The source of nitrogen (NH4+ or NO3–) affects the concentration of oxalate in the shoots and the growth of Atriplex nummularia (oldman saltbush)

2013 ◽  
Vol 40 (10) ◽  
pp. 1057 ◽  
Author(s):  
Hussein Al Daini ◽  
Hayley C. Norman ◽  
Paul Young ◽  
Edward G. Barrett-Lennard

Atriplex nummularia Lindl. (oldman saltbush) is a halophytic shrub used widely as a forage for ruminant production in saline farming systems. However, it can contain high concentrations of oxalate in the leaves, which may cause calcium deficiency in grazing animals. We hypothesised that supplying NH4+ instead of NO3– to a clone of this species would decrease oxalate concentrations in the shoots, and also decrease plant growth. Oxalate concentrations were measured in plants in the field, and a glasshouse experiment was conducted in which plants were grown with 10 mM NO3– or NH4+, with 50, 200 or 500 mM NaCl. The field survey showed effects of site (P < 0.001), with average oxalate concentrations in shoots varying between 2.4 and 6.4% dry mass (DM). In the glasshouse, oxalate concentrations and plant growth were both affected by N-source and salinity (P < 0.001). Averaged across salinities, plants grown with NH4+ for 24 days had only 43% of the shoot DM but 25% of the oxalate concentration of plants grown with NO3–. We discuss the effects of N-source on oxalate concentrations, the implications of this for halophyte growth, and the opportunity to select halophytes with lower oxalate and higher nutritive value for livestock.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 474d-474
Author(s):  
N.K. Damayanthi Ranwala ◽  
Dennis R. Decoteau

This study was conducted to evaluate the spectral properties of various colored plastic color mulches and to determine the effects of upwardly reflected light from the mulch surfaces on watermelon plant growth when differences in root zone temperatures are minimized. Two-week-old watermelon plants were grown with black mulch, red-painted mulch, SRM-Red mulch (Sonoco, Inc., Harstville, S.C.), and white mulch. Total light reflection (58 μmol·m–2·s–1 in 400–700 nm) and red: far-red (R:FR = 0.44) of reflected light were lower in black mulch and highest in white mulch (634 and 0.92, respectively). Both black mulch and white mulch had same blue:red (B:R = 0.6) while white mulch had higher B:FR (0.58) in reflected light compared to black mulch (0.26). Reflective properties of red mulches were somewhat similar, and R:FR, B:R, and B:FR were 0.8, 0.2, and 0.18, respectively. However, SRM-Red mulch had highest total light (355 μmol·m–2·s–1 in 400–700 nm) transmission through the mulch, and R:FR, B:R, and B:FR were 0.84, 0.28, and 0.23, respectively. Light transmission through the other mulches was nonsignificant. Watermelon plants grown with black mulch and red mulches had higher internode lengths compared to white mulch after 20 days. Further, plants grown under black had significant higher petiole elongation accompanied with higher dry mass partitioning to petioles, and lower partitioning to roots, stems, and leaves. There was no effects of surface mulch color on total plant dry mass or photosynthesis although plants with black had higher transpiration rate. This suggests the differential regulation of dry mass partitioning among plant parts due to mulch color. The similar plant responses with black mulch and white mulch to plants treated with FR or R light at the end of photoperiod implies the involvement of phytochrome regulation of growth due to mulch surface color.


1933 ◽  
Vol 17 (1) ◽  
pp. 63-76 ◽  
Author(s):  
James Bonner

1. Sections of Avena coleoptiles are found to show a considerable elongation when suspended in solutions of growth substance. 2. This elongation does not take place in the absence of O2 and is inhibited by KCN and phenylurethane. 3. The rate of respiration of sections of coleoptiles is increased by the addition of growth substance in concentrations which cause growth. High concentrations of growth substance inhibit growth and also respiration. 4. The increase in respiration is inhibited by KCN and phenylurethane in the concentrations which inhibit normal respiration. These concentrations are the same as those which inhibit growth. 5. From 2, 3, and 4, it seems possible that the increase in respiration caused by growth substance may be an essential part of its action in growth.


2017 ◽  
Vol 35 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Roberto BF Branco ◽  
Sally F Blat ◽  
Tais GS Gimenes ◽  
Rodrigo HD Nowaki ◽  
Humberto S Araújo ◽  
...  

