Cabbage, lentil, pepper and tomato seed germination monitored by an image analysis system

An image analysis system is applied to study the imbibition time - course in cabbage, lentil, pepper and tomato seeds. The measurement software determined for each seed an area and a roundness factor as descriptors of seed size and shape, respectively. Using the area parameter, the swelling process for all four seed species was described by a series of curves in which Phase I and Phase 11 of the triphasic water uptake pattern could be distinguished. Limits between Phase 11 and Phase 111, when radicle protrusion and elongation take place, can be determined by analyzing the seed images with the roundness factor, which increases rapidly when seed shape changes following radicle growth. The close correlations established between the normalised values of the roundness factor and radicle length, detected for a single seed from emergence to 1.5-2.0 mm extent, indicated that the seed shape descriptor could be used to estimate indirectly radicle elongation at the beginning of the 'visible germination'.