Aplikasi Bacillus spp. untuk Pengelolaan Penyakit Bercak Daun Neopestalotiopsis pada Bibit Cengkih

DICKY EKA SETYAWAN, Dr. Suryanti, S.P., M.P.; Dr. Tri Joko, S.P., M.Sc.

2024 | Skripsi | ILMU HAMA & PENYAKIT TUMBUHAN

Cengkih (Syzygium aromaticum) merupakan salah satu komoditas penting asli Indonesia. Organisme Pengganggu Tumbuhan (OPT) merupakan faktor yang menjadi kendala dalam budidaya cengkih khususnya penyakit bercak daun Neopestalotiopsis yang berdampak pada kerusakan fase pembibitan. Diperlukan pengendalian ramah lingkungan ditengah isu pestisida yang telah menjadi permasalahan kerusakan lingkungan. Pemanfaatan Bacillus spp. sebagai agens hayati merupakan salah satu upaya alternatif untuk terus menjaga keseimbangan lingkungan. Penelitian ini bertujuan untuk skrining 20 isolat Bacillus spp. yang berpotensi sebagai agens pengendali hayati terhadap penyakit bercak daun Neopestalotiopsis. Pengujian dilaksanakan di Rumah Kaca dan Laboratorium Ilmu Penyakit Tumbuhan, Departemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, UGM. Uji antagonis co-culture dan perkecambahan spora digunakan dalam skrining isolat potensial penghambat pertumbuhan Neopestalotiopsis sp. secara in vitro. Empat isolat terbaik B. velezensis B-27, Bacillus sp. RB77, B. subtilis EA64, dan Bacillus sp. DM2 dipilih untuk uji lanjut pada rumah kaca menggunakan Rancangan Acak Lengkap (RAL). Perlakuan perendaman bibit cengkih dengan suspensi Bacillus spp. diawal dan kombinasi semprot serta tuang secara temporal 2 minggu sekali selama 3 bulan. Hasil uji rumah kaca menunjukan bahwa isolat Bacillus sp. RB77, B. subtilis EA64 dan Bacillus sp. DM2 mampu menurunkan intensitas penyakit bercak daun Neopestalotiopsis secara signifikan. Bacillus sp. RB77 dan B. subtilis EA64 mampu menurunkan insidensi penyakit secara signifikan. B. velezensis B-27 dan B. subtilis EA64 memberikan pengaruh nyata terhadap pertambahan tinggi tanaman secara signifikan serta B. subtilis EA64 memberikan pengaruh nyata terhadap pertambahan volume kanopi secara signifikan.

Cloves (Syzygium aromaticum) are one of the important commodities native to Indonesia. Plant Pest Organisms is a factor that becomes an obstacle in clove cultivation, especially Neopestalotiopsis leaf spot disease which impacts damage to the seedling phase. Environmentally friendly control is needed to address the pesticide issue, which has become a problem of environmental damage. The utilization of Bacillus spp. as a biological agent is an alternative effort to maintain ecological balance. This study aimed to screen 20 isolates of Bacillus spp. that have potential as biological control agents against Neopestalotiopsis leaf spot disease. Tests were carried out in the Greenhouse and Plant Disease Laboratory, Department of Plant Protection, Faculty of Agriculture, UGM. Antagonist co-culture and spore germination tests were used in screening potential growth inhibitor isolates of Neopestalotiopsis sp. in vitro. The four best isolates B. velezensis, B-27, Bacillus sp. RB77, B. subtilis EA64, and Bacillus sp. DM2 were selected for further testing in the greenhouse using a Completely Randomized Design (CRD). Clove seeds were treated with a suspension of Bacillus spp. by soaking at the beginning and with a combination of spraying and pouring periodically once every 2 weeks for 3 months. The greenhouse test results showed that the isolate Bacillus sp. RB77, B. subtilis EA64 and Bacillus sp. DM2 was able to significantly reduce the intensity of Neopestalotiopsis leaf spot disease. Bacillus sp. RB77 and B. subtilis EA64 were able to reduce the incidence of disease significantly. B. velezensis B-27 and B. subtilis EA64 had a real influence on the significant increase in plant height and B. subtilis EA64 had a real influence on the significant increase in canopy volume.

Kata Kunci : Neopestalotiopsis sp., Syzygium aromaticum, Bacillus spp., B. velezensis, B. subtilis.