<p>ABSTRAK<br />Nilam (Pogostemon cablin Benth) merupakan salah satu tanaman<br />penghasil minyak atsiri yang dikenal dengan minyak nilam (patchouli oil).<br />Salah satu kendala dalam pengembangan tanaman nilam adalah peka<br />terhadap kekurangan air. Perubahan iklim cenderung menyebabkan lebih<br />sering terjadi kekeringan di sejumlah wilayah termasuk Indonesia sehingga<br />dalam pengembangan tanaman nilam diperlukan varietas toleran terhadap<br />cekaman kurang air. Terdapat tiga varietas unggul nilam (Tapaktuan,<br />Sidikalang, dan Lhokseumawe) dengan produksi minyak (290-375 kg/ha)<br />dengan kadar patchouli alkohol 32–33%. Penelitian bertujuan untuk<br />mengevaluasi respon fisiologis 4 varietas/aksesi tanaman nilam terhadap<br />cekaman kurang air. Penelitian dilaksanakan di rumah kaca di Bogor pada<br />tahun 2012. Penelitian menggunakan RAK faktorial dengan tiga ulangan.<br />Faktor pertama 4 varietas/aksesi nilam (V) yaitu Sidikalang,<br />Lhokseumawe, Tapaktuan, dan Bio-4. Faktor kedua empat interval<br />penyiraman (W) yaitu 1, 3, 6, dan 9 hari sekali. Evaluasi pengaruh<br />cekaman kurang air dilakukan terhadap beberapa karakter fisiologi<br />tanaman nilam. Pengamatan dilakukan antara lain terhadap peubah kadar<br />lengas tanah, konduktivitas stomata (Gs), laju transpirasi (Tr), kandungan<br />air nisbi (KAN), potensial air daun (PAD) dan kandungan prolin daun.<br />Hasil penelitian menunjukkan bahwa terjadi penurunan kadar lengas tanah,<br />konduktivitas stomata, laju transpirasi, dan KAN pada semua varietas,<br />sedangkan PAD dan kadar prolin meningkat seiring dengan semakin<br />lamanya interval penyiraman. Kadar prolin tertinggi pada interval 9 hari<br />sekali pada varietas Sidikalang. Tidak terdapat perbedaan respon<br />varietas/aksesi nilam yang diuji.<br />Kata kunci: Pogostemon cablin Benth, cekaman kurang air, karakter<br />fisiologis.</p><p>ABSTRACT<br />Patchouli (Pogostemon cablin Benth) is one of plant that produces<br />patchouli oil call patchouli oil. However, patchouli is susceptible to<br />drought. The effect of global warming which changes rainfall pattern<br />caused droughts in several regions including Indonesia. Therefore, it is<br />important to find patchouli variety which is relatively tolerant to drought.<br />Tapaktuan, Sidikalang, dan Lhokseumawe are three varieties of patchouli<br />which produce high essential oil (290-375 kg/ha) with high patchouli<br />alcohol content (32–33%). The objective of this research was to evaluate<br />the physiological responses of four varieties/clone of patchouli to drought.<br />The experiment was conducted at greenhouse at Cimanggu, Bogor from<br />February to July 2012. The research was designed in randomized factorial<br />block design (RBD) with three replications. The first factor was four<br />varieties/clone of patchouli (V) Sidikalang, Lhokseumawe, Tapaktuan, and<br />Bio-4. The second factor was four watering intervals (W) every 1, 3, 6<br />and 9 days of watering. Parameters evaluated were physiological<br />characteristics, soil moisture content, stomatal conductance, transpiration<br />rate (Tr), leaf water potential, relative water content, and proline content of<br />leaf. The results showed that soil moisture content, stomatal conductivity,<br />transpiration rate and relative water content decreased, while leaf water<br />potential and proline levels increased along with the increase of watering<br />intervals. The highest proline level was at interval of nine days watering<br />treatment on Sidikalang varieties. However, all varieties/clone have not<br />different responses to water deficit.<br />Key words: Pogostemon cablin Benth,water deficit, physiological<br />characteristics</p>
THE RELATION OF LEAF WATER DEFICIT TO SOIL MOISTURE TENSION IN PINUS SYLVESTRIS L.. I. THE EFFECT OF SOIL MOISTURE ON DIURNAL CHANGES IN WATER BALANCE
