A b s t r a c tPlant density is an important variable for achieving maximum yields and uniform vegetable maturity. Optimal plant density can be achieved by establishing appropriate distances both between the rows as well as in the rows of plants. The experiment was carried out between 2010-2012 at the experimental field of the Crimean Agrotechnological University in Simferopol, Ukraine. The experiment was established as randomised blocks with four replications. This study aimed to determine the effect of plant density on the growth, development and yield of Brussels sprouts. Increasing the area per plant resulted in a shortening of the time to the beginning of head formation, technical maturity and harvest. In all study years, increasing the distance between plants caused an increase in leaf assimilation area, stalk diameter and the number of heads per plant, however, the height of plants was lower. The most favourable parameters characterising marketable yield were found at an area per plant of 0.56 m 2 , however, the maximum yield from 1 ha (determining the profitability of the cultivation) was found at an area of 0.49 m 2 per plant.

A direct and secondary effect of liming and organic fertilization on the cadmium content in soil and in vegetables was examined. Celeriac (Apium graveolens L. var. rapaceum) was cultivated in the first year after lime application and organic fertilization whereas leek (Allium ampeloprasum ssp. porrum J. Gay) was grown in the next year. Soil was limed with a calcium carbonate fertilizer at the rate of 2.0 t CaO/ha. The following were applied as organic fertilizers: farmyard manure (60 t/ha), rye straw (4 t/ha), rye and winter vetch, both the plants cultivated as winter catch crops for green manure. Liming significantly reduced the available cadmium content in the soil in the first and second year after its application. Also, it significantly reduced the cadmium content in celeriac and leek compared with no-liming cultivation. Organic fertilization, especially farmyard manure and straw, significantly reduced the soil available cadmium content as compared to the untreated control (without organic fertilization). The aforementioned factor significantly reduced the cadmium content in the examined vegetables. Cadmium lowest content in celeriac leaves and leek was recorded after the application of farmyard manure. A combined application of liming and organic fertilization in the form of farmyard manure most beneficially influenced celeriac leaves with respect to their cadmium content.

The aim of the study was to determine the effect of weather components (air temperature, precipitation) on the growth, yield and the length of the growing season of sweet corn cultivated in eastern Poland. The results come from a field experiment conducted in 2006-2011. Weather conditions in the successive years of the study significantly modified the yield of ears, weight and number of formatted ears, high of plants and the length of the growing season of sweet corn. Good yielding of sweet corn favoured years with moderate air temperatures in July and uniform distribution of precipitation during the growing season. The highest yield of ears was found in 2011, the lowest in the very difficult in terms of weather 2006. The shortest growing season was characterized corn grown in the years 2006 and 2010 with the high air temperatures in July and August, the longest in the years 2009 and 2011, in which the temperatures in the period June-August were the lowest of all the years of research. Irrespective of the year of study, cv 'Sheba F 1 ' was formatted eras with higher weight than cv 'Sweet Nugget F 1 '.

The experiment investigated the effect of different irrigation methods (no irrigation, irrigation by means of a drip tape) and method of AgroHydroGel application (control, AgroHydroGel applied to seedlings, AgroHydroGel applied to plants in the field, half of the AgroHydroGel applied to seedlings, the other half to plants in the field) on the yield level and quality of celeriac grown in the field. Irrigation significantly increased yields as well as the average weight of the marketable root; however, it had no influence on the nutrient contents. The application of AgroHydroGel to plants in the field or in a split proportion resulted in the most favourable influence on yielding. In the non-irrigated combination, AgroHydroGel applied entirely to plants in the field or in a split proportion increased marketable root yields. In the irrigated treatments, the highest yield was obtained in the plots where hydrogel was applied to plants in the field. Roots from the treatments where AgroHydroGel had been applied in a split proportion contained more dry matter as compared to the control. In the non-irrigated combination, AgroHydroGel applied entirely to plants in the field and in a split proportion increased ascorbic acid content. Simultaneously, irrigation and hydrogel application in a split proportion increased total sugar content as compared to the plants in which the hydrogel was only applied to the seedlings.

SummaryThe effect of three methods of soil mulching: autumn or spring ploughing and leaving mulch as a cover crop on the soil surface without incorporation till the end of cabbage growth on the contents of selected nutrients in red cabbage and onion was investigated. The following plants were used as intercropped mulches: phacelia, vetch, serradella and oat. Mulching effects were compared to a non-mulched control as well as a farmyard manure application at the rate of 40 t·ha -1 . Nutrient content in both vegetable species depended on weather conditions and varied in study years. Accumulation of dry matter in cabbage was favoured by phacelia and oat mulches, irrespective of the date of ploughing. Non-incorporated oat and autumn-incorporated phacelia increased dry matter content in onion. An increase in the protein content in cabbage was observed when following serradella and vetch mulches. The protein content in onion cultivated in the second year following mulching did not change significantly as a result of the influence of examined factors. Among an the mulches taken into study, serradella and oat increased the content of vitamin C in cabbage. Similarly, autumn-or spring-incorporated oat mulch and non-incorporated serradella mulch increased the content of vitamin C in onion.