Shallots (Allium cepa L. Aggregatum group) are cultivated on small areas, mostly to harvest mature bulbs with dry scales. Due to their exceptional taste and nutritional value, and a short growing season, they can also be grown for early bunch harvest. New shallot cultivation strategies are being sought to meet consumers’ growing expectations regarding the quality of vegetables, and their increasing awareness of global food safety. Therefore, the aim of this study was to evaluate the effect of selected biostimulants on the biometric parameters, yield and nutritional value of shallot bulbs and leaves. The experimental factors were as follows: two biostimulant types—Effective Microorganisms (EM) and Goëmar Goteo (GG), two shallot cultivars—Bonilla F1 and Matador F1, grown for bunch harvest, and year of the study. Shallot leaves had a higher content of L-ascorbic acid, reducing sugars and nitrates than bulbs. Young bulbs had a higher content of DM and total sugars than leaves. The leaves and bulbs of shallot plants treated with EM accumulated the highest amounts of minerals. Macronutrient ratios were closer to optimal in shallot leaves than bulbs. The nitrate content of bulbs was inversely proportional to the nitrate content of leaves. Therefore, an increase in the nitrate content of leaves by around 330% led to an approximately 40% decrease in the nitrate content of bulbs. The correlations between the parameters of the chemical composition of shallots and shallot leaves show that the increase in the dry matter content of the bulbs (by approx. 60%) was accompanied by an increase in the L-ascorbic acid content in the leaves (by approx. 240%). The use of biostimulants in the cultivation of A. cepa L. Aggregatum group contributed to the reduction of L-ascorbic acid content in bulbs and had no positive effect on the leaves. Moreover, no positive effect of biostimulants on the reduction of nitrate content in shallot leaves and bulbs was observed, which is undesirable from the consumer’s point of view. After the use of biopreparations, the yield of shallots was lower than that of the control—by approx. 14% (EM) and approx. 4% (GG). Therefore, the measurable benefits of biostimulants in the cultivation of shallots grown for early bunch harvest do not balance the costs of their purchase and use.

The aim of this study was to determine the effect of amino acid biopreparations on the yield of summer savory, marjoram, and lemon balm, and the concentrations of selected biochemical and mineral compounds in their herbage. The first experimental factor was plant species: summer savory (Satureja hortensis L.) var. Saturn, marjoram (Origanum majorana L.) var. Miraż, and lemon balm (Melissa officinalis L.). The second experimental factor was the effect exerted by two biopreparations, Calleaf Aminovital and Maximus Amino Protect, on herbage yield and quality. In the control treatment, plants were sprayed with water. The analyzed herb species differed considerably in yield and the concentrations of selected biochemical compounds and minerals. Lemon balm was characterized by the highest yield (1.73 kg m⁻²). Marjoram var. Miraż was characterized by the highest concentrations of reducing sugars (0.89 g 100 g⁻¹ FM) and L-ascorbic acid (39.7 mg 100 g⁻¹ FM). Summer savory was most abundant in total N, K, and Ca. The tested biostimulants contributed to a decrease in nitrate concentrations in the studied plants. The interaction between the experimental factors significantly affected the content of nitrates and mineral compounds and total N, P, K, and Ca in the herbage of the analyzed plant species.

Soil affects plant growth and development, and it is one of the factors that determine crop yields and quality. Broccoli (Brassica oleracea var. italica Plenck) plants cv. Cezar were grown in an experiment conducted in 2021–2022 on a horticultural farm. The biometric parameters of broccoli plants were determined in the first stage. The chemical composition of the edible parts of broccoli was determined in the second stage, which involved two experimental factors. The first factor was the edible parts of broccoli: florets, leaves, and stalks. The second factor was the effect of soil type on the chemical composition of the edible parts of broccoli. Albic Luvisol (II) had a significant positive effect on floret height and the number of florets. Leaf yield was significantly lower when broccoli plants were grown in Eutric Cambisol (I) compared with Albic Luvisol (II) and degraded chernozem (III). Soil type had no significant influence on the macronutrient content of broccoli florets, leaves, and stalks, but the accumulation of macronutrients varied across the edible plant parts. The content of iron, zinc and manganese in broccoli plants was not significantly affected by soil type, but soil type exerted a significant effect on copper content.

A field experiment was conducted in 2017-2018 in the Agricultural Experiment Station owned by the University of Warmia and Mazury in Olsztyn. The experiment had a randomized block design with three replications. The first experimental factor was common onion cultivar: ‘Whitney Wing F1’,...

A field experiment was conducted in the years 2017-2018 in the area of the Didactic and Experimental Centre, University of Warmia and Mazury in Olsztyn. The experiment was set up in the randomised split block design, in three replicates. The first experimental factor was four winter cultivars of...

The aim of this study, which involved a field experiment conducted in north-eastern Poland, is to evaluate the phytometric parameters, yield, and biological value of fruit of three tomatillo cultivars grown in soil mulched with black PE (polyethylene) film and covered with PE film and non-woven PP (polypropylene) fabric. A two-factor field experiment was conducted in 2015 and 2017–2018 in the Agricultural Experiment Station owned by the University of Warmia and Mazury in Olsztyn. In the control treatment, tomatillo plants were grown without protective covers or mulch. Tomatillo fruits were harvested gradually, upon physiological maturity, which was determined based on changes in the color of the peel and calyx, and the aroma. The growth and development of tomatillos were evaluated based on plant measurements performed in the field. The chemical composition of tomatillo fruits was analyzed at the stage of full fruiting. During the three-year study, the weight, vertical diameter, and horizonal diameter of fruit were highest in cv. ‘Rio Grande Verde’ and lowest in cv. ‘Purple’. The combined use of mulch and plant covers accelerated fruit ripening. The total and marketable yields of tomatillo fruit were highest in cv. ‘Rio Grande Verde’ and lowest in cv. ‘Purple’. The fruit of cv. ‘Purple’ had the highest content of dry matter, total sugars, extract, β-carotene, and total polyphenols.