1.

論文(リポジトリ)

論文(リポジトリ)
本村, 恵二 ; 石嶺, 行男 ; 村山, 盛一 ; 比嘉, 照夫 ; 呉屋, 昭 ; 友寄, 哲夫 ; Motomura, Keiji ; Ishimine, Yukio ; Murayama, Seiichi ; Higa, Teruo ; Goya, Akira ; Tomoyose, Tetsuo
出版情報: 熱帯農業 = Japanese Journal of Tropical Agriculture.  45  pp.202-208,  2001-09-01.  日本熱帯農業学会 — Japanese Society for Tropical Agriculture (JSTA)
URL: http://hdl.handle.net/20.500.12000/5009
概要: Oryza rufipogonの1系統K98を一回母本に栽培イネの台中65号で8回の連続戻し交雑をし, その後自殖をくり返して核置換系統RT98Cを育成した.同育成系統は正常な花粉および種子稔性をもつが, 台中65号との交雑後代においては不 稔個体を生ずる場合があった.そこで稔性に関する遺伝実験を行った結果, 次の結論を導くことができた.稔性は細胞質と核内の1座性の稔性回復遺伝子(Rf-rf)により支配されており, また配偶体支配型であった.ただし, 雌性配偶子は細胞質や稔性回復遺伝子の種類に関わらず常に正常稔性を示しており, 稔性支配を受けるのは雄性配偶子のみであった.すなわち, RT98Cの細胞質は雄性不稔細胞質(msc)であり, この中ではRf遺伝子をもつ花粉は正常に発育するが, rf遺伝子をもつ花粉は退化して受精機能をもたなかった.一方, 台中65号の細胞質は正常な細胞質(mfc)であり, この中ではRfをもつ花粉もrfをもつ花粉も正常に発育した.ヘテロ個体(msc)Rfrf個体を自殖させた場合, 全て種子稔個体となり種子不稔個体が全く現れなかったことから, 稔性は配偶体支配型であることが認められた.なお, ヨード・ヨードカリ液での花粉の染色具合, あるいは花粉の大きさなどは接合体の遺伝子型に関係なく正常花粉も退化花粉もほぼ同様であり, 区別できなかった.<br />Through successive backcrosses, the cytoplasm and nuclear fertility restorer gene of K98,a line of Oryza rufipogon, were introduced into Taichung 65,O. sativa, and a nuclear-substituted line, RT98C, was developed. This line showed a high degree of spikelet fertility, but it produced fertile and sterile plants in the cross with Taichung 65. To analyze the mode of inheritance of the fertility, crossing tests were carried out, and the following results were obtained. Pollen fertility was controlled by the interaction of the cytoplasm and the single restorer fertility gene (Rf-rf), but the function of the embryosac was not affected by the cytoplasm and restorer fertility gene. That is, all the pollen grains in the cytoplasm of Taichung 65 were normal regardless of the dominance or recessiveness of the restorer fertility gene they carried. On the other hand, the pollen grains carrying the Rf gene in the cytoplasm of RT98C were normal, while the pollen grains carrying the rf gene in this cytoplasm became sterile. The normal cytoplasm of Taichung 65 was designated as (mfc) and the sterile cytoplasm of RT98C as (msc). When the (msc) Rfrf plants were selfed, in all the resulting plants, spikelet fertility was restored, and no sterile plants were observed, suggesting that the pollen grains carrying the rf gene were not viable. Thus, the male sterility and fertility restoration in this line were controlled by the genotype of the gamete itself but not by that of the zygote, indicating the presence of a gametophytic control of fertility. Only in the (msc) rfrf plants spikelet fertility was not restored, while in the plants with all the other genotypes, viz. (msc) RfRf, (msc) Rfrf, (mfc) RfRf, (mfc) Rfrf and (mfc) rfrf, spikelet fertility was restored, resulting in a high degree of spikelet fertility. Although pollen grains carrying rf in (msc) degenerated regardless of the plant genotype (Rfrf or rfrf), they all stained well in a I_2KI solution and showed a normal size. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
米盛, 重保 ; 比嘉, 照夫 ; Yonemori, Shigeyasu ; Higa, Teruo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.121-128,  1988-12-05.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/3900
