The growth and yield of shallot (Allium Cepa L. var. aggregatum) bima brebes variety from TSS due to plasma radiation combined with paclobutrazol

True Shallot Seed (TSS) technology offers an alternative strategy for enhancing the quality of shallot seeds. However, the use of TSS as a substitute for tuber seeds still encounters challenges in terms of growth and yield. Plasma radiation technology and the application of paclobutrazol are innovative agricultural approaches that can potentially accelerate growth and boost shallot production. This study aimed to assess and determine the optimal plasma radiation exposure time and paclobutrazol concentration to improve the growth and yield of shallots cultivated from TSS. The research was conducted from August to November 2024 in the laboratory of Plasma Laboratory, Department of Physics, Faculty of Science and Mathematics, Diponegoro University, Semarang and the Installation of Testing and Application of Agricultural Instrument Standards (IP2SIP) Ungaran. The experiment utilized a 6 x 5 factorial arrangement within a Completely Randomized Design (CRD) with five replications. Cold Atmospheric Pressure Plasma and a paclobutrazol solution were used as treatments. The first factor was the duration of plasma radiation, with six levels: R0=Control (no radiation), R1=5 minutes, R2=10 minutes, R3=15 minutes, R4=20 minutes, and R5=25 minutes. The second factor was the paclobutrazol concentration, with five levels: P0=Control (no paclobutrazol), P1=0.25 ml/L, P2=0.50 ml/L, P3 = 0.75 ml/L, and P4=1.00 ml/L. Data were analyzed using ANOVA, and significant results were further examined using Duncan’s Multiple Range Test. The findings revealed that 15 minutes of plasma radiation combined with 0,50 ml/L paclobutrazol significantly improved the growth and yield of Bima Brebes shallots.