RESPON TANAMAN NILAM (Pogostemon cablin Benth) TERHADAP CEKAMAN KEKERINGAN
SETIAWAN, Prof. Dr. Ir. Tohari, MSc
2013 | Tesis | S2 AgronomiNilam (Pogostemon cablin Benth) merupakan salah satu tanaman penghasil minyak atsiri yang dikenal dengan minyak nilam (patchouli oil) yang cukup penting peranannya, baik sebagai sumber devisa maupun sebagai sumber pendapatan petani. Nilam diusahakan oleh lebih dari 65.000 petani dengan luasan lahan 24.718 ha Salah satu kendala dalam pengembangan tanaman nilam adalah nilam sangat peka terhadap kekeringan. Adanya perubahan iklim pemanasan global cenderung meningkatkan frekuensi El-Nino dan menguatkan fenomena La-Nina. Kejadian iklim ekstrim antara lain menyebabkan: peningkatan frekuensi, luas, dan bobot/intensitas kekeringan sehingga dalam pengembangan tanaman nilam diperlukan varietas toleran terhadap cekaman kekeringan. Saat ini terdapat tiga varie tas unggul nilam (Tapak Tuan, Sidikalang, dan Lokseumawe) yang telah dilepas oleh Balittro yang unggul dalam produk minyak (290-375 kg/ha) dengan kadar patchouli alkohol 32 – 33 %. Hasil penelitian ini diharapkan dapat memberikan informasi tentang tingkat toleransi kekeringan pada varietas nilam. Penelitian menggunakan rancangan faktorial dalam pola Rancangan Acak Kelompok (RAK) dengan tiga kali ulangan. Faktor pertama yaitu varietas yaitu Sidikalang, Lokseumawe, Tapaktuan dan Klon Bio-4. Faktor kedua interval penyiraman yaitu 1, 3 , 6 dan 9 hari sekali. Pengumpulan data meliputi perubahan kadar lengas tanah, potensial air daun, kadar air nisbi, konduktivitas stomata, laju transpirasi, laju fotosintesis, kadar prolin, tinggi tanaman, jumlah dan luas daun, luas daun spesifik, nisbah luas daun, panjang akar total, luas permukaan akar, bobot kering akar, bobot kering tajuk, nisbah akar/tajuk, analisa laju asimilasi bersih dan laju pertumbuhan nisbi, kadar minyak dan kadar patchouli alcohol, serta indeks sensitivitas. Data dianalisis menggunakan program software SAS 9.1.3 with SP4 dan program Microsoft office excel 2007. Hasil memperlihatkan interval penyiraman 9 hari sekali nyata menurunkan kadar lengas tanah, kadar air nisbi, potensial air daun, konduktivitas stomata, laju transpirasi dan laju fotosintesis, jumlah daun, luas daun, luas daun spesifik, dan kandugan minyak per tanaman, serta meningkatkan luas permukaan akar dan kandungan prolin per tanaman pada tanaman nilam. Lokseumawe memiliki karakteristik yang lebih toleran terhadap cekaman kekeringan dibanding varietas Sidikalang. Hasil minyak tertinggi berturut-turut varietas Lhoksemawe, Tapaktuan dan Sidikalang sedangkan Bio-4 memiliki rendemen minyak paling rendah.
Patchouli (Pogostemon cablin Benth) is one of species which produce essential oil. It is known as Patchouli oil. In Indonesia, Patchouli oil is one of important economically. It occupies an area 24.718 ha which cultivate by 65.000 farmers in Indonesia. Yield losses from Patchouli were reported caused by global climate change (global warming). Global warming increases the effect both of frequency and intensity of El Nino which cause reduce rainfall. Low frequency and intensity rainfall, and increasing of global temperature cause the drought. Patchouli is known susceptible to drought stress. Now, there are three cultivars which produce high essential oil (290-375 kg/ha) with patchouli alcohol content about 32 – 33 %. They are Tapaktuan, Sidikalang, dan Lokseumawe. The aim of this research was evaluated resistance to drought stress degree on Patchouli cultivars. The field experiment was carried out from Nopember 2011 to Juli 2012 at the green house Research Institute for Spice and Medicine Crop, Bogor. The experimental design was laid-out in Randomized Completely Block Design with three replications as block. The experiment was involved two factors. Factor one was cultivars (Sidikalang, Lokseumawe, Tapaktuan dan Klon Bio-4). Factor two was watering- interval (once each 1, 3 , 6 and 9 days). All data were statistically analyzed using the analysis of variance procedure in SAS program to assess the differences of cultivars. Duncan’s Multiple Range Test would be tested to determine the significant differences among treatments. The details of data recorded were soil moisture, leaf water potential, relative water content, stomata conductivity, transpiration rate, photosynthetic rate, prolin content, plant height, sum of leaves, leaf area, specific leaf area, leaf area ratio, total length of root, root area, weight of root, weight of shoot, root/shoot ratio, crop growth rate and net assimilate rate, essential oil content per plant and patchouli alcohol content, and sensitivity index. The result showed that watering- interval once each nine days significantly decreased of soil moisture, relative water content, leaf water potential, stomata conductivity, transpiration rate, photosynthetic rate, prolin content, plant height, sum of leaves, leaf area, specific leaf area, and essential oil content per plant, and increased root area and prolin content. Sidikalang and Lokseumawe showed more tolerant to drought stress than Tapaktuan. The highest essential oil content per plant showed that Loksemawe, followed by Tapaktuan and Sidikalang. Bio-4 showed that the lowest essential oil per plant.
Kata Kunci : Nilam, interval penyiraman, kekeringan
