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 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.