ABSTRACT The production of horticultural crops in no-tillage and in rotation with cover crops reduces the dependency in nitrogen fertilizer, due to increased soil organic matter and by biological fixation performed by legumes. Thus, the aim of this work was to study rates of nitrogen fertilization and cover crops in the agronomic performance of tomato and broccoli grown under no-tillage. The experiment was conducted in a split plot design with four replications. Treatments consisted of cover crops, sunn hemp and millet, and four rates of nitrogen fertilization (0, 50, 100 and 200 kg/ha of nitrogen), for both the tomato and broccoli crops. All soil management was performed in no-tillage. For tomato crops we evaluated the plant growth, the nitrate concentration of sprouts and fruits and yield of commercial and non commercial fruits. For broccoli we evaluated plant growth and yield. There was an interaction effect between cover crop and nitrogen rates to tomato growth measured at 100 days after transplanting, for plant height, number of fruit bunches, dry mass of leaves and diameter of the stalk. The tomato commercial fruit number and yield showed maximum values with 137 and 134 kg/ha of N respectively, on the sunn hemp straw. The nitrate concentration of the tomato sprouts was linearly increasing with the increase of nitrogen rates, when grown on the millet straw. For broccoli production, the maximum fresh mass of commercial inflorescence was with 96 kg/ha of N, when grown on the millet straw.


2012 ◽  
Vol 30 (4) ◽  
pp. 683-696 ◽  
Author(s):  
F.P. Guimaraes ◽  
R. Aguiar ◽  
J.A. Oliveira ◽  
J.A.A. Silva ◽  
D. Karam

The potential of three aquatic macrophytes, Azoll caroliniana, Salvinia minima and Lemna gibba, was evaluated in this work aimed at selection of plants to be used in remediation of environments contaminated by arsenic (As). The experiments were carried out in a greenhouse during six days in pots containing Hoagland solution (¼ ionic strength) at As concentrations of 0.5; 2.5 and 5.0 mg L-1. The three species showed greater As accumulation as the concentration of the metalloid in solution increased. However, a reduction was detected in fresh and dry mass gain when the plants were exposed to high As concentrations. The macrophytes showed differences in efficiency of removal of As in solution. A. caroliniana, S. minima and L. gibba accumulated, on average, 0.130; 0.200; and 1.397 mg mDM-1, respectively, when exposed to 5.0 mg L-1 of As. The macrophytes absorbed a greater quantity of As in solution with low phosphate content. The greater As concentration in L. gibba tissues lowered the chlorophyll and carotenoid contents as shown by the high chlorosis incidence. Lemna gibba also exhibited a decrease in leaf size, with the total chlorophyll and carotenoid synthesis not being affected by As in A. caroliniana. This species exhibited purplish leaves with high concentration of anthocyanin, whose presence suggested association to phosphate deficiency. Marginal necrosis occurred on S. minima floating leaves, with the released daughter-plants not showing any visual symptoms during the treatment. The percentage of As removed from the solution decreased when the plants were exposed to high concentrations of the pollutant. Among the three species studied, only L. gibba could be considered an As hyper-accumulator. The use of this plant species for remediation of aquatic environments was shown to be limited and requires further investigation.


Author(s):  
Artur Roque Domingues Barreiros ◽  
Ulysses Cecato ◽  
Camila Fernandes Domingues Duarte ◽  
Mariangela Hungria ◽  
Thiago Trento Biserra ◽  
...  

The aim of this study was evaluating the effect of the inoculation of plant growth promoting bacteria (PGPB) in forage mass, tillering, nutritive value and root system of ruzigrass (Urochloa ruziziensis (R. Germ. & Evrard) Crins (syn. of Brachiaria ruziziensis) associated with doses of N-fertilizer. The bacteria inoculated were Azospirillum brasilense Ab-V5, Pseudomonas fluorescens CCTB03 and Pantoea ananatis AMG 521, plus the control treatment (non-inoculated), associated with doses of N-fertilizer (0, 50 and 100 kg N ha-1). The experiment was performed in a randomized block design, in a 4x3 factorial scheme, with four replicates, totaling 48 plots (12 m2). There were no effects of the PGPB and the use of N-fertilizer on the leaf blade, stem+sheath, forage mass, daily and yearly accumulation of forage mass. The PGPB did not have influence on the density of tillers. The doses of 50 and 100 kg of N ha-1 increased the amount of tillers. The AMG 521 strain associated with N-fertilizer provided heavier tillers. There was no effect of the PGPB on crude protein (CP), neutral detergent fiber (NDF), as well as acid detergent fiber (ADF), and in vitro digestibility of the dry matter (IVDDM).  The use of 100 kg of N ha-1 contributed to an increase in CP and a decrease in NDF. The AMG 521 strain contributed to a smaller diameter of the root. Strains CCTB03 and AMG 521 demonstrated a smaller area, length and root density when associated with the dose of 50kg of N ha-1. In general, the PGPB were not efficient in promoting productive increments in ruzigrass.


