When its cold, farmers spray trees, how does spraying the cold water on the trees prevent freezing damage?

Question

When there is a late cold snap, fruit farmers spray water on their trees to prevent the flower buds from freezing. The water comes out of the farm pond and is not at all warm! How does spraying the cold water on the trees prevent freezing damage?

Answer 1

The water acts as an insulation to the plant. Instead of the plant itself freezing the water on the outside freezes and provides a protective coat around it. It keeps the warmth inside the plant.

Answer 2

Actually what you are seeing is only part of the process. Irrigation prior to a freeze is best done a couple of days prior to the freeze. Moist soil will hold more heat than dry soil, if the farmer has time to irrigate and let the sun warm up the moist soil. Irrigation just prior to a freeze can actually cool the soil, as wind blows over the soil surface, evaporating the water. Water sprayed on the leaves can protect any plant from freeze damage, with a couple of VERY important provisos. Water has to be applied CONTINUOUSLY after the temps reach freezing to the point at which temps rise above freezing, usually the following morning. The continuous flow of water keeps the ice which forms, and therefore the plant, at 32 degrees. Without the continuous water flow the temperature will continue to drop, causing MORE damage to the plant than would have occurred if no water was applied. Also it takes a lot of water to cold protect with this method. Something like one inch per hour. If less water is used, the temps drop and the freeze/ice damage will be more severe than if no water was applied. Modern citrus groves use micro-sprinklers placed under the trees. These are turned on during a freeze, and help keep temperatures above freezing under the canopy of the tree. In a severe freeze (citrus is not damaged until 27 degrees F) outer branches and fruit may be damaged, but the trunk and main branches can be saved.

Answer 3

The pond water has a higher freezing point than pure water.

Answer 4

I believe they spray it into the air to make a fog.
However, the water acts by freezing before the flowers.

Answer 5

When you spray it, it ices over, so the temperature can't go below 32 degrees. In most cases, the trees can withstand 32 degrees and it's better than it being out because it will probably get colder out in the open, so the chances of survival are far greater.

Answer 6

Pure water has lower freezing point.

Answer 7

Act as an insulation barrier to keep the "fruit" from freezing.
:-})

Answer 8

it forms ice around the buds to insulate it. Like an igloo

Answer 9

It keeps the frost from forming on the plant to a point.

Answer 10

because the water then absorbs the cold and loses it's heat, and it's not the fruit that it's losing warmth.