Evaluasi Penyakit Bercak dan Hawar Daun pada Bibit Manglid (Manglietia glauca) di Persemaian Permanen Dramaga

Abstract

Bibit manglid rentan terhadap penyakit bercak dan hawar daun yang berpotensi menurunkan kualitas bibit. Penelitian bertujuan mengevaluasi tingkat kejadian, keparahan dan perkembangan penyakit bercak dan hawar daun pada bibit manglid, serta mengidentifikasi patogen penyebabnya. Penelitian menggunakan dua petak contoh dengan intensitas sampling 10% dari populasi bibit. Pengamatan kejadian dan keparahan penyakit dilakukan lima kali dengan interval dua minggu. Daun bergejala diisolasi untuk uji Postulat Koch dan identifikasi patogen. Hasil penelitian menunjukkan bahwa kejadian penyakit bercak dan hawar daun pada bibit manglid umur 6 bulan dan 8 bulan mencapai 100%. Keparahan penyakit meningkat selama pengamatan pada kedua kelompok umur bibit. Nilai Area Under the Disease Progress Curve (AUDPC) bibit umur 6 bulan lebih tinggi dibandingkan bibit umur 8 bulan. Namun hasil uji Mann–Whitney perbedaan tersebut tidak signifikan, sehingga umur bibit tidak berpengaruh nyata terhadap perkembangan penyakit. Patogen penyakit bercak dan hawar daun yang berhasil diidentifikasi yaitu, Colletotrichum sp. Calonectria sp., Rhizoctonia sp. Seluruh isolat bersifat patogenik dengan masa inkubasi 4 - 5 hari setelah inokulasi.

Manglid seedlings are susceptible to leaf spot and leaf blight diseases, which can potentially reduce seedling quality. This study aimed to evaluate the incidence, severity, and progression of leaf spot and leaf blight in manglid seedlings and to identify the causative pathogens. Two sample plots were used, with a sampling intensity of 10% of the seedling population. Observations of disease incidence and severity were conducted five times at two-week intervals. Symptomatic leaves were isolated for Koch's postulates testing and pathogen identification. The results showed that the incidence of leaf spot and leaf blight reached 100% in both 6-month-old and 8-month-old manglid seedlings. Disease severity increased throughout the observation period for both age groups. Area Under the Disease Progress Curve (AUDPC) value was higher for the 6-month-old seedlings than for the 8-month-old ones. However, the Mann–Whitney test results showed that the difference was not significant; thus, seedling age did not have a significant effect on disease development. The pathogens identified as causing leaf spot and leaf blight were Colletotrichum sp., Calonectria sp., and Rhizoctonia sp. All isolates were pathogenic, with an incubation period of 4–5 days post-inoculation.