The efficiency of natural insecticide was studied in control Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) in corn crop cultivated in low agroecossistem, under natural infestation. The experiment was conducted at the experimental area of Embrapa Clima Temperado - Estação Experimental Terras Baixas, agricultural year 2005/2006. The experimental diagram was of blocks in factorial design (9 x 2), with 9 treatments: T1- NeemAzal-T/S (0.25%); T2- NeemAzal-T/S (0.5%); T3- Rotenat CE (0.5%); T4- Natuneem agrícola (0.5%); T5- Rotenat CE + Natuneem agrícola (0.25+0.25%); T6- Dalneem emulsionable (0.5%); T7- Organic neem (0.5%); T8- Match CE (0.1%) (Standard) and T9- Water (check), with two times of sowing and four repetitions. Three applications of treatments were carried for time, determining the percentage of plants attacked eight days after each application and yield of grain in kg ha-1. There was significant difference in control of fall armyworm among time of sowing, with a major efficiency of control for first time, pointing out among the natural insecticide the NeemAzal - T/S (0.5%) and Dalneem emulsionable (0.5%), with great potential of use in sowing carried out in November. The yield doesn't differ among time, pointing out among the natural insecticide the Neem Azal - T/S at 0.5%, bringing an alternative in control of S. frugiperda. There is a negative and significant correlation among plants attacked and yield of grain in kg ha-1, with major potential of control for the first time sowing.
Fall armyworm; Zea mays; control; Azadirachta indica
