JP3871192B2

JP3871192B2 - Seedling storage lighting method and seedling storage lighting device

Info

Publication number: JP3871192B2
Application number: JP2001193809A
Authority: JP
Inventors: 正紀石渡; 慎一安部; 章英工藤; 敏彦阪口
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2001-06-26
Filing date: 2001-06-26
Publication date: 2007-01-24
Anticipated expiration: 2021-06-26
Also published as: JP2003009661A

Description

【０００１】
【発明の属する技術分野】
本発明は、野菜や花卉などの出荷前の植物苗を低温、弱光下で保存する苗貯蔵照明方法および苗貯蔵用照明装置に関するものである。
【０００２】
【従来の技術】
最近の植物苗の低温貯蔵に関する研究により，苗を貯蔵する際には、苗に対して弱光を照射する方が暗黒より苗質を維持できることが明らかになってきている。また、この際の弱光は光補償点（植物の光合成によるCO₂の吸収と、呼吸によるCO₂の排出が釣り合い、見かけ上CO₂濃度の増減がゼロになる光強度）が保てる量が望ましいことも明らかになってきている（参考文献：Acta Horticulturae No.393, March, 1995 久保田，古在、他）。
さらに、この研究結果を受けて、次のような、光補償点を保つように光の量を調節する光照射手法が提案されている。
植物苗の光補償点を維持するために低温貯蔵庫内の二酸化炭素濃度を測定し、それに基づき照明装置の光強度を制御する技術。
上記に加えて温度も測定して、光補償点を維持する照明方式（特開２０００−１８８９５７号参照）。
【０００３】
また、従来の弱光貯蔵用装置の構造としては、苗保存棚に照明器具を配置したものが主流であった（特開２００１−２８９４６号公報参照）。
なお、苗貯蔵ではなく、植物の生育に必要な光を照射する各種の照明方法乃至装置が知られている（例えば、特開昭６０−１８６２２９号公報、特開昭６０−１９２５２５号公報、特開昭６３−３６７１４号公報、特開昭６１−７０９２８号公報、特開平２−２５５０１９号公報、特開昭６０−５４６１８号公報等参照）。これら育成用照明装置においては、照射光量の大きい明期と小さい暗期とを設け、明・暗期間比などを生長段階に応じて変化させるものである。
【０００４】
【発明が解決しようとする課題】
ところで、出荷時における植物苗の活性度が要求される苗貯蔵（保存）のための光照射と、植物生育のための光照射とは異質なものである。そして、一般に植物苗を低温で貯蔵する場合、照射される光の量は光補償点を保てるレベルにするのが望ましいとされているが、光補償点自体は苗の生長や温度、湿度に依存して変化するため、実際に苗へ照射する光の量を光補償点に合わせるためには、センサなどを組み込んだ複雑なシステムが必要であった。そのため、実際の現場では予め定められた一定の照度で光照射しているのが現状である。
【０００５】
しかし、このような光照射では、完全には光補償点に合っていないため、苗質を維持できる期間が短くなり、苗が一定照度に慣れてしまい光合成能力が低下するなどの問題が生じていた。また、上述の特開２０００−１８８９５７号公報に示される弱光貯蔵用照明装置を用いて苗を貯蔵しようとした場合、設備投資にかなりのイニシャルコストおよびランニングコストがかかっていた。
【０００６】
本発明は、前述したようなセンサなどを組み込んだ複雑な装置を用いることなく、光照射方法の工夫のみで、低温貯蔵中の苗質を従来の一定光照射した場合よりも長期間維持すること、および貯蔵における照明器具の初期投資と消費電力量を低く抑えることが可能な苗貯蔵照明方法および苗貯蔵用照明装置を提供することを目的とする。
また、実際の市場においては苗の梱包箱のまま冷蔵庫で一定期間保管される梱包箱流通が一般的であることを考慮して、梱包箱に入ったままの苗に対して上記光照射を行うことが可能な苗貯蔵用照明装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するために請求項１の発明は、外光および外気を略遮断した低温の空間内に植物苗を配置し、前記空間内で前記植物苗を照明装置により光照射しつつ植物苗を保存する苗貯蔵照明方法において、照明装置により植物苗の略光補償点以上となる高照度の光を照射する期間（明期という）と、略光補償点以下となる低照度の光を照射する期間（暗期という）とを組み合わせて植物苗に対して光照射するものである。なお、光補償点とは、植物の光合成によるCO₂の吸収と、呼吸によるCO₂の排出が釣り合い、見かけ上CO₂濃度の増減がゼロになる光強度のことをいう。この方法においては、低温貯蔵中の苗に対して、略光補償点以上となる明期と略光補償点以下となる暗期とを組み合わせて光照射することにより、従来の一定光照射の場合よりも、消費電力量を低く抑えつつ、光合成速度が低下することなく苗質を長期間維持することができる。また、センサなどを必要とせず貯蔵における照明器具の初期投資を抑えることが可能となる。
【０００８】
請求項２の発明は、請求項１記載の苗貯蔵照明方法において、前記明期と前記暗期との組み合わせが所定の周期で繰り返されるものである。この方法においては、明期と暗期の組み合わせ周期を適宜に選択することにより、請求項１の作用が顕著に得られ、貯蔵期間の延長が図れる。
【０００９】
請求項３の発明は、請求項１又は請求項２記載の苗貯蔵照明方法において、前記暗期が略暗黒であるものである。この方法においては、請求項１の作用が顕著に得られる。
【００１０】
請求項４の発明は、請求項１乃至請求項３のいずれかに記載の苗貯蔵照明方法において、２４時間における前記明期および前記暗期に照射される積算光量が、光補償点を保てる光量により略１２時間照射した場合と略同量となるように照射光量を制御するものである。この方法においては、明期および暗期の積算光量を一定光照射の場合と略同量とすることで、一定光照射の場合よりも苗の光合成能力を良好に維持することができ、苗の長期貯蔵が可能となる。
【００１１】
請求項５の発明は、請求項１ないし請求項４のいずれかに記載の苗貯蔵照明方法において、前記明期の中に光補償点を超える強度の光を短時間照射する期間を設けたものである。この方法においては、一定光照射の場合よりも苗の光合成能力が良好に維持される。
【００１２】
請求項６の発明は、請求項５記載の苗貯蔵照明方法において、前記強光照射の前に、略暗黒の暗期を設けた場合に、強光照射直前に１時間以上の略光補償点以下の順応光を照射するものである。この方法においては、請求項５記載の作用が顕著に得られる。
【００１３】
請求項７の発明は、外光および外気を略遮断した低温の空間内に植物苗を配置し、前記空間内で前記植物苗を保存するため光照射する苗貯蔵用照明装置において、植物苗の略光補償点以上となる高照度の光を照射する期間（明期という）と、植物苗の略光補償点以下となる低照度の光を照射する期間（暗期という）とを組み合わせて植物苗に対して光照射するものである。この構成においては、請求項１と同等の作用が得られる。
【００１４】
請求項８の発明は、請求項７記載の苗貯蔵用照明装置において、前記明期と前記暗期との組み合わせを所定の周期で繰り返すものである。この構成においては、請求項２と同等の作用が得られる。
【００１５】
請求項９の発明は、請求項７又は請求項８記載の苗貯蔵用照明装置において、前記暗期が略暗黒であるものである。この構成においては、請求項３と同等の作用が得られる。
【００１６】
請求項１０の発明は、請求項７乃至請求項９のいずれかに記載の苗貯蔵用照明装置において、２４時間における前記明期および前記暗期に照射される積算光量が、光補償点を保てる光量により略１２時間照射した場合と略同量となるように照射光量を制御するものである。この構成においては、請求項４と同等の作用が得られる。
【００１７】
請求項１１の発明は、請求項７ないし請求項１０のいずれかに記載の苗貯蔵用照明装置において、前記明期の中に光補償点を超える強度の光を短時間照射する期間を設けたものである。この構成においては、請求項５と同等の作用が得られる。
【００１８】
請求項１２の発明は、請求項１１記載の苗貯蔵用照明装置において、前記強光照射の前に、略暗黒の暗期を設けた場合に、強光照射直前に１時間以上の略光補償点以下の順応光を照射するものである。この構成においては、請求項６と同等の作用が得られる。
【００１９】
請求項１３の発明は、請求項７ないし請求項１２のいずれかに記載の苗貯蔵用照明装置において、苗と光源との位置関係を相対的に移動させることで、前記明期および暗期を設けるものである。この構成においては、貯蔵時に複数の苗に対して少ない照明器具台数で必要な照射光量を確保することができる。
【００２０】
請求項１４の発明は、請求項１３記載の苗貯蔵用照明装置において、前記移動時の苗または光源の相対的な移動速度が等速であるものである。この構成においては、貯蔵時に複数の苗の各々に対する照射光の積算量を一定に保つことができる。
【００２１】
請求項１５の発明は、請求項１３記載の苗貯蔵用照明装置において、前記移動時の苗または光源の相対的な移動が離散的で、苗と光源が同時に一定時間停止するものである。この構成においては、請求項１４と同等の作用が得られる。
【００２２】
請求項１６の発明は、請求項７ないし請求項１２のいずれかに記載の苗貯蔵用照明装置において、苗出荷用梱包箱に苗照射光を入射させるための窓部を設け、この窓部に発光部を臨ませたものである。この構成においては、苗出荷用梱包箱に苗を入れたまま苗に対する光照射を行うことができ、苗貯蔵期間の延長を図ることができる。発光部としては、光ファイバを使用することができる。
【００２３】
請求項１７の発明は、請求項１６記載の苗貯蔵用照明装置において、前記苗出荷用梱包箱は積み重ね可能に形成され、積み重ねられた状態においても前記窓部から発光部を挿入可能に構成されたものである。この構成においては、貯蔵時の苗出荷用梱包箱が嵩張らない状態で、苗に対する光照射を行うことができる。
【００２４】
【発明の実施の形態】
本発明を具体化した実施形態について以下に説明する。
本発明は、外光および外気を略遮断した低温の空間内に植物苗を配置し、空間内で植物苗を照明装置により光照射しつつ植物苗を保存する苗貯蔵照明方法乃至装置において、植物苗の略光補償点以上となる高照度の光を照射する期間（明期）と、略光補償点以下となる低照度の光を照射する期間（暗期）とを組み合わせて植物苗に対して光照射することを基本とし、その組み合わせを適宜に所定の周期で繰り返すものである。
この苗貯蔵照明方法の妥当性を証明するために、実際のサツマイモ苗を用いて、様々な光照射条件で低温貯蔵実験を行い、光照射方法と苗質維持との関係を明確にした。以下にその実験の概要を説明する。
【００２５】
（実験の背景）
閉鎖型苗生産システム、すなわち、外光および外気を遮断した空間内に植物苗を配置し、前記空間内にある前記植物苗に対して、適切な温湿度環境および光環境を人工的に提供して苗を育てるシステムにおいて、効率的に苗生産を行うためには苗の生産計画が必要である。さらにまた、ある期間、苗の生長を一時的に停止または抑制しながら苗質を維持する貯蔵技術を併用することにより、出荷や移植時期の調節が可能となる。
今回の実験では、苗に対する光照射方法を変化させ、苗個葉の光合成速度を指標として、苗貯蔵における光照射方法と苗質維持との関係を求めた。
【００２６】
（実験方法）
供試材料としては、サツマイモ（品種：ベニアズマ）を用いて、気温27〜29℃、相対湿度70％、CO₂濃度1000μmol/molの環境条件下で苗を２週間生長させた。生育に用いた光源は白色蛍光灯であり、光合成有効光量子束（以下、PPF）は、100μmol/m²/s（０から２日目）、200μmol/m²/s（３から11日目）、300μmol/m²/s（12から14日目）で、１日の光照射時間は、明期が16時間、略暗黒の時間が8時間とした。その後の苗貯蔵においては、室温は12℃、相対湿度は70％、CO₂濃度は無制限、光の照射方法は以下の通りとした。なお、光はエネルギーを持つ一個の粒子の集まりであるとみなされ、単位時間当たりに放射される粒子の数を光量子束と呼ぶ。そのうち光合成に有効な400〜700nmの波長域に含まれる光量子束を光合成有効光量子束（PPF：Photosynthetic Photon Flux）と定義している。本実験では、苗を植えているトレイ面から高さ10cmの平面上の平均値をPPFとして定義している。
【００２７】
（貯蔵時の苗への光照射方法）
光照射は24時間を１単位として、図１に示したような６種類のパターンを設け、これを貯蔵日数分、繰り返した。本実験では、24時間の積算光量を一定（240μmol/m²/s・時間）とした（試験区２を除く）。ここに、20μmol/m²/s以上の光を照射した期間を明期、これより低い光を照射した期間を暗期と呼ぶ。斜線部が光照射区間である。光補償点は、苗の種類や培地ショ糖濃度、温湿度など様々な条件により変化するものであり、個々に求められる。
＜試験区１＞24時間一定光照射（常に暗期の条件）
暗期のPPF：10μmol/m²/s
（積算光照射量：10μmol/m²/s×24時間＝240μmol/m²/s・時間）
＜試験区２＞24時間一定光照射（常に明期の条件）
明期のPPF：20μmol/m²/s （本実験における略光補償点の光強度）
（積算光照射量：20μmol/m²/s×24時間＝480μmol/m²/s・時間）
＜試験区３＞明期は12時間の一定光照射、暗期は12時間の略暗黒
明期のPPF：20μmol/m²/s、暗期のPPF：0μmol/m²/s
（積算光照射量：20μmol/m²/s×12時間＝240μmol/m²/s・時間）
＜試験区４＞明期は６時間の一定光照射、暗期は６時間の略暗黒（これらを１日に2回繰り返した）
明期のPPF：20μmol/m²/s
（積算光照射量：20μmol/m²/s×（6＋6）時間＝240μmol/m²/s・時間）
＜試験区５＞明期は30分の一定光照射、暗期は23時間半の一定光照射
