Curvularia sp. Jamur Patogen Baru Penyebab Penyakit Bercak Daun pada Tanaman Sawi

Curvularia sp. a new fungal pathogen causing leaf spot on the leaf of mustard greenA new diseases symptom as small spots of 1.5 - 1 mm diameter has been found on mustard green's leaf of farmer's field at Tanjungsari Regency of Sumedang. This symptom is different from those previously known incited by Alternaria brassicae and A. brassicola, Pseudocercosporella capsellae as well as by Myscosphaerella brassicicola. Although the spots are small, they are abundant and accompanied with yellowing, making these symptoms detrimental to mustard green production which has to be green and healthy. A Koch Postulate has been performed and successfully identified that the fungal causal agent was of the genera of Curvularia. Previously, curvularia leaf spot disease has never been reported on mustard green in Indonesia.Keywords: Curvularia, Leaf spots, Mustard green, Brassica junceaABSTRAKGejala penyakit baru, berupa bercak hitam berukuran diameter 0,5 - 1 mm ditemukan pada daun tanaman sawi milik petani di daerah Tanjungsari Kabupaten Sumedang. Gejala demikian berbeda dengan gejala-gejala penyakit bercak yang selama ini dikenal disebabkan oleh Alternaria brassicae dan A. brassicola, Pseudocercosporella capsellae dan Myscosphaerella brassicicola. Walaupun gejalanya berukuran kecil, namun karena jumlahnya banyak dan menyebabkan daun menguning, menjadikan gejala penyakit ini merugikan tanaman sawi yang harus hijau dan sehat. Uji Postulat Koch telah dilaksanakan, dan berhasil mengidentifikasi bahwa berdasarkan morfologi mikroskopiknya, jamur tersebut adalah dari genus Curvularia. Penyakit bercak daun curvularia, sebelumnya, belum pernah dilaporkan terdapat pada tanaman sawi di Indonesia.Kata Kunci: Curvularia, Bercak daun, Sawi, Brassica juncea