Respons Fisiologis dan Pertumbuhan Tembakau (Nicotiana tabacum L. ‘Manilo’) terhadap Pemberian Pupuk Urea dan Cekaman Salinitas

Jovanka, Prof. Dr. Diah Rachmawati, S.Si., M.Si.

2026 | Skripsi | BIOLOGI

Tembakau merupakan salah satu tanaman non-pangan yang paling banyak dibudidayakan di dunia, termasuk Indonesia sebagai salah satu negara penghasil terbesarnya. Produksi tembakau masih belum optimal akibat cekaman salinitas, sehingga dilakukan pemberian pupuk urea sebagai sumber nitrogen untuk mengurangi dampak negatif sekaligus meningkatkan ketahanan tanaman. Pada penelitian ini dilakukan analisis pertumbuhan dan respons fisiologis tanaman tembakau (Nicotiana tabacum L. ‘Manilo’) pada kondisi salinitas. Perlakuan yang diberikan berupa variasi pemberian dosis pupuk urea dan NaCl pada media tanam. Penelitian dilakukan menggunakan metode Rancangan Acak Lengkap Faktorial dengan pemberian pupuk urea (0,6 g, 1,2 g, dan 1,8 g per 5 kg media tanam) serta pemberian NaCl (0 g, 0,75 g, dan 1,5 g per 5 kg media tanam). Parameter pengamatan meliputi Kadar Air Nisbi (KAN), Indeks Stabilitas Membran (ISM), aktivitas superoksida dismutase (SOD), kadar H2O2 daun, kadar klorofil dan karotenoid, kadar prolin daun, keberadaan alkaloid daun, tinggi tanaman, jumlah dan luas daun, berat basah, berat kering, serta rasio akar-tajuk. Data yang diperoleh kemudian dianalisis menggunakan ANOVA, diikuti uji Duncan dengan taraf signifikansi 95% (p = 0,05). Hasil menunjukkan bahwa pemberian pupuk urea dapat meningkatkan ketahanan tanaman tembakau ‘Manilo’ terhadap cekaman salinitas. Pemberian pupuk urea berpengaruh positif terhadap kondisi fisiologis tanaman yang ditunjukkan dengan peningkatan persentase KAN, ISM, dan aktivitas SOD serta penurunan kadar prolin dan kadar H2O2 tanaman. Pemberian pupuk urea juga meningkatkan tinggi tanaman, jumlah daun, luas daun, berat basah, dan berat kering. Dosis optimal pupuk urea, yaitu 1,2 g/5 kg media tanam untuk mempertahankan tembakau dalam cekaman salinitas.

Tobacco is one of the most widely cultivated non-food crops globally, with Indonesia being among its primary producing country. Tobacco production remains suboptimal due to salinity stress, necessitating the application of urea fertilizer as a nitrogen source to mitigate the adverse effects and enhance plant tolerance. This study analyzed the growth and physiological responses of tobacco (Nicotiana tabacum L. ‘Manilo’) under saline conditions. Treatments consisted of varying doses of urea fertilizer and NaCl within the growing medium. The experiment employed a Factorial Completely Randomized Design, featuring urea applications of 0.6 g, 1.2 g, and 1.8 g per 5 kg of growing medium, along with NaCl treatments of 0 g, 0.75 g, and 1.5 g per 5 kg of growing medium. Observation parameters included Relative Water Content (RWC), Membrane Stability Index (MSI), superoxide dismutase (SOD) activity, leaf H2O2 content, chlorophyll and carotenoid contents, proline content, leaf alkaloids availability, plant height, leaf number and area, fresh weight, dry weight, and root-to-shoot ratio. Data were analyzed using ANOVA followed by Duncan's Multiple Range Test at a 95% significance level (p = 0.05). The results demonstrated that urea fertilizer application enhances the resilience of the Manilo tobacco variety under salinity stress. Urea application positively influenced plant’s physiological status, as evidenced by increased RWC, MSI, and SOD activity, along with reduced proline and H2O2 content. Additionally, urea application increases plant height, leaf number, leaf area, fresh weight, and dry weight. The optimal urea dose to sustain tobacco under salinity stress was determined to be 1.2 g/5 kg of growing medium.

Kata Kunci : pupuk urea, respons fisiologis, salinitas, tembakau