Nigel,
Thank you very much for this information. New York is a cold place in
Winter. Am I to understand from the points you make that the trees will be
evergreen in warmer climes, but desiduous where the winter temperature
drops? Is the data below applicable to all subspecies? I was under the
impresssion -- probably wishful thinking and just plain wrong -- that there
were subspecies that tolerate a much lower temperature range.
Michael
Nigel at
4/21/04
> I do not have specific data for Connecticut but the following are
> typical requirements for growing Camellia sinensis commercially:
>
> 1. Average air temperature 20 to 30 °C but bushes become dormant if
> night temperatures drop below 13 °C
> 2. Dormant season temperature minima should be above minus 5 deg C
> 3. Soil temperature between 16 and 25 °C
> 4. Annual rainfall between 1,500 and 3,500 mm, well spread through the
> growing season
> 5. Soil pH between 4.5 and 5.5 - death occurs at ph 7.0 and above.
> 6. Soil structu well drained but retentive.
> 7. Soil water deficit less than 40-100 mm (SWD = difference between
> field capacity and the actual water in the soil. Tea crop can
> evaporate 3 to 6 mm per day = 1,000 to 2,000 mm per year. Rainfall is
> therefore marginal below 1,500 mm.)
> 8. Water table below 2 metres
> 9. Humidity: high enough not to limit growth (a saturation deficit
> below 2.3 kPA, this can rise for example to 7 kPA in the hot dry
> unproductive period in Malawi).
> 10. Light intensity: at least 700 to 800 W per m2 – that is typical
> winter sun intensity in tropics = 75% of summer levels. Interception
> is extremely high in tea grown commercially - only 40 w/m2 will reach
> ground under healthy monoculture bushes.
>
> All of these requirements are important, though in true Orwellian
> fashion, some are more important than others.
>
> Nigel at Teacraft
> www.teacraft.com
> www.nothingbuttea.co.uk