SEED SCIENCE AND TECHNOLOGY, cilt.36, sa.1, ss.21-30, 2008 (SCI-Expanded)
The high emergence and uniform seedling size required for glasshouse production of modular transplants of peppers is not always achieved due to vigour differences among commercial seed lots. The mean germination time (MGT) at IS and 25 degrees C was determined in laboratory germination tests for 11 lots of the cultivar Demre and found to be related to seedling size (root and hypocotyl length) and variation. The longer the MGT (germination slower and more spread in time) the smaller and more variable the seedlings. MGT at both temperatures was also related to mean emergence time (MET) in transplant modules in two experimental runs. In turn, MET was related to mean seedling weight (R-2 = 0.72, R-2 = 0.75, p<0.001 for fresh weight and R-2 = 0.83, p<0.001; R-2 = 0.68, p<0.01 for dry weight) in both runs. Slow germinating lots (high MGT) were slower to emerge in modules (high MET) and produced smaller seedlings. The MGT at 25 degrees C of five further lots of Dentre was related to MET in modules (R-2 = 0.84, p<0.05). MGT and MET were both inversely related to the variation in fresh weight of individual seedlings (MGT: R-2 = 0.79, p<0.05; MET: R-2 = 0.96, p<0.01) and variation in dry weights (MGT: R-2 = 0.74, NS; MET: R-2 = 0.89, p<0.05). Germination after controlled deterioration (CD) for the five lots was inversely related (R-2 = 0.93, p<0.01) to MGT indicating that seed ageing was a cause of low vigour and high MGT. The need for repair of deterioration is discussed as a possible explanation of differences in MGT and performance in modules.