イチゴの促成栽培における主茎腋芽の発達に及ぼす定植後の温度および施肥量の影響(栽培管理・作型)  [in Japanese] Effects of Temperature and Amount of Fertilizer Applied after Transplanting on the Development of Axillary Buds on Primary Crowns in Strawberry Forcing Culture(Crop Production & Cropping Type)  [in Japanese]

代表的な促成栽培用品種である'とちおとめ','女峰'および'とよのか'を用いて,主茎腋芽の発達に及ぼす定植後の温度と施肥量の影響を検討した.植物体は温度条件と施肥量を各2段階に変え,これらを組み合わせた4条件下で栽培した.頂花房直下の腋芽を第1節腋芽とし,第4節までの腋芽のタイプを定植後52日目に調べた.腋芽は休眠芽,一次側枝,ランナーに分類した.3品種とも第1節腋芽はすべて一次側枝に発達した.いずれの品種でも第3,4節の腋芽は低温下では休眠芽となるものが多かったが,高温下ではラソナーとなるものが増加した.'とちおとめ','女峰'では施肥量が増えると休眠芽の割合加減少したが,'とよのか'では施肥量の影響は小さかった.第2節では,休眠芽の割合は低く,高温下でランナーの割合が増加した.施肥量が増えると,'とちおとめ'では一次側枝の割合が増加したが,他の2品種では一次側枝の割合はほとんど変化しなかった.以上の結果は,第2節の腋芽の発達を調節するため,品種によって温度や施肥条件を変える必要があることを示唆している.

The effects of temperature and amount of fertilizer applied after transplanting on the development of axillary buds on primary crowns were studied in three leading strawberry cultivars used for forcing, i.e., Tochiotome', 'Nyoho' and 'Toyonoka'. The nodes were numbered basipetally; the nodes just below the primary inflorescence were designated as node 1. Plants were grown with different amounts of fertilizer (210 and 420 mg N/pot) under two temperature conditions (32/27 and 22/17℃). The axillary buds remained dormant, or developed into secondary crowns or runners. The developmental pattern of axillary buds at nodes 1 to 4 was checked 52 days after planting, for 15 plants per treatment. All axillary buds at node 1 developed into secondary crowns regardless of cultivars and treatments. In these cultivars, most axillary buds at nodes 3 and 4 remained dormant under 22/17℃, while they developed into runners under 32/27℃. In 'Tochiotome' and 'Nyoho', an increase in the amount of applied fertilizer decreased the number of plants with dormant buds at nodes 3 and 4, but there was little effect of fertilizer application rate on the fate of axillary buds in 'Toyonoka'. There were few plants with dormant buds at node 2 in these three cultivars under 22/17℃, but the number of plants that formed runners at node 2 increased as temperature increased from 22/17℃ to 32/27℃. An increase in the fertilizer application rate increased the number of plants that formed secondary crowns at node 2 in 'Tochiotome', but not in 'Nyoho' and 'Toyonoka'. These findings suggest that temperature and the amount of applied fertilizer should be adapted to the cultivar to control the number of secondary crowns at node 2 according to the preference.