Lettuce seeds are small with little mass and irregular shape and thus pelletization is the form used to facilitate their distribution and handling. Although the technique has been known for many years, little has been studied on the methods for assessing seed physiological quality after this treatment. The objective of this study was to compare the efficiency of some tests in assessing the vigor in loose and pelletized lettuce seeds. Six batches of loose and pelletized seeds of the Regina and Vera cultivars were used and the germination, first counting, accelerated aging, osmotic solution and germination speed index tests were applied. A completely randomized block design was used with four replications and the means were compared by the Tukey test at 5% probability. The pelletized seeds presented less vigor than the loose seeds. The accelerated aging, osmotic solution (-0.25 MPa) and the germination speed index were efficient in stratifying loose lettuce seed batches for vigor and are also recommended for use on pelletized seeds. However, pelletization can influence the results, requiring adaptations to the methodology for use in comparison among loose and pelletized seeds.
Lactuca sativa; physiological quality; pellets; vigor tests
