New report on sprinkler frost protection for vineyards


Vines covered in layer of ice(Click for larger image)

White ice covering the vines indicates insufficient application rate for the frost conditions, and that vine damage is likely.

A new report published by Lincoln Ventures on the effective use of sprinklers to prevent frost damage in vineyards is the culmination of four years of investigations in the Hawke’s Bay.

 

A research team led by Dr Ian Woodhead began a frost protection study following serious frost damage there in Spring 2003.  Their work was supported by local grapegrowers and MAF’s Sustainable Farming Fund.

 

For grapes, the most sensitive period for frost damage is when the new buds and florets are emerging in the early spring.

 

Sprinkler frost protection uses the heat released when water changes from liquid water to ice.  By spraying water at the correct rate onto a crop under frost conditions, a layer of ice slowly develops over the plants.  Provided the surface of this ice layer is kept wet, the temperature of the enclosed plant tissue will generally be greater than minus half a degree, even though the surrounding air may be at a much lower temperature.

 

The work was based in the Sileni Estates in the Hawke’s Bay, including a control section and a trial block with more than 15 sprinkler configurations.

 

The study also looked at techniques including pulsing during light frost conditions to enable water use efficiency while maintaining adequate protection of the vines, startup, freezing in laterals and application rate.

Dr Woodhead said there were clear benefits from investing in an adequate sprinkler frost protection system coupled with good monitoring practice. 

 

Other wine regions in New Zealand have also been showing interest in the findings.  Dr Woodhead shared some of the results earlier this year with grape growers from Marlborough.

 

The report entitled, Improving Sprinkler Frost Protection in New Zealand Vineyards, can be downloaded here:

pdf symbol pdf attachment (2MB).

 

Lincoln Ventures is a research and development company owned by Lincoln University.  It has particular expertise in measuring systems, biosensor and electronic sensor technology.