Paclobutrazol and planting density improved onion growth, reduced lodging and enhanced seed yield and quality in mid-hills of Himachal Pradesh.

To address the increasing demand for Onion globally, enhancing seed production is crucial. In India, mid hill regions of Himachal Pradesh offer favorable conditions for onion seed production. The experimental site in Himachal Pradesh is located at an altitude of 1183 m above mean sea level in the mid-hill sub-humid temperate agro-climatic zone. The region is characterized by mild summers and cool winters, receiving an average annual rainfall of 1000-1300 mm. During the growing season, the maximum temperature ranges from 27.1 to 29.0 °C while the minimum temperature varies between 1.5 °C and 19.4 °C. However, frequent lodging of scapes due to western disturbances hampers seed yield and quality. A two-year field study (2022-2023 and 2023-2024) evaluated the efficacy of paclobutrazol (PBZ) bulb dipping as a solution in onion cv. Palam Lohit. Evidence from study indicated that bulb dipping in 100 ppm PBZ for 18 h + spacing 30 × 30 cm (T12), yielded optimal outcomes. This treatment led to reduced seed scape height (71.42 cm), enhanced leaf greenness (83.39 SPAD), delayed flowering (131.67 days) and minimized lodging (18.92%). Moreover, it achieved the highest plot yield (156.00 g) and economic return with a benefit-cost ratio of 3.26:1. Thus, bulb dipping in 100 ppm PBZ for 18 h + spacing 30 × 30 cm (T12) is recommended to enhance onion seed yield and quality under challenging ago- climatic conditions, after multi-location validation.