<![CDATA[Mustard (Brassica juncea L.) is one of the most widely cultivated vegetable crops in Sumatra. Severe infestations by insect pests can cause extensive leaf damage, leading to significant yield losses and even plant death. This study aimed to evaluate the effectiveness of papaya (Carica papaya L.) leaf extract in controlling the armyworm Spodoptera litura on mustard plants. The research was conducted in Ujung Gurap Village, Batunadua District, Padangsidimpuan City, Indonesia, from November 2025 to February 2026. The experiment was arranged in a Randomized Complete Block Design (RCBD) consisting of five treatments with six replications, resulting in 30 experimental units. The treatments were: A0 = without papaya leaf extract (control), A1 = papaya leaf extract at 100 g L⁻¹ water, A2 = papaya leaf extract at 150 g L⁻¹ water, A3 = papaya leaf extract at 200 g L⁻¹ water, and A4 = papaya leaf extract at 250 g L⁻¹ water. The observed parameters included the percentage of plants infested by S. litura, the number of damaged leaves, and fresh yield. The results showed that increasing the concentration of papaya leaf extract significantly reduced both the number of infested plants and the number of damaged leaves caused by S. litura. The highest fresh yield was obtained from the application of papaya leaf extract at a concentration of 250 g L⁻¹ water, with an average production of 6,650 g. Keywords: botanical insecticide, Brassica juncea, Carica papaya, mustard, Spodoptera litura. ]]>
