Protecting wine grapes from heat and drought

Feb 17, 2009
Particle film used to protect wine grapes from heat and drought. Photo by Krista Shellie

Deficit irrigation is an agricultural technique used to achieve a variety of results depending on the crop. For white wine grapes, it balances the crop load by limiting the canopy size so there aren't too many leaves shading the grapes. For red wine grapes, deficit irrigation again limits canopy size, but also affects berry components associated with wine quality.

A drawback of this canopy-limiting process is that fruit can become sunburned, especially under sunny, arid conditions, which can adversely affect productivity and fruit maturity. A particle film, which increases light reflection and reduces leaf temperature, has been tested on several crops. It acts as a sunscreen by reflecting the harmful ultraviolet rays off of the leaves and fruit, but still allows the right radiation for photosynthesis through to nourish the plant.

Krista Shellie of the U.S. Department of Agriculture led a study to learn more about foliar particle film's effects on wine grapes when the grapes were grown under varying levels of water stress. The study, published in the American Society for Horticultural Science journal HortScience, also noted particle film's effect on grape yield and maturity. Grapes were grown according to commercial practice with the exception of the watering schedule and application of the particle film. Film effectiveness was monitored by measuring the amount of leaf gas exchange, but particle film's influence on this process seemed to differ depending on the amount of water stress the vine was experiencing.

Particle film did not prevent sunburn on exposed fruit when vines were under the most stressful growing conditions, but did increase the weight of a red-skinned wine grape by 7% and increased a white-skinned wine grapes' soluble solids concentration by 11%. But, the weight of white-skinned wine grape and the soluble solids concentration of the red-skinned grape were unaffected. Other factors pertaining to yield, including grape maturity, were not influenced by particle film.

The study's findings support a classification of these grapes as anisohydric, meaning the plant is affected by the amount of soil moisture available and is unable to restrict its own water loss under dry soil conditions. This is also known as a "drought-avoiding" classification.

Particle film may increase the yield potential of the vines, but it did not protect against sun damage when vines were grown under deficit irrigation. The cost-benefit of particle film must be decided by growers and wine makers and its potential benefit of more uniform fruit maturity, increased yield, and berry size.

More information: The complete study and abstract are available on the ASHS HortScience electronic journal web site: hortsci.ashspublications.org/c… t/abstract/43/5/1392

Source: American Society for Horticultural Science

Explore further: Honey bees sting Texas man about 1,000 times

add to favorites email to friend print save as pdf

Related Stories

How Kindle Unlimited compares with Scribd, Oyster

9 hours ago

Amazon is the latest—and largest—company to offer unlimited e-books for a monthly fee. Here's how Kindle Unlimited, which Amazon announced Friday, compares with rivals Scribd and Oyster.

NASA sees powerful thunderstorms in Tropical Storm Matmo

9 hours ago

Strong thunderstorms reaching toward the top of the troposphere circled Tropical Storm Matmo's center and appeared in a band of thunderstorms on the storm's southwestern quadrant. Infrared imagery from NASA's ...

ISS 'space truck' launch postponed: Arianespace

12 hours ago

The July 24 launch of a robot ship to deliver provisions to the International Space Station has been postponed "for a few days", space transport firm Arianespace said Friday.

Recommended for you

Study indicates large raptors in Africa used for bushmeat

13 hours ago

Bushmeat, the use of native animal species for food or commercial food sale, has been heavily documented to be a significant factor in the decline of many species of primates and other mammals. However, a new study indicates ...

The microbes make the sake brewery

13 hours ago

A sake brewery has its own microbial terroir, meaning the microbial populations found on surfaces in the facility resemble those found in the product, creating the final flavor according to research published ahead of print ...

Fighting bacteria—with viruses

14 hours ago

Research published today in PLOS Pathogens reveals how viruses called bacteriophages destroy the bacterium Clostridium difficile (C. diff), which is becoming a serious problem in hospitals and healthcare institutes, due to its re ...

User comments : 0