studied. The aim of the present research was to verify the effect of mineral nutrition (NPK 200 kg/ha) and humic acids applied to the soil (HUMAC Agro 250 kg/ha) on the main biometric parameters and the intensity of photosynthesis of milk thistle grown under less favourable climatic conditions of the semi-cold and humid foothills in Central Europe. The highest seed yield was achieved with the NPK variant in terms of dry matter 0.534 t/ha, in the HUMAC Agro variant 0.254 t/ha and with the untreated control 0.087 t/ha. The soil before the trial establishment was characterised by low nutrient content. The use of mineral fertiliser on NPK treatment eliminated the influence of low PK nutrients content of the soil, influencing the crop growth and yield/quality, while no doses of NPK were used on the HUMAC Agro variant and the untreated control. For both of the two sequences created (temperature and light), the highest photosynthesis rate was measured on untreated control (20.115 and 12.386 mmol/m2/s1), markedly lower on HUMAC Agro (16.386 and 9.653 mmol/m2/s1) – and the lowest on the NPK (10.933 and 7.813 mmol/m2/s1, respectively), in inverse proportion to the crop yield. Therefore, the size of the leaf area of the crop was decisive for the increased crop yield. The polynomial trend line of the photosynthesis rate according to the temperature sequence shows the photosynthesis rate and the torrential decrease by temperature increasing on untreated control compared with both treated variants. Both of these threats, mineral nutrition and use of humic preparations to soil, although they reduce the photosynthesis rate, have a wide range of complex effects that provide an opportunity to optimise the growth and yield of milk thistle. Ideally, the mineral nutrition and humic preparations should be used in combination with the crop of milk thistle for medicinal and energy purposes.