Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates

Nitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3-) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 5² factorial design was used, with 13 combinations of N and K rates in the nutrient solution. The experimental units were arranged in a randomized block design, with four replications. Plants were harvested twice. The first harvest occurred 36 days after seedling transplanting and the second 29 days after the first. Significance occurred for the interaction between the N and K rates to SPAD readings and to RNO3- assessment taken on the NL during the first growth. Besides, RNO3- and SPAD readings increased only with the NL N concentration, reaching the highest values of both variables up to about 25 g kg-1, but were ratively constant at higher leaf N. Significant relationships either between SPAD readings or RNO3- activity and shoot dry mass weight were also observed. The critical levels of N concentration in the NL were, respectively, 22 and 17g kg-1 in the first and second harvest. Thus, SPAD instrument and RNO3- assessment can be used as complementary tools to evaluate the N status in forage grass.

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Chromium (VI) accumulation reduces chlorophyll biosynthesis, nitrate reductase activity and protein content in Nymphaea alba L.

Chemosphere ◽

10.1016/s0045-6535(99)00426-9 ◽

2000 ◽

Vol 41 (7) ◽

pp. 1075-1082 ◽

Cited By ~ 147

Author(s):

P Vajpayee ◽

R.D Tripathi ◽

U.N Rai ◽

M.B Ali ◽

S.N Singh

Keyword(s):

Nitrate Reductase ◽

Protein Content ◽

Nitrate Reductase Activity ◽

Reductase Activity ◽

Chlorophyll Biosynthesis ◽

Chromium Vi ◽

Nymphaea Alba

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Application methods of Azospirillum brasilense in first- and second-crop corn

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v23n11p840-846 ◽

2019 ◽

Vol 23 (11) ◽

pp. 840-846

Author(s):

Rita de C. F. Alvarez ◽

Jamile Benetão ◽

Gustavo R. Barzotto ◽

Maria G. de O. Andrade ◽

Sebastião F. de Lima

Keyword(s):

Nitrate Reductase ◽

Azospirillum Brasilense ◽

Nitrate Reductase Activity ◽

Reductase Activity ◽

Fertilizer Application ◽

Early Maturity ◽

N Concentration ◽

Chlorophyll Index ◽

Crop Harvest ◽

Corn Plants

ABSTRACT This study investigated whether inoculation of Azospirillum brasilense in the seeds or sowing furrow could reduce the need for nitrogen fertilizer application in the corn grown in the first and second crop harvest. The experiments were conducted, in the municipality of Chapadão do Sul, MS, Brazil, in the first crop harvest (2014/2015) and in the second crop harvest (2016). The early maturity hybrids CD 384 HX and P3132H were used in the first and in the second harvest corn, respectively. In both experiments, the experimental design was the randomized blocks with eight treatments and three repetitions. At the silking (R1 stage), the leaf N concentration, relative chlorophyll index and nitrate reductase activity were measured, at the physiological maturity (R6 stage), the plant height, first ear insertion height, one hundred grain mass, grain yield and grain N concentration were measured. In the first crop harvest, the application of Azospirillum brasilense at the sowing furrow resulted in higher N concentration and relative chlorophyll index in corn leaves, while the inoculation of A. brasilense in the seeds provided higher N concentration in the grains. The nitrate reductase activity in corn leaves was lower when inoculation was performed. In the second crop harvest, the inoculation did not affected the N concentration in the leaves and in the grains, the relative chlorophyll index and the growth of corn plants. Inoculation in the sowing furrow associated with the application of 20 kg N ha-1 at sowing and 120 kg N ha-1 at topdressing resulted in lower nitrate reductase activity.