90μmol/m²/sの光を照射する前に1時間の順応時間を設けるために、暗期（1時間）から開始した。
明期のPPF：90μmol/m²/s、暗期のPPF：8.3μmol/m²/s
（積算光照射量：90μmol/m²/s×0.5時間＋8.3μmol/m²/s×23.5時間＝240μmol/m²/s・時間）
＜試験区６＞明期は３０分の強光照射、暗期は１２時間の略暗黒と光補償点以下となる低照度の光を１１．５時間照射（略暗黒終了後１時間を強光に対する順応時間とするために、光補償点以下となる低照度の光を照射。さらに強光終了後、１０．５時間光補償点以下となる低照度の光を照射）
明期のPPF：90μmol/m²/s、暗期のPPF：17μmol/m²/s、
0μmol/m²/s
（積算光照射量：90μmol/m²/s×0.5時間＋17μmol/m²/s×11.5時間＝240μmol/m²/s・時間）
【００２８】
（測定装置）
測定は、LI-COR社製の携帯型光合成測定装置LI-6400を用いて、個葉の光合成速度を1試験区当り2個体について測定した。携帯型光合成測定装置のリーフチャンバ（葉をはさんで測定するための中空チャンバ）内の環境条件は、葉温25℃、相対湿度60％、CO₂濃度350μmol/m²/s、PPF400μmol/m²/s、空気流量250μmol/sとした。
【００２９】
（測定結果）
図２に貯蔵開始後3日目と7日目に入った直後に行った測定結果を示す。
横軸は、各試験区から実験者が任意に選んだ葉をリーフチャンバにはさんで測定を開始してからの時間を表している。縦軸は、測定を開始してからの光合成速度を表している。両日とも、試験区３乃至６は、試験区１（24時間一定照射）の結果と比べて、早い時間で光合成速度が速い状態となり、試験区１より苗の状態が良いことが読み取れる。また、最終的に光合成速度が飽和する値を比較してみても、試験区１に対して試験区３乃至６の光合成速度は速い状態となっている。さらに、略光補償点の一定光照射を行った試験区2と比べてみても、試験区３乃至６の苗は、ほぼ同じくらいの光合成速度を維持していることから、試験区３乃至６の苗は光補償点の光を連続的に浴びた時と同じ程度に良い苗質を維持できていることが分かる。
【００３０】
これらの測定結果から、次のことが確認できた。試験区３，４のように、植物苗の略光補償点以上となる高照度の光を照射する明期と略光補償点以下となる低照度の光を照射する暗期とを組み合わせて光照射すれば、たとえ積算した光照射量が光補償点の光を連続的に照射した光量に達していなくても、光補償点の光照射を連続した場合と同じ程度に苗質を維持できる（請求項１乃至３）。
【００３１】
また、試験区５，６のように、２４時間における明期と暗期との繰り返しの積算光量が光補償点の光照射を略１２時間連続した時と略同量となるように光照射すれば、光補償点の一定光照射の場合以上に良好に苗質を維持できる（請求項４）。また、試験区５，６のように、明期の中に光補償点を超える強度の光を短時間照射する期間を設けることで、一定光照射の場合よりも苗の光合成能力が良好に維持される（請求項５）。また、強光照射の前に、略暗黒の暗期を設けた場合に、強光照射直前に１時間以上の略光補償点以下の順応光を照射することで、上記作用が顕著に得られる（請求項６）。
【００３２】
（実施例）
図３および図４に本発明の苗貯蔵照明方法を実現するための照明装置を含んだ苗貯蔵装置の構成を示す（請求項１乃至１２に対応）。図３（ａ）（ｂ）（ｃ）（ｄ）は、１つの苗貯蔵用のチャンバ−または部屋１（苗貯蔵室という）に１つの照明器具４が設置されている例である。苗貯蔵室１は、低温下に外光および外気を略遮断し、苗３を植えた苗植え付け用トレイ２を収納する空間を形成する。苗３の上部には人工照明としての苗貯蔵用照明器具４（光源または発光部）が配置されている。その照明器具４の調光用安定器５，６，７，８は苗貯蔵室１の内部または外部に設けられる。各調光用安定器はライトコントローラ９により制御される。調光用安定器５，６はタイマー機能付きであるのに対して、調光用安定器７，８はタイマー機能無しである。すなわち、後者の調光用安定器７，８は、調光機能のみ有り、光出力を時間変化させるための機能を有しない。このため、この場合はライトコントローラ９の先に制御用パーソナルコンピュータ１０（パソコン）などを接続し、これにより時間変化機能をもたせる。
【００３３】
図４（ａ）は苗貯蔵室１内を多段にして各段ごとに照明器具４を設置した例であり、図４（ｂ）は各段ごとに照明器具４を設置した棚を複数設け、各棚ごとおよび各段ごとに点灯制御を行う例である。タイマー機能付きのライトコントローラ９は、調光用安定器７を介してそれぞれの段、棚における照明器具４の点灯時間を一括または個別に請求項１乃至６のいずれかに記載の方法にしたがって制御する。
【００３４】
本実施例の構成においては、上記のように光照射を制御するので、センサなどの複雑なシステムを用いることなく、低温貯蔵中の苗の質を長期間維持することが可能となる。また、従来の光補償点の光照射をする場合よりもトータル光量およびそれに応じた電力消費量が少なくて済む。また、光を照射する時間帯と照射しない時間帯を設けるので、電力消費量の多い時間帯や少ない時間帯を自由に設定でき、従って、深夜電力など電気代の安い時間帯に光照射をする時間を設定すればよい。さらには、棚および段を複数設けて、一括点灯させずに各棚または各段ごとに明期と暗期を設けることにより、照明器具４の発熱による苗貯蔵室１内の温度上昇が低減できるため、空調負荷が低減可能となる。
【００３５】
図５（ａ）〜（ｇ）は照明器具４と苗３の相対位置関係が変化する構成例を示す（請求項１３乃至１５に対応）。いずれも外光および外気を略遮断した低温の空間内に植物苗を配置した状態とし、（ａ）（ｄ）（ｅ）（ｇ）は苗植え付け用トレイ２に対して照明器具４（光源）が移動する例であり、（ｂ）（ｃ）（ｆ）は照明器具４に対して苗植え付け用トレイ２が移動する例である。１７は照明器具４内蔵の苗貯蔵室である。いずれも苗３と照明器具４とを相対的に移動させることで、明期および暗期を設ける。また、上記のような構成により、貯蔵時に複数の苗に対して少ない照明器具４の台数で必要な照射光量を確保することができる。そして、移動時の苗３または照明器具４の相対的な移動速度を等速とし、および／または、苗３または照明器具４の相対的な移動を離散的として苗３と照明器具４を同時に一定時間停止させることにより、苗３への照射光の積算量を均一にすることができる。
【００３６】
図６（ａ）〜（ｆ）は苗出荷用梱包箱に送光窓部を設けた苗貯蔵用照明装置の例を示す（請求項１６乃至１７に対応）。これらの図において、１１は光源ボックス、１２は光ファイバー、１３はダンボールなどで成る苗貯蔵用梱包箱、１４は苗貯蔵用梱包箱１３に設けた送光窓部を成す透明な溝、１５は同じく送光窓部を成す孔、１６は内側が中空で光を導光するパイプから成る中空ライトガイドである。光ファイバ１２、中空ガイドライト１６は、側面発光ができる照明器具であり、それら発光部を苗貯蔵用梱包箱１３に設けた溝１４または孔１５に臨ませている。しかも、発光部が苗貯蔵用梱包箱１３の上部で凸形状にならない構造とされる。光照射は上記と同様、明期と暗期とを設ける。
【００３７】
上記のような構成とすることにより、既存の梱包箱による苗貯蔵の仕組みを変えることなく所望の照明を行うことが可能で、しかも苗貯蔵用梱包箱１３を上下に積み重ねることができ、苗貯蔵の省スペース化が図れ、貯蔵期間の延長にも容易に対応することができる。
【００３８】
なお、本発明は上記構成に限られず種々の変形が可能であり、例えば、苗の出荷時期に応じて苗に対し適切な光照射ができるように、光照射の明暗の周期を適宜に組み合わせ調整すればよい。
【００３９】
【発明の効果】
以上説明したように請求項１乃至３の発明に係る苗貯蔵照明方法によれば、センサなどの複雑なシステムを用いることなく光照射の工夫のみで、積算光量が光補償点以下であっても低温貯蔵中の苗の質を長期間維持することが可能となり、従来の光補償点の光照射をする場合よりもトータル光量およびそれに応じた電力消費量が少なくて済む。また、光を照射する時間帯と照射しない時間帯を設けることによって、時間帯による電力消費量に差が生まれ、電力消費量の多い時間帯や少ない時間帯を自由に設定できる。これにより、深夜電力など電気代の安い時間帯に光照射をする時間を設定すれば、電気代の節約が図れる。
【００４０】
請求項４乃至６の発明に係る苗貯蔵用照明方法によれば、従来の一定光照射の場合よりも、苗の光合成能力を良好に維持することができ、苗を長期貯蔵することが可能となる。
請求項７乃至１２の発明に係る苗貯蔵用照明装置によれば、上記方法と同等の効果が得られる。
【００４１】
請求項１３乃至１５の発明に係る苗貯蔵用照明装置によれば、一つの照明器具で光照射する苗の数が多くなってもよく、従来型の貯蔵棚と比べて照明器具台数を大幅に削減することができ、器具のイニシャルコストを低減することができる。また、苗の真上に常に照明器具が固定されている貯蔵棚では、PPFを変化させる際に調光をかける必要があったが、本照明装置では器具の移動によって明暗を変化させることができるため、照明器具に調光機能を必要としない。また、照明器具が苗上を連続的に移動しながら光照射するものとすることができ、一つの苗に照射される光の積算量を一定に保つことができる。
請求項１６，１７の発明に係る苗貯蔵用照明装置によれば、大掛かりな苗貯蔵装置を用いずに、一般に流通に用いられている梱包箱を僅かに改良するだけで少ない光源で有効な光照射を行うことが可能で、しかも梱包箱を積み重ねることができるので省スペースとなり、長期貯蔵に有効となる。
【図面の簡単な説明】
【図１】従来および本発明の苗貯蔵照明方法の実験に用いた光照射条件を示す図。
【図２】試験開始３日目と７日目の実験結果であって、400μmol/m²/sの光を各葉に照射した場合の光合成速度の時間変化を示す図。
【図３】本発明の実施形態に係る苗貯蔵用照明装置であって照明器具が1台の場合の構成図。
【図４】本発明の実施形態に係る苗貯蔵用照明装置であって、複数棚とし照明器具を多段に設置する場合の構成図。
【図５】本発明の他の各種実施形態に係る苗貯蔵照明方法を示す図。
【図６】本発明のさらに他の各種実施形態に係る苗貯蔵用照明装置の構成図。
【符号の説明】
１苗貯蔵室
２苗植え付け用トレイ
３苗
４苗貯蔵用照明
５，６，７，８タイマー機能付き調光用安定器
９ライトコントローラ
１０制御用パーソナルコンピュータ
１１光源ボックス
１２光ファイバー
１３苗貯蔵用梱包箱
１４溝（送光窓部）
１５孔
１６中空ライトガイド[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seedling storage lighting method and a seedling storage lighting device for preserving plant seedlings such as vegetables and flower buds under low temperature and low light.
[0002]
[Prior art]
Recent research on low-temperature storage of plant seedlings has revealed that when seedlings are stored, the seedling quality can be maintained more than darkness by irradiating the seedlings with low light. In addition, the amount of weak light at this time should be an amount that can maintain the light compensation point (the light intensity at which the increase in CO ₂ concentration apparently balances the absorption of CO ₂ by plant photosynthesis and the emission of CO ₂ due to respiration). This has also become clear (Reference: Acta Horticulturae No. 393, March, 1995 Kubota, Kyu, et al.).
Furthermore, in response to this research result, the following light irradiation method for adjusting the amount of light so as to maintain the light compensation point has been proposed.
Technology that controls the light intensity of the lighting device based on the measurement of the carbon dioxide concentration in the low-temperature storage in order to maintain the light compensation point of the plant seedling.
In addition to the above, an illumination method for measuring the temperature and maintaining the light compensation point (see JP 2000-188957 A).
[0003]
Moreover, as a structure of the conventional device for storing low light, a structure in which a lighting fixture is arranged on a seedling storage shelf has been the mainstream (see Japanese Patent Application Laid-Open No. 2001-28946).
