Greenhouse Canada

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New tomato research on temperature effects


March 31, 2010
By Dave Harrison


Topics

WEB EXCLUSIVE

New tomato research on temperature effects

A team from the
Basque Institute for
Agricultural Research and Development (Neiker-Tecnalia) has questioned
the
generally held belief that the quality of tomatoes depends primarily on
their
exposure to natural light and states that the most determining factor is
temperature.



March 31, 2010 – A team from the Basque Institute for
Agricultural Research and Development
(Neiker-Tecnalia) has questioned the
generally held belief that the quality of tomatoes depends primarily on their
exposure to natural light and states that the most determining factor is
temperature. The research was drawn up by the Institute’s Department of
Agricultural Production and Protection and opens up great possibilities for
starting new plantations in zones where light intensity is low due to weather
conditions.

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The findings are of particular interest in geographic zones
such as the Cantabrian mountain range in the north of Spain, where there is
frequent cloud cover and an average of 140 rainy days per year, and which could
be suitable for growing greenhouse tomatoes, despite low levels of solar
radiation.

The study evaluated the different indicators for organoleptic
(taste and texture) quality and nutritional quality, such as acidity, soluble
solids, phenolic compounds, pH and vitamin C content. To this end, the tomato
plants were exposed to photosynthetic radiation between 30 and 50 per cent less
than the usual for the sunny zones in the south of the Iberian Peninsula, at
the same time as studying other tomato plants undergoing 100 per cent exposure.
Cultivation was carried out on soil, in a greenhouse without artificial heating
and shaded in a small area so that air currents were able to homogenize the
temperature within the plantation.

The results showed that the organoleptic and nutritional
quality was very similar between the plants exposed to greater solar radiation
and those with less.

Another conclusion of the research opens up the possibility of
reducing costs of heating, something that researchers in other European
countries such as the Netherlands are working on – through the selection of
seed varieties that need less energy. According to report author Patrick Riga,
“heating bills can be reduced while obtaining the same quality of tomato,”
although, as a disadvantage, yield is less. In Riga’s opinion, “growers have to
choose between production or quality.”

Researchers
are now focusing on analyzing how much the temperature can be reduced in order
to cut down on energy consumption without affecting quality parameters. These
findings can also be applied to other kinds of fruit with high nutritional
value, such as strawberries, cucumbers, melons and watermelons.