概要: 2mm以下の粒状の軽石をパミスサンドと称することにし, パミスサンドを培地に利用してパパヤの養液栽培の可能性を試みた。また, パミスサンド栽培における栽培液濃度とわい化剤がパパヤの生育に及ぼす影響について検討した。1.培養液濃度はOKF-1 を500倍, 1,000倍, 2,000倍および3,000倍区に設定し, 生育試験を行なった結果, 濃度が最も高い500倍区が草丈, 葉数, 茎径および着花(果)とも良く濃度が低くなるにつれて生育の遅延, 着花数の減少が顕著に現れた。これらの結果からパパヤは基本栄養生長型の作物であることが明らかになった。2.スミ7,スリトーン, B-9およびCCCの4種類のわい化剤を用いてわい化試験を行なった結果, 全てのわい化剤にわい化効果が確認され, スミ7の5倍区が最も高いわい化効果があった。3.パミスサンドを培地にしたパパヤの養液栽培は十分可能であることが明らかとなり, パパヤの施設栽培における連作障害対策として新しい方向性が示唆された。<br />The purpose of this experiment is to determine the possibility of hydroponic cultivation of Papaya plants in aPumice Sandgrowth medium.PumiceSandis as defined a pumice rock ground to a fineness of no larger than 2mm. Separate applications of culture solution and growth retardant were utilized in this experiment. 1. The culture solution aspect of the experiment was carried out in four separate cultivation beds using OKF-1 fertilizer concentrate diluted 500,1000,2000 and 3000 times. Optimum observed solution was 500 which yielded the best resulte in plant length, diameter, leafing and flowering duration and size. Increased dilution resulted in growth delay. From these results it is evident that the Papaya plant is a basic vegetative growth plant. 2. The growth retardant aspect of the experiment was also conducted in four cultivation beds with four solutions. The optimum solution observed was the sprayed application of SUMI-7 diluted five times. 3. The possibility of hydroponic cultivation of Papaya plants in aPumice Sandmedium was wholly confirmed. Additionally, a new tendency for the prevention of replant failure was suggested for the long term protected hydroponic cultivation of Papaya. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; Higa, Teruo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.1-5,  1982-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4018
概要: 沖縄地域における早生温州の着果安定を目的とし, 2,4-Dの効果について検討した結果次の諸点が明らかとなった。1,11,3月上旬の2,4-D10&acd;20ppmの3回散布は冬&acd;春期の落葉を防止し着果率を著しく増加 させる。50ppm以上の濃度では葉が黄化し畸形果の発生が多くなり, 新梢も畸形となる。処理樹が窒素不足となった場合は二次落果期に落葉が多くなるため, 窒素不足にならないようにすることが望ましい。<br />The purpose of this study was to get the fruit set of citrus unshu (Satsuma wase) using 2,4-D. The results of this study are as follows. 1. Three times treatment of 10-20ppm of 2,4-D early in January, November and March prevented the defoliation during the winter and spring, and increased remarkably the fruit set percentage. 2. At concentrations above 50ppm of 2,4-D, the leaves were etiolated and revealed a number of the malformed fruits, and the current shoot became malformed. 3. In the case of nitrogen defficiency, the defoliation was increased considerably during the second fruit drop, therefore it is desirable to give a suitable quantity of nitrogen. 続きを見る
4.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 竹島, 久善 ; Higa, Teruo ; Takeshima, Hisayoshi
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.21-29,  1981-11-30.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4045
概要: 柑橘類の無核化の研究の一環として種子発達におよぼすルチンの影響について調査を行なった結果, 次の諸点が明らかとなった。1.シークワーシヤ(C. depresa Hayata)とカーブチ(C. keraji var kabuchii)に対しル チン250ppm処理で種子発達に対し強い抑制効果が認められた。2.ルチンの種子発達抑制効果の発現は開花後から30日内外である。3.セミノールタンゼロに対しルチン500ppmの葉面処理で種子減少に対する安定した効果が認められた。4.ルチン処理による無核果は小果となり易い。<br />This study was carried out one of the subject to make for seedless of citrus the effect of rutin on the seed development. The results obtained summarized as follows; 1. The treatment by 250ppm of rutin had recognized strong effect to control for seed development of Citrus depressa Hayata and Citrus keraji var kabuchii. 2. The effect of rutin to control for seed development had occured during from after full blooming to about 30 days after blooming period. 3. Folia spray of 500ppm of rutin for seminol tanzelo had recognized constantly effect to reduce for number of seed. 4. The seedless fruit treating by rutin as apt to become small compare with normal fruit. 続きを見る
