scholarly journals The positive function of selenium supplementation on reducing nitrate accumulation in hydroponic lettuce (Lactuca sativa L.)

2018 ◽  
Vol 17 (4) ◽  
pp. 837-846 ◽  
Author(s):  
Bo LEI ◽  
Zhong-hua BIAN ◽  
Qi-chang YANG ◽  
Jun WANG ◽  
Rui-feng CHENG ◽  
...  
Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 315
Author(s):  
Noémi Kappel ◽  
Ildikó Fruzsina Boros ◽  
Francia Seconde Ravelombola ◽  
László Sipos

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).


Author(s):  
Haluk Çağlar Kaymak ◽  
Adem Aksoy

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.


2017 ◽  
Vol 2 (01) ◽  
pp. 115-127
Author(s):  
Siti Hilalliyah ◽  
Intan Sari ◽  
Zahlul Ikhsan

Sistem hidroponik memungkinkan sayuran ditanam di daerah yang kurang subur dan daerah sempit yang padat penduduknya. Alasan penerapan teknik hidroponik yang utama adalah karena terbatasnya lahan pertanian yang produktif untuk memenuhi kebutuhan manusia yang semakin banyak tiap tahunnya, sehingga dibutuhkan suatu terobosan baru untuk memecahkan masalah tersebut. Penelitian ini telah dilaksanakan pada bulan November 2015 sampai bulan Januari 2016 yang bertempat di kampus Fakultas Pertanian Jl. Propinsi Kecamatan Tembilahan Hulu Kabupaten Indragiri Hilir Propinsi Riau.Metode penelitian yang digunakan adalah Rancangan Acak Lengkap (RAL) pola faktorial yang terdiri dari 2 faktor. Faktor pertama adalah jenis POC (N) yang terdiri dari 3 taraf perlakuan yaitu POC Jus Bumi, POC Bonggol Pisang danPOC Limbah Sayuran. Faktor kedua adalah konsentrasi larutan (K) yang terdiri dari 3 taraf perlakuan yaitu 150 ppm, 200 ppm dan 250 ppm. Parameter pengamatan adalah Tinggi Tanaman , Jumlah Daun , Luas Daun , Diameter Batang, Panjang akar ,Volume Akar, Kadar Air, dan Bobot Hasil.Hasil pengamatan menunjukkan bahwa perlakuan jenis POC jus bumi dengan konsentrasi larutan 150 ppm memberikan pertumbuhan dan produksi terbaik untuk tanaman selada secara hidroponik sistem wick. Perlakuan jenis POC limbah sayuran dengan konsentrasi 250 ppm memberikan pertumbuhan dan produksi terbaik selain POC jus bumi sehingga dapat dijadikan sumber POC alternatif.


Author(s):  
Nguyễn Minh Trí ◽  
Nguyễn Hạnh Trinh ◽  
Nguyễn Thị Hoàng Phương

Xà lách (Lactuca sativa L.) là một loại rau ăn lá quan trọng có giá trị dinh dưỡng và kinh tế cao. Cây Xà lách có đặc điểm là loại rau ngắn ngày, có thời gian sinh trưởng ngắn khoảng từ 45 - 55 ngày, có thể phát triển tốt trên nhiều loại đất, là loại rau ăn sống được sử dụng rất phổ biến trong bữa ăn hàng ngày của người dân Việt Nam nên nó được trồng quanh năm, do vậy vấn đề về chất lượng lại càng phải được quan tâm nhiều hơn. Bài báo này giới thiệu kết quả phân tích về dư lượng nitrat và các kim loại nặng (Cu, Pb, Zn) trong rau Xà lách vụ Xuân - Hè 2012 - 2013 ở phường Hương Long - thành phố Huế. Kết quả nghiên cứu cho thấy: đất trồng rau Xà lách tại phường Hương Long – thành phố Huế đạt tiêu chuẩn về hàm lượng kim loại nặng (Pb, Zn) theo QCVN 03:2008/BTNMT, nhưng hàm lượng Cu và nitrat là khá cao. Rau Xà lách thành phẩm có dư lượng nitrat cao hơn 1,21% so với quy định và các kim loại nặng (Pb, Zn, Cu) tồn dư trong rau lại ở mức cao và vượt tiêu chuẩn cho phép nhiều lần sẽ ảnh hưởng đến sức khỏe của người sử dụng.


Author(s):  
Ferreira Gabriel Menezes ◽  
Souza Antonio Tassio de Oliveira ◽  
Souza Alisson Silva de ◽  
Gomes Igor Thiago dos Santos ◽  
Cunha Denise de Andrade

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