In the experiment, carried out between 2005–2007, the influence of the application of two rootstocks and mycorrhizal vaccine on the growth of maiden trees and the trees of ‘Woodii’ cultivar in the third year after planting them into the ground was compared. A higher percentage of maiden trees was obtained on Prunus tomentosa rootstock when mycorrhizal vaccine was applied as well. The applied rootstocks did not differ the growth of maiden trees in a nursery. Also the use of mycorrhizal vaccine did not cause any significantly stronger growth of maiden trees on both rootstocks, what is more they even reduced the sum of the lengths of lateral shoots. The reaction of rootstocks was differentiated. The considered rootstocks, however, influenced all the parameters of growth of trees in the third year after planting. Stronger growth of ‘Woodii’ cultivar trees was observed on the Prunus cerasifera rootstock compared with those growing on Prunus tomentosa. However, the trees growing on the Prunus cerasifera rootstock bloomed poorer than those on Prunus tomentosa. Application of mycorrhizal vaccine increased the thickness of the tree trunk and the diameter of crowns of ‘Woodii’ cultivar trees, but it did not influence their flowering and fruiting.

Seedlings and young plants of lenten rose (Helleborus orientalis Lam.) were grown for two years (2006–2007) in containers on peat substrate which was deacidified with calcium carbonate at doses (g∙dm^-3) of 2.5, 5.0, 7.5 and 10.0. Within each dose of CaCO₃ plants were divided into two groups, of which one was fertilized with a lower (0.1%) and the other with a higher (0.3%) concentration of Peters Professional PL Special (15:11:29). The CaCO₃ dose applied to deacidify high moor peat had a significant effect on plant height irrespective of their age. In the first and second year of pot cultivation the tallest plants were produced on a substrate to which calcium carbonate was added at 2.5 g·dm^-3 CaCO₃, while the lowest at 10 g·dm^-3 CaCO₃. The number of leaves and flowering of lenten rose did not depend on the amount of calcium carbonate introduced to the substrate. Fertilization of lenten rose cv. ‘New Hybrids F1’ with Peters Professional PL Special (15:11:29) at a higher concentration (0.3%) made it possible to produce taller plants, with a larger number of leaves, and earlier and more abundant flowering.

The research was carried out in the years 1991–1994 in agricultural landscape of medium mosaic degree in the area of Łęczyca. It covered parasitoids of the Pimplinae subfamily (Hymenoptera, Ichneumonidae), inhabiting refugium habitats such as shrubberies, field borders, roadsides and forest edges. The method used was scooping in order to catch imagos. 48 species were found, which made up 36.1% of this subfamily’s domestic fauna and 63.1% of those reported for Wielkopolska. Dominant species were Endromopoda detrita (Holmgr.) (D = 19.5%), Itoplectis maculator (F.) (D = 11.5%), I. alternans (Grav.) (D = 11.3%), Pimpla contemplator (Muell.) (D = 9.2%) and Zaglyptus multicolor (Grav.) (D = 7.1%). The greatest species diversity was reported from the forest edge (34 species), while the highest number was found in the shrubberies (268 individuals). The greatest stability of species composition was found in the shrubbery communities. The greatest species similarity between communities was reported for the shrubberies and the forest edge (SM = 53.5%). The highest similarity in terms of quantity occurred between the groups on the field border and road edge (Re = 64.5%).

The purpose of the paper was to establish the protective effect of the microbiological material prepared from the cells of Bacillus sp. Bk 30 and Pseudomonas sp. Pk 28 and their post-culture liquids against soil-borne pathogenic fungi. The use of biological control improved the emergences, healthiness of pea plants and their yielding. Despite using the microbiological material for seed dressing, pea plants were infected by Altenaria alternata, Ascochyta pisi, Botrytis cinerea, Fusarium culmorum, Fusarium oxysporum f. sp. pisi, Fusarium solani, Phoma exigua, Pythium irregulare, Rhizoctonia solani and Sclerotinia sclerotiorum. Among the applied microbiological material, the best protective effect against plant pathogens was observed for bacterium Bacillus sp. Bk 30 and its post-culture liquid.

Studies were carried out in the years 2006–2008 in Przybroda near Poznań. Objects of studies consisted of 8-year old peach trees ‘Harbinger’ cultivar grown on three rootstocks: Manchurian Peach, Sand Cherry and Rakoniewicka Seedling. Tree crowns had a vase form and they were strongly damaged by frost during the winter 2005/2006. In spring 2006, intensive tree pruning was carried out. The objective of the studies was the estimation of the effect of a radical pruning of frostbitten trees on their regeneration and yielding, as well as to estimate the role of rootstocks in this process. Studies have shown that the tree pruning evoked a very strong compensation growth, the reaction of trees was the stronger, the more intensive was the tree pruning. As a result of the pruning, after 3 years, the lowered tree height (on the average by 40–50 cm) was maintained in relation to the control trees. After pruning, in the tree crown, longer productive long-shoots with diameters > 0.5 cm, developed as compared with the control. However, the radical pruning of trees caused in the third year after pruning a decrease in tree yielding from 30 to 40%, in comparison with the not pruned trees.

