Heat treatment for fruit drying and insect control in Prosopis chilensis

Abstract

Prosopis pods must be dried to favour mechanical thrashing and reduce moisture before storage. Pods should be treated to remove all field-infecting insects before storage.

The aim of this work was to assess a single-step method that may control both insects and moisture for thrashing and storage without affecting viability and vigour, by means of heat. For the treatment, pods were exposed to rising temperatures of 40°, 50°, and 60°C in a stove, every forty-eight hours. Next, pods were mechanically thrashed, and the seeds obtained were separated under a binocular lens into both healthy and infested seeds. The healthy seeds were used for germination and accelerated aging tests, while the infested seeds were stored in a breeding chamber at 25°C for 7 months. It was found that this treatment consistently reduced and/or delayed bruchid emergence affecting the seeds. On the other hand, this technique allows, in a single step, moisture reduction for efficient thrashing and safe seed storage. In both germination and accelerated aging tests, significant differences (P ≤ 0.05) between treated and control seeds were found, as a result of the higher percentage of hard seeds in the treated group, which remain viable.