Hailstorm, is a descendant of Cumulonimbus cloud. A type of vertical developing cloud that starts very near to the surface of 0.5 km and extends up to 16 km. This is a heap of clouds that causes rain, thunderstorm, dust storm, and hailstorm, depending upon atmospheric conditions. When we discuss hailstorm, the main reason for the formation of hails is mainly due to the vertical extent of the cloud, that result in the development of ice balls (hails) inside these clouds. When the weight of the hail increases, they will start to descend through the cloud and fall to the ground as a hailstorm. A hailstorm is a combination of hail and very strong winds.
When we discuss about hailstorm with respect to grapevine, then the destruction is severe and it depends on the hail size, intensity and strong winds. Adding to the hail damage, the injury caused by them will act as a source for infection from pests and diseases and will attribute to the loss of the crop depending upon the intensity of the damage. In the picture below the damage caused by hails in vineyards is evident, that most of the plant parts are broken and grapes are damaged. The physiological stage of the crop at the time of hail occurrence decides the crop damage.
One of the best commercial options to reduce the vineyard from the mechanical damage of hail is the use of anti-hail nets. After the hailstorm applying plant protectors and pesticides, helps the plant in healing process and prevent more spread of pests.
Anti-hail nets might be the protective solution for you. For that you can think of it like this: Hail can destroy "x" % of my yield. It occurs once every "y" years. Therefore, I lose an average "x/y" % of my yield. Hail nets cost "z". Then the question is whether "x/y * yield price" > z?
Hail nets can protect against sunburn and reduce the wind speed that helps in effective pesticide application. Sometimes we feel that the installation of hail net might affect the grape maturity or quality. Seems like there are basically no downsides as this article from the wine searcher mentions apart from the cost. Though hail nets are costly, the investment in hail nets can be done, considering the benefits.
We don't sell anti-hail nets, but we are interested in the well-being of your grapes. So this might be the time to check out some hail net suppliers.
To know more about hail damage on grapevine, do read the article titled " Hail and severe storms" by Dr Aude Gourieroux; National Wine and Grape Industry Centre, Wagga Wagga. Darren Fahey and Adrian Englefield – NSW DPI Development Officers – Viticulture. pp. 36-38.
We wish you successful and healthy farming. Without hail damage.