In presented studies not significant effect of the illumination of blue sticky traps with red pulsating light on their effectiveness in the monitoring of the western flower thrips (Franklinie/la occidentalis Pergande) was found. Observed increase of the number of caught imagines on lighted blue sticky traps was not statistically significant in comparison to the control combination (blue sticky traps without any light).

From the naturally infected cucumber plane spherical virus was isolated that mainly on basis of its serological properties has been identified as Tomato black ring virus (TBRV). Using antiserum against TBRV-ED for the specific crapping of virus followed by PCR test (immunocapture-RT-PCR) allowed co distinguish TBRV from related viruses, especially Beet ringspot virus (BRSV). Presence of as many as rwo satellite RNAs should be found as a unique feature of the cucumber isolace.

Rhizoctonia solani was isolated from 91 % of alder and birch seedlings with stem rot symptoms and 2-3% of seeds. Sowing of seeds to substratum infested with R. solani resulted in pre-and postemergence damping off. On leaves and stem parts of alder and birch, inoculated with 3 isolates of R. solani, necrosis spread from 0.22 to 0.52 mm/hr.

The effect of density on individual and population fertility, and selected morphometric characters (height, number of: ramifications, generative branches, inflorescences and leaves) of Echinochloa o-us-gaili plants was studied in a glasshouse. A decrease in individual fertility was observed in all density variants examined, but it did not result in a decrease in population fertility per unit of area. In response to worse developmental conditions there appeared plants characterized by reduced height and simplified external conformation.

Common alder (Alnus glutinosa) decline has been observed in most of European countries since 1993. In Poland decline of alder trees has been observed during the last 6 years. Alder Phytophthora was recorded, however, only from one sampling area in the middle of the country. Species of Armillaria, Fusarium, Mucor, Penicillium and Trichoderma were also isolated from diseased trees. Inoculation of alder stem pans, leaves and seedlings with Phytophthora isolates resulted in the development and spread of necrosis. Studies will be continued in the nearest years.

In 2001, a total of 2125 samples of plant origin were analysed for residues of the most commonly used pesticides in Poland. Detectable residues were found in 18% of the samples, while in about 0.9% of the samples the residues exceeded national or/and EU harmonised Maximum Residue Limits (MRLs). The long-term (chronic) dietary intake, based on monitoring data, was calculated for 7 pesticides in 9 commodities. The intake of 1 of the pesticide analysed (endosulfan/black currant combination) exceeded 1 % of Acceptable Daily Intake (ADI) indicating a sufficient margin of safety for the adult consumer. The short-term (acute) intake was estimated for 19 pesticides in 12 commodities according to the European Commission recommendations. The ADI level was exceeded for toddlers in 7 cases, carbendazim in mushroom, linuron in carrot, chlorothalonil in greenhouse tomato, tolylfluanid and EBDC in strawberry and flusilazole and diazinon in apple. In all cases, however, the safety factor of 2 for a toddler still existed.

The observations on Myzus persicae and Macrosiphum euphorbiae development were carried out on boxthorn (Lycium halimifolium) growing in various places of the city ofWroclaw in 1999-2001. They concerned the following issues: aphid population dynamics and aphid age and morph diversity in population structure. Aphids infested only certain boxthorn bushes and other bushes were free of these insects. M. persicae infested more bushes than M. euphorbiae did. The first species appeared 7-10 days earlier on boxthorn than the second one. Time of the maximum population density of both aphid species was similar. Age structure of M. persicae and M. euphorbiae populations was similar. The youngest larvae (L,-L,) predominated and the least numerous were alatae females. Coccinellids were the most numerous aphid predators on boxthorn.