Tanggapan Fisiologi Tanaman Tembakau Temanggung terhadap Dosis Pupuk Nitrogen serta Kaitannya dengan Hasil dan Mutu Rajangan - . Djumali (Balai Penelitian Tanaman Pemanis dan Serat, 2012)
Tembakau temanggung merupakan tembakau lokal yang berkadar nikotin tinggi. Ketersediaan hara N dalam tanah dapat mempengaruhi hasil dan kandungan nikotin rajangan kering. Percobaan dilakukan di rumah ka-ca Balittas Malang selama Maret–Agustus 2009. Perlakuan terdiri atas 6 dosis pupuk N (0; 1,62; 3,64; 4,86; 6,48; dan 8,10 g N/tanaman) disusun dalam rancangan acak kelompok dengan 3 ulangan. Setiap perlakuan dalam satu ulangan terdiri atas 4 pot dan setiap pot diberi pupuk dasar 2,70 g P2O5 + 1,35 kg pupuk kandang. Hasil penelitian menunjukkan bahwa peubah fisiologi tanaman (kandungan N-daun, klorofil, bobot spesifik daun, laju fotosintesis, respirasi, efisiensi cahaya mereduksi CO2 (EF0), dan koefisien respirasi pemeliharaan daun (KRPD)), hasil rajangan kering, dan kandungan nikotin tembakau temanggung dipengaruhi oleh dosis pu-puk N dengan membentuk kurva kuadratik tertutup, dosis maksimum masing-masing sebesar 7,89; 7,89; 54,75; 9,50; 26,25; 21,50; 10,00; 6,08; dan 6,86 g N/tanaman. Peubah fisiologi tanaman yang paling menen-tukan hasil rajangan kering berturut-turut adalah klorofil, N-daun, laju respirasi, dan bobot spesifik daun. Adapun peubah fisiologi tanaman yang paling menentukan kandungan nikotin berturut-turut adalah fotosin-tesis, KRPD, respirasi, dan kandungan klorofil. Physiological Responses of Temanggung Tobacco to Dose of Nitrogen Fertilizer and Its Relationship with Dry Slice Yield and Nicotine Content ABSTRACT Temanggung tobacco is a local tobacco, with high nicotine content. Nitrogen available in soil affects dry sliced yield and nicotine content. The experiment was conducted in glasshouse of IToFCRI Malang from March–August 2009. The treatment consist of six levels of N fertilizer (0, 1.62, 3.64, 4.86, 6.48, and 8.10 g N/plant), were arranged in randomized block design with three replications. Every threatment in one repli-cation received 2.70 g P2O5 + 1.35 kg manure. The results showed that physiological plant parameters (N-leaf, chlorophyll content, specific leaf weight, photosynthesis rate, respiration rate, light efficiency to CO2 re-duction (EF0), and coefficient of leaf maintenance respiration (CLMR)), dry slice yield, and nicotine content were affected by N rates. The response of these parameters on N fertilizer were expressed by closed qua-dratic curves, which maximum rate of N fertilizer were 7.89, 7.89, 54.75, 9.50, 26.25, 21.50, 10.00, 6.08, and 6.86 g N/plant respectively. Dry sliced yield were affected by chlorophyll content, respiration rate, and specific leaf weight. Nicotine content were affected by photosynthesis rate, CLMR, respiration rate, and chlo-rophyll content.