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The diversity and physiological activities of weeds in land cultivated with various corn cultivars and fertilized with various nitrogen doses

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200302 ◽

2019 ◽

Vol 20 (3) ◽

pp. 622-628

Author(s):

MUJI RAHAYU ◽

PRAPTO YUDONO ◽

DIDIK INDRADEWA ◽

EKO HANUDIN

Keyword(s):

Nitrate Reductase ◽

Leaf Area Index ◽

Leaf Area ◽

Chlorophyll Content ◽

Nitrate Reductase Activity ◽

Reductase Activity ◽

Block Design ◽

Cyperus Rotundus ◽

Area Index ◽

Dactyloctenium Aegyptium

Abstract. Rahayu M, Yudono P, Indradewa D, Hanudin E. 2019. The diversity and physiological activities of weeds in land cultivated with various corn cultivars and fertilized with various nitrogen doses. Biodiversitas 20: 622-628. Both weeds and corn have nutrient needs. Nitrogen is one of the essential elements required by weeds and corn. Each corn cultivar and weed also has different ability to absorb nitrogen. This study aimed to determine the effect of corn cultivar and nitrogen dose on the diversity and physiological activities of weeds. The research was conducted in Banguntapan, Bantul, Yogyakarta from December 2016 to May 2017. The study used a completely randomized block design with 2 factors with three replications. The first factor was corn cultivar, consisting of four cultivars (Bisi 18, NK 33, DK 95 and Sukmaraga) and the second factor was the nitrogen dose, consisting of three levels (25 kg N ha-1, 150 kg N ha-1 and 275 kg N ha-1). The data were analyzed using 5% variance analysis and continued with Duncan test at 5% level. The results showed that the most commonly found weeds were broadleaves, but the most dominant weed was a grass, namely Dactyloctenium aegyptium, except Sukmaraga with nitrogen doses of 25 kg ha-1 and 150 kg ha-1 in 4 weeks after planting (WAP). In 8 WAP, weeds that grew in land planted with all combinations of cultivars and nitrogen doses were Cyperus rotundus, Dactyloctenium aegyptium, Digitaria ciliaris, Eleusine indica, Eragrostis tenella, Amaranthus spinosus, and Richardia scabra. There were no significant differences on the nitrate reductase activity, chlorophyll content, leaf area index, and dry weight among cultivars. The treatment of 25 kg N ha-1 resulted in the lowest leaf area index and total chlorophyll content, but the highest nitrate reductase activity.

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Hubungan Aktivitas Nitrat Reduktase dan Kadar Klorofil Kultivar Kedelai Tahan Kekeringan

Agrotek ◽

10.30862/agt.v3i2.571 ◽

2018 ◽

Vol 3 (2) ◽

Author(s):

Ivonne Fitri Mariay

Keyword(s):

Drought Stress ◽

Nitrate Reductase ◽

Drought Tolerance ◽

Nitrate Reductase Activity ◽

Reductase Activity ◽

Leaf Growth ◽

Block Design ◽

Soybean Cultivar ◽

Tissue Water ◽

Drought Tolerant

<em>Plants suffering from drought stress can be indicated by the changing of character on the morphology, anatomy and physiology, characterized by inhibition of leaf growth, accelerated root growth, stomata closure and leaf curly. Cultivars that are tolerance to drought can physiologically adapted by increasing prolin level reduce the osmotic potential in order to maintain turgor in the condition of low tissue water potential. The research was aimed to study the physiological characters of drought tolerant soybean cultivar of determine the relationship of nitrate reductase activity and chlorophyll content of drought-tolerance cultivars and susceptible to drought stress conditions. The research was conducted at Tridharma Garden Agricultural Faculty of Gadjah Mada University, Banguntapan, Bantul, Daerah Istimewa Yogyakarta from January to March 2012. The experiment was arranged on Factorial Complete Block Design with three replications. The first factor was soybean cultivar consist of five levels those are Wilis (drought tolerance), Tidar (drought tolerant), Gema (drought tolerant), Grobogan (susceptible) and Argomulyo (susceptible). The second factor was watering interval consist of four levels which were watering once a day, every 2 days, every 4 days and every 8 days. Drought stress treatment begans at 24 DAP. Parameters observed were moisture content, nitrate reductase activity, chlorophyll a, chlorophyll b, and total of chlorophyll at 56 DAP. Portable data analysis using SAS 9.1. for windows. The results showed that nitrate reductase activity contributes to greater levels of chlorophyll of drought tolerance cultivars "Wilis", "Tidar" and "Gema" on the conditions of drought stress than the susceptible cultivar "Grobogan" and "Argomulyo".</em>

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