Agriculture Reference
In-Depth Information
6
The production and agronomy of onions was reviewed by Brewster (1990b)
and Bosch-Serra and Currah (2002), and tropical onion production by Currah
and Proctor (1990). Leek production was reviewed by de Clercq and van
Bockstaele (2002), and shallot production by Rabinowitch and Kamenetsky
(2002) and Messiaen
et al.
(1993); the latter authors also describe garlic
production in some depth. This chapter draws on these sources, and more
detailed bibliographies can be found in the above reviews.
Type of crop
Onions are grown for a variety of purposes, namely as fresh shoots for green
'salad' onions and as bulbs for: (i) consumption uncooked; (ii) consumption
cooked; (iii) pickling; (iv) use in factory-made food; (v) dehydration; (vi) seed
production; and (vii) sets. Particular varieties have been developed for most of
these purposes; for example, cultivars for dehydration have higher bulb dry
matter (17-20%) than the typical 10-12%. Bulbs for consumption uncooked
are frequently sweet, mild-flavoured and large, with single centres suitable for
making onion 'rings'. A particular type for pickling is the small, white-skinned
'silverskin'. Special cultivars are usually used for salad production and for sets.
On the other hand, bulbs for the pickling, cooked consumption, the large
'jumbo' bulb market and for use in food manufacturing could be the small,
medium, large and damaged grades, respectively, from a crop of the same
cultivar. Normally though, bulb production is targeted at one of these outlets
by controlling bulb size by varying the plant density of the crop.
