Narcissus and Daffodil

62 G.R. Hanks
lost, resulting in the production of many offsets. The disorders ‘chocolate spot’
and ‘root rot’ may have the appearance of fungal diseases, but no pathogen has
been associated with them. Finally, there are a number of disorders in flower development,
resulting in the death or deformity of the flower bud or floral organs.
STANDARD PRODUCTION OF NARCISSUS BULBS IN THE FIELD
Planting material
In obtaining bulbs as planting material, the potential grower needs to consider
cultivar, source and quality, and bulb grade.
Cultivars
Although many narcissus cultivars are grown, few are cultivated in significant
amounts, so stocks of relatively few cultivars can be obtained in quantity. The choice
of planting stock will depend on the characteristics required (e.g., flower quality
or galanthamine concentration) and the amount of biomass produced, linked with
the price of different cultivars; these aspects are considered in Chapter 10 of this
volume. General sources of information on the main commercial cultivars grown
include ADAS (1982b, 1985a) and IFC (undated). The classified list of narcissus
names is published by the Royal Horticultural Society (RHS), the International
Registration Authority for the genus (Kington, 1998). The American Daffodil Society
(ADS) publishes an abridged list (Throckmorton, 1989) and an illustrated database
on CD (ADS, in press). Data from cultivar trials have been reported from the
UK (Fry and Shepherd, 1961; ADAS, 1963, 1967, 1971; Hanks, 1994a; Hanks and
Withers, 1998), Czechoslovakia (Petrová, 1983), Germany (Loeser, 1979), Poland
(Szlachetka, 1989) and the USA (Nelson, 1988). Dutch information on narcissus
cultivars appears in the annual guide Narcissengids, published by the Coöperatieve
Nederlandse Bloembollencentraal, Lisse, and in the descriptive lists of ornamental plant
cultivars issued by RIVRO (the National Institute of Crop Variety Research).
Further information appears in articles in the periodicals Bloembollencultuur,
HOBAHO and Vakblad voor de Bloemisterij. There are several public collections of narcissus
cultivars in the Netherlands, including the CNB-Showtuin ‘Hein Schrama’
(Heemstede), Narcissen Showtuin K.J. van der Veek (Burgervlotbrug), HOBAHO
Keurtuin ‘De Buitenhof’ (Lisse) and ‘Hortus Bulborum’, a collection of old cultivars
(Limmen) (P.J.M. Vreeburg, personal communication). In the UK, bulb cultivars
are displayed at Springfields Garden (Spalding) and are trialled at the RHS garden
at Wisley, while there are a number of private collections under the aegis of the
National Council for the Conservation of Plants and Gardens (NCCPG, 1999).
Bulb source and quality
Bulbs may be obtained by private sales or from auctions, or may be grown under
contract arrangements. Obviously, a reputable source should be used to ensure
trueness-to-type and quality, and, if possible, the stock should be inspected during
the previous growing season. Stocks should be checked for the main pests and