Various lighting methods or apparatuses for irradiating light necessary for plant growth instead of seedling storage are known (for example, JP-A-60-186229, JP-A-60-192525, (See JP-A 63-36714, JP-A 61-70928, JP-A 2-255019, JP-A 60-54618, etc.). In these nurturing illumination apparatuses, a bright period with a large amount of irradiation light and a small dark period are provided, and the ratio between the light and dark periods is changed according to the growth stage.
[0004]
[Problems to be solved by the invention]
By the way, light irradiation for seedling storage (preservation) in which the activity of plant seedlings is required at the time of shipment is different from light irradiation for plant growth. In general, when plant seedlings are stored at low temperatures, it is desirable that the amount of light irradiated be at a level that can maintain the light compensation point, but the light compensation point itself depends on the growth, temperature, and humidity of the seedling. Therefore, in order to adjust the amount of light actually irradiated to the seedling to the light compensation point, a complicated system incorporating a sensor or the like is required. For this reason, the actual situation is that light irradiation is performed at a predetermined fixed illuminance at an actual site.
[0005]
However, such light irradiation does not perfectly match the light compensation point, so the period during which the seedling quality can be maintained is shortened, and the seedlings become accustomed to a certain illuminance, resulting in a decrease in photosynthetic ability. It was. Further, when attempting to store seedlings using the illumination device for storing low light shown in the above-mentioned Japanese Patent Application Laid-Open No. 2000-188957, considerable initial cost and running cost are required for capital investment.
[0006]
The present invention maintains the seedling quality during low-temperature storage for a longer period of time than in the case of conventional constant light irradiation, only by devising the light irradiation method, without using a complicated device incorporating a sensor as described above. An object of the present invention is to provide a seedling storage lighting method and a seedling storage lighting device capable of suppressing the initial investment and power consumption of the lighting fixture in storage.
In addition, in the actual market, considering that the distribution of packing boxes stored in a refrigerator for a certain period of time with a seedling packing box is common, the light irradiation is performed on the seedlings that are still in the packing box. An object of the present invention is to provide a lighting device for storing seedlings.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a plant seedling is disposed in a low-temperature space in which outside light and outside air are substantially blocked, and the plant seedling is irradiated with light by a lighting device in the space. In the seedling storage lighting method for preserving seedlings, the illumination device irradiates light with high illuminance above the approximate light compensation point of the plant seedling (referred to as light period) and low illuminance light below the approximate light compensation point. The plant seedling is irradiated with light in combination with a period of time (called dark period). The light compensation point refers to the light intensity at which the increase or decrease in CO ₂ concentration apparently balances between the absorption of CO ₂ by plant photosynthesis and the emission of CO ₂ by respiration. In this method, in the case of conventional constant light irradiation, the seedlings during low-temperature storage are irradiated with light combined with a light period that is above the light compensation point and a dark period that is below the light compensation point. In addition, it is possible to maintain the seedling quality for a long period of time without reducing the photosynthesis rate while keeping the power consumption low. In addition, it is possible to suppress the initial investment of the lighting fixture in storage without requiring a sensor or the like.
[0008]
According to a second aspect of the present invention, in the seedling storage lighting method according to the first aspect, the combination of the light period and the dark period is repeated at a predetermined period. In this method, by appropriately selecting the combination period of the light period and the dark period, the effect of claim 1 can be remarkably obtained and the storage period can be extended.
[0009]
A third aspect of the present invention is the seedling storage lighting method according to the first or second aspect, wherein the dark period is substantially dark. In this method, the effect of claim 1 is remarkably obtained.
[0010]
A fourth aspect of the present invention is the seedling storage lighting method according to any one of the first to third aspects, wherein the integrated light amount irradiated in the light period and the dark period in 24 hours maintains a light compensation point. Therefore, the amount of irradiation light is controlled so as to be approximately the same as when irradiated for about 12 hours. In this method, the photosynthesis ability of the seedling can be maintained better than that in the case of constant light irradiation by making the accumulated light amount in the light period and dark period substantially the same as in the case of constant light irradiation. Long-term storage is possible.
[0011]
The invention of claim 5 is the seedling storage lighting method according to any one of claims 1 to 4, wherein a period of short-time irradiation with light having an intensity exceeding the light compensation point is provided in the light period. It is. In this method, the photosynthetic ability of the seedling is maintained better than in the case of constant light irradiation.
[0012]
The invention of claim 6 is the seedling storage lighting method according to claim 5, wherein a substantially dark compensation period of 1 hour or more immediately before the intense light irradiation is provided when a dark period of darkness is provided before the intense light irradiation. The following adaptive light is irradiated. In this method, the effect of claim 5 can be remarkably obtained.
