Uptake of Systemic Insecticides After Application to the Stems of the Cotton Plant1

Abstract

When 32P-labeled phosphamidon in lanolin or 14C-labeled monocrotophos in gel were applied to 5 cm of cotton stem, uptake and translocation were greater than when the treated area was 2.5 cm or less in width. Also, uptake was much less when the treatments were applied to older stems with bark than when they were applied to young waxy stems without bark and was greater when a 2nd treatment was applied to the same area. Less uptake of monocrotophos occurred when the insecticide was applied in a gel than when it was applied in lanolin. Phosphamidon was found in all plant parts, but greater amounts were found in mature leaves.