Sinergisme Heterorhabditis sp. dengan Penyarungan Buah dalam Mengendalikan Penggerek Buah Kakao Conopomorpha cramerella

Penggerek buah kakao (PBK) Conopomorpha cramerella merupakan hama utama tanaman kakao di Indonesia. Pengendalian hama ini sulit karena larva berada di dalam buah. Pengendalian biologi dengan memanfaatkan nematoda patogen serangga Heterorhabditis sp. diharapkan mampu mengendalikan larva yang ada di dalam buah. Tujuan penelitian ini untuk mengetahui keefektifan Heterorhabditis sp. yang dikombinasikan dengan penyarungan buah untuk mengendalikan PBK. Penelitian dilaksanakan di Kabupaten Mamuju, Sulawesi Barat dari bulan April sampai November 2012. Sebelum dilakukan pengujian, tingkat serangan dan kerusakan biji akibat PBK di lokasi penelitian diamati terlebih dahulu. Penelitian menggunakan rancangan acak kelompok (RAK), ukuran buah muda yang diberi perlakuan dikelompokkan menjadi 2, yaitu: kelompok ukuran panjang 8-10 cm dan 11-15 cm, masing-masing perlakuan menggunakan 10 pohon yang diambil secara acak, dan dari masing-masing pohon digunakan 2 buah muda dan diulang 3 kali. Perlakuan yang diujikan adalah penyarungan dengan kantong plastik transparan ukuran 30 cm x 17 cm x 0,02 mm, Heterorhabditis sp. 500 juvenil infektif (JI/ml), kombinasi penyarungan dengan plastik dan Heterorhabditis sp. 500 JI/ml, dan kontrol. Pengamatan dilakukan pada saat panen. Parameter yang diamati adalah persentase serangan dan kerusakan biji akibat serangan PBK dan persentase buah terserang penyakit busuk buah. Hasil penelitian menunjukkan bahwa penyarungan buah dengan plastik yang dikombinasikan dengan Heterorhabditis sp. efektif menurunkan persentase serangan dan kerusakan biji akibat PBK sampai 90%. Heterorhabditis sp. bekerja sinergis dengan penyarungan buah dalam mengendalikan PBK. Pemanfaatan Heterorhabditis sp. harus dipadukan dengan penyarungan buah, untuk menghindari meningkatnya serangan penyakit busuk buah. Kata Kunci: Conopomorpha cramerella, kakao, Heterorhabditis sp. , penyarungan Cocoa pod borer (CPB) Conopomorpha cramerella is one of main pests on cocoa plantations in Indonesia. Controlling of this pest is very difficult because the larvae lives inside the pods. Biological control by using entomophatogen nematode Heterorhabditis sp. is a promising method being able to control the CPB larvae which are already inside cocoa pods. The purpose of this study was to determine the effectiveness of Heterorhabditis sp. combined with pod sleeving application on CPB infestation. The study was conducted in Mamuju, West Sulawesi from April to November 2012. Prior of this research revealed that infestation rate and the number of damaged cocoa beans caused by CPB in the research location were high. This research used a randomized block design (RBD). The young cocoa pods used were devided into two categories of length (8-10 cm and 11-15 cm) randomizely selected of ten plants each on which two young cocoa pods were used with three replications. The treatments tested were the use of pod sleeving with transparent plastic bag having size of 30 cm x 17 cm x 0.02 mm, Heterorhabditis sp 500 JI/ml, combined pod sleeving with Heterorhabditis sp. 500 JI/ml, and the control. Each treatment was applied to the 20 cocoa pods and replicated 3 times. The observations were made at the time of harvest. The parameters observed were the percentage of CPB infestations, the number of damaged beans caused by CPB and the percentage of cocoa pods infected by pod rot disease. The results showed that the use of pod sleeving combined with Heterorhabditis sp. effectively reduced the level of CPB infestations and the number of damaged beans caused by CPB to 90%. Heterorhabditis sp. works sinergically with pod sleeving in controlling of CPB. The application of Heterorhabditis sp. alone can increase the pod rot disease infections. Therefore, its application on the cocoa plantations should be integrated with the pod sleeving.