Effects of Deltamethrin on Field Grown Potato Plants:Biochemical and Ultrastructural Aspects

The effects of repeated spraying of field grown plants of Solanumtuberosum L. with deltamethrin 24, 41 and 55 d after emergence,on chlorophyll level, oxygen uptake, RuBisCo activity and leafultrastructure, were studied. Chlorophyll amount increased in treated plants after the secondand third spraying, whereas RuBisCo activity showed a highervalue than in the controls only after the last treatment. Incontrast, the respiratory activity was stimulated by the firstspraying and no significant differences were found with theensuing treatments. The general ultrastructure of mesophyllcells was not altered by deltamethrin, but morphometric analysisof electron micrographs showed that the fractional volume ofchloroplasts and starch in the treated leaves were consistentlylower than in controls. The biochemical and ultrastructural data suggested that thevegetative cycle of the sprayed plants had been extended.Copyright1993, 1999 Academic Press Solanum tuberosum L., potato plant, deltamethrin