[Disease control of leaf spot and rust on peanut]

English. The major diseases that always found attacks together on the peanut are leaf-spot (Cercospora sp.) and rust (Puccinia arachidis Speg). There are two species of leaf spots: early leaf spot (C. arachidicola Hori) and late leaf spot (C. personatum Deighton). The symptom of those two species was found at three to five weeks after planting, the highest infection was found on 80 days after planting. Temperature between 25 deg. - 30 deg. C and high relative humidity are the good condition for their development. Yield reduction could reach until 50 percent. There was a positive correlation between yield reduction and intensity of infection and leaf defoliation. Varieties like Rusa, Anoa, Landak, Komodo, Kelinci, and Zebra showed the high resistant/tolerant to leaf-spot and rust. Plant rotation and sanitation/eradication could decrease infection. Fungicide application like Baycor 300EC (a.i. Bitertonal) and Daconil 75WP (a.i. Chlorolatonil) six times starting at one month after planting with two weeks intervals, could reduce infection of leaf-spot and rust. Daconil could reduce infection of leaf-spot and rust as much as 30.3 percent and 79 percent respectively and Baycor 25 percent and 40.6 percent respectively up to 13 weeks after planting

unknown. Penyakit utama yang selalu ditemukan menyerang pada tanaman kacang tanah secara bersamaan adalah bercak daun (Cercospora sp.) dan karat (Puccinia arachidis Speg). Bercak daun dikenal dua species yaitu bercak daun awal (Cercospora arachidicola Hori) dan bercak daun akhir (Cercosporidium personatum Deighton). Gejala kedua bercak tersebut ditemukan 3-5 minggu setelah tanam, serangan tertinggi didapati setelah tanaman berumur 80 hari. Suhu 25 derajat C - 30 derajat C dan kelembaban nisbi yang tinggi adalah kondisi ideal untuk perkembangannya. Penurunan hasil dapat mencapai 50 persen. Tingkat penurunan hasil berkorelasi positif dengan intensitas serangan dan tingkat defoliasi daun. Varietas unggul seperti Rusa, Anoa, Landak, Komodo, Kelinci dan Zebra mempunyai tingkat ketahanan/toleransi/terhadap bercak daun dan karat. Pergiliran kacang tanah dengan tanaman lain yang bukan inang, sanitasi/eradikasi sisa tanaman dapat mengurangi peluang terjadinya serangan yang tinggi. Penyemprotan fungisida Baycor 300 EC (bahan aktif: Bitertonal) dan Daconil 75 WP (bahan aktif Klorolatonil) sebanyak 6 kali yang dimulai pada umur satu bulan, interval 2 minggu, dapat menekan intensitas bercak daun dan karat. Sampai pada umur 13 minggu, Daconil dapat menekan bercak daun dan karat yaitu berturut-turut 30,3 persen dan 79 persen, demikian pula Baycor, 25 persen dan 40,6 persen