The reports on milk thistle include a number of discrepancies, which concern, first of all, the Latin name of the plant, components of silymarin, mixing fruits with seeds, and the use of the term ‘endosperm’. Based on the applicable literature, it was shown that Silybum marianum (L.) Gaertn. is the proper name of the species, fruits are the milk thistle yield and seeds are endospermless. Silymarin (as the sum of flavonolignans: silybin, silychristin and silydianin) is accumulated in the pericarp and the seed shell. Depending upon growing conditions, the plants are from 0.7 to 1.7 m high, while the growing period on the raw material plantations takes 80-110 days.

The field experiment which involved the alfalfa seed laser bio-stimulation (M. sativa: ‘Legend’ and M. madia: ‘Radius’) was performed over 2002-2004 by means of randomized blocks. The divergent laser beam power surface density doses were 0 (control) as well as 3 and 6 mW·cm^-2 (R0, R3 and R6, respectively). Seeds were irradiated once, three and five times, directly before sowing. The highest green and dry matter yields in the alfalfa sowing year (2002) were recorded for R3x5 (27.8 and 6.62 t·ha^-1, respectively) and for R6x5 (27.2 and 6.41 t·ha^-1). The laser irradiation significantly increased the shoot density per 1 m², and decreased the weight of a single shoot. For R6x5, R6x1, R6x3 and R3x3 (2003-2004 full performance years) the seed irradiation significantly increased the alfalfa shoot density per 1 m² and for R6x3 and R6x5 – the green and dry matter yields, as compared with the control. Besides the R6x1, R6x3 and R6x5 seed laser stimulation increased the share of the first cut (by 4.6-5.5%) in the annual yield, and decreased – of the third and fourth cut mostly, as compared with the control.

Six experiment stations with wheat and rye complexes soils, exposed to a different weather course, were involved over 2001 and 2002 in the evaluation of yielding and chemical composition of common vetch seeds of indeterminate (traditional ‘Jaga’, ‘Kwarta’, ‘Fama’, ‘Niwa’ cultivars) and determinate (self-terminating ‘Ina’ and SZD breeding line) growth type. The yielding potential of traditional cultivars accounted for 4.36 t·ha^-1 and of the self-terminating ones – 5.02 t·ha^-1. The vetch seed yields on the wheat complexes soils were on average 10% higher than on the rye complexes soils. When the weather conditions were favorable to the vegetative development, in the self-terminating cultivars there was recorded a decreased stem length growth and a lower seed yield decrease than in the traditional cultivars.

Field experiments were carried out over 2002-2004 at the Mochełek Experiment Station, of the University of Technology and Agriculture in Bydgoszcz, on light good-rye-complex soil. Blue lupin was grown after winter wheat. Two factors were examined: post-harvest tillage: A – skimming + harrowing, B – skimming + harrowing + white mustard intercrop, C – without post-harvest tillage; dose of herbicide: a – Afalon 50 WP – 1.25 kg·ha^-1, b – Afalon 50 WP – 0.83 kg·ha^-1. It was demonstrated that eliminating post-harvest tillage led to a decrease in the blue lupin seed yield. However the favourable effect of the white mustard stubble intercrop ploughing-in on blue lupin yielding was not significant. The increase in weed infestation as a result of the Afalon 50 WP herbicide dose reduction from 1.25 to 0.83 kg·ha^-1 did not affect blue lupin yielding.

The paper presents a field experiment model to investigate the competition between the crop and weeds in agrophytocenosis. Indicators were proposed to be used to evaluate the effects of these interactions. The indicators are based on the relative differences in the number of individuals, amount of biomass and the value of biometric characters of the plants, thus allowing us to define and to compare the reactions of the crop to weed infestation, reactions of respective weed species and weed communities to the competition from the crop and to evaluate the competition between the crop and weeds in a given agrophytocenosis. The method of defining respective indicators of competitive effects makes it possible to compare these effects in different species, at different development stages and for different plant organs.