5.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 平良, 文男 ; 米盛, 重友 ; Higa, Teruo ; Taira, Fumio ; Yonemori, Shigetomo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.9-17,  1980-11-29.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4082
概要: 高温多雨時に収穫される早生温州の品質対策として, リン酸-カリ, ルチンを安定剤としたホウ素とマンガンの葉面散布剤(DA)NAA, BA等の功果について, 開花後40&acd;50日目を1回処理とし, その後30日おきの計3回の散布 処理を行なった結果, 次の諸点が明らかとなった。1.リン酸-カリは250倍, 500倍ともに増糖の効果があるのに対し, 減酸については500倍のみに認められた。2.DAは増糖, 減酸に高い効果を示し, 500倍の1回, 2000倍の3回が顕著である。3.リン酸-カリ500倍, DA2000倍の併用は, 1回散布で著しい効果が認められる。4.NAAは10ppmおよび25ppmの3回散布で増糖, 減酸の効果が認められるが濃度よりも回数が重要である。5.BAもNAA同様10ppmおよび25ppmで増糖, 減酸の効果が認められ, 2&acd;3回の復数散布がより効果的である。6.樹の栄養状態による差が認められるが樹勢が強い場合は2&acd;3回, 樹勢の弱い場合は1&acd;2回を目安とする。<br />As one of the methods to produce high-quality Satsuma wasa (Citrus unshiu) in the hot season with much rain, the effect of the folia spray by KH_2PO_4,DA (a substance including rutin for buffer of Bo, Mn solution), NAA, BA was investigeted. The folia spray was started 40 to 50 days after blooming. The treatment was done three times 30 days intervals. The result obtained are brifly summarized as fallows : 1. The sugar content of Satsuma wase treated by KH_2PO_4 of 250 times and 500 times became higher than that of non-treatment. The acid content was reduced when treated by KH_2PO_4 of 500 times. 2. DA had a great effect to increase the sugar content and to reduce the acid content. The treatment by one-time spray of 500 times and three-times spray of 2000 times had highly effct. 3. Mixing treatment by one time-spray of 500 times' KH_2PO_4 and 2000 times' DA was recognized to have very effect increasing sugar content and reducing acid content. 4. The treatment by three-times spray of 10 and 25ppm of NAA was recognized to increase sugar content and reduce acid content. The number of NAA spray was more impotant than the concentration. 5. As treated by NAA, the treatment by 10 and 20ppm of BA was recognized to increase sugar content and to reduce acid content. The effect was greater when sprayed two or three times. 6. The effect of spray was diffrent according to each trees growth condition. Two or three spray were necessary for high-vigar trees but one or two spray for low-vigar trees. 続きを見る
6.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; Higa, Teruo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.1-7,  1979-12-11.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4141
概要: 本研究は沖縄地域におけるセミノールの生態について調査を行なったもので, 次の諸点が明らかとなった。1.開花期は3月下旬から4月上旬で比較的安定している。2.糖は2月中旬に12.5&acd;13.5度に達し次第に減少する。3.酸は経時 的に減少し, 3月の上旬までに1.2&acd;1.5度まで低下する。4.1月中旬で完全着色となり3月上旬から次第に退色する。5.葉果比は35枚内外で300g以上となり, 30枚以下でも隔年結果性は認められず, 多肥, 多収の性質を有している。<br />This paper is to study on the ecology of Seminole tangelo in Okinawa district. The result obtained are briefly summarized as follows; 1. The blooming time of Seminole tangelo is every which during the end of March to first of April. 2. The highest sugar content of Seminole tangelo is 12.2 to 13.5 percent in the middle of Febrary. The content reducing slightly after that. 3. The acid content becomes reduced starting early December. It is less than 1.2 to 1.5 percent by early March. 4. The fruit complete coloring falls in the middl of January and begins lesscoloring at early March. 5. Therty five leaves are needed to make one fruit of more than 300g. Alternate bearing can not be recognized even if less than therty leaves per fruit. Seminole tangelo has a charactor to set more fruits with if more fartilization. 続きを見る
