The artificially made kernels from ground wheat grain, commercial wheat starch and wheat proteinaceous a-amylase inhibitors in different proportions were used as feed for adults of the granary weevil iSitophilus granarius L.). In the case of larvae of the confused flour beetle (Tribolium con/usum Duv.) and the Mediterranean flour moth (Anagasta kuehniella Zell.) the friable feed mixture were used. The survival of S. granarius adults has not been correlated with the soluble proteins extracted from wheat and amylolytic activity located in this protein fraction. On the other hand the weight of dust (the index of feeding intensity) produced during feeding has depended on the presence of a-amylase and trypsin inhibitors in wheat-based feed. A. kuehniella larvae have not developed at all on feed consisted of 50% wheat starch and 50% of crude a-amylase inhibitors from wheat. The same feed has caused 15.1 days of extension in development time of T. confusum larvae. It attests to specific native enzymatic apparatus existing in alimentary canals of three damaging grain species which can overcome some obstacles even if extremely highly active insect a-amylase inhibitors were present in feed. However, the sufficient nutrient should be available in feed compounds. Nevertheless, some reduction of insects population can be expected.

Two potato cultivars, sprayed and nonsprayed with fungicides, were evaluated to determine the association of late blight (caused by Phytophtora infestans) and radiometric leaf reflectance to disease development. Spectral radiance measurements were taken with Cl MEL CE3132 luminancemeter in the visible (450 nm, 550 nm and 650 nm) and near-infrared (850 nm) range of the electromagnetic spectrum. The measurements were taken at two view zenithal angles.ó.> 0° (at nadir) and o.> 50°. Six vegetative indices based on these measurements were used to detect differences between sprayed and nonsprayed plants. Vegetation indices based on the reflectance measurement enable to distinguish infected potato plants from noninfected plants. Among the vegetation indices used in this studies the best indicators of disease were NlR/RED and ELA!. Results of our study show that for Mila cultivar oblique viewing may be more effective then nadir viewing (perpendicular to the ground surface) for distinguishing between plants infested at different degree.

The aim of the work was to study the feeding deterrent activity ofprecocenes, their synthetic analogues, and some related compunds to storage pests: Sitophi/us granarius L., Tribolium con/usum Duv., Trogoderma granarium Ev., and aphids: Myzuspersicae (Sulz.). Among all tested compounds precocenes I and 11 exhibited the best feeding deterrent activity against all tested insects. 4-Chromanols ( 16, 17 and I 8), alcohols 19, 20 and 3-chromanone (15) showed high deterrence towards the larvae of T con/usum. The best antifeedant activity towards the adults of both T confusum and S granarius was observed for substituted phenols with methoxy group at benzene ring. The biological tests carried out on aphids showed that the presence ofmethoxy group in the molecule was a crucial structural factor for the appearance of antifeedant activity against these insects.

The quality of wheat spraying obtained while applying drift guard Turbo TeeJet 11 O 02 VP nozzles was tested. A standard boom and a boom equipped with an air sleeve were applied. Krukowiak-Bravo sprayer was used to test the influence of the air flux. The coverage was estimated on water sensitive papers. The spray coverage of wheat with TT 11 O 02 VP nozzles was satisfactory, both in case of conventional and air assisted applications.

The paper presents results of studies on the occurrence and economic importance of maize pests: european com borer (Ostrinia nubilalis Hbn.) and frit fly (Oscinellafri1 L.) (conducted in 1977-2000) as well as aphids (Aphididae) and thrips iThysanopterai (in I 982-1983, I 985 and 1988-2000).

The objective of the study was to determine feeding preferences of the khapra beetle (Trogoderma granarium Everts) towards some plant products. The material for the investigations was composed of grain of four barley varieties: Brenda, Krona, Maresi, Rasbet; barley malt, and nutlets of three varieties of buckwheat: Hruszowska, Emka and Kora. The reference material comprised wheat grain of the commercial variety Almari. The results showed that the development of T granarium larvae on barley grain and malt took longer than on wheat grain. The authors observed that buckwheat nutlets were comparable to barley kernels as a food for the development of the pest. The pest showed more feeding preferences to buckwheat products, grits and meal to barley grain.

