EFFECTS OF DELTAMETHRIN ON FIELD-GROWN POTATO PLANTS - BIOCHEMICAL AND ULTRASTRUCTURAL ASPECTS

The effects of repeated spraying of field grown plants of Solatium tuberosum L. with deltamethrin 24, 41 and 55 d after emergence, on chlorophyll level, oxygen uptake, RuBisCo activity and leaf ultrastructure, were studied. Chlorophyll amount increased in treated plants after the second and third spraying, whereas RuBisCo activity showed a higher value than in the controls only after the last treatment, In contrast, the respiratory activity was stimulated by the first spraying and no significant differences were found with the ensuing treatments. The general ultrastructure of mesophyll cells was not altered by deltamethrin, but morphometric analysis of electron micrographs showed that the fractional volume of chloroplasts and starch in the treated leaves were consistently lower than in controls. The biochemical and ultrastructural data suggested that the vegetative cycle of the sprayed plants had been extended. © 1993 Annals of Botany Company.