培養液中NaCl濃度がピートバッグ栽培イチゴの生育,収量と品質に及ぼす影響(土壌管理・施肥・灌水)  [in Japanese] Salinity Levels Affecting Growth, Yield and Quality of Strawberry Grown in Peat Bags (Soil Management, Fertilization & Irrigation)  [in Japanese]

培養故に使用可能な原水中塩濃度の限界を明らかにするため,イチゴ'女峰'をピートバッグ(28×80cm,培地量18liter,8株植え)で栽培し,水道水(EC15mS/m; Na, 0.35; Cl, 0.29mM)で作成した培養液へのNaCl添加がイチゴの生育,収量に及ぼす影響について検討した.NaCl(0, 4, 8, 12mM)以外の基本培養液濃度(NO_3-N, 8; NH_4-N, 0.85; P, 0.85; K, 3.8; Ca, 2.05; Mg, 0.93mM)は,季節に応じて50〜100%の間で変化させた.葉柄中のNaとClの濃度は,NaCl濃度が高くなるほど高くなった.果実の糖濃度と滴定酸度は,対照区が最も高かったが,NaCl濃度による差は認められなかった.12mM区では各花房1番花のガクにチップバーンが多発し,平均果実重と総収量が他の3処理区より低くなった.8mM区でも,チップバーン発生が増加する傾向にあったが,総収量は対照区とほぼ同等であったことから,NaClやその他のイオンを含む場合であっても,原水のECが8mM区に相当する100mS/m程度までであれば,ピートバッグでのイチゴ栽培に利用できる可能性が高いと考えられる.

To estimate the critical salinity level of nutrient solution for strawberry (Fragaria × ananassa Duch.), 'Nyoho' plants were grown in peat bags (8 plants in 28 × 80cm bags containing 18 liter of medium) with solutions prepared with tap water (EC 15 mS/m; Na, 0.35; Cl, 0.29 mM). NaCl (0, 4, 8 and 12 mM) was added to the standard solution containing NO_3-N, 8; NH_4-N, 0.85; P, 0.85; K, 3.8; Ca, 2.05; Mg, 0.93 mM and micro elements. Only the strength of mineral elements, but not that of NaCl, was changed according to the seasons, ranging from 50 to 100% of the standard solution. Concentration of Na and Cl in petiole increased with increases in the concentration of NaCl. Total soluble solids and titratable acidity were highest in the control fruit, but the concentration of NaCl did not affect significantly. Severe tip burn occurred in the calyx of the primary flower in plants supplied with 12 mM of NaCl. Average fruit weight and total yield were significantly lower in 12 mM of NaCl compared to the others. The occurrence of tip burn was also stimulated slightly by 8 mM of NaCl, but it only slightly affected the yield. When the EC value of the obtainable water containing NaCl and/or other ions is lower than 100 mS/m, equivalent to 8 mM of NaCl, the water may be available for strawberry production with peat bags.