Pengendalian penyakit busuk buah kakao menggunakan Trichoderma dan pupuk Kalium

AbstrakKerugian akibat serangan penyakit busuk buah kakao (BBK) mencapai 40-100%, produktivitas hanya 669,9 kg/ha/tahun. Upaya pengendalian dapat dilakukan melalui penggunaan cendawan antagonis Trichoderma dan peningkatan dosis pupuk Kalium. Penelitian bertujuan menguji efektivitas Trichoderma viride dan pupuk K dalam mengendalikan penyakit BBK. Penelitian dilakukan pada Januari sampai Desember 2019 di kebun kakao rakyat (Klon CSA 6) berumur 10 tahun dengan tanaman pelindung Gliricidia sp.  Desa Suka Bandung, Kecamatan Natar, Kabupaten Lampung Selatan. Penelitian menggunakan rancangan acak kelompok dengan 12 perlakuan dan 3 ulangan. Macam perlakuan yaitu fungisida Trichoderma viride, fungisida kimia (mancozeb), pupuk KCl 100 g/phn, dosis KCl 110 g/phn, dosis KCl 125 g/phn, Trichoderma + KCl 100 g/phn,  Trichoderma + KCl 110 g/phn, Trichoderma + KCl 125 g/phn, fungisida kimia + KCl 100 g/phn,  fungisida kimia + KCl 110 g/phn,  fungisida kimia + KCl 125 g/phn, dan  cara petani (tanpa fungisida + KCl 50 g/phn). Hasil penelitian menunjukkan bahwa intensitas serangan terendah (7,79%), daya hambat penyakit tertinggi (68,84%), dan produksi biji kering mencapai 1.327,86 kg/ha/tahun (166,86%) diperoleh pada penggunaan Trichoderma viride dan pupuk KCl 125 g/pohon. Efektivitas fungisida Trichoderma viride tidak berbeda dibandingkan dengan fungisida  kimia dalam mengendalikan penyakit BBK, dan makin tinggi dosis pupuk K, makin tinggi pula daya hambat terhadap penyakit.Kata Kunci: Busuk buah kakao, pengendalian, pupuk kalium, Trichoderma virideAbstractLosses due to cacao pod rot disease is varied from 40 to 100% leaving the productivity into 669.9 kg per ha per year. To control the disease, Trichoderma and potassium (K) fertilizer are used. The study aimed to test the effectiveness of Trichoderma viride and K fertilizer in controlling cocoa pod rot disease. The study was conducted from January to December 2019 in South Lampung Regency, by using cocoa clone of CSA 6 aged 10 years as plant material. The study used a randomized block design with 12 treatments and 3 replications. The treatment were Trichoderma viride fungicide, chemical fungicide (mancozeb), KCl fertilizer 100 g plant-1, KCl 110 g plant-1, KCl 125 g plant-1, Trichoderma + KCl 100 g plant-1, Trichoderma + KCl 110 g plant-1, Trichoderma + KCl 125 g plant-1, chemical fungicide + KCl 100 g plant-1, chemical fungicide + KCl 110 g plant-1, chemical fungicide + KCl 125 g plant-1, and farmer's method (no fungicide + KCl 50 g plant-1). The results showed that the lowest attack intensity (7.79%), the highest disease inhibition (68.84%), and production reached 1,327.86 kg per haper year (166.86%) was obtained in the combination treatment of Trichoderma viride + KCl 125 g plant-1. The effectiveness to control the disease on the treatment of Trichoderma viride was not different compared to chemical fungicides, and the higher applied dose of K fertilizer, the higher the inhibition against cacao pod rot disease.Keywords: Cocoa pod rot, control, Trichoderma viride, potassium fertilizer