[0013]
According to a seventh aspect of the present invention, there is provided a lighting device for storing seedlings in which a plant seedling is disposed in a low-temperature space in which outside light and outside air are substantially blocked, and the plant seedling is irradiated with light to preserve the plant seedling in the space. A plant combining a period of irradiating light with high illuminance above the approximate light compensation point (referred to as light period) and a period of irradiating light at low illuminance below the approximate light compensation point of the plant seedling (referred to as dark period). The seedling is irradiated with light. In this configuration, an action equivalent to that of the first aspect can be obtained.
[0014]
The invention of claim 8 is the seedling storage lighting device according to claim 7, wherein the combination of the light period and the dark period is repeated at a predetermined period. In this configuration, an operation equivalent to that of the second aspect is obtained.
[0015]
A ninth aspect of the present invention is the seedling storage lighting device according to the seventh or eighth aspect, wherein the dark period is substantially dark. In this configuration, an action equivalent to that of the third aspect is obtained.
[0016]
According to a tenth aspect of the present invention, in the seedling storage lighting device according to any one of the seventh to ninth aspects, the integrated light amount irradiated in the light period and the dark period in 24 hours can maintain a light compensation point. The amount of irradiation light is controlled so as to be substantially the same as when irradiated for about 12 hours with the amount of light. In this configuration, an action equivalent to that of the fourth aspect is obtained.
[0017]
The invention of claim 11 is the seedling storage lighting device according to any one of claims 7 to 10, wherein a period of short-time irradiation with light having an intensity exceeding a light compensation point is provided in the light period. Is. In this configuration, an operation equivalent to that of the fifth aspect is obtained.
[0018]
According to a twelfth aspect of the invention, in the illumination device for storing a seedling according to the eleventh aspect, when a substantially dark dark period is provided before the intense light irradiation, the substantial light compensation is performed for 1 hour or more immediately before the intense light irradiation. Irradiate the adaptation light below the point. In this configuration, an action equivalent to that of the sixth aspect is obtained.
[0019]
A thirteenth aspect of the present invention is the seedling storage lighting device according to any one of the seventh to twelfth aspects, wherein the light period and the dark period are controlled by relatively moving a positional relationship between the seedling and the light source. It is provided. In this configuration, it is possible to secure the necessary irradiation light quantity with a small number of lighting fixtures for a plurality of seedlings during storage.
[0020]
In a fourteenth aspect of the present invention, in the seedling storage lighting device according to the thirteenth aspect, the relative movement speed of the seedling or the light source during the movement is constant. In this configuration, the integrated amount of irradiation light for each of the plurality of seedlings can be kept constant during storage.
[0021]
According to a fifteenth aspect of the present invention, in the seedling storage lighting device according to the thirteenth aspect, the relative movement of the seedling or the light source during the movement is discrete, and the seedling and the light source are simultaneously stopped for a certain time. In this configuration, an action equivalent to that of the fourteenth aspect is obtained.
[0022]
A sixteenth aspect of the present invention is the seedling storage lighting device according to any one of the seventh to twelfth aspects, wherein a window for allowing the seedling irradiation light to enter the seedling shipping packaging box is provided, It faces the light emitting part. In this configuration, the seedling can be irradiated with light while the seedling is placed in the seedling shipping packaging box, and the seedling storage period can be extended. An optical fiber can be used as the light emitting unit.
[0023]
According to a seventeenth aspect of the present invention, in the seedling storage lighting device according to the sixteenth aspect, the seedling shipping packaging box is formed so as to be able to be stacked, and the light emitting portion can be inserted from the window portion even in the stacked state. It is a thing. In this configuration, the seedling can be irradiated with light in a state where the packaging box for shipping the seedling during storage is not bulky.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments embodying the present invention will be described below.
The present invention relates to a seedling storage lighting method or apparatus in which plant seedlings are arranged in a low-temperature space in which outside light and outside air are substantially blocked, and the plant seedlings are stored in the space while irradiating the plant seedlings with a lighting device. A combination of a period during which light with high illuminance above the approximate light compensation point of the seedling is irradiated (light period) and a period during which light with low illuminance below the approximate light compensation point is irradiated (dark period) Therefore, the combination is repeated at a predetermined cycle as appropriate.
In order to prove the validity of this seedling storage lighting method, we conducted low temperature storage experiments under various light irradiation conditions using actual sweet potato seedlings, and clarified the relationship between the light irradiation method and seedling quality maintenance. The outline of the experiment will be described below.
[0025]
(Background of the experiment)
