Durian (Durio zibethinus) merupakan salah satu tanaman yang banyak dikembangkan sebagai tanaman dalam sistem agroforestri di Kecamatan Cangkringan dan Kemalang di lereng selatan Gunung Merapi. Namun demikian, walaupun areal pertanamannya terus meningkat, produktivitas Durian tidak cukup optimal. Hal ini disinyalir karena kurangnya tindakan silvikultur yang tepat. Penelitian ini bertujuan untuk mengetahui pengaruh sifat fisiologi dan faktor lingkungan terhadap durian pada sistem agroforestri yang ada di pekarangan dan tegalan milik petani, serta mengamati kondisi perakarannya di kedua lokasi tersebut. Identifikasi ekofisiologi durian dilakukan dengan pengambilan sampel daun untuk mengukur sifat fisiologis (aktivitas nitrat reduktase, kandungan air nisbi daun, stomata, prolin dan klorofil), serta pengamatan langsung di lapangan untuk mengukur faktor lingkungan (suhu, kecepatan angin, sekapan cahaya dan kelembaban). Analisis yang digunakan adalah analisis varian dengan uji lanjut DMRT dan analisis statistik bertatar. Pengamatan kondisi perakaran durian dilakukan dengan metode resistivitas geolistrik. Hasil penelitian dari gatra ekofisiologi menunjukkan bahwa ada perbedaan nyata pada hasil produksi buah durian dengan umur relatif sama di kedua lokasi, dimana hasil analisis statistik bertatar menunjukkan bahwa produksi durian dipengaruhi oleh kecepatan angin. Angin dengan kecepatan tinggi akan berpengaruh terhadap gugurnya buah muda. Perbedaan hasil durian juga diduga dipengaruhi oleh curah hujan yang menyebabkan proses metabolisme pada buah menjadi tidak sempurna. Hujan juga menyebabkan banyaknya buah Durian busuk sebelum dipanen. Selanjutnya diketahui bahwa kondisi tanah di kedua wilayah relatif sama, dengan kondisi rizhosfer perakaran Durian yang didominasi oleh kerikil, pasir dan air.Ecophysiology and Development Opportunities of Durian (Durio zibethinus) Through Agroforestry Systems in the Southern Slopes of Mount Merapi, IndonesiaAbstractDurian (Durio zibethinus) is widely cultivated through agroforestry system in the Cangkringan and Kemalang sub district, in the southern slope of Merapi Mountain, Yogyakarta, Indonesia. Although the area to crop Durian has increased since 1990’s, the productions were not optimal, which probably is due to lack of silviculture treatments. This research aimed to assess the influence of physiological and environmental factors on Durian planted through agroforestry system of homegarden and dryland, and to analyze the condition of durian root systems under those two locations. Ecophysiological studies of Durian were carried out by leaf sampling for physiological properties (i.e.nitrate reductase activity, relative water content, stomata, proline and chlorophyll content) and field observations on environmental factors (i.e. mean air temperature, wind speed, light and moisture). Variance analysis was conducted with advanced DMRT and stepwise statistical analysis. Observation on durian rooting system was conducted by geoelectric resistivity method. The results showed that the soil conditions of the two locations were relatively similar and the root rhizosphere of durian mostly consisted of small stones, sand, and water. It was found that the Durian fruit yield between agroforestry system of homegarden and dryland were different, and based on the stepwise statistical analysis, the Durian production was mostly influenced by wind speed. It was observed that the presence of wind has caused the abscission of young fruits, where faster wind resulted in more abscission of young fruits. Another factor affecting the Durian production was rainfall. It was observed that rainfall has interfered the metabolism processes of the fruits causing fruits being rotten before harvest time.