Effect of Bulb Size on the Growth of Tulips

A study of the growth in the field of tulip plants from bulbsof four different sizes showed marked differences of leaf areaand shoot dry weight, those produced by larger bulbs being thegreater. Relative growth rates of the smaller plants were higherthan those of the large ones; this was due to different proportionsof total plant weight being non-growing mother bulb, as therelative growth rates of the shoots were not affected by bulbsize. The relative growth rates of daughter bulbs were alsounaffected by the mother bulb size, being very similar to previouslydetermined values in other sites and seasons. The final bulbyield was proportional to daughter bulb weight early in theseason. It is suggested that daughter bulb weight, shoot weight,and leaf area are directly related to the size of the motherbulb, and controlled by the factors determining mother bulbsize during its development.