Pengaruh Formula Fungisida Nabati Minyak Cengkeh dan Serai Wangi terhadap Penyakit Busuk Buah Kakao

Penyakit utama busuk buah kakao disebabkan oleh Phytophthora palmivora dapat menurunkan hasil 20%-30%. Pengendalian penyakit dengan fungisida nabati saat ini banyak dikembangkan, dengan tujuan mengurangi dampak negatif dari fungisida sintetik. Fungisida nabati yang digunakan adalah minyak cengkeh dan serai wangi karena mudah didapat dan bersifat fungisidal. Penelitian bertujuan menganalisis pengaruh formula fungisida nabati minyak cengkeh dan serai wangi terhadap perkembangan penyakit busuk buah kakao (BBK) yang disebabkan oleh Phytophthora palmivora. Penelitian dilaksanakan di kebun petani Kabupaten Mamuju, Sulawesi Barat, menggunakan rancangan acak kelompok 7 perlakuan, 4 ulangan. Setiap perlakuan diamati 20 buah kakao berukuran 8-10 cm. Perlakuan yang diuji adalah 1) minyak cengkeh+serai wangi, 2) minyak cengkeh+asam salisilat, 3) minyak cengkeh+silikon, 4) serai wangi+asam salisilat, 5) serai wangi+silikon, 6) fungisida sintetik sebagai pembanding, dan 7) kontrol. Larutan formula (5ml/liter) disemprotkan pada buah setiap 2 minggu sekali sampai buah masak atau dipanen. Parameter yang diamati adalah persentase serangan, intensitas serangan, kadar senyawa fenol, dan bobot biji kakao. Hasil penelitian menunjukkan bahwa formula fungisida nabati cengkeh dan serai wangi yang diperkaya dengan asam salisilat dan silikon dapat menekan intensitas serangan penyakit busuk buah kakao sebesar 20,48%-65,62%, tidak berbeda nyata dengan fungisida sintetik (73,15%). Besarnya tingkat penekanan penyakit sejalan dengan kandungan senyawa fenol pada kuit buah kakao. Semakin tinggi kadar fenol pada kulit buah, maka semakin tinggi penekanan penyakit busuk buah kakao. Penggunaan formula fungisida nabati dapat menekan kehilangan produksi kakao 23,94%-43,02%. Formula terbaik dan dapat dianjurkan untuk pengendalian penyakit busuk buah kakao adalah minyak cengkeh+serai wangi, cengkeh+asam salisilat, dan serai wangi+silikon. Kata Kunci: Kakao, Phytophthora palmivora, busuk buah kakao, fungisida nabati Black pod disease caused by Phytophthora palmivora is a major disease on cacao crops, which can cause yield losses until 20%-30%. Disease control using botanical fungicide such as the use of clove and citronella oil, which have fungicidal effect, have been developed to reduce the negative impact of synthetic fungicide residues. The objectives of this study was to analyze the effect of clove and citronella oil as botanical fungicide formula on the development of black pod disease and seed weight of cocoa in the field. The study was carried out at farmer’s fields in Mamuju District, West Sulawesi using a randomized block design with 4 replications and 7 treatment. In each treatment was observed 20 cacao pods with size 8-10 cm. The treatments were 1) clove + citronella oil, 2) clove oil + salicylic acid, 3) clove oil + silicone, 4) citronella + salicylic acid, 5) citronella + silicone, 6) synthetic fungicides as a comparison treatment, and 7) control. The botanical formula was applied by spraying onto the entire surface of pod with a concentration of 5 ml/litre every 2 weeks. Observations were include the percentage of attacks, intensity of the attack, the levels of phenolic compounds, and seed weight of cacao. The results showed that the formula of botanical fungicide containing clove and citronella oil enriched with salicylic acid and silicon can suppress disease attack of black pod (20.48%-65.62%), which was not significantly different from synthetic fungicide (73.15%). The level of disease suppression in line with phenolic compounds of cocoa husk. In which, high phenolic contents can reduce black pod disease at a higher level . The use of botanical fungicides formula can suppress the yield loss until 23.94% to 43.02%. The best formulas that can be recommended in suppressing intensity of black pod disease were clove oil + citronella, clove oil + salicylic acid, and citronella + silicon.