Frost Risk Assessment in Slovenia in the Period of 1981–2020

Abstract

As spring frost proves to be an increasing risk throughout Slovenia and Europe, a better assessment of frost risk is needed. The statistical approach presented in this article consists of the conditional probability that the last spring frost occurs before budburst or flowering. The analysis was conducted using two separate phenological models and phenological data of various grapevine (Vitis vinifera L.), apple (Malus domestica), and sweet cherry (Prunus avium L.) varieties in locations across Slovenia. The increase in risk of spring frost for grapevine ranged from 1 to 1980, from 0.06 to 12 for apple, and from 1 to 180 for sweet cherry. Overall, the varieties most prone to frost proved to be Refošk (Teran) and Merlot grapevine varieties as well as the Germersdorf sweet cherry variety. We have identified the location in the hilly region with moderate climate where the Bobovec apple variety is grown as the least exposed to frost. Although counterintuitive, the GDD generally proved somewhat more efficient than the two-phase phenological model BRIN, although not in all cases. For the purpose of the study, the phenological models were calibrated, and the model parameters can serve as invaluable information for further research of this topic.

The Spatiotemporal Evolution of the Growing Degree Days Agroclimatic Index for Viticulture over the Northern Mediterranean Basin

“…Given the projected NMB's vulnerability to climate change [18,22,23,72], numerous surveys have been undertaken regarding the basin's traditional viticultural regions, based on the GDD index. The most common aspects of scientific interest, with matters of phenology and production quantity and quality playing a leading role, are the following: phenological behavior assessment, modeling, seasonal forecasting, future projections, and past-future trends [73][74][75][76][77][78]; the impact of the climate on harvest time; harvest variation and harvest period prediction [79,80]; and the description of growing-season weather conditions and thermal-climatic characterization.…”

The Spatiotemporal Evolution of the Growing Degree Days (GDD) Agroclimatic Index for the Viticulture over the Northern Mediterranean Basin

“…Given the projected NMB's vulnerability to Climate Change [18,22,23,72], numerous surveys of the aforementioned nature have been undertaken for the Basin's traditional viticultural regions based on the GDD index. Phenology's behavior assessment, modeling, seasonal forecasting, future projections, and past-future trends [73][74][75][76][77][78]; the impact of climate on harvest time; harvest variation and harvest period prediction [79,80]; growing season's weather conditions description, thermalclimatic characterization appear as the most common aspects of scientific interest with matters on phenology and production quantity and quality aspects playing a leading role.…”