著者

岩堀 修一 大畑 徳輔 イワホリ シュウイチ オオハタ IWAHORI Shuichi OOHATA J.T

出版者

鹿児島大学

雑誌

南海研紀要 (ISSN:03895351)

巻号頁・発行日

vol.2, no.1, pp.67-73, 1981-11-10

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Two experiments were conducted to evaluate the alleviative effects of calciumacetate on defoliation and fruit drop induced by the spray of Ethephon (2-chloro-ethylphosphonic acid)solution which is used to accelerate the degreening of ponkan, Citrus reticulata Blanco, fruit. The effect of Figaron (Ethyl 5-chloro-1 H-3-indazolyl acetate) on degreening was also investigated.In experiment 1, a split-plot design was employed where the main plots consistedof three levels of Ethephon concentration (0, 200, 400, ppm) and six replicates, whilethe sub-plots consisted of four limbs designated to four levels of calcium acetateadded (0, 0.2, 1.5%). The spray treatment was done on November 1, and Ethephonand calcium acetate were mixed just before the spray application.Ethephon substantially increased defoliation and fruit drop, however, this wasalmost completely prevented by the addition of calcium acetate. Ethephon markedlyincreased the coloration of ponkan fruit. The addition of calcium acetate slightlydecreased the color acceleration, but the color was still considerably increased whencompared with the unsprayed control group.In experiment 2,200 ppm Ethephon with 1% calcium acetate and 200 ppmFigaron treatments were compared as a factorial combination consisting of fourtreatments. Figaron was sprayed on September 9, and Ethephon on November 4.No defoliation and fruit drop were observed in any treatment plots. Ethephonwith calcium acetate remarkably accelerated degreening and coloration of ponkanfruit. Figaron also appreciably improved fruit color but no additive effects ofEthephon and Figaron treatments were observed over Ethephon treatment alone.It is suggested that spraying 200 ppm Ethephon mixed with 1% calcium acetatein early November accelerates degreening and coloration without defoliation andfruit drop, and the method is commercially feasible.ポンカン(Citrus reticulata Blanco)果実の着色促進にエスレル(2-chloroethylphosphonic acid)を散布する際の,酢酸カルシウム混用による落葉・落果防止効果を検討した。またフィガロン(Ethyl 5-chloro-1 H-3-indazolylacetate)の着色促進効果も試験した。実験1では分割区法でエスレル濃度(0, 200, 400ppm)と酢酸カルシウム濃度(0, 0.2, 1, 5%)を組みあわせ,11月1日に散布した。高濃度のエスレルで落葉・落果が増加したが,酢酸カルシウムの混用により,落葉・落果が抑制された。エスレルによる着色は著しく促進されたが,酢酸カルシウムの混用はいく分その効果を弱めた。実験2では要因配置法で1%酢酸カルシウム混用200ppmエスレル散布,無散布と,200ppmフィガロン散布,無散布をくみあわせ,4処理の試験を行なった。フィガロンは9月9日,エスレルは11月4日に散布した。どの区でも落葉・落果はほとんど認められなかった。エスレルは着色を著しく促進した。フィガロンも着色を促進したがエスレルには劣った。エスレル,フィガロンともに果実中の糖やクエン酸含量に影響を及ぼさなかった。1%酢酸カルシウム混用200ppmエスレルの11月上旬散布がポンカンの着色促進のため実用化できると考えられる。