7.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 喜屋武, 清子 ; 米盛, 重保 ; Higa, Teruo ; Kiyan, Kiyoko ; Yonemori, Shigeyasu
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.9-15,  1979-12-11.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4142
概要: ネットメロンの品質向上対策の一環として, リン酸-カリと蔗糖の葉面散布の効果について検討を行なった結果, 次の諸点が明らかとなった。1交配10日, 20日, 30日後の3回にわたって, リン酸-カリ500倍にクエン酸500倍加用の散布区は糖 度が著しく高くなり, 1%レベルで有意の差が認められた。2交配10日, 20日, 30日, 40日後の3回散布されたリン酸-カリ及び糖のクエン酸加用区も0.7度以上もの糖の増加が認められた。3交配20日, 25日, 30日, 35日, 40日後の5回にわたって散布されたリン酸-カリ及び糖のクエン酸加用区は, いずれも糖含量が低下し多用の結果は逆効果となることが認められた。4クエン酸を加用せず, リン酸-カリ単独散布の場合は5回散布区の糖度が高くなっておりクエン酸加用の効果が認められた。クエン酸の濃度については500倍と1000倍区の間では差は認められなかった。5果肉の厚さについては処理間に差は認められなかったが, 果重については処理区はやや減少することが認められた。6処理区は全般に葉が立ち気味となり, 受光体勢が改善され, 糖度の高い区程, 顕著であった。<br />As one of the methods to prevent how to make high-quality net melon, the folia supply by KH_2PO_4 and sucrose of the effect to the quality of net melon was investigated, The results obtained are briefly summarized as follows; 1. Folia supply of KH_2PO_4 by 500 times with citric acid of 500 times on 10,20,and 30 days after pollination, the sugar content of fruits became higher than the nontreatment. The signifcant of 1% level was recognized. 2. Three times of folia supply of KH_2PO_4 and sucrose with citric acid of the same concentration on 20,30,and 40 days after pollination, the sugar content increased more than 0,7 percent. 3. Five times of folia supply of same concentration on 20,25,30,35,and 40 days after pllination, the sugar content became reducing although the supply times were encreased. 4. In this case of mono supply of KH_2PO_4 without citric acid the sugar content became higher when given five times than three times. It means the effect of citric acid as carrier was proved. The effect of concentration of citric acid was not recognized betweem 500 times and 1000 times., 5. The thickness of fruit was not diffrent between each treatment and nontreatment. The weigh of fruit on traetment was less than slightly. 6. The leaves treated became setting up rightly compeard with nontreated leaves. The treated could received the sun shine easily which means the sugar content would be increased remarkably. 続きを見る
8.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 米盛, 重友 ; Higa, Teruo ; Yonemori, Shigetomo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.77-87,  1978-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4185
概要: 沖縄地域における早生温州の隔年結果対策の一環としてNAA処理による梢枝発生の調節と, 次年度における着花や結実におよぼす影響について検討を行なった結果, 次の諸点が明らかとなった。1.夏季高温時の多肥条件下におけるNAAの萌芽抑制は, 20 0ppmで無処理区の47%, 500ppmで22%, 1000ppmで12%となり, 濃度が高くなるにつれて著しい効果が認められる。2.萌芽抑制効果の持続期間は, 200ppmで10&acd;15日, 500ppmで25&acd;30日, 1000ppmで35&acd;40日となり, 萌芽抑制と類似の傾向が認められる。3.一般圃場における夏秋梢の抑制については, 新芽発生直前の500ppm, 晩秋梢は200&acd;500ppmで十分な効果が認められる。4.NAA処理による夏秋または晩秋梢の抑制は, 次年度の着花率をかなり増加させ, 特に生理落果防止に対し著しい効果が認められる。5.NAA処理による梢枝の調節は, 開花期や収穫期の調節にも極めて効果的である。