ワケギ初夏どり栽培用の鱗茎生産における日長延長および暗期中断が鱗茎肥大に及ぼす影響

<p>The effects of long-day treatment (day-extension and night break treatment with an incandescent lamp) were investigated to obtain hypertrophied seed bulbs of <i>Allium</i> × <i>wakegi</i> Araki for early summer-harvesting cultivation. A day length longer than 15 hours accelerated bulb hypertrophy (bulb hypertrophy index about 2.5 compared with conventional production) and early plant growth in 'Shimonoseki'. Similar effects were observed by 3–4 hour night break treatment, which reduced the cost of electricity. Long and early long-day (16 hr) treatment increased the bulb hypertrophy index, but this index and the bulb weight at planting were lower after experimental periods of 40 and 60 days. A period of supplemental lighting treatment longer than 80 days and starting on January 1st would promote bulb enlargement, as in conventional production.</p>