The results of experiments showed an effect of magnetized water on the effectiveness of some selected zoocides. The control of red spider mite (Tetranychus urticae Koch) by Ortus 05 SC showed the highest effectiveness with strongly magnetized water, with use of one magnetizer and two semi-rings. On the other hand, the application of Magus 200 SC in combination with magnetized water showed a decreased effectiveness of insecticide. In the control of grain weevil (Sitophilus granarius L.), an increase in the effectiveness was found for the zoocides Talstar 100 EC, Karate 025 EC and Winylofos 550 EC in combinations with strongly magnetized water (three magnetizers or one magnetizer with two rings). In case of Sumi-Alpha 050 EC, high effectiveness of the treatment was obtained in combinations where water was magnetized in lesser degree, with use of one or two magnetizers. No significant differences were found in the effect of magnetized water on germination of bean (Phaseolus vulgaris L.) and cuckoo flower (Cardamine amara L.) plants.

The influence of different nozzle types and adjuvants on the biological efficacy of fungicides in potato was investigated in four growing seasons in the years 1997-2000. The studied foliar plant disease was late blight (Phytophthora infestans). The biological efficacy of fungicides (alone or with adjuvants) applied with coarse air induction nozzles was comparable to fine standard flat fan nozzle. The differences between the nozzle types tested were small in control oflate blight in potato with systemic and contact fungicides. Coverage of upper side of leaf blades was from three to four times higher than lower side of leaf blades. In general, the highest coverage of upper and lower side of leaf was achieved when the full dosage rate of fungicide (copper oxychloride) was used with both the flat fan XR 110-03 and air induction DB 120-03 nozzle. Adding Atpolan 80 EC and Zero Piany 62 SL to 50% dosage rate of copper oxychloride decreased the spray coverage on lower side ofleaf as well as with both the XR 110-03 and DB 120-03 nozzles. However, addition of adjuvants to spray solution did not decrease the deposition on upper side of leaf blade. In general, adjuvants did not considerably influence the biological efficacy of the fungicide treatments sprayed with both the flat fan and the air induction nozzles but had favourable influence on potato yield.