Effectivity of X-ray test to evaluate the physiological quality of sesame seeds due to fruits position at the plant

Abstract

The IAC-Ouro sesame cultivar has recently expanded to Brazilian Northeast, but the studies related to physiological quality and vigor of seeds produced under these conditions are scarce yet. Due to difference in fruits maturity from different parts of the plant, the aim of this study was to relate X-ray images with the seed maturation degree and evaluate the quality of seeds from fruits located on the lower, middle and upper third of the stem. We growth the sesame in an experimental area and harvest the fruits from different positions at 103 days after sown. Seeds were taken out from fruits and evaluated through the following tests at laboratory: germination test, germination first count, germination speed index and germination average time, dry mass of 1,000 seeds, seedling dry mass, electrical conductivity and X-ray test. The seeds of fruits from lower plant third showed similar quality to the middle plant third, while the upper plant third fruits provided seeds less vigorous. The X-ray test was efficient in evaluating the degree of maturation of seeds, indicating a better quality of seeds from the lower and middle third of the plant, verified by more radiopacity. The fruits from the bottom of stem develop first, and therefore, are the first to mature, which can be harvested early, without loss of seeds quality and vigor.