Closed-type seedling production system, that is, a plant seedling is placed in a space where outside light and outside air are blocked, and an appropriate temperature / humidity environment and light environment are artificially provided to the plant seedling in the space. In order to efficiently produce seedlings in a system for raising seedlings, a seedling production plan is required. Furthermore, by using together with a storage technique that maintains seedling quality while temporarily stopping or suppressing seedling growth for a certain period of time, it becomes possible to adjust the shipping and transplanting time.
In this experiment, the light irradiation method for seedlings was changed, and the relationship between the light irradiation method and seedling quality maintenance in seedling storage was obtained using the photosynthesis rate of individual seedling leaves as an index.
[0026]
(experimental method)
As a test material, sweet potato (variety: veneer) was used, and seedlings were grown for 2 weeks under environmental conditions of a temperature of 27 to 29 ° C., a relative humidity of 70%, and a CO ₂ concentration of 1000 μmol / mol. The light source used for growth was a white fluorescent lamp, and the photosynthetic effective photon flux (hereinafter referred to as PPF) was 100 μmol / m ² / s (from 0 to 2 days), 200 μmol / m ² / s (from 3 to 11 days). 300 μmol / m ² / s (from the 12th day to the 14th day), the daily light irradiation time was 16 hours for the light period and 8 hours for the darkness. In subsequent seedling storage, the room temperature was 12 ° C., the relative humidity was 70%, the CO ₂ concentration was unlimited, and the light irradiation method was as follows. Note that light is regarded as a collection of single particles having energy, and the number of particles emitted per unit time is called a photon flux. Among them, the photon flux included in the wavelength range of 400 to 700 nm that is effective for photosynthesis is defined as photosynthesis effective photon flux (PPF). In this experiment, the average value on a 10 cm high plane from the tray surface where seedlings are planted is defined as PPF.
[0027]
(Light irradiation method for seedlings during storage)
Light irradiation was performed for 24 days as a unit, and six types of patterns as shown in FIG. 1 were provided, and this was repeated for the number of storage days. In this experiment, the cumulative amount of light for 24 hours was constant (240 μmol / m ² / s · hour) (excluding Test Zone 2). Here, a period in which light of ²⁰ μmol / m ² / s or more is irradiated is called a light period, and a period in which light lower than this is irradiated is called a dark period. The shaded area is the light irradiation section. The light compensation point varies depending on various conditions such as seedling type, medium sucrose concentration, temperature and humidity, and is individually obtained.
<Test Zone 1> 24 hours constant light irradiation (always in the dark period)
Dark phase PPF: 10 μmol / m ² / s
(Integrated light irradiation amount: 10 μmol / m ² / s × 24 hours = 240 μmol / m ² / s · time)
<Test Zone 2> Constant light irradiation for 24 hours (always light conditions)
Light period PPF: 20μmol / m ² / s (Light intensity at the approximate light compensation point in this experiment)
(Integrated light irradiation amount: 20 μmol / m ² / s × 24 hours = 480 μmol / m ² / s · time)
<Test group 3> Light irradiation for 12 hours in the light period, PPF in the dark period of approximately 12 hours in the dark period: 20 μmol / m ² / s, PPF in the dark period: 0 μmol / m ² / s
(Integrated light irradiation amount: 20 μmol / m ² / s × 12 hours = 240 μmol / m ² / s · time)
<Test Zone 4> Light exposure for 6 hours in the light period, 6 hours of darkness in the dark period (these were repeated twice a day)
Light period PPF: 20μmol / m ² / s
(Integrated light irradiation amount: 20 μmol / m ² / s × (6 + 6) time = 240 μmol / m ² / s · time)
<Test Zone 5> 30 minutes constant light irradiation in the light period, 23 hours and a half constant light irradiation in the dark period
The dark period (1 hour) was started in order to provide an adaptation time of 1 hour before irradiating with 90 μmol / m ² / s light.
Light period PPF: 90 μmol / m ² / s, Dark period PPF: 8.3 μmol / m ² / s
(Integrated irradiation amount: 90μmol / m ² /s×0.5 hours + 8.3μmol / m ² /s×23.5 hours = 240μmol / m ² / s · hour)
<Test Zone 6> 30 minutes of intense light irradiation in the light period, 12 hours of darkness and low illumination light below the light compensation point for 11.5 hours (high light for 1 hour after the dark period) In order to make it an adaptation time for light, irradiate light with low illuminance below the light compensation point, and then irradiate light with low illuminance below the light compensation point for 10.5 hours after the end of strong light)
Light period PPF: 90 μmol / m ² / s, Dark period PPF: 17 μmol / m ² / s,
0 μmol / m ² / s
(Integrated irradiation amount: 90μmol / m ² /s×0.5 hours + 17μmol / m ² /s×11.5 hours = 240μmol / m ² / s · hour)
[0028]
(measuring device)
The measurement was carried out using a portable photosynthesis measuring device LI-6400 manufactured by LI-COR, and the photosynthesis rate of individual leaves was measured for 2 individuals per test group. The environmental conditions in the leaf chamber of the portable photosynthesis measuring device (hollow chamber for measuring between leaves) are: leaf temperature 25 ° C, relative humidity 60%, CO ₂ concentration 350 μmol / m ² / s, PPF 400 μmol / m ^The flow rate was ² / s and the air flow rate was 250 μmol / s.
[0029]
(Measurement result)
FIG. 2 shows the results of measurements performed immediately after entering the third and seventh days after the start of storage.
