San Luis Obispo County
University of California
San Luis Obispo County

Frost Protection

UCCE Frost Protection Training Units

The two websites below contain narrated training units in a variety of important frost protection topics. These narrated presentations are also available in Spanish. All of these presentations are viewable online in Flash format; you will need audio on your computer to hear the narration.

English versions:

http://lawr.ucdavis.edu/ce_frost_protection.htm

Spanish versions:

http://lawr.ucdavis.edu/ce_frost_protection_spanish.htm

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UC Davis Biometeorology Program Frost Protection Website

The UC Davis Biometeorology program provides detailed frost protection information at the following website:

UC Davis Biometeorology frost information

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FAO Frost Protection Publication

A very detailed publication covering all aspects of frost protection is the book titled "Frost protection: fundamentals, practice, and economics" which is available free online at the following website of the UN FAO:

http://www.fao.org/docrep/008/y7223e/y7223e00.htm

A Spanish language version of the above document is available as a free PDF file at the following website:

http://www.fao.org/docrep/012/y7223s/y7223s00.htm

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Other Frost Protection Resources

Dr. Robert Evans, Supervisory Agricultural Engineer with the USDA-ARS (retired), has written these comprehensive summaries of frost protection science and practice:

Frost Protection in Orchards and Vineyards

The Art of Protecting Grapevines From Low Temperature Injury

 

Temperature inversion information

The December 2011 Grape Notes newsletter provides a detailed example of how temperature measurements using inexpensive portable towers can be used to evaluate the temperature inversion conditions on frost nights; with this information we can estimate the benefits of wind machines for frost protection at a given location. This brief video explains the use of these towers for assessing inversion conditions.

The instruction sheet below provides information on how to assemble and install the 35 foot towers for assessing the temperature inversion conditions. These are very inexpensive and highly portable, but are not intended for permanent or long-term use.

Inversion tower instructions

The instruction sheet below explains how to visually analyze the temperature data collected by the above inversion towers. If you are operating your own towers following the system described above, this visual analysis is the easiest and most efficient way to evaluate the temperature measurements.

Visual analysis of inversion tower temperature data

The Zip folder below contains two example temperature data files from one inversion tower, and a combined data file produced following the instruction sheet above. To view these files you will also need a copy of the HOBOware software installed on your computer.

Example inversion data

 

Assessing and Responding to Winter Cold Injury to Grapevine Buds

The website below created by Dr. Robert Pool at Cornell University discusses winter cold damage to grapevine buds, and has very detailed pictures of the compound bud and how individual buds within the compound bud can be damaged to varying degrees:

http://www.fruit.cornell.edu/grape/pool/winterinjurybuds.html

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Wind machines for reducing winter cold damage

In some parts of California vine losses due to winter cold damage can be a concern. The following detailed report from research in Ontario, Canada provides good background on wind machine function and their use for protecting against such winter cold damage:

Reducing cold injury to grapes through the use of wind machines

Additional information is available at the following website:

Wind machines for minimizing cold injury to horticultural crops

 

Webmaster Email: kjerdin@co.slo.ca.us