INFLUENCE OF HEAVY METALS IN SOIL UPON BROAD BEAN (Vicia faba L.) SEED INFECTION BY DISEASES AND PESTS

The paper presents effect of the medium pollution of soil with single heavy metals upon the broad bean (Vicia faba L.) seed injuries by Bruchus rufimanus Boh. (Col., Bruchidae) and their infection by fungi Botrytis fabae and Ascochyta fabae. Broad bean, White Windsor c. v. was cultivated on: soil with natural heavy metal concentrations (Control); soil with natural content of heavy metals receiving mineral fertilizers (Control + NPK); soil polluted with Cd (4 mg . kg(-1) d.m.); soil polluted with a Pb (530 mg . kg(-1) d.m.); soil contaminated with Cu (85 mg . kg(-1) d.m.), soil polluted with Zn (1000 mg . kg(-1) d.m.) and soil contaminated with Ni (110 mg . kg(-1) d.m.). A harm from Bruchus rufimanus was assessed based on the number and weight of injured seeds per the total number and weight of seeds. The seed infection by Botrytis fabae and Ascochyta fabae was assessed under laboratory conditions. Soil contamination with zinc caused that broad bean plants did not form seeds. Contamination with nickel was fatal for number of delivered seeds, their weight, and number of pods. The contamination with either cadmium, copper or lead improved all indices and among them lead performed best. Bruchus rufimanus injured approximately ca 60-90 % seeds. The contamination with lead was the most critical in that respect. More intensive infection by Botrytis fabae (80-93%) was found among the seeds injured by Bruchus rufimanus whereas among non-injured seeds this count was between 40 and 67 %. Ascochyta fabae caused similar, 30 to 67 % infection of injured and healthy seeds. No marked differences were found between the kind of the soil contamination and degree of the seed infection by these diseases.