Assessment of Mechanical Harvesting Performance in Castor Cultivation: Identifying Operational Challenges

This is the authors' abstract. We don't add key points for this paper.

Castor (Ricinus communis L.) is a high-value industrial crop widely utilized in bio-based applications, primarily due to its high oil content and strong adaptability to marginal environments. Despite its significant agronomic potential, the large-scale cultivation of castor is currently limited by critical constraints in mechanical harvesting. These limitations hinder the development of efficient supply chains necessary for the bioeconomy. This study evaluates the feasibility of mechanically harvesting castor under real agricultural conditions. Specifically, the research focuses on identifying key operational and mechanical constraints during the harvesting process and assessing overall harvesting performance based on seed integrity, biomass residues, and field efficiency. Field trials were conducted utilizing adapted combine harvesting systems, involving the systematic adjustment of key machine parameters, specifically cutting height, threshing intensity, and forward speed. The field trials demonstrated that mechanical harvesting is technically feasible, although the process is not yet fully optimized. Seed integrity was generally maintained throughout the process, confirming the crop's suitability for industrial use post-harvest. However, critical bottlenecks were observed, including variable harvesting efficiency caused by uneven ripening, biomass accumulation negatively affecting machine performance, and significant seed losses linked to capsule shattering. Overcoming these harvesting barriers has profound implications for the broader bioeconomy, enabling the scaling-up of castor production for bio-based industries and significantly reducing labor dependency.