ＮＦＴ栽培における培養液量がスプレイギクの養分吸収と切り花品質に及ぼす影響

Abstract

Two cultivars of spray chrysanthemum (Dendranthema grandiflorum), ‘Sei Aloha’ (summer-to-autumn flowering cultivar) and ‘Pinky’ (autumn flowering cultivar), were grown in NFT system and the effects of varying nutrient solution volumes (0.25, 0.50, 0.75, 1.00, 2.00 L plant-1) on mineral uptake and cut flower quality were investigated. The N, P and K uptake remained unaffected with the varying nutrient solution volumes. Nutrient solution volumes of <0.75 L plant-1 resulted into considerable reduction in the shoot length and shoot weight, thus giving rise to poor cut flower quality. Root growth inhibition was observed under 0.25 L plant-1. Reduction in plant growth under smaller nutrient solution volumes occurred possibly via unstable root environment, large fluctuation in EC and pH, and excess accumulation of root exudates in the recirculated nutrient solution. Charcoal addition did not alleviate the reduction in plant growth under 0.25 L plant-1. Also, weekly renewal of nutrient solution with 0.25 L plant-1 resulted in less plant growth compared to 1.00 L plant-1 without renewal.