初夏どりネギ栽培におけるトンネル被覆資材と施肥方法が生育,抽苔および収量に及ぼす影響(栽培管理・作型)  [in Japanese] Effects of Tunnel Covering Plastic Films and Fertilization Methods on Growth, Bolting, and Yield in Welsh Onion (Allium fistulosum L.) Harvested in Early Summer(Crop Production & Cropping Type)  [in Japanese]

初夏どりネギ栽培において,トンネル被覆資材と施肥方法が生育,抽苔および収量に及ぼす影響について調査した.昼間の平均気温および平均地温は,ポリオレフィンフィルム(PO)で最も高く,有滴ポリエチレンフィルム(農ポリ)で低かった.また,POおよび無滴農ポリでは,土壌の乾湿の差が大きい傾向が見られた.抽苔率は,有滴農ポリでは全層区に比べ植え溝区で低かったが,POおよび無滴農ポリでは全層区に比べて植え溝区で高く,抽苔率および収量に被覆資材と施肥方法の交互作用が認められた.初夏どりネギ栽培においては,保温性の高い被覆資材ほど花芽分化の抑制に有効であることが明らかとなった.また,保温性の高い被覆資材を用いる場合には,窒素施肥を調整することにより抽苔抑制効果を高める肥培管理が必要であることが明らかとなった.

Effects of tunnel covering plastic films and fertilization methods on growth, bolting, and yield were investigated in welsh onion (Allium fistulosum L.) harvested in early summer. Polyolefine plastic film (PO) induced the highest mean air and soil temperatures, while dripped polyethylene plastic film (DP) showed the lowest temperatures. Coefficient of variance on soil water content was higher in PO and non-dripped polyethylene plastic film (NDP). Application of an overall layer of fertilizer produced a lower bolting rate than application of fertilizer in a planting furrow only when using DP, but opposite results were demonstrated with PO and NDP. Effects of covering films and fertilization methods on bolting rate and yield showed significant interaction. Higher thermo-keeping films suppressed flower initiation. When higher thermo-keeping films were used to cover tunnels, management to control nitrogen concentration is required to inhibit bolting in this culture.