EFFECT OF DIFFERENT COVERS ON GROWTH AND NITRATE ACCUMULATION IN ICEBERG LETTUCE (LACTUCA SATIVA L.) AND ESCAROLE (CICHORIUM ENDIVIA L.)

2008 ◽  
pp. 655-662 ◽  
Author(s):  
E.M. Suarez-Rey ◽  
T. Soriano ◽  
F.M. Quesada ◽  
M.I. Morales ◽  
N. Castilla
Keyword(s):  
Lactuca Sativa ◽  
Nitrate Accumulation ◽  
Iceberg Lettuce ◽  
Lactuca Sativa L ◽  
Cichorium Endivia

scholarly journals EC Sensitivity of Hydroponically-Grown Lettuce (Lactuca sativa L.) Types in Terms of Nitrate Accumulation

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 315
Author(s):  
Noémi Kappel ◽  
Ildikó Fruzsina Boros ◽  
Francia Seconde Ravelombola ◽  
László Sipos
Keyword(s):  
Lactuca Sativa ◽  
Nitrate Content ◽  
Saline Condition ◽  
Fresh Weight ◽  
Nitrate Level ◽  
Nitrate Accumulation ◽  
Strong Negative Correlation ◽  
Lactuca Sativa L ◽  
Hydroponically Grown ◽  
European Markets

The goal of this research was to investigate the effect of electrical conductivity (EC) levels of the nutrient solution on the fresh weight, chlorophyll, and nitrate content of hydroponic-system-grown lettuce. The selected cultivars are the most representative commercial varieties grown for European markets. Seven cultivars (‘Sintia,’ ‘Limeira,’ ‘Corentine,’ ‘Cencibel,’ ‘Kiber,’ ‘Attiraï,’ and ‘Rouxaï’) of three Lactuca sativa L. types’ (butterhead, loose leaf, and oak leaf) were grown in a phytotron in rockwool, meanwhile the EC level of the nutrient solutions were different: normal (<1.3 dS/m) and high (10 dS/m). The plants in the saline condition had a lower yield but elevated chlorophyll content and nitrate level, although the ‘Limeira’ and ‘Cencibel’ cultivars had reduced nitrate levels. The results and the special characteristic of the lollo-type cultivars showed that the nitrate level could be very different due to salinity (‘Limeira’ had the lowest (684 µg/g fresh weight (FW)) and ‘Cencibel’ had the highest (4396 µg/g FW)). There was a moderately strong negative correlation (−0.542) in the reverse ratio among the chlorophyll and nitrate contents in plants treated with a normal EC value, while this relationship was not shown in the saline condition. Under the saline condition, cultivars acted differently, and all examined cultivars stayed under the permitted total nitrate level (5000 µg/g FW).

Effect of Ozonated Water Treatment on Microbial Control and on Browning of Iceberg Lettuce (Lactuca sativa L.)

2006 ◽  
Vol 69 (1) ◽  
pp. 154-160 ◽  
Author(s):  
SHIGENOBU KOSEKI ◽  
SEIICHIRO ISOBE
Keyword(s):  
Water Treatment ◽  
Lactuca Sativa ◽  
Combined Treatment ◽  
Microbial Control ◽  
Hot Water ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
A Value ◽  
Lactuca Sativa L ◽  
Ozonated Water

We examined the effect of ozonated water treatment on microbial control and quality of cut iceberg lettuce (Lactuca sativa L.). Fresh-cut lettuce was washed in ozonated water (3, 5, and 10 ppm) for 5 min at ambient temperature. The native bacterial population on the lettuce declined in response to a rise in ozone concentration. However, there was no further bacterial reduction (1.4 log CFU/g) above 5 ppm ozone. Although ozonated water treatment increased the phenylalanine ammonia lyase (PAL) activity of the lettuce stored at 10°C compared with the water wash treatment after 1 day of storage, the concentration of ozone did not affect PAL activity. The a* value of the residue of the lettuce methanol extracts, which reflects the extent of browning, increased dramatically in lettuce treated with 10 ppm ozonated water compared with other treatments. Treatment with 3 or 5 ppm ozonated water resulted in more rapid changes in the a* value than after the water treatment. The combined treatment of hot water (50°C, 2.5 min) followed by ozonated water (5 ppm, 2.5 min) had the same bactericidal effect as treatment with ozonated water (5 ppm, 5 min) or sodium hypochlorite (NaOCl, 200 ppm, 5 min), giving a reduction in bacteria numbers of 1.2 to 1.4 log CFU/g. The ascorbic acid content of the lettuce was not affected by these treatments. The combined treatment of hot water followed by ozonated water greatly inhibited PAL activity for up to 3 days of storage at 10°C. Treatment with this combination greatly suppressed increases in the a* value, thus retarding the progress of browning compared with other treatments throughout the 6-day storage. NaOCl treatment also inhibited browning for up to 3 days of storage. Bacterial populations on the lettuce treated with sanitizers were initially reduced but then showed rapid growth compared with that of the water wash treatment, which did not reduce bacterial counts initially.

