Pengendalian Ulat Grayak (Spodoptera litura) Menggunakan Ekstrak Daun Kenikir (Cosmos caudatus) di Tanaman Bayam

Abstract

Spinach is known as a distinguished vegetable that has high nutritional content among other vegetables. However, many factors found that affect the productivity of this vegetable, including armyworm (Spodoptera litura) pest attacks. Pest control currently uses a lot of chemical insecticides whose use is very risky to have a bad effect on the environment. Efforts that can be made to minimize damage to the environment are to use botanical pesticides. Leaves of Cosmos caudatus reported various pharmacological properties such as anti-inflammatory, antibacterial, anti-diabetic, and bone-protective agents. These properties may have inhibited the growth of armyworms that attack in the Spinach plant. The purpose of this study was to determine the effect of C. caudatus's leaf extract on percent of pest mortality and percent of attack intensity of armyworms in spinach plants. The experimental design in this study was a non-factorial Completely Randomized Design (CRD), consisting of five treatment and four replicants to obtain 20 experimental units consisting of P1 = control/0% concentration, P2 = 20% plant leaf extract (200 ml extract + 800 ml water), P3=25% plant leaf extract (250 ml extract + 750 ml water), P4=30% plant leaf extract (300 ml extract + 700 ml water), and P5=35% plant leaf extract (350 ml extract + 650 ml water). The result showed the 35% plant leaf extract had the highest mortality value; at 55% in 3 days of observation. The Lethal Concentrate of 50% (LC50) of plant extract was 336.607 ml/L with a concentration interval of 294.132 – 502.409 ml/L. There were differences in the intensity of armyworm attacks in each treatment but did not provide a significant difference, especially in treatments P1, P2, and P3 which had attack intensity ranges from 83.6% to 63.5% and were significantly different from treatments P4 and P5 which had intensity range of 54.1% to 53.2%. In this observation, the best treatment was at P4 which gave the lowest armyworm attack intensity at 53.2%.