<br />As one of the method to prevent the alternate bearing of Wase Satuma (C. unshiu var. praeox) in Okinawa district, this study was investigated the control of new shoots sprouting treated by NAA and the influence to the flowering and fruits set in the next year. The results obtained are briefly summarized as fallows : 1. The control of new shoots sprouting treated by NAA under the high nutritional condition with high temperature in summer shows 47 percent by 200ppm, 22 percent by 500ppm, 12 percent by 1000ppm compared with nontreatment. A remarkable effect is recoginized accoding to the concentration of NAA. 2. The period of the effect of buds sprouting control treated by NAA is 10 to 15 days by 200ppm, 25 to 30 days by 500ppm, 35 to 40 days by 1000ppm. It is apt to show the similar percentage of the new shoots sprouting. 3. In the practical application of NAA right befor the new sprouting come out, 500ppm is enough to control the summer and autumn shoots in common citrus orchards, 200 to 500ppm is enough to control the late autumn shoots. 4. The effect of NAA treatment on summer, autumn and late autumn shoots control has fairly increased the rate of flowering and fruits set in the next year. Especially, it has a considerable effect to prevent the phsyiological fruit drop. 5. The regulation of shoots sprouting by NAA treatment has a remarkable effect to control the flowering and harvesting time. 続きを見る
9.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 上原, 周夫 ; 小橋川, 共志 ; Higa, Teruo ; Uehara, Chikao ; Kobashigawa, Kiyoshi
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.89-95,  1978-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4186
概要: 沖縄地域における早生温州の隔年結果対策の一環として, 収穫後の萌芽促進, 新梢の充実, ならびに次年度の着花や着果におよぼすGAの影響について検討を行なった結果, 次の諸点が明らかとなった。1.GA 50,100,250ppmのいずれの処理 区の萌芽率は無処理区の2&acd;3.5倍に達し, 著しい効果が認められ, 濃度の高い順に, 更には窒素(尿素)の葉面散布を併用した区ほど高くなっている。2.次年度の結果量を予測する有効予備枝数も処理区は無処理区の2&acd;3倍に達し, 萌芽率と同様に窒素の葉面散布を併用した区ほど多くなっている。3.新葉数の増加率も各処理は無処理の1.8&acd;2.8倍に達し, 萌芽率とほぼ類似の傾向となっている。4.有効予備枝の次年度における有花節率は, 全区とも87&acd;100%とかなり高い値いを示し, 実用上, GAの花芽抑制作用の影響は全く認められなかった。5.着果数は, 前年度の有効予備枝数と深い関係にあり, 予備枝数の多い区ほど着果数の増加が認められた。<br />As one of the method to prevent the alternate bearing of Wase Satsuma (C. unshiu var. praeox) in Okinawa district, this study investgate the effect of GA on promoting of buds sprouting after harvest, maturing of new shoots, flowering and fruits set of the next year. The results obtained are briefly summarized as fallows : 1. The percentage of buds sprouting of each GA treatment by 50,100,250ppm is 2 to 3.5 times of nontreatment. A remarkable effect is by the order of the high concentration of GA. Folia spray of nitrogen (urea) results in higher percentage of buds sprouting. 2. As for number of preliminary shoots that may predict the next harvest, each GA treatment is 2 to 3 times compared with nontreatment. Like the buds sprouting percentage, folia spray of nitrogen reaults in higher percentage of preliminary shoots. 3. As for the increasing rate of new leaves, each treatment is 1.8 to 2.8 times compared with nontreatment. It is apt to show the similar percentage of the buds sprouting. 4. The sprouting node-flower rate of preliminary shoots in the next year shows conciderable high percentage from 87 to 100 in each treatment. In case of the plactical apprication, the influence of controling of flower iniciation of citrus by GA is not recognized at all. 5. The number of the fruit set has a close connection with the preliminary shoots. It is recoginized that the more the preliminary shoots, the more the number of the fruit set. 続きを見る
10.

