INTENSITAS SERANGAN AKIBAT HAMA PEMAKAN DAUN SETELAH APLIKASI EKSTRAK DAUN JERUK NIPIS (Citrus aurantifolia (Cristm.) Swingle) PADA TANAMAN SAWI (Brassica juncea L.)

Penelitian ini bertujuan untuk mengevaluasi intensitas serangan akibat hama pemakan daun setelah aplikasi ekstrak daun jeruk nipis pada tanaman sawi. Penelitian ini dilaksanakan di lahan percobaan di Kelurahan Lansot Kecamatan Tomohon Selatan Kota Tomohon pada bulan Desember 2018 – Februari 2019. Penelitian ini menggunakan metode eksperimen rancangan acak lengkap (RAL) yang terdiri atas 5 perlakuan konsentrasi ekstrak daun jeruk nipis yaitu J0(kontrol), J1  = 100 g ekstrak daun/L, J2 = 200 g ekstrak daun/L, J3 = 300 g ekstrak daun/L, dan J4 = 400 g ekstrak daun/L. Parameter yang diamati yaitu intensitas serangan akibat hama pemakan daun. Hasil penelitian menunjukkan bahwa pemberian ekstrak daun jeruk nipis berpengaruh nyata terhadap intensitas serangan pada tanaman sawi dan konsentrasi ekstrak daun jeruk nipis yang dapat menekan serangan hama pemakan daun yaitu konsentrasi perlakuan J3 (300 g ekstrak).Kata kunci : Sawi (Brassica juncea L.) , hama pemakan daun, jeruk nipis                    (Citrus aurantifolia)THE ATTACK INTENSITY DUE TO LEAF-EATING PESTS AFTER APPLICATION OF LIME (Citrus aurantifolia (Cristm.) Swingle) LEAF EXTRACT ON MUSTARD PLANTS (Brassica juncea L.)  ABSTRACTThis study is aimed to evaluate the intensity of the attacks due to leaf-eating pests after the application of lime leaf extract on mustard plants. This research was carried out on experimental fiel in Lansot Sub-District, South Tomohon District, Tomohon City in December 2018 - February 2019. This study used a completely randomized design consisting of 5 treatments of lime leaf extract concentrations, namely J0 (Control), J1 = 100 g leaf extract / L, J2 = 200 g leaf extract / L), J3= 300 g leaf extract/ L, and J4 = 400 g leaf extract / L. The intensity of the attack was observed based on the area of leaf damaged by pest. The results showed that the application of lime leaf extract significantly affected the intensity of attacks on mustard plants and the concentration of lime leaf extract which was able to suppress leaf-eating pests which was the highest in the  J3 treatment (300 g extract).Keywords: Mustard (Brassica juncea L.), leaf-eating pests, lime (Citrus aurantifolia).