| Publication date | December 26, 2019 |
|---|---|
| Sector | Agriculture, Forestry, Fisheries |
| Region name | Kanto（Shizuoka Prefecture） |
Due to the effects of extreme high temperatures and decreased rainfall in summer, issues such as defoliation, blight, and stem canker caused by drought have caused some decreases in first flush tea (ichibancha) of the following year. Although the effect of summer droughts on the first harvest in the following year is not yet completely clear, it is anticipated that global warming will accelerate the process of budding and sprouting and plucking of the first flush.
Shizuoka Prefecture is promoting the use of sprinklers and other irrigation methods as countermeasures against rising temperatures and droughts in the summer season (Fig. 1). Frost-protection as a countermeasure to late frosts (see Note) in the spring are also being incorporated into the cultivation process, as a consequence of early sprouting and picking due to climate change. Anti-frost fans are being widely employed to increase the temperature of tea shrubs by blowing warmer air from elevated positions down to the ground surface, which has lost heat through radiative cooling (Fig. 2).
Summer droughts are not the sole reason for the decline in first flush crop, and it is difficult to establish the degree to which different factors are significant. However, by applying technological countermeasures such as irrigation and frost protection, it is expected that the impact on tea cultivation will be reduced.
(Note) A late frost is considered one that occurs between late spring and early summer. Crops are often damaged. (Source: Japan Meteorological Agency website)
Fig. 1 Sprinkler irrigation technology
(Source: Shizuoka Prefecture's Policy on Climate Change Impacts and Adaptation in Shizuoka Prefecture formulated in March 2019)
Fig. 2 Late frost protection using anti-frost fans
(Source: Shizuoka Prefecture's Policy on Climate Change Impacts and Adaptation in Shizuoka Prefecture formulated in March 2019)
