GIS-aided analysis of vineyards damaged by winter frosts. Case study: Cotnari vineyard (Romania)

Abstract

Thermal regime of Cotnari vineyard, Iaşi County, Romania, was surveyed between 2011-2012 using 10 Tinytag temperature loggers TK-4014, spread in 10 different lands of the vineyard. Research is developed in the framework of the international project TERVICLIM (France), by means of was created a global network of analyses points of vineyard climate, spread in 13 countries from both hemispheres of the globe, at different latitudes. The data recorded by temperature loggers in Cotnari vineyard shows that in 2011-2012 winter, the minimum temperatures dropped to -28.6ºC, with differences of up to 7.1ºC between the coldest and the mildest lands of the vineyard. Spatial distribution of the most harmful frost (12 February 2012) shows that more than 80% from the vineyard area was exposed to temperatures lower than -24ºC, 17% to harmful temperatures between -21..- 24ºC and 3% to temperatures between -18..- 21ºC, less damaging to vines. As consequences, the damages in the vine plantations varied from less significant negative consequences for vines in the mildest location, up to massive losses of winter buds, damages of annual branches and frozen vines in the coldest land of the vineyard. Analytical data of winter buds losses spatial distribution shows that at - 28.6ºC (absolute minimum temperature for the vineyard), 0.46% (7.29 ha) of vine plantations were exposed to vines losses, 3.81% of plantations to losses of annual branches, 62.49% from vine plantations to winter buds losses exceeding 40%, difficult to compensate by pruning, 13.5% to losses of winter buds exceeding 60%, requiring reestablishing the vegetative potential of vines. The only vine plantations protected by harmful frosts were those located at over 175 m altitude, in the highest lands of the vineyards.