<![CDATA[ABSTRACT This study aims to examine the effect of giberalin ZPT concentration and duration of irradiation on the growth and yield of chrysanthemum (Chrysanthemum morifolium) cut flowers. The study took place in February - June 2018. The study was conducted in Mendongan Village, Sumowono District, Semarang Regency, Central Java. ABSTRACT This study aimed to examine the effect of giberalin concentration and duration of irradiation on the growth and yield of chrysanthemum (Chrysanthemum morifolium) cut flowers. The study took place in February - June 2018. The study was conducted in Mendongan Village, Sumowono District, Semarang Regency, Central Java. The design used in the study was a Completely Randomized Factorial 4x4 Design. The first factor was gibberallin treatment consisted of G1: GA 0 ppm, G2: GA 10 ppm, G3: GA 20 ppm, G4: GA 30 ppm. The second factor was the irradiation time consisted of R1: 1 hour irradiation time, R2: 2 hours irradiation time, R3: 3 hours irradiation time, and R4: 4 hours irradiation time. Parameters observed were plant height, stem diameter, number of leaves, leaf area, number of flowers, flower diameter, flowering age and flower harvesting age.The results showed that the treatment of giberalin concentration significantly affected the parameters of the amount of interest. While the irradiation treatment time significantly affected the parameters of plant height, number of leaves, flower diameter, stem diameter, age of flowering, and leaf area. Keywords: Giberalin, Chrysanthemum, Irradiation Period ABSTRAK Penelitian ini bertujuan untuk mengkaji pengaruh konsentrasi ZPT giberalin dan lama penyinaran terhadap pertumbuhan dan hasil bunga potong tanaman krisan (Chrysanthemum morifolium). Penelitian berlangsung pada bulan Februari - Juni 2018. Penelitian dilakukan di Desa Mendongan, Kecamatan Sumowono, Kabupaten Semarang, Jawa Tengah. Rancangan yang digunakan dalam penelitian adalah Percobaan Faktorial 4x4 Rancangan Acak Lengkap (RAL). Faktor pertama yaitu perlakuan giberalin sebanyak 4 taraf yaitu G1 : GA 0 ppm, G2 : GA 10 ppm, G3 : GA 20 ppm, G4 : GA 30 ppm. Faktor kedua adalah lama penyinaran dengan 4 taraf yaitu R1 : lama penyinaran 1 jam, R2 : lama penyinaran 2 jam, R3 : lama penyinaran 3 jam, dan R4 : lama penyinaran 4 jam. Parameter yang diamati adalah tinggi tanaman, diameter batang, jumlah daun, luas daun, jumlah bunga, diameter bunga, umur berbunga dan umur panen bunga. Hasil penelitian menunjukkan bahwa konsentrasi giberalin berpengaruh nyata terhadap peningkatan jumlah bunga yang bertambah banyak. Sedangkan lama penyinaran berpengaruh nyata terhadap peningkatan tinggi tanaman, jumlah daun, diameter bunga, diameter batang, umur berbunga, dan luas daun. Kata Kunci :Giberalin, Krisan, Lama Penyinaran]]>
