flimbin wrote:
I think we require a period of cold weather to grow apples. If that is
so, how do they manage it in hot countries like South Africa?

Apples do need a period of chilling to flower but the amount of chilling
depends on the cultivar, for some it is quite short. So I can grow many
apples here in Australia in an area which would be classed as quite hot by
most people in Europe or North America. A typical summer day range is from
20-30C and it can reach 43C. The reason apples fruit here is that in winter
there are enough cold days to meet the chilling requirement, typical day
range is 4-14C but a minimum of -4C is possible. My understanding is that
South Africa would be similar, especially the inland away from the
moderating effect of the ocean.

In the tropics where the seasons are more likely wet/dry than hot/cold the
summer maximum is less than here but the winter minimum is much higher, this
lack of winter chilling makes it harder to get apples to flower in the
tropics. I am not aware of any apple cultivar that has no chilling
requirement but apparently there are chemicals that simulate the effect to
some degree.

here is some data on local cultivars:

http://www.newcrops.uq.edu.au/acotan...s/campbel1.htm

David