Mnの土壌施用とpH調整によるカキ'西条'の樹上軟化防止効果(土壌管理・施肥・灌水)  [in Japanese] Effects of Mn Application into Soil and Adjustment of Soil pH on the Prevention of On-Tree Fruit Softening in Japanese Persimmon 'Saijo'(Soil Management, Fertilization & Irrigation)  [in Japanese]

カキ'西条'の樹上軟化防止を目的に,硫酸Mnの葉面散布,Mn肥料の土壌施用および土壌pHの酸性化の効果について検討した.硫酸Mnの葉面散布処理による,葉,ヘタおよび果肉中Mn含量向上効果はみられなかった.しかしながら,イオウ華施用により土壌pHを4.5程度に矯正し,さらにMn資材を施用することにより,葉,ヘタ,果肉および1年生枝中Mn含量が著しく増加するのに伴い,果実のエチレン生成が抑制される傾向が認められ,樹上軟化の発生が減少した.樹上軟化多発園において,成熟期の果肉中Mn含量が100ppm以上になるように,土壌pHの矯正とMn資材を施用することにより,樹上軟化発生を抑制できる可能性があると考えられた.

In order to prevent on-tree fruit softening in Japanese persimmon 'Saijo' (Diospyros kaki Thunb.), the effects of foliar application of MnSO_4 and soil application of manganese manure along with soil pH adjustment to acidity were investigated. Foliar application of MnSO_4 did not affect Mn concentration in the leaves, calyx and flesh. However, soil application of manganese after pH adjustment by sulfur powder application remarkably increased in the Mn concentration in the leaves, calyx, flesh and one-year-old shoots. In accordance with this increase, ethylene production in the fruit was decreased and the occurrence of fruit softening reduced. These results suggested that the maintenance of Mn concentration over 100ppm by Mn manure application to the soil and pH reduction is necessary to prevent on-tree fruit softening of Japanese persimmon.