The horizontal axis represents the time from the start of measurement with the leaf arbitrarily selected by the experimenter from each test section sandwiched between the leaf chambers. The vertical axis represents the photosynthetic rate after starting measurement. In both days, it can be seen that the test groups 3 to 6 have a faster photosynthesis rate in a faster time than the result of the test group 1 (constant irradiation for 24 hours), and the condition of the seedling is better than that of the test group 1. Further, even if the values at which the photosynthetic rate is finally saturated are compared, the photosynthetic rates in the test groups 3 to 6 are faster than the test group 1. Further, compared with the test group 2 where constant light irradiation at a substantially light compensation point was performed, the seedlings in the test groups 3 to 6 maintained almost the same photosynthetic rate. It can be seen that the seedlings of No.1 are able to maintain the same seedling quality as when they were continuously exposed to the light at the light compensation point.
[0030]
From these measurement results, the following could be confirmed. Combined with the light period of irradiating light with high illuminance above the approximate light compensation point of the plant seedling and the dark period of irradiating light with low illuminance below the approximate light compensation point as in the test sections 3 and 4 If irradiated, the seedling quality can be maintained to the same extent as in the case of continuous light irradiation at the light compensation point, even if the integrated light irradiation amount does not reach the amount of light continuously irradiated at the light compensation point ( Claims 1 to 3).
[0031]
Further, as in test sections 5 and 6, light irradiation is performed so that the cumulative amount of light in the light period and dark period in 24 hours is approximately the same as when light irradiation at the light compensation point is continued for approximately 12 hours. Thus, the seedling quality can be maintained better than in the case of constant light irradiation at the light compensation point (claim 4). In addition, as in test sections 5 and 6, the photosynthesis ability of the seedlings is maintained better than in the case of constant light irradiation by providing a period in which light with an intensity exceeding the light compensation point is irradiated for a short time during the light period. (Claim 5). In addition, in the case where a substantially dark dark period is provided before the intense light irradiation, the above-described effect can be obtained remarkably by irradiating the adaptation light below the approximate light compensation point for 1 hour or more immediately before the intense light irradiation. (Claim 6).
[0032]
(Example)
3 and 4 show the configuration of a seedling storage device including a lighting device for realizing the seedling storage lighting method of the present invention (corresponding to claims 1 to 12). 3A, 3B, 3C, and 3D are examples in which one lighting device 4 is installed in one seedling storage chamber or room 1 (referred to as a seedling storage room). The seedling storage chamber 1 substantially blocks external light and outside air at a low temperature, and forms a space for storing the seedling planting tray 2 in which the seedlings 3 are planted. On the upper part of the seedling 3, a seedling storage lighting device 4 (light source or light emitting section) is disposed as artificial lighting. The dimming ballasts 5, 6, 7, 8 of the luminaire 4 are provided inside or outside the seedling storage chamber 1. Each dimming ballast is controlled by a light controller 9. The dimming ballasts 5 and 6 have a timer function, whereas the dimming ballasts 7 and 8 have no timer function. In other words, the latter dimming ballasts 7 and 8 have only a dimming function and do not have a function for changing the optical output over time. Therefore, in this case, a control personal computer 10 (personal computer) or the like is connected to the tip of the light controller 9, thereby providing a time change function.
[0033]
FIG. 4 (a) is an example in which the inside of the seedling storage chamber 1 is multi-staged and the lighting fixtures 4 are installed for each stage, and FIG. 4 (b) is provided with a plurality of shelves with the lighting equipment 4 installed for each stage, It is an example which performs lighting control for every shelf and every stage. The light controller 9 with a timer function controls the lighting time of the luminaires 4 at each stage and shelf via the dimming ballast 7 according to the method according to any one of claims 1 to 6. To do.
[0034]
In the configuration of the present embodiment, since light irradiation is controlled as described above, the quality of seedlings during low-temperature storage can be maintained for a long time without using a complicated system such as a sensor. In addition, the total light amount and the power consumption corresponding to the total light amount can be reduced as compared with the case where light is irradiated at the conventional light compensation point. In addition, since a time zone for irradiating light and a time zone for not irradiating light are provided, it is possible to freely set a time zone with a large amount of power consumption or a time zone with a small amount of power consumption. Set the time. Furthermore, by providing a plurality of shelves and steps and providing a light period and a dark period for each shelf or each stage without turning on all at once, an increase in temperature in the seedling storage chamber 1 due to heat generated by the lighting device 4 can be reduced. Therefore, the air conditioning load can be reduced.
[0035]
5A to 5G show configuration examples in which the relative positional relationship between the lighting device 4 and the seedling 3 changes (corresponding to claims 13 to 15). In any case, the plant seedlings are arranged in a low-temperature space in which outside light and outside air are substantially blocked, and (a), (d), (e), and (g) indicate the lighting fixture 4 (light source) with respect to the seedling planting tray 2. (B), (c), and (f) are examples in which the seedling planting tray 2 moves relative to the luminaire 4. Reference numeral 17 denotes a seedling storage room with a built-in lighting device 4. In any case, the light period and the dark period are provided by relatively moving the seedling 3 and the lighting device 4. In addition, with the above-described configuration, it is possible to secure a necessary irradiation light quantity with a small number of lighting fixtures 4 for a plurality of seedlings during storage. And the relative moving speed of the seedling 3 or the lighting fixture 4 at the time of movement is made constant, and / or the relative movement of the seedling 3 or the lighting fixture 4 is made discrete, and the seedling 3 and the lighting fixture 4 are simultaneously fixed. By stopping the time, the integrated amount of the irradiation light to the seedling 3 can be made uniform.