The experimental material was made up of ‘Korweta’ winter wheat grain samples from 2000/2001-2002/2003 field experiments, while the experimental factors were: 5 nitrogen fertilization doses from 0 to 160 kg N·ha^-1 applied during vegetative development stages (0; 40 = 40 – 0 – 0 – 0; 80 = 40 – 40 – 0 – 0; 120 = 40 – 40 – 40 – 0; 160 = 40 – 40 – 40 – 40, the first dose was sown at the beginning of vegetation, the next one – after 14, 28 and 42 days) and 4 variants of late fertilization applied at earing and at the end of flowering (0; 40 = 40 – 0; 40 = 0 – 40; 80 = 40 – 40). Nitrogen fertilization, both early and late, had an inconsiderable effect on the physical properties of grain and falling number. Much bigger differentiation of results was caused by weather conditions. A favorable effect of early fertilization on quality traits of grain and flour was observed. The total protein content, gluten content and Zeleny test values increased after the application of 80 to 160 kg·ha^-1 of nitrogen, yet the improvement of farinograph traits (dough resistance and softening and valorimeter value) was recorded for the nitrogen dose of 120 and 160 kg·ha^-1. Late nitrogen application much improved the wheat grain quality; even if at early development stages low nitrogen fertilization was used. The effect of early nitrogen fertilization on wheat grain quality traits was similar irrespective of the weather conditions during the vegetation period. A positive reaction of wheat to late nitrogen fertilization was stronger in the years in which weather conditions were unfavorable for obtaining high quality grain. A high protein yield was recorded when nitrogen fertilization was minimum 160 kg·ha^-1, half of which was applied at the early dose.

The aim of the present research was to determine the effect of the sowing method and date as well as row spacing on the germinability and germination energy of seeds over the three-year full use of perennial ryegrass for seed. The research demonstrated that the sowing values of ryegrass seeds sown in autumn and in spring as a companion crop and in pure stand were similar, a slight favorable effect of the cover crop on the germinability was recorded only in the second year. A variation in row spacing from 12 to 46 cm did not affect the sowing value of the seeds obtained, in the third year only the germination energy was, in general, higher if ryegrass was grown with a very wide row spacing applied. A longer use of perennial ryegrass grown for seed showed a more negative effect on the energy than on the germinability.

A three-year field experiment, carried out over 2001-2003, investigated the effect of cultivars and weed control methods on the weed infestation of pea (Pisum sativum L.) and on its yielding. The research involved low-, medium- and high-input growing technologies, including the mechanical and chemical weed control methods. The experiment involved four pea cultivars: two edible, general-use, cultivars: Rola and Agra and two fodder cultivars: Sokolik and Wiato. Analyzing the weed infestation and weed control methods and the competitiveness of cultivars towards weeds, it was found that the weed infestation had a priori a significant effect on yield components (plant density, number of pods per plant, seed weight per pod and 1000 seed weight), as well as on yielding of each cultivar researched. A negative effect of weed infestation was observed in all the research years, especially in the second year with the least favorable climatic conditions of the entire vegetation period, which concerned especially crops grown using the low-input technology which involved mechanical weed control. However the application of the chemical weed control facilitated a weed reduction and the competitiveness towards the plants of all the cultivars grown using the high-input technology, even under the least favorable climatic conditions of the vegetation period. The analysis of the reaction of cultivars to the degree of weed infestation revealed that Rola was the most competitive cultivar towards weeds, especially under extremely unfavorable conditions.

Three-year field experiments investigated the effectiveness of Sunspray 850 EC mineral oil protection against PVY, PVM, PLRV. Every seven days six to eleven treatments were applied, depending on the year. Regular protective mineral oil treatments reduced the number of aphids, especially over peak aphid infestation periods – almost by 60% when compared with the control plants. Besides the mineral oil treatment reduced the infection of progeny tubers with PVY and PVM considerably; a significant effect was found on PVY infection, especially in Mila, which was susceptible to that virus. With that in mind it seems justifiable to apply mineral oil to protect cultivars highly susceptible to PVY (scoring 5.5 using the 1-9 degree scale).

Over 2000-2002 there was investigated the effect of seed potato sprouting of two mid-early potato cultivars (Balbina and Mila) on the potato tuber infection with spore-forming rhizoctoniosis and common scab and on the tuber yield and its structure, especially the seed potato fraction. The results demonstrated that sprouting seed potatoes significantly reduced the infection of tubers with common scab and increased the share of tubers infected with black scurf, however it did not show a significant effect on the total yield increase yet it increased the seed potato fraction, especially in Mila.