Agriculture Reference
In-Depth Information
28°F (−2°C):
Blossoms are killed
32 to 55°F (0 to 13°C):
Chilling units accumulate
45°F (7°C):
Optimum temperature for chilling unit accumulation
Above 70°F (21°C):
Chilling can be reversed if temperature maintained
for 4 hours or more
Winds
Wind damage is not a serious problem in many fruit-growing areas of North
America, but there are exceptions. Frequent and prolonged wind can tatter
leaves, dry out soil, and desiccate trees, the last of which is particularly a
problem during subfreezing temperatures in winter. Winds can rub the fruit
against branches and other fruits, causing bruises and scarring. Wind can
also cause trees to lean, and the trees may require trellising to stay upright
and properly trained.
If you are in an area known for frequent winds, it is a good strategy to
select an orchard site on a bench (a more-or-less level area on a slope above
a valley floor) or gentle slope facing away from the prevailing winds. Anoth-
er option is to plant a windbreak of taller trees around your fruit trees to
protect them. Windbreaks are common, for example, around orchards along
both sides of the Columbia River in Washington and Oregon. Windbreaks
can also be useful in the High Plains, the Prairie Provinces, and parts of the
Midwestern United States.
