Radiographic analysis to test maize seeds for the presence of Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract

Examining seeds for insect infestation is one of the requirements established by the Brazilian standards for the release of seed lots. The traditional methodology prescribed in the Rules for Seed Analysis involves soaking and cutting of individual seeds which is time consuming, leads to visual fatigue and jeopardises the analyst's safety. Radiographic imaging analysis is an excellent method to detect insect infestation, both externally and internally to the seeds, and may be a viable alternative to the traditional methodology. The aim of this study was to evaluate the use of the radiographic analysis to test for infestation by the weevil Sitophilus zeamais (Coleoptera: Curculionidae) in maize seeds. The radiographic analyses were evaluated by 40 seed analysts, belonging to 10 laboratories, accredited by the Ministry of Agriculture, Livestock and Supply (MAPA), which received radiographs of maize seeds from four samples with 0, 1, 3 and 5% infestation. The data were submitted to statistical procedures for withdrawal of discrepant values and outliers in the variances; to evaluate the effects of laboratories and levels; to estimate repeatability and reproducibility; and to verify the accuracy and robustness. The methodology proposed showed accuracy, robustness and precision within the critical limits of 0.01 and 0.05%.