Biological methods of weed control are alternative to chemical treatments. Biological techniques are used where no possibility for chemical spraying occurs. Rumex confertus Willd. is an example of a plant-eater which is potentially more important than chemical compounds. The objective of the study was to evaluate population dynamics and the development of l-fypera rumicis L. ( Coleoptera, Cucurlionidae) on Rumex confer/us Willd. as well as to determine effects of the injuries on growth of a plant.

N.W. Schaad, J.B. Jones, W. Chun (eds.) 2000. Laboratory Guide for Identification of Plant Pathogenic Bacteria. Third Edition. APS Press, The American Phytopathological Society, St. Paul, Minnesota. ISBN 0-89054-263-5.

The purpose of the studies conducted in the years 1996-1998 was to determine the quantitative and qualitative composition of bacterial and fungal communities in rhizosphere of soybean cultivated in monoculture and non-rhizosphere soil. Besides, the proportion of bacteria and fungi, which were distinguished by their antagonistic effect towards soil-borne pathogens was established. A microbiological analysis of lg of dry weight of soil from rhizosphere of soybean resulted in 3.21 x I ()6 to 8.70 x 106 bacterial colonies and from 70.51 x I 03 to 123.74 x 103 fungal colonies. In the case of non-rhizosphere soil, 3.50 x 106 to 4.75 x 10" bacterial colonies and 16.16 x 10' to 51.38 x 10' fungal colonies were obtained. Besides, soybean cultivation in monoculture had a negative effect on the number of antagonistic isolates of bacteria (Bacillus spp., Pseudomonas spp.) and fungi (Gliocladium spp., Penicillium spp., Trichoderma spp.). Smaller numbers of antagonistic bacteria and fungi in rhizosphere soil of soybean cultivated in monoculture as compared to non-rhizosphere soil, can prove little biological activity, which results in a worse phytosanitaty condition of the soil.

Investigations on the occurrence of Barley stripe mosaic virus (BSMV, Hordeivirus) in Poland were performed by testing seeds of 22 barley cultivars. BSMV was detected in seeds of winter barley cv. Tiffany and of spring barley cvs. Scarlett and Stratu s. The virus presence was revealed by ELISA test and then confirm ed by electron microscopy. Preliminary data on the rate of seed transmission of BSMV in cvs. Scarlett and Stratus are presented.

Piesma quadratum is the only vector of beet leaf curl - virosis affecting sugar beet. The sugar content of beets infected by beet leaf curl is reduced by an average of 9% and the root weight is decreased by an average of 58.4%. P quadratum appeared in Poland in the beginning of this century after migration from the territory of Germany. This bug has one generation a year. Its occurrence is characterised by 2-3-years-long gradations in periods of every 9-11 years. Chemical control of beet leaf bug caused disturbance of this rhythm. Recent gradations of the pest occurred every 17 years.

Investigations were carried out in 1996-1998 on experimental plots sown with different oat cultivars and lines. Symptoms of the fusarium panicle blight developed on 0.5-15% of oat plants. Results of this studies showed that fusarium blight of oat panicles is widespraed in Lublin region. Fusarium avenaceum and F. poae proved to be the cause of the disease. Also F. culmorum, F. crookwellense, F. equiseti, F. oxysporum, F. sporotrichioides were isolated from infected panicles.

The influence of oilseed rape glucosinolates on the grown in vitro pathogenic fungi was studied. Two pathogenic to oilseed rape fungi species: Fusarium roseum and Rhizoctonia so/ani were taken into consideration. It was observed that glucosinolates added to the medium limited the growth of both tested fungi to some extent, especially when higher concentrations of glucosinolates was supplied.