Respons fisiologis tanaman kentang terhadap jenis zat pengatur tumbuh pada berbagai kondisi cekaman kekeringan di dataran medium

Sari Peningkatan suhu global akibat peningkatan konsentrasi CO2 di atmosfer sangat berpotensi terjadi cekaman kekeringan pada tanaman kentang. Fenomena ini dapat mempengaruhi proses fisiologis tanaman. Zat Pengatur Tumbuh (ZPT) asam salisilat dan paclobutrazol mampu memberikan perlindungan bagi tanaman terhadap cekaman kekeringan melalui serangkaian proses fisiologis seperti peningkatan aktivitas fotosintesis. Penelitian ini bertujuan untuk mengetahui interaksi antara ZPT dan cekaman kekeringan serta memperoleh jenis ZPT dan kondisi cekaman kekeringan yang masih mampu menghasilkan karakter fisiologis tanaman kentang terbaik di dataran medium. Percobaan bertempat di Kebun Percobaan Ciparanje, Jatinangor, pada ketinggian 685 m di atas permukaan laut. Rancangan percobaan yang digunakan adalah rancangan petak terbagi. Petak utama terdiri dari interval penyiraman 1, 4, 8, dan 12 hari, sedangkan anak petak terdiri atas tanpa ZPT, asam salisilat, paclobutrazol, serta kombinasi asam salisilat dan paclobutrazol. Setiap perlakuan diulang sebanyak 3 kali. Hasil penelitian menunjukkan bahwa tidak terdapat pengaruh interaksi antara jenis ZPT dengan cekaman kekeringan terhadap seluruh parameter fisiologis. Penambahan ZPT paclobutrazol mampu menghasilkan respons terbaik terhadap konduktansi stomata serta suhu kanopi. Sementara itu, tanaman kentang pada 9 MST masih mampu memberikan respons fluoresensi klorofil terbaik hingga interval penyiraman 4 hari.Kata kunci: Kentang ∙ Cekaman kekeringan ∙ Asam salisilat ∙ Paclobutrazol Abstract. The rising of CO2 concentration increases global temperature. This phenomenon potentially causes drought stress in potato plant and lead to interfere its physiological process. Plant growth regulator (PGR) such as salicylic acid and paclobutrazol are expected to protect the plant due to the drought stress through improving photosynthesis activity. This study aimed to understand the interaction between PGR and drought stress; and find out the types of PGR and drought stress condition which are able to provide the best physiological responses of potato plant in medium altitude. The experiment was conducted in Ciparanje Experimental Field, Jatinangor, at an altitude 685 m above sea level. Split plot design was used as the experimental design. The main plot was watering interval, consisted of 1, 4, 8, and 12 day; while the subplot was PGR treatment, consisted of non-PGR, salicylic acid, paclobutrazol, and the combination of salicylic acid and paclobutrazol. All of the treatments were replicated for 3 times. The results showed that interactions were not occurred between PGR and drought stress to all physiological parameters. The treatment of paclobutrazol exhibited stomatal conductance and canopy temperature. Meanwhile, the potato plant showed good responses on chlorophyll fluorescence 9 WAP until 4 days watering interval.Keywords: Potato ∙ Drought stress ∙ Salicylic acid ∙ Paclobutrazol