Study on Physico Engineering Properties of Cotton Seed for Designing of Metering Mechanism of Pneumatic Planter

Abstract

Understanding the physical properties of seeds is essential for designing efficient seed metering systems in precision planting. This study focuses on the characterization of Bt cotton seeds (variety: Rudra-666), widely cultivated in Andhra Pradesh, to assist in the development of a robotic pneumatic planter (Bapatla, Andhra Pradesh, Jun-Jan). A total of 100 seeds were analysed under laboratory conditions. The average length, width, and thickness of the seeds were 8.94 mm, 4.48 mm, and 4.69 mm, respectively. The arithmetic mean diameter was 6.04 mm, and the geometric mean diameter was calculated as 5.86 mm. The seeds exhibited a sphericity of 64.11% and an aspect ratio of 50.10%, indicating a moderately elongated shape. The 100-seed weight was recorded at 10.4 grams. Bulk density and true density were found to be 733.02 kg/m³ and 1038.4 kg/m³, respectively, with a porosity of 29.40%. The angle of repose measured at 41.40°, reflecting fair flowability of the seeds. The terminal velocity was recorded at 8.01 m/s, relevant for pneumatic separation and delivery. The moisture content ranged from 7.05% to 8.60%, with an average of 7.83% on a wet basis. These parameters provide critical input for optimizing the seed handling and placement systems in robotic and precision-based sowing technologies.