Studies carried out in 2003–2005 included determinations of free phenolic acids content in edible parts (shoots, pseudostem) of onion, shallot, and Welsh onion grown for green bunching in the field and forced in the greenhouse. Plants for phenolic acids contents analyses were achieved from setting the small bulbs (common onion, shallot) or annual plants from the seedling setting in the case of Welsh onion. In the field cultivation, plants were grown under short-term covers made of perforated PE film and non-woven PP, while forcing was realized in heated and unheated greenhouse. Free phenolic acids contents were determined after plant harvest, when plants reached the size useful for trading in bunches. Phenolic acids contents were determined in shoots and pseudostem by means of spectrometric Arnova method with recalculation onto caffeic acid. Performed study revealed that shoots contained significantly more free phenolic acids as compared to the pseudostem. Referring to the field cultivation, the component concentration in shoots was 0.23 mg·100 g^-1 FW, whereas due to forcing 0.135 mg·100 g^-1 FW, on average. Contents of phenolic acids at pseudostems of studied plants from the field cultivation were 0.05 mg·100 g^-1 FW, while at forced plants 0.04 mg·100 g^-1 FW. No significant differences related to the level of phenolic acids between common onion and shallot were found, both in shoots and pseudostem. However, shoots of Welsh onion contained significantly less phenolic acids, regardless the cultivation place and cover application. The accelerated field cultivation resulted in shoots of Welsh onion was 0.19 mg·100 g^-1 FW phenolic acids in FW, whereas the greenhouse forcing 0.11 mg·100 g^-1 FW. Regardless the species, forced plants contained considerably less phenolic acids (namely in shoots) as compared to plants grown in the field.

The paper presents literature data on the flowering biology of eggplant and the influence of flower heterostyly on yielding. Flowers with long–styled pistol are the majority among all flowers on a plant (60%). Number of flowers with medium and short style is lower (10–15% and 22–30%, respectively). Eggplants set fruits from flowers with long style in 49–100% and with medium style in 46–85%. These flower’s stigmata have well – developed nodules and well – permissible tissues rich in polysaccharides, proteins styled flowers have small stigmata with underdeveloped nodules and, due to worse absorption, they are not pollinated and do not set fruits. Taking into account the complexity of many factors that make difficult or impossible to self-pollinate the eggplant’s flowers, the efficiency of three procedures intensifying the fruit budding has been presented: bunch vibrating, flower harmonization, and natural pollinating by bumblebees. Many authors’ studies confirm that flower bunch vibrating has not caused sufficient pollen setting on stomata and has not been sufficient for good eggplant flower pollination. Applying growth regulators appears to be more efficient and significantly affects the improvement of eggplant’s yielding. The highest efficiency has been achieved when applying insects as natural pollinators at cultivating the eggplant under covers.

Vegetation experiments were conducted in the years 2002–2004, in two specialist horticultural farms. The dynamics of nitrogen, phosphorus and potassium contents were analyzed in the index parts of selected anthurium cultivars (Anthurium cultorum Birdsey): ‘Baron’, ‘Choco’, ‘Midori’, ‘Pistache’, ‘President’ and ‘Tropical’. Plants were grown in expanded clay using drip fertigation with standard nutrient solution. Fully expanded leaves after fresh-cut flowers as the index parts for chemical analyses were collected every 2 months over the period of 3 years. A varied dynamic of nutrient contents was found in the index parts of plants. During the 3 years of studies a downward trend was recorded for nitrogen content, while an upward trend was observed for contents of phosphorus and potassium. A cultivar differentiation was shown for contents of the above mentioned nutrients and quantitative proportions between them.

The field study was carried out between 2000 and 2003. The plants of Sparaxis tricolor were sprayed twice prior to flowering with a fertilizer called titanium (0.8% Ti) in three concentrations: 0.02, 0.04 and 0.08%. Application of titanium in the concentration of 0.04% increases the total yield of corms by 20% on average and the commercial yield by 7%. Spraying the plants with titanium in the concentration of 0.02% increased the share of corms with > 5cm circumference in total yield and improved yield structure of corms of the first selection. A higher concentration of the preparation (0.08%) had unfavorable effect on the commercial yield of corms. In 2001 titanium applied in the concentration of 0.02% increased the nitrogen content in offspring corms and decreased content of other macro-elements. In 2003 offspring corms of plants treated with titanium in the concentration of 0.02–0.04% had more dry weight, N, P, K, Ca, Mg and Na.