The aim of the experiment was to assess the effect of applied fertilizers: Hydrocote + Kristalon, Osmocote + Peters and Polyon + Hortimix on the length of the production period and the quality of two heterosis cultivars of Cyclamen persicum from Halios group during two years of the study late date cultivation. The experiment was conducted in the following cycles: 04.08.2003–12.01.2004 and 29.07.2004–30.12.2004. Plant growth was evaluated on the basis of the following characters: total height, plant diameter, the number of leaves, the weight of the aboveground part and tuber diameter. The following characters were assessed in the evaluation of flowering: earliness of the cultivar, flower development rate and the number of flowers and buds. The experiment was completed when most plants reached commercial value, i.e. after developing five flowers per plant. It was found that slow-release fertilizers did not have a significant effect on the growth and flowering of Cyclamen persicum from Halios group, only the application of fertilizer Osmocote resulted in an increase of plant diameter and weight. A bigger effect was found for the year of cultivation: bigger insolation during cultivation boosts growth. Earliness of flowering was not affected by the year of cultivation, cultivars formed similar numbers of flowers, whereas the rate of flower development depended on both factors and in the year with bigger insolation it was higher and resulted in the formation of a bigger number of flowers.

The purpose of the studies was to observe the dynamics of number of Metopolophium dirhodum (Walk.) on rugosa rose, multiflowered rose, park rose cv. ‘Grandhotel’ and different varieties of border roses. Observations were conducted in four different sites in the green area of Lublin in the years 2001–2003. M. dirhodum was observed on all the analyzed roses. Annually this aphid colonized only the shrubs of rugosa rose and park rose ‘Grandhotel’ in all the sites. This is a host-alternating species, with the migration to the summer host of obligatory character (the colonies were observed in spring and autumn). The weather conditions had a significant effect on the date of the spring appearance and the autumn disappearance of aphids. The most numerous aphids were observed in the street site, while in the park one the population of this aphid was the lowest. Rosa rugosa was exceptionally willingly colonized by M. dirhodum. Those aphids occurred there in much higher numbers as compared with the other roses.

Effect of auxins: (NAA, IAA), cytokinin BAP and culture conditions (light, darkness) on callus induction in cotyledons of tomato cultivar ‘Maskotka’ and the wild form of Lycopersicon peruvianum was investigated. Callus was obtained in all experimental combinations, except of the culture with L. peruvianum on the medium with 1.0 mg·dm^-3 of IAA. Callus weight, colour and structure depended on the tomato genotypes and experimental conditions. Best medium for the culture of tomato cultivar ‘Maskotka’ and the wild form L. peruvianum proved to be MS medium supplemented with 2.0 mg·dm^-3 of IAA and 1.0mg·dm^-3 of BAP.

The object of the studies were soybean plants grown of the seeds dressed with Polyversum, Biochikol 020 PC and Biosept 33 SL. At anthesis those plants were sprayed with the same biopreparations. The experiment considered a combination with the chemical preparation Zaprawa Oxafun T for seed dressing, and Bravo Plus SC for spraying plants at anthesis. It can be stated on the basis of the obtained results that the application of biopreparations for seed dressing and spraying plants at anthesis was similar to that of chemical preparations. Among the studied biopreparations, Biosept 33 SL turned out to be the most effective in protecting plants from soil-borne pathogenic fungi.

The purpose of the studies was to determine the effect of such preparations as Biochikol 020 PC, Polyversum and Biosept 33 SL on the formation of microorganisms communities in the rhizosphere soil of soybean. Results of the studies pointed to a positive effect of biopreparations on the increase number of cfu total bacteria, Bacillus spp. and Pseudomonas spp. After the application of biopreparations balance between pathogens and saprobionts was maintained in the rhizosphere soil of soybean. Such relation did not exist after using chemical preparations. Biopreparations increased the number of antagonistic bacteria – Bacillus spp., Pseudomonas spp. and fungi – Gliocladium spp., Trichoderma spp.

On the basis of the experimental data of COBORU the time and spatial distribution of the dates of sowing, harvesting and of the cucumber (conserve varieties) growth stages in western Poland was characterized. The length of the conserve cucumber growth periods varied more in the years 1965–2004, and it was on average seven times as large as the length of agrotechnical and phenological periods and the largest was the period from fruit setting to the beginning of harvesting (v = 57%), and the smallest was attributed to the date of sowing (v = 3%). During 1965–2004, a linear trend was proved and it was found to be negative for almost all phenological dates, for harvesting and for the length of conserve cucumber growth periods, except for the date of sowing and the period from the end of emergence to the beginning of fruit setting. On the basis of the date of sowing, the former phenological dates and the time trend, the dates of phenological stages, harvesting and the length of cucumber vegetation periods can be separately forecast in the area of western Poland with the accuracy of 92.3 to 99.3%. The length of the period from sowing to the end of conserve cucumber harvesting in western Poland (113 days) was longer by 46 days than that of the period from sowing to the beginning of harvesting and at the same time it was slightly less differentiated spatially.

Vegetation studies were conducted from 2002 to 2004, in two leading farms, located near Poznan where have obtained optimum anthurium (Anthurium cultorum Birdsey) yielding. Plants were grown in expanded clay with the application of fertigation with a standard nutrient solution (in mg·dm^-3): N-NH₄<14.0, N-NO₃ 105.0, P 31.0, K 176.0, Ca 60.0, Mg 24.0, S-SO₄ 48.0, Fe 0.840, Mn 0.160, Zn 0.200, B 0.220, Cu 0.032, Mo 0.048, pH 5.5 – 5.7, EC 1.5 – 1.8 mS·cm^-1. Significant changes of macroelement contents were found in drainage water in comparison to nutrient solution. The most decreased contents (in %) of macroelements were found for phosphorus (51.2), potassium (26.7) and nitrogen (15.4). The EC value showed a downward trend of about 9.5%. Nutrients which concentration increased in drainage water were (in %): calcium (27.9), sulphur (14.3) and magnesium (5.5). The knowledge of variations of nutrient concentrations in drainage waters is the basis for the practical application of closed fertilization systems with the recirculation of nutrient solution.