IMPROVING FORCING ABILITY – THE BREEDER’S CONTRIBUTION

Forcing ability can be defined as the amount of dry matter in the aerial parts of the plant at the time of flowering, in relation to the number of days needed for forcing.
An important, but quite separate quality criterion is the length of the flowering stem at the time of flowering.

On the basis of an analysis of growth and development of twelve cultivars, forced at five different temperatures, a ‘model’ could be drawn up describing the mobilization of the dry matter present in the planted bulb, its increase (throught assimilation) and its decrease (through respiration) and its distribution over sprout and newly formed daughter bulbs.
The individual components of forcing ability were reviewed and their value as a pre-selection parameter or as a criterion for selection of breeding partners is discussed.

Prospects for improvement of forcing ability through breeding depend on:

• the range of variation of individual components within the available breeding material

• the degree to which they inherit additively and independently

• the possibility to increase their variation through interspecific crosses.

IV International Symposium on Flower Bulbs

L.D. Sparnaaij, J.P. van Eijk, L. Smeets

https://doi.org/10.17660/ActaHortic.1986.177.54