Efficiency of Agave sisalana extracts on the two-spotted spider mites Tetranychus urticae (Koch, 1836) and the occurrence of toxicity symptoms in cotton (Gossypium hirsutum L. r latifolium Hutch) plants

Abstract

It was aimed to evaluate the efficiency of fresh extracts (24 hours after maceration) and tanned (after 35 days) of two genotypes of Agave (Agave sisalana Perrine) in the control of Tetranychus urticae (Koch) (Tetranychidae) in plants cotton (Gossypium hirsutum L. r latifolium Hutch) and the effects of phytotoxicity of these applications. The treatments were: untreated plants, fresh extract of Agave sisalana; fresh extract of hybrid 11648; tanned extract of A. sisalana and; tanned extract of hybrid 11648. It was evaluated the efficiency of Agave ́s extracts on striped mite and Iphiseiode ssp. (Phytoseiidae), the percentage of affected plants and the intensity of the symptons of phytotoxicity in cotton plants in the 10, 35 and 65 days after germination, it was used Completely Randomized Delimitation with five repetitions for evaluations of phytotoxicity and 10 repetitions for efficiency. It was observed reduction of the number of alives mites with the applications of the Agave ́s extracts, the efficiency of hybrid ́s tanned extract was 100%, the percentage of affected plants was 100% when it was sprayed on both sides of the sheet and the intensity of phytotoxicity was from very weak to weak in the 10 and 35 days and strong in the 65 days after the germination.