[0036]
FIGS. 6A to 6F show examples of a seedling storage lighting device in which a light transmission window is provided in a seedling shipping packaging box (corresponding to claims 16 to 17). In these drawings, 11 is a light source box, 12 is an optical fiber, 13 is a seedling storage packaging box made of corrugated cardboard, 14 is a transparent groove forming a light transmission window provided in the seedling storage packaging box 13, and 15 is the same. A hole 16 forming a light transmission window is a hollow light guide made of a pipe that is hollow inside and guides light. The optical fiber 12 and the hollow guide light 16 are luminaires that can emit light from the side, and these light emitting portions face a groove 14 or a hole 15 provided in the seedling storage packaging box 13. In addition, the light emitting part is structured not to have a convex shape at the top of the seedling storage packaging box 13. As described above, light irradiation has a light period and a dark period.
[0037]
With the above configuration, it is possible to perform desired illumination without changing the mechanism of seedling storage using the existing packaging box, and the seedling storage packaging box 13 can be stacked up and down, Therefore, it is possible to easily cope with the extension of the storage period.
[0038]
The present invention is not limited to the above-described configuration and can be variously modified. For example, the light irradiation cycle of light irradiation is appropriately combined and adjusted so that appropriate light irradiation can be performed on the seedling according to the shipping time of the seedling. do it.
[0039]
【The invention's effect】
As described above, according to the seedling storage lighting method according to the first to third aspects of the present invention, even if the integrated light quantity is less than the light compensation point by using only light device without using a complicated system such as a sensor. The quality of the seedlings during low-temperature storage can be maintained for a long period of time, and the total amount of light and the power consumption corresponding to the total amount of light can be reduced as compared with the case where light is irradiated at a conventional light compensation point. In addition, by providing a time zone for irradiating light and a time zone for not irradiating light, a difference occurs in power consumption depending on the time zone, and a time zone with a large amount of power consumption or a time zone with a small amount of power can be freely set. Thus, if the time for light irradiation is set in a time zone where electricity costs are low, such as midnight power, electricity costs can be saved.
[0040]
According to the illumination method for seedling storage according to the inventions of claims 4 to 6, the photosynthesis ability of the seedling can be maintained better than in the case of conventional constant light irradiation, and the seedling can be stored for a long time. Become.
According to the seedling storage lighting device according to the seventh to twelfth aspects of the present invention, the same effect as the above method can be obtained.
[0041]
According to the lighting device for seedling storage according to the inventions of claims 13 to 15, the number of seedlings irradiated with light by one lighting device may be increased, and the number of lighting devices is greatly increased as compared with a conventional storage shelf. The initial cost of the instrument can be reduced. In addition, in storage shelves where lighting fixtures are always fixed directly above seedlings, it was necessary to adjust the light when changing the PPF, but in this lighting device, the brightness can be changed by moving the fixtures. For this reason, the light fixture does not require a dimming function. Further, the lighting device can irradiate light while continuously moving on the seedling, and the integrated amount of light irradiated to one seedling can be kept constant.
According to the lighting device for seedling storage according to the inventions of claims 16 and 17, light that is effective with a small number of light sources by slightly improving a packing box generally used for distribution without using a large seedling storage device. Irradiation can be performed, and the packaging boxes can be stacked, saving space and being effective for long-term storage.
[Brief description of the drawings]
FIG. 1 is a diagram showing light irradiation conditions used in experiments of conventional and seedling storage lighting methods of the present invention.
FIG. 2 is a graph showing experimental results on the 3rd and 7th days from the start of the test, showing the temporal change in the photosynthetic rate when each leaf is irradiated with 400 μmol / m ² / s light.
FIG. 3 is a block diagram of a seedling storage lighting device according to an embodiment of the present invention in the case of a single lighting fixture.
FIG. 4 shows a seedling storage lighting device according to an embodiment of the present invention, and is a configuration diagram in a case where a plurality of shelves are installed and lighting devices are installed in multiple stages.
FIG. 5 is a diagram showing seedling storage lighting methods according to other various embodiments of the present invention.
FIG. 6 is a configuration diagram of a seedling storage lighting device according to still other various embodiments of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seedling storage room 2 Seedling planting tray 3 Seedling 4 Seedling lighting 5, 6, 7, 8 Light control ballast with timer function 9 Light controller 10 Control personal computer 11 Light source box 12 Optical fiber 13 Seedling storage packaging box 14 Groove (light transmission window)
15 hole 16 hollow light guide

