אסיף מאגר המחקר החקלאי

Nitrogen nutrition of greenhouse pepper. II. Effects of nitrogen concentration and NO3:NH4 ratio on growth, transpiration, and nutrient uptake

Year:

2001

Source of publication :

Authors :

Volume :

36

Co-Authors:

Bar-Tal, A., Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Aloni, B., Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Karni, L., Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Rosenberg, R., Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel

Facilitators :

Link :

Abstract:

The objective of this research was to study the effects of N concentration and N-NO3:N-NH4 ratio in the nutrient solution on growth, transpiration, and nutrient uptake of greenhouse-grown pepper in a Mediterranean climate. The experiment included five total N levels (0.25 to 14 mmol·L-1, with a constant N-NO3:N-NH4 ratio of 4) and five treatments of different N-NO3:N-NH4 ratios (0.25 to 4, with a constant N concentration of 7 mmol·L-1). Plants were grown in an aero-hydroponic system in a climate-controlled greenhouse. The optimum N concentrations for maximum stem and leaf dry matter (DM) production were in the range of 8.0 to 9.2 mmol·L-1. The optimum N-NO3:N-NH4 ratio for maximal stem DM production was 3.5. The optimum value of N concentration for total fruit DM production was 9.4 mmol·L-1. Fruit DM production increased linearly with increasing N-NO3:N-NH4 ratio in the range studied. The N concentration, but not N source, affected leaf chlorophyll content. Shorter plants with more compacted canopies were obtained as the N-NO3:N-NH4 ratio decreased. The effect of N concentration on transpiration was related to its effect on leaf weight and area, whereas the effect of a decreasing N-NO3:N-NH4 ratio in reducing transpiration probably resulted from the compacted canopy. Nitrogen uptake increased as the N concentration in the solution increased. Decreasing the N-NO3:N-NH4 ratio increased the N uptake, but sharply decreased the uptake of cations, especially Ca.

Note:

Related Files :

תוכן קשור

More details

You may also be interested in