| dc.description.abstract | This study was conducted to evaluate the effectiveness of preparations offve kinds of natural insecticides (methanol twig extract of Aghia odor&, an active fraction of stem bark extract of Dysoxylum acutangulum, aLnciirochtin, abamectin, andspinosad) against the leafrniner Uriomyza huidobrenris on marigold (Tagetes erecta) andpetunia (~ehn&sp. ). The results showed that the treatment with &ecfin d a conce&n of l 8 . l p a~p pliedfve times once a week was very effective in suppressing the leafminer infestation, Ie. no infested leaves nor leafminer pupae were found both in marigold and petunia The MgAcsl percentages of infested leaves in the conlroh were 8.0% and 9.m respectively, for water and methanol control in marigold, and 31.0% and 27.2% for similar conlroh in petunia The treatment with aradirachtin at 30 ppm was su$)ic&ntly effective, e.i the highest percentages of infested kaves in marigold and petunia were 2.6% and 8.7%, respectively, and the number of Icqfminer pupae rangedfn,m 0.3 to 2.6perpW on marigold (in the controls: 1 - 10.1 pupae/pht). The treatment with spinosad at 18.75 ppm was kss effective than that with e m n . The treatment3 with the active fraction of D. acutangulum at 40ppm and A. odorata extract at 0.35% were considered ineffective. Moreover, A. odorata extract causedphytotoxicity to both marigold and petunia a&r three times of application. | id |
