スプレーギクのベンチ栽培における見かけの養分吸収濃度に基づいた灌水同時施肥栽培法の開発

To develop a simple and rational fertigation technology of spray chrysanthemum in bench culture, the effects of fertigation method by apparent nutrient uptake concentration (ANUC) on growth and cut flower quality were investigated. Twenty-five percentage of the total nitrogen application amount (267mg/shoot) was fertilized as basal fertilizer before planting. The ohter was fertilized by the following four methods after pinching. The other elemental nutrients were applied in proportion to nitrogen. 1) Fixed quantity: an equal amount of nitrogen was fertilized every week. Moreover, water was applied so as not to leach through the bench when pF value is more than 1.8. 2) Fixed time: liquid fertilizer by ANUC was applied everyday at 8 a.m. The applied quantities on every growth stage were calculated based on former water consumption. 3) pF: liquid fertilizer by ANUC was applied so as not leach through the bench when pF value is more than 1.8. 4) Fixed time and pF: liquid fertilizer by twice ANUC was applied everyday at 8 a.m. Moreover, water was applied so as not to leach through the bench when pF value was more than 1.8. Incontract, 5) Manual: liquid fertilizer by the fertigation manual for field was applied. Total nitrogen application was 357 mgN per plant. The growth and cut flower quality were good regardless of fertigation method. Total nitrogen application amount was approximately 267mg per plant in Fixed quality, Fixed time, pF plots and Fixed Time and pF plot. However, 19 mg and 100 mgN per plant in order to leaching run off through the bench on Fixed time plot and Manual plot, respectively. Usually pF value changed between 1.5 and 2.0 during growing period in Fixed quantity, pF plots and Fixed time and pF plot. On the other hand pF value during late growth reached more than 2.0 in Fixed time and Manual plot, and strong water stress occured.