Previous work on maize and other crops has indicated that measurements of mean germination time (MGT), the reciprocal of which is the rate of germination, is a possible alternative assessment of vigour to the cold test. Emergence comparisons were made of 11 commercial seed lots from different hybrids from four different production years, over two experimental runs in unsterilised soil in growth cabinets at 13°C. The lots, all with high warm (25°C) germinations, but differing in the cold test, showed significant differences in final emergence in both runs. Emergence was significantly related to mean emergence time (MET) in soil, slower emergence being associated with lower emergence. Smaller and more variable seedlings were significantly associated with slower emergence. These differences in soil corresponded with differences in germination in moist towels. At 13oC the mean just germination rate (MJGT), calculated from the time of the first appearance of the radicle, and the mean germination rate (MGT), calculated from the 2mm radicle germination stage, were significantly correlated with measurements in soil: positively with MET, negatively with seedling size and positively with variation in seeding length. In towels, MJGT at 20°C was closely related to MJGT and MGT at 13°C and for both temperatures mean root length was lower and more variable in the slower germinating lots. The earliness and synchronicity of the first signs of germination are proposed as a determining influence on performance in soil. The view that deterioration was the cause of higher MJGT, MGT, MET (i.e. slower rates) and differences in soil in final emergence, seedling size and variation is discussed. In conclusion, there is potential for comparative measurements of mean germination time as an indicator of field emergence in maize.

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