ChileanJAR

Eight spring wheat genotypes classified in pairs according to mature plant height as tall, standard, semi-dwarf and dwarf, were studied at two leve1s of temperature, 14 and 24°C, and three depths of planting, 5 -7,5 - 10 cm., to determine the effect of these factors on coleoptile elongation.
Both tall varieties had the longest coleoptiles, while the semi-dwarfs developed coleoptiles which were significantly the shortest. When the temperature was increased from 14 to 24°C the average length of this structure increased significantly. Both standard varieties elongated their coleoptiles comparatively more; one semi-dwarfincreased while the other decreased its coleoptile length when the temperature was raised.
Emergency rate indexes (ERI) were 42% lower at 14°C. When depth of planting was increased the ERI decreased 66% at 14°C, and between 26 and 28% at 24°C. A negative correlation was found between the percent emergence and depth of planting, -.77667 at 14°C and -.92878 at 24°C. The tall and standard genotypes had the highest ERI. A positive association was found between mature plant height and ERI, as well as between coleoptile length and ERI. A positive correlation was also found between mature plant height and coleoptile length, highly significant at 24°C for the three depths of planting.