キリンソウと四季の彩り日記屋上緑化システム株式会社
技術顧問　山下 律正

酷暑は続く！

屋上緑化は植える植物の選択が重要です！

耐暑性四季彩9キリンソウを試してください。

安心の夏を過ごせます。

The scorching heat continues! When greening your rooftop, it’s important to choose the right plants! Try the heat-tolerant Shikisai 9 Kirinsou. You’ll be able to spend the summer in peace.

球の温度は上昇を続け、動けない植物は生存温度を越す事態となり衰退を始めます。

10年後を見越す緑化の第１条件は「高温・ひでり耐性の植物」を導入する事です。

２０００年から２０２２年までの世界の気温上昇　資料：NASA climate change

Global temperature rise from 1955 to 2022 Source: NASA climate change

As the earth’s temperature continues to rise, plants that do not move reach a point where their survival temperature is exceeded and they begin to decline. The first condition for greening in anticipation of 10 years from now is to introduce plants that are resistant to high temperatures and heat, which will lead to safe greening.

四季彩９キリンソウ　６2日ひでり耐性試験

 ６２日ひでり試験　（６2日耐乾燥性試験）

試 験 品 種 ：四季彩9キリンソウ

試　験　体　１年育成苗

条　　　件　：透明波板軒下直下2ｍ　雨水の飛沫が届かない壁面側に

ポット苗をプラスチック網容器に入れて配置

置き場所方位：南南西

開 始 日 時 ：２０２３年5月31日～7月31日　62日間

試験終了日　：２０２３年7月31日

60-day drought resistance Shikisai 9 Kirinsou

60-day drought test (60-day drought resistance test) Test variety: Shikisai 9 Kirinsou Test specimen: 1-year-old seedlings Conditions: 2m directly below the transparent corrugated eaves, on the wall side where rainwater splashes cannot reach Pot seedlings placed in plastic mesh containers Placement orientation: South-southwest Start date and time: May 31st to July 31st, 2023, 62 days Test end date: July 31st, 2023

期間中の天気　（気象庁資料）Weather during the period (data from the Japan Meteorological Agency)

期間中の最高気温は25℃から35℃に10℃上昇している

日照は半月ごとの周期となり６月１５日からは酷暑が続いている

The maximum temperature during this period has risen by 10 degrees from 25°C to 35°C. The sunshine cycle is now bimonthly, and the extreme heat has continued since June 15th.

６2日ひでり耐性試験　62day drought resistance test

写真：試験開始時　Start of test　　

断水35日経過後　 After 35 days of water outage

断水40日経過状況　Status after 40 days of water outage

断水62日経過状況　Status after 62 days of water outage

試験結果

• 断水35日経過までに吸水停止状態でも3試験体は成長を続けている
• 断水35日経過の6月の日照は曇天が多く植物体への影響は少ない事から、葉色の変化も少ない
• 断水40日経過の7月中旬までは気温・日照は１５日周期で変化し平均気温２５以下、最高気温３５℃以下で季彩９キリンソウには単純に乾燥に対する耐性のみで克服していると推定される
• 40日経過後、平均気温３０℃最高気温３５℃に達し、平均日照１０時間の酷暑期間となる。

給水が無い状態で酷暑状態が続くと体力復元の状態になれず植物体に影響を与え、葉色が黄色に変化し耐性色になっている。

• ６2日経過、 落葉は少しで目立った体力保持の組織切り離しは見られず生育維持余力があると判断できる。

結果まとめ

• 株の枯損無し、葉の落葉少なく日照と無給水で葉脈が浮き出たが、落葉は少なくほぼ試験前の草姿を維持している。
• 側芽の発生が遅れる
• 四季彩９キリンソウのひでりによる生育障害無い
• 充分育成した四季彩９キリンソウ苗では、植栽後６０日程度のひでりが継続しても枯損は発生しない結果を得た

Test results

• Even after 35 days without water, the three test specimens continued to grow even though they had stopped absorbing water.
• 2. After 35 days without water, the sunshine in June was mostly cloudy, so there was little impact on the plant, and there was little change in leaf color.
• 3. Until mid-July, after 40 days without water, the temperature and sunshine changed in a 15-day cycle, with the average temperature below 25°C and the maximum temperature below 35°C, and it is estimated that Shikisai 9 Kirinsou simply overcame the dryness resistance.
• 4. After 40 days, the average temperature reached 30°C and the maximum temperature reached 35°C, and there was a period of extreme heat with an average of 10 hours of sunshine. If the extreme heat continues without water supply, the plant cannot recover its strength, which affects the plant, and the leaf color changes to yellow and becomes resistant.
• 5.62 days have passed. There is only a small amount of leaf fall, and no noticeable detachment of tissue that maintains strength is observed, so it can be judged that the plant still has the capacity to maintain growth.

Summary of results

① No withering of the plants, little leaf fall, leaf veins visible due to sunlight and no watering, but little leaf fall and the plant shape before the test is almost the same.

② Lateral buds emerge late.

③ No growth problems due to drought in Shikisai 9 Kirinsou.

④ Well-grown Shikisai 9 Kirinsou seedlings did not wither even after 60 days of drought.