Narcissus and Daffodil

100 G.R. Hanks
respond to ethylene or smoke treatments with faster or better flowering (Imanishi,
1983; Imanishi and Ohbiki, 1986).
Tazetta bulbs can be converted to summer crops to provide a means of bulb
production where they are not naturally hardy (Tompsett, 1988; ADAS, 1989a).
This involves warm-storage techniques for retarding flowering: bulbs were stored
at 30 °C over winter and then for 4 weeks at 25 °C before planting outdoors in
March, producing satisfactory yields in south-west England when bulbs were lifted
in late-October. The technique was also used successfully in eastern England (G.R.
Hanks, unpublished data). In the Netherlands, bulbs imported from Israel were
stored at 30 °C from receipt until planting in spring. The best bulb yields were
obtained when bulbs were planted in April to May and harvested in late-October
(van der Weijden, 1988; Vreeburg and Korsuize, 1989; Vreeburg and Dop, 1990).
Bulbs could be stored at 2 °C instead of 30 °C, but prolonged cold storage resulted
in damage to the leaves.
While Tazetta narcissus are resistant to base rot, serious losses have been
reported in Israel due to the nematode Aphelenchoides subtenuis (Mor and Spiegel,
1993). The nematode infects the roots and secondary infections of fungi such as
Fusarium cause bulb rotting, giving the syndrome the name ‘basal plate disease’. In
the Isles of Scilly the nematode Pratylenchus penetrans can attack narcissus bulbs,
leading to a ‘root rot’ in conjunction with the fungus Nectria radicicola.
Production of dwarf and small-bulbed cultivars and Narcissus species
The importance of dwarf and small-bulbed narcissus, such as Cyclamineus, Jonquilla
and Triandrus types, was referred to in the section on production statistics. Many
of these types have small bulbs, requiring the use of sandy soils to facilitate bulb
lifting, and requiring more labor-intensive bulb handling generally. It may be
appropriate to modify equipment designed for handling small bulbs like freesias
or onion sets. Many are relatively ‘delicate’ or, like ‘Tête-à-Tête’, are prone to
diseases such as Penicillium rots, skin diseases or smoulder (van der Weijden,
1989). The production of these types therefore requires extra care in pesticide use
and in drying and storing bulbs, and examples have already been cited in the
section on the production of standard narcissus bulbs.
There is very little commercial production of Narcissus species and it is limited to
specialist nurseries, but bulbs of many species have been exported from Mediterranean
countries, especially Portugal (Oldfield, 1989). Several Narcissus species are
considered to be under threat as a result of over-collecting or loss of habitats
(Koopowitz and Kaye, 1990). Commercial bulb companies are now very aware of
the environmental implications of trading wild-collected bulbs, and, because of
consumer interest in these attractive species, there would be scope for commercial
production if appropriate, sustainable farming methods and stocks were available
(Hanks and Mathew, 1997).
Integrated crop management and organic production
At the present time the demand for more ‘environmentally friendly’ or ‘organic’
production of ornamental crops is in its infancy, but is probably inevitable that it
will increase, following trends in food crops, particularly as multiple retailers