Variations in pod detachment forces in Arachis hypogaea forecast the most suitable conditions for mechanical harvesting

AbstractPeanut cultivation is regaining interest in Italy due to its agronomic and nutritional value, but profitable production requires well-defined practices that ensure efficient harvesting. In this context, one of the most affordable approaches for mechanised harvesting involves a two-phase process: first, plants are dug from the soil and left drying naturally, then pods are separated from vines. In this perspective, it remains crucial to investigate whether morphological traits of the plant affect the detachment forces between pods, peduncles, and vines, which influence harvest losses. The study investigated the effects of two planting densities and inoculation with Azotobacter spp. bacteria on yield, maturation, and detachment forces. Relevant morpho-physiological traits were sampled along the maturation phase, and A multivariate analysis of variance was performed to identify the variables most associated with tensile resistance. In addition, the productivity of the harvesting system was assessed, with particular attention to field losses. Results showed that pod moisture and peduncle length were correlated with pod-peduncle detachment forces. The peduncle-vine connection showed greater resistance than the pod peduncle one, indicating strong pod–vine attachment during digging but reduced resistance during separation, which facilitated efficient kernel separation. The application of Azotobacter spp. did not significantly affect yield or detachment forces. Average harvesting efficiency reached 85 %, although losses were greater in high-density traits. These findings contribute to defining harvest timing and crop management strategies suitable for Italian environments where peanut production is being reintroduced.Science4Impact Statement (S4IS)This study provides quantitative evidence on the temporal variation of pod detachment forces in Arachis hypogaea, demonstrating how moisture content decrease, plant morphology and agronomic management influence tensile resistance. The field measurements were conducted under optimal agronomic conditions and through standardized and scalable protocols, ensuring data robustness for further technology assessment. The results offer operational benchmarks to support manufacturers to develop new experimentation protocols for peanut harvesting and to enhance the working efficiency. At the regional scale, the findings inform decision-making processes for reintroducing peanut cultivation in Italy, fostering a more sustainable and locally integrated supply chain through evidence-based cultivation scale.