Effect of combined treatment of methomyl and lindane on the activities of auxins and gibberellins in Zea mays plants

ABSTRACT

Treating maize plants at two different growth stages [1 = 45 days and 2 = 60 days] with either methomyl or methomyl followed by lindane led to reduction in the percentage and activity of auxins and gibberellins. The degree of reduction was found to depend on the growth stage as well as the type of insecticide treatment. On the other hand, the growth inhibitors showed a reverse trend, thus increasing in percentage and activity with the plant age and the application of more than one insecticide. The reduction of the promoting zones following the application of insecticide[s] is probably due to an inhibitory effect on the activity of IAA-oxidase system which results in an increase in the phenolic compounds. The inhibitory effect of insecticide[s] on gibberellins might be due to the inhibition of their precursors