Respons Fisiologi dan Pertumbuhan Bibit Jambu Air (Syzygium aqueum) terhadap Perbedaan Intensitas dan Spektrum Cahaya Buatan Light Emitting Diode

Abstract

Aplikasi 4 LED ungu + strip LED merah mampu meningkatkan pertumbuhan jumlah pucuk, tinggi tanaman, jumlah cabang, panjang ruas, diameter ruas, mempercepat waktu muncul pucuk pertama, namun tidak pada waktu perluasan daun. Perlakuan 4 LED ungu + strip LED biru mampu meningkatkan jumlah daun, panjang daun, dan lebar daun. Perlakuan 2 LED putih mampu meningkatkan diameter batang. Perlakuan 2 LED ungu + strip LED merah meningkatkan kandungan klorofil a dan klorofil b, sementara itu rasio klorofil a/b pada perlakuan 4 LED ungu + strip LED merah. Pada perlakuan 4 LED ungu + strip LED merah meningkatkan sintesis glukosa dan fruktosa paling banyak pada daun. Akumulasi kadar hara N, P, Mg, S, Fe, Cu, Zn, dan B dominan turun hampir di semua perlakuan, namun pada hara K, C-organik, Ca, Na, Mn, dan C/N rasio mengalami peningkatan. Perlakuan 4 LED ungu + strip LED merah mampu meningkatkan jumlah stomata, kerapatan stomata, bukaan stomata, laju transpirasi, laju fotosintesis, CO2 intraseluler dan konduktansi stomata, namun ketebalan daun pada perlakuan 4 LED putih + strip LED biru. Dominansi metabolit sekunder yang terbentuk dari penambahan LED berasal dari kelompok senyawa phenylpropanoids. LED biru meningkatkan produksi metabolit sekunder di daun jambu air dibandingkan perlakuan LED merah. Dengan demikian dari penelitian ini dominansi cahaya merah mampu meningkatkan pertumbuhan dan aspek fisiologis bibit jambu air.

Results showed that 4 purple LED + red strip supported flush amount growth, crop height, branch amount, internode length, internode diameter, first leaf time flushing, but not leaf expansion time. 4 purple LED + blue strip increased leaves amount, leaf length, leaf width. 2 white LED enhanced stem diameter. 2 purple LED + red strip promoted chlorophyll-a and b synthesis, meanwhile ratio a/b synthesis in 4 purple LED + red strip. 4 purple LED + red strip synthesized more glucose and fructose. Almost all LED treatments showed reduction in N, P, Mg, S, Fe, Cu, Zn, and B content, but not in K, C-org, Ca, Na, Mn, and C/N ratio. 4 purple LED + red strip enhanced stomatal amount, stomatal density, transpiration rate, photosynthesis rate, CO2 intracellular, and stomatal conductance, meanwhile leaf thickness in 4 white LED + blue strip. Blue LED increases total amount of secondary metabolites in Water Rose Apple Madu deli leaves and mostly identified as phenylpropanoids group. In conclusion, the role of dominance red light LED can enhance growth and physiological aspects of water rose apple seedling.