論文(リポジトリ)

論文(リポジトリ)
比嘉, 照夫 ; 米盛, 重友 ; Higa, Teruo ; Yonemori, Shigetomo
出版情報: 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus.  pp.159-168,  1977-12-01.  琉球大学農学部
URL: http://hdl.handle.net/20.500.12000/4233
概要: 本研究は沖縄地域におけるタンカンの導入過程や生態調査を行なったもので次の諸点が明らかとなった。1.沖縄地域におけるタンカンは, 1935年頃, 台湾から見本程度に導入されたが, 全域的な経済栽培は1966年からである。2.開花期の早晩は, 開花前冬季の気温や雨量, 更には, 前年の新梢の発生時期と深い関係にあり, 暖冬多雨の場合は早く, 新梢の発生時期が早く早期に充実した樹ほど早期開花となっている。3.着化率も前年の新梢発生時期と深い関係にあり, 発生時期が早く早期に充実した樹ほど高くなり, また, 着果樹よりも無着果樹の方が高い着花率となっている。4.糖は11月中旬より増加し始め, 2月下旬において最高に達するが, 糖含量は気象条件によって大きく異なり, 暖冬多雨の場合は13&acd;14度, 気温が平年なみで乾燥が続く場合は, 15&acd;16度となり, 全般に高い糖度を示している。5.酸含量は11月中旬より低下し2月中下旬で1%以下となり, 暖冬の年ほど減酸の程度が早くなっている。6.着色については, 気温と乾燥が大きく影響し暖冬多雨の年は2月中下旬, 低温乾燥の年は12月下旬で完全着色となり著しい幅が認められる。7.タンカンは気象条件の大幅な変動にもかかわらず品質は安定し, 病害虫や台風にも強く沖縄地域にとって好適な品種である。<br />This paper is to do reserch on the process of introduction of Citrus tankan Hayata to Okinawa district and the ecology. As a result the following have been proved. 1. Citrus tankan Hayata was introduced to Okinawa as a sample about 1935 from Taiwan. It has been actively planted as industry since 1966. 2. The blooming time is closely connected not only with the temperature and rainfall of the previous winter but with the sprouting time of new shoots of the year before. The blooming comes earlier when it is warm and there is much rain. 3. The rate of flower see it closely connected with the sprouting time of new shoots of the year before. The trees bloom earlier in the winter when it is warm and rainy. The trees which have new shoots sprouted earlier in the previous year, bloom earlier. The earlier sprouted shoots and nonbearing trees show higher rate of flowerset. 4. The sugar content is greatly influenced by the weather condition. In a warm year with much rain the sugar content is 13 to 14 percent. In the mean year with little rain the content is 15 to 16 percent. Citrus tankan Hayata shows a high percentage of the sugar content under any weather conditions. 5. The acid content begins decreasing in mid-November and it is less than one percent at the end of February. The acid content rapidly decrease in a warm winter. 6. The coloring has greatly influenced by the temperature and the rainfall. In a warm year with much rain the complete coloring is in or after the middle of February. In a cold year with little rain the coloring fulls at the end of December. 7. Although the weather condition in Okinawa is unfavorable, Citrus tankan Hayata is one of the best species for planting in Okinawa district which is strong against disease and insect pest and typhoon. It constantly show a good quality. 続きを見る