FOR RELEASE: April 7, 1997
Contact: Blaine P. Friedlander, Jr.
Office: (607) 255-3290
Internet: [email protected]
Compuserve: Larry Bernard 72650,565
http://www.news.cornell.edu
ITHACA, N.Y. -- What started as a casual screening of raspberry varieties
in the greenhouse grew into a graduate student class project and may soon
blossom into a large-scale, full-fledged agricultural industry for New
York: fresh, sweet raspberries in winter.
"A lot of greenhouses sit empty up here between December and April," said
Marvin Pritts, Cornell professor of fruit and vegetable science. "Once the
poinsettias are gone, the growers have empty greenhouses through April.
Until they're ready with their bedding plants, raspberries may be a great
crop for these growers."
Greenhouse-grown, winter raspberries have been but a dream. But, thanks to
the efforts of Cornell scientists and their students, that dream could
become next year's torte.
With greenhouse space contributed by Robert W. Langhans, Cornell professor
of floriculture and ornamental horticulture and controlled-environment
horticulture specialist, Thomas H. Whitlow's woody-plant physiology class
set out to learn how western-United States varieties respond to the
low-light conditions of winter in upstate New York.
"Teaching woody plant physiology in the middle of winter in Ithaca is
challenging," said Whitlow, Cornell assistant professor of floriculture and
ornamental horticulture. "We were looking for a crop to manipulate at
full-scale indoors, to study photosynthesis, and canaopy architecture. As
a teacher, raspberries suited my needs perfectly."
The researchers studied several varieties under these wintry conditions,
including Chiliwack, Tulameen, Titan and Jewel. They studied another
variety known as NY7, which has not been given a formal name.
The greenhouse results were impressive. Titans weighed in at 8 grams a
berry, while Jewel weighed in at 6 grams each -- sizes approaching that of
strawberries.
Lighting was an important consideration, since the growing season starts
near the winter solstice, when sunshine is scarce. The researchers used
off-peak supplemental lighting between
10 p.m. and 6 a.m., to spur the raspberries.
Even more important than lighting: pollination. Moving pollen from the
anthers to stigma proves tedious and nearly impossible, so the researchers
brought in domesticated bumble bees.
"They pollinate better than honey bees or hand pollination," Pritts said.
"Now we use them exclusively. Bumble bees are not aggressive, and we have
never been stung by them -- that's in contrast to the honey bees!" Bumble
bee hives are short-lived, he said, lasting only about six to eight weeks.
The researchers have to replace them regularly. Bumble bee hives can be
obtained from numerous vendors who import them from Holland or Canada.
Insect pests are another problem. "One advantage of greenhouse production
is the absence of weeds. However, the controlled climate is ideal for
other arthropod and fungal pests, if they are introduced," Pritts said.
During this research, the students and faculty did not find it necessary to
use any form of pesticide, and they used biological controls exclusively.
Fruiting began in late February and by late March, the harvest season was
in full swing. Whitlow and Pritts invited local restaurateurs and Cornell
Hotel School staff to a blind-tasting, March 21, where they compared
greenhouse raspberries with offerings from a local supermarket. Opinions
were favorable.
"Now that we can see that it works, we can now compete for grants and study
this on an even larger scale," Whitlow said. It also could make an
excellent doctoral dissertation for a graduate student. "It's a Ferrari
ready to drive," he said.
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