In this first contribution we report the outcome of the growth analysis, yield and water use efficiency (WUE) as well as of nitrate content in hydroponically grown endive with two N levels (8 and 16 mM) supplied in two NH4+:NO3- ratios (50:50 and 0:100). Upon application of the 8 mM N nutritive solution, plants accumulated more dry matter than with 16 mM N. With the first N level, CGR and RGR were higher and also yield was greater, particularly when N was supplied in mixed form. On average, with 8 mM N, 3.9 g dry matter per litre of uptaken water were produced; with 16 mM N, instead, 3.6 and 3.2 g·l-1 were produced depending, respectively, on whether N had been supplied in mixed form or as nitrate only. Also shoot quality was positively affected by the mixed form and the lower level of N. With 50:50 NH4+:NO3- ratio, dry matter content was, on average, lower than with 100 % NO3--N (6.0 vs 6.6 g.100g-1 fresh product) and also nitrates decreased (4,116 vs 5,676 mg.kg-1 of fresh product). By increasing N level from 8 to 16 mM, nitrate leaf content increased from 4,157 to 5,634 mg.kg-1 of fresh product.
Effects of two N levels and two NH4+:NO3- ratios on endive (Cichorium endivia L. var. crispum Hegi). I. Growth, yield and water use
SANTAMARIA, Pietro;
1997-01-01
Abstract
In this first contribution we report the outcome of the growth analysis, yield and water use efficiency (WUE) as well as of nitrate content in hydroponically grown endive with two N levels (8 and 16 mM) supplied in two NH4+:NO3- ratios (50:50 and 0:100). Upon application of the 8 mM N nutritive solution, plants accumulated more dry matter than with 16 mM N. With the first N level, CGR and RGR were higher and also yield was greater, particularly when N was supplied in mixed form. On average, with 8 mM N, 3.9 g dry matter per litre of uptaken water were produced; with 16 mM N, instead, 3.6 and 3.2 g·l-1 were produced depending, respectively, on whether N had been supplied in mixed form or as nitrate only. Also shoot quality was positively affected by the mixed form and the lower level of N. With 50:50 NH4+:NO3- ratio, dry matter content was, on average, lower than with 100 % NO3--N (6.0 vs 6.6 g.100g-1 fresh product) and also nitrates decreased (4,116 vs 5,676 mg.kg-1 of fresh product). By increasing N level from 8 to 16 mM, nitrate leaf content increased from 4,157 to 5,634 mg.kg-1 of fresh product.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
