Articles
THE EFFECTS OF N CONCENTRATION IN PRE-TRANSPLANT NUTRIENT SOLUTION ON THE N USE EFFICIENCY AND DRY MASS PARTITIONING OF VEGETABLE SOLANACEAE SEEDLINGS
Article number
830_57
Pages
405 – 412
Language
English
Abstract
The influence of nitrogens concentration in nutrient solution on N use efficiency (NRE) and dry mass portioning in the nursery stage of vegetable solanaceae crops (tomato, pepper and eggplants) seedlings were tested in experiments conducted in a plastic greenhouses during the period 20052007. Graded seeds of each specie were individually seeded in to foam trays filled with vermiculite.
Differentiated N concentrations were applied in the nutrient solution (25 to 100 mg L-1 and 100 to 250 mg L-1), while NPK ratio equal to 1:0.4:1.2 was maintained in the first experiment, and a constant concentration of phosphorus (40 mg L-1) and potassium (250 mg L-1) in other cases.
The necessary microelements were also added to the nutrient solutions and equal quantities of 2050 ml/plant were periodically supplied, each module.
Root, stems and leaf dry matter were weighted and stem length and plant leaf area were successfully measured.
The stem elongation rate, the leaf expansion rate, root to whole plant dry weight ratio (RWR), root to shoot dry weight ratio (RSR), and the respective fractions of roots, stems and leaf dry mass versus total plant weight (RMF, SMF, LMF) were calculated.
N content in the dry matter of plants was analysed in weekly intervals and cumulative NRE values were estimated.
The increase of nitrogen concentration in the nutrient solution was followed by a progressive increase of the whole plant dry weight, but in the meantime a steady decrease of root dry weight versus total plant dry weight and of root dry weight versus shoot dry weight was observed.
The stem mass fraction (SMF) seems to be the most responsible fraction of the above ground mass weight increase.
N content in the plant dry matter was increased due to the increase of N concentration, but NRE values were gradually decreased.
However, NRE values became gradually higher parallel to the gradual increase of the plant root volume and leaf area index.
Differentiated N concentrations were applied in the nutrient solution (25 to 100 mg L-1 and 100 to 250 mg L-1), while NPK ratio equal to 1:0.4:1.2 was maintained in the first experiment, and a constant concentration of phosphorus (40 mg L-1) and potassium (250 mg L-1) in other cases.
The necessary microelements were also added to the nutrient solutions and equal quantities of 2050 ml/plant were periodically supplied, each module.
Root, stems and leaf dry matter were weighted and stem length and plant leaf area were successfully measured.
The stem elongation rate, the leaf expansion rate, root to whole plant dry weight ratio (RWR), root to shoot dry weight ratio (RSR), and the respective fractions of roots, stems and leaf dry mass versus total plant weight (RMF, SMF, LMF) were calculated.
N content in the dry matter of plants was analysed in weekly intervals and cumulative NRE values were estimated.
The increase of nitrogen concentration in the nutrient solution was followed by a progressive increase of the whole plant dry weight, but in the meantime a steady decrease of root dry weight versus total plant dry weight and of root dry weight versus shoot dry weight was observed.
The stem mass fraction (SMF) seems to be the most responsible fraction of the above ground mass weight increase.
N content in the plant dry matter was increased due to the increase of N concentration, but NRE values were gradually decreased.
However, NRE values became gradually higher parallel to the gradual increase of the plant root volume and leaf area index.
Publication
Authors
GL. Sallaku, A. Bani, A. Balliu
Keywords
N concentration, N recovery efficiency, root : whole dry plant ratio, root : shoot dry weight ratio, growth stage, leaf area index, N pollution
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