Pengaruh Pemberian Paclobutrazol terhadap Pertumbuhan dan Produksi Dua Varietas Sorgum (Sorghum bicolor L.)

Abstract

JAY ANSHORI PARDOMUAN SIREGAR: The Effect of Paclobutrazol Application on Growth and Production of Two Sorghum Varieties (Sorghum bicolor (L.). (Under the guidance of Chairani Hanum). Sorghum is a crop with great potential for cultivation in Indonesia. However, sorghum cultivation shows that varieties with excessive plant height tend to experience lodging. This study aimed to determine the effect of paclobutrazol application on the growth and production of two sorghum varieties. The research was conducted in Kampung Lalang Village, Sunggal District, Deli Serdang Regency from June to October 2025. The study used a Split Plot Design with two treatment factors: sorghum varieties (Super 1 and Super 2) as the main plot and paclobutrazol concentrations (0, 600, 1200, and 1800 ppm) as subplots with three replications. The results showed that the Super 2 variety had a longer flowering time (90.13 days), higher root fresh weight (194.02 g), and higher panicle weight per plot (1732.55 g) compared to Super 1. Paclobutrazol application significantly reduced plant height by up to 25.9%, decreased leaf number and leaf area, and reduced shoot fresh weight. The concentration of 1800 ppm provided the highest vegetative growth suppression with plant height reaching only 194.69 cm at 9 weeks after planting. There was no significant interaction between variety and paclobutrazol concentration on all observed parameters. Paclobutrazol was effective in suppressing plant height without reducing sorghum production compared to the control treatment.