Claims

In a seedling storage and lighting method of storing plant seedlings in a low-temperature space that substantially blocks outside light and outside air, and storing the plant seedlings while irradiating the plant seedlings with a lighting device in the space,
A period (referred to as a light period) of irradiating light with a high illuminance that is equal to or higher than the approximate light compensation point of the plant seedling by the illumination device, and a period (referred to as a dark period) to irradiate a low illuminance light that is approximately equal to or less than the light compensation point A seedling storage lighting method characterized by irradiating a plant seedling with light in combination.

The seedling storage lighting method according to claim 1, wherein the combination of the light period and the dark period is repeated at a predetermined cycle.

The seedling storage lighting method according to claim 1, wherein the dark period is substantially dark.

The amount of irradiation light is controlled so that the integrated amount of light irradiated in the light period and the dark period in 24 hours is approximately the same as that in the case of irradiation for approximately 12 hours by a light amount capable of maintaining a light compensation point. The seedling storage lighting method according to any one of claims 1 to 3.

The seedling storage lighting method according to any one of claims 1 to 4, wherein a period of short-time irradiation with light having an intensity exceeding a light compensation point is provided in the light period.

6. The seedling according to claim 5, wherein, in the case where a substantially dark dark period is provided before the intense light irradiation, the adaptation light having an approximate light compensation point of 1 hour or more is irradiated immediately before the intense light irradiation. Storage lighting method.

In a lighting device for storing a seedling that places a plant seedling in a low-temperature space that substantially blocks outside light and outside air, and irradiates light to preserve the plant seedling in the space,
A period during which light with a high illuminance that is higher than or equal to the approximate light compensation point of the plant seedling (referred to as the light period) and a period during which light with a low illuminance that is equal to or lower than the approximate light compensation point for the plant seedling (referred to as the dark period) are used. A lighting device for storing seedlings, wherein the plant seedlings are irradiated with light in combination.

8. The seedling storage lighting device according to claim 7, wherein the combination of the light period and the dark period is repeated at a predetermined cycle.

The seedling storage lighting device according to claim 7 or 8, wherein the dark period is substantially dark.

The amount of irradiation light is controlled so that the integrated amount of light irradiated in the light period and the dark period in 24 hours is approximately the same as when irradiated for approximately 12 hours by the amount of light that can maintain the light compensation point. The illumination device for seedling storage according to any one of Items 7 to 9.

The lighting device for storing seedlings according to any one of claims 7 to 10, wherein a period of short-time irradiation with light having an intensity exceeding a light compensation point is provided in the light period.

The seedling according to claim 11, wherein when a dark period of substantially darkness is provided before the intense light irradiation, the adaptation light having an approximate light compensation point of 1 hour or more is irradiated immediately before the intense light irradiation. Storage lighting device.

The lighting device for seedling storage according to any one of claims 7 to 12, wherein the light period and the dark period are provided by relatively moving a positional relationship between the seedling and the light source.

The seedling storage lighting device according to claim 13, wherein a relative moving speed of the seedling or the light source during the movement is constant.

The seedling storage lighting device according to claim 13, wherein the relative movement of the seedling or the light source during the movement is discrete, and the seedling and the light source are simultaneously stopped for a certain time.

The seedling storage package according to any one of claims 7 to 12, wherein a window for allowing seedling irradiation light to enter is provided in the seedling shipping packaging box, and the light emitting section is exposed to the window. Lighting device.

17. The seedling storage lighting device according to claim 16, wherein the seedling shipping packaging box is formed so as to be able to be stacked, and the light emitting portion can be inserted from the window portion even in the stacked state.