The effects of bulb storage temperature, planting date and soil temperature on the growth of Narcissus in the field

Three experiments with field-grown narcissus 'Carlton', each lasting two ye ars, were set up starting in 1995, 1996 and 1997. In each experiment there were 12 treatments, consisting of all combinations of two pre-planting stor age temperatures (pre-cooling and no pre-cooling), two planting dates (earl y and late) and three straw mulch treatments (no mulch, early mulch and lat e mulch). Treatments were applied only in the first year of each experiment , but crops were recorded and sampled in both year one and year two. The ma jor effects were those of planting date and preplanting storage temperature . Early planting, pre-cooling and early mulching consistently affected the pattern of growth and gave earlier emergence, earlier flower cropping and e arlier senescence in year one but had no effect in year two. Early planting increased and pre-cooling reduced the total number of flowers in both year s and both advanced the date of competed flower initiation ("stage Pc") in year one. The number of marketable bulbs was reduced by early planting and pre-cooling in both years, and while pre-cooling reduced total bulb weight, early planting increased it, giving more marketable bulbs in the saleable 12-16 cm circumference grades. There were positive correlations between num ber of flowers and bulb yield in year two and bulb yield in year one, indic ating that, to achieve high flower numbers and bulb yields in year two, gro wers meed to apply treatments which will maximize bulb yield in year one. T he data indicate that, by applying simple treatments, the growth of narciss us can be manipulated to alter the timing of flowers in year one and the nu mber of flowers and bulb yield in both years.