Rit Búvísindadeildar - 10.07.1996, Page 48

The Use of Unheated Plastic Greenhouses in Horticulture
SUMMARY IN ENGLISH
• In an unheated plastic greenhouse, growing early sub-varieties of carrot,
Nantes Napoli, was successful.
• Unusual varieties of horticultural crops can enhance interest in hoiticulture,
particularly in kitchen gardening. Professionals can also introduce unusual
vai'ieties to increase diversity on the market. For instance, Parisian carrots are
round in shape and small, and are considered by many to be tastier than the
more conventional varieties as e.g. Nantes. It can provide a pleasant change in
traditional cuisine to use light-yellow carrots, e.g. of the variety Palatinato.
• Cultivation of cucumbers was quite successful in unheated plastic green-
houses. This applies to all types of cucumbers: Smooth skinned cucumbers,
grape cucumbers and pickling cucumbers. Growing pickling cucumbers was
particularly successful.
• Cucumbers have to be grown in a heated greenhouse and must not be
transferred to an unheated greenhouse until night-temperature is certain not to
go below 3-4° centigrade. At Hvanneyri it has usually been safe to move the
plants to the unheated house in early June.
• The average time from planting until the first Wilma pickling cucumbers were
harvested was 32 days. The growth period was similar for most of the other
varieties.
• Some vaiieties of pickling cucumbers gave highly satisfactory results, e.g.
Lisanna, Nadina, Jolina, and Wilma. Only one variety of smooth skinned
cucumbers was tried but the yield was smaller than what the best varieties of
pickling cucumbers yielded.
• Attempts were made to grow sweet peppers, tomatoes, and summer squash,
but with poor results.
• Five varieties of leaf lettuce were tried. The plants were pre-cultivated in an
unheated plastic greenliouse and were ready to be harvested 40-60 days from
sowing.
• Eleven vaiieties of cabbage lettuce were tiied. Good results were achieved
from the following varieties: Of butterhead lettuce: Atlanta, Orestro, and
Tannex; Of crisphead lettuce: Nabucco, and Webbs Wonderful; Of Batavia
lettuce: Hanson Improved.
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