scholarly journals Reduction of Ethylene-induced Physiological Disorders of Carrots and Iceberg Lettuce by 1-Methylcyclopropene

HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1312-1314 ◽  
Author(s):  
X. Fan ◽  
J.P. Mattheis
Keyword(s):  
Respiration Rate ◽  
Lactuca Sativa ◽  
Daucus Carota ◽  
Rate Increase ◽  
Quality Loss ◽  
Ethylene Treatment ◽  
Physiological Disorders ◽  
Iceberg Lettuce ◽  
Lactuca Sativa L

Whole carrots (Daucus carota L.) and midrib tissues of iceberg lettuce (Lactuca sativa L.) were treated with 42 μmol·m-3 MCP, then exposed to ethylene. Exposure to 42 μmol·m-3 ethylene at 10 °C increased isocoumarin content ≈40-fold in both peel and pulp of nontreated carrots within 4 days, but treatment with MCP for 4 hours at 20 °C before exposure to ethylene prevented isocoumarin accumulation. Ethylene-induced acidity loss and respiration rate increase in carrots were also prevented by MCP treatment. Ethylene treatment (126 μmol·m-3) of lettuce at 6 °C had induced russet spotting >5% to 10% of the midrib tissue by day 3 and 30% to 35% by day 9, while pretreatment with MCP for 4 hours at 6 °C prevented development of russet spotting. The results indicate that ethylene-induced physiological disorders and quality loss in carrots and iceberg lettuce can be prevented by MCP treatment prior to exposure to ethylene. Chemical name used: 1-methylcyclopropene (MCP).

Impact of different washing procedures on quality of fresh-cut iceberg lettuce (Lactuca sativa var. capitata L.) and endive (Cichorium endivia L.)

2012 ◽  
Vol 236 (2) ◽  
pp. 229-241 ◽  
Author(s):  
Sabine Wulfkuehler ◽  
Lisa Kurfiss ◽  
Dietmar R. Kammerer ◽  
Agnes Weiss ◽  
Herbert Schmidt ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Iceberg Lettuce ◽  
Cichorium Endivia ◽  
Fresh Cut

scholarly journals Farklı Azot Kaynakları ile Yapılan Yaprak Gübrelemesinin Marul (Lactuca sativa L.)’da Verim, Nitrat Birikimi ve Maliyet Üzerine Etkisi

2020 ◽  
Vol 8 (4) ◽  
pp. 971-976
Author(s):  
Haluk Çağlar Kaymak ◽  
Adem Aksoy
Keyword(s):  
Lactuca Sativa ◽  
Calcium Nitrate ◽  
Potassium Nitrate ◽  
High Yield ◽  
Nitrate Accumulation ◽  
Nitrate Sources ◽  
Foliar Fertilization ◽  
Profitability Analysis ◽  
Lactuca Sativa L ◽  
Different Doses

The aim of this study was to determine effect of additional foliar fertilization with different doses of nitrate sources on yield, nitrate accumulation and cost of lettuce (Lactuca sativa L.) in field conditions. A summer heat resistant crisphead lettuce (cv. ‘Bohemia F1’) was used as plant material. Also urea (CO(NH2)2), potassium nitrate (KNO3) and calcium nitrate (Ca(NO3)2) were used as additional foliar fertilization with doses of 0.4%, 0.6% and 0.8%. Total nitrogen values of lettuce leaves ranged from 2.20% (KNO3 0.4%) to 3.00% (Urea 0.8%). The highest nitrate accumulation was determined with 0.8% application of Ca(NO3)2 with 2610 mg kg-1, while the lowest nitrate accumulation was determined with 2070 mg kg-1 only in base fertilization (NH4NO3). As a result of additional foliar fertilization with different nitrogen sources, it was determined that the highest yield values were 4926 kg da-1 (Urea 0.6%), 4787 kg da-1 (Urea 0.8%) and 4719 kg da-1 (Ca(NO3)2) in lettuce, respectively. However, considering the fertilizer costs in the research where the other agricultural inputs are the same, in the profitability analysis, the highest profit was determined in additional foliar fertilization with different doses of urea (0.6%) due to its low cost compared to other fertilizers. According to the results of the research, when the profitability is taken into consideration, it can be clearly said that the treatments with urea are more suitable and recommendable additional foliar fertilization for both high yield and more profit.

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