Fig. 1. Symptoms of different levels of dieback on damaged or killed yuzu trees in Goheung-gun in 2018.
Fig. 2. Plant hardiness zone map based on the average annual minimum winter temperature for 2000-2010 in Korea.
Fig. 3. Annual variations of the monthly minimum value of daily minimum temperatures in Goheung for January and February from 2000 to 2018. Red dotted lines indicate a climatological value of the monthly minimum of daily minimum temperature during 1981-2010 as a reference for comparison.
Fig. 4. Daily variations of the minimum temperature during Jan-Apr in Goheung in 2018 (black line), compared to the one in 2017 (gray line). Dotted circles indicate the days with a minimum temperature below -10°C, and two incidences (1st and 2nd shocks) where possible freeze damage may happen were marked on the graph.
Table 1. Incidence of severe diebacks on yuzu trees in the investigated orchards in Pungyang-myeon, Goheung-gun in 2018
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