2000 ◽  
Vol 18 (2) ◽  
pp. 93-98 ◽  
Author(s):  
R.L. Hummel ◽  
S. Kuo ◽  
D. Winters ◽  
E.J. Jellum

Abstract Utilization of fish waste for producing fishwaste compost (FWC) as a value-added product is preferred to disposing of it in ocean dumping or landfills. This study determined: (i) the effectiveness of FWC as a container-growth medium and N source for greenhouse production of marigolds (Tagetes patula L. ‘Queen Sophia’) and geraniums (Pelargonium x hortorum L.H. Bailey ‘Sprinter Scarlet’) that were drip-irrigated to prevent leaching; and (ii) if leaching was necessary to sustain plant growth. In a 3 by 3 factorial experiment, plants were grown in 100% FWC, 50% FWC:50% Douglas-fir bark (B), and 100% B at 0, 160, and 320 mg (0, 0.0056, 0.0112 oz) N container−1 applied as NH4NO3 every 2 weeks. Under drip irrigation, FWC in the 100% FWC growing medium supplied a sufficient amount of available N up to 7 weeks after transplanting to produce plant quality, shoot growth index (SGI), and shoot and root dry weights comparable to those treated with 320 mg N container−1. In the 50% FWC: 50% B growing medium fertilization with 320 mg N improved plant growth and quality 7 weeks after transplanting. The concentration of inorganic N (NO3 plus NH4) in the 100% FWC declined to very low levels 7 weeks after transplanting. This indicated that FWC used as the sole component of the growing medium was an effective N source for marigolds and geraniums up to 7 weeks after transplant. Compared with no leach plants, irrigation of 100% FWC marigolds with a weekly leaching fraction of about 0.55 did not affect quality, SGI, and shoot dry weight at the time-of-sale, 7 weeks after transplant. The FWC did not have sufficiently high salt content to require minimum leaching to prevent salt injury to the plants.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Praveen Kumar Goteti ◽  
Leo Daniel Amalraj Emmanuel ◽  
Suseelendra Desai ◽  
Mir Hassan Ahmed Shaik

Zinc (Zn) is one of the essential micronutrients required for optimum plant growth. Substantial quantity of applied inorganic zinc in soil is converted into unavailable form. Zinc solubilising bacteria are potential alternates for zinc supplement. Among 10 strains screened for Zn solubilisation, P29, P33, and B40 produced 22.0 mm clear haloes on solid medium amended with ZnCO3. Similarly, P17 and B40 showed 31.0 mm zone in ZnO incorporated medium. P29 and B40 showed significant release of Zn in broth amended with ZnCO3(17 and 16.8 ppm) and ZnO (18 and 17 ppm), respectively. The pH of the broth was almost acidic in all the cases ranging from 3.9 to 6.1 in ZnCO3and from 4.1 to 6.4 in ZnO added medium. Short term pot culture experiment with maize revealed that seed bacterization with P29 @ 10 g·kg−1significantly enhanced total dry mass (12.96 g) and uptake of N (2.268%), K (2.0%), Mn (60 ppm), and Zn (278.8 ppm).


1972 ◽  
Vol 12 (56) ◽  
pp. 281 ◽  
Author(s):  
JK Teitzel ◽  
RC Bruce

Results of fifteen investigations into the fertility status of soils derived from metamorphic rocks in the wet tropical coast of Queensland are presented. Phosphorus deficiency is general. Molybdenum and potassium deficiencies are also widespread. Significant plant growth increases in seven of the nine general nutritional experiments were brought about by the calcium treatment. However, the involvement of additional calcium in molybdenum release and in alleviating aluminium toxicity appears more important than in correcting a calcium deficiency. There were also some positive responses to sulphur and negative ones to copper.


2015 ◽  
Vol 33 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Cristina B Lima ◽  
Ana C Boaventura ◽  
Marli M Gomes

We aimed to establish the period of time required for seedlings formation, as well as to evaluate the effect of substrates and plant growth regulators in cuttings of L. alba. Three experiments were performed, with statistical designs chosen according to each test objectives. Rooting (%), shoot height (cm), longest root length (cm), leaves number, fresh and dry matter masses (g), were analyzed. The absolute rate of shoot and root system growth, together with the relationship between dry mass of roots and shoots were efficient in predicting the period of greatest speed and accumulation of organic matter in plants. The plant growth regulators favored the vegetative performance of seedlings, with better development 30 days after the cuttings containing mineral fertilizers, vermicompost, clay soil and sand commercially known as 'medium sand'.


2018 ◽  
Vol 10 (7) ◽  
pp. 455
Author(s):  
Hozano De Souza Lemos Neto ◽  
Marcelo De Almeida Guimarães ◽  
Rosilene Oliveira Mesquita ◽  
Italo Marlone Gomes Sampaio ◽  
Ana Régia Alves de Araújo Hendges ◽  
...  

Silicon (Si) is a mineral element that provides many benefits to plants and may also assist in tolerance to abiotic stresses such as salinity. The aim of the study was to evaluate the use of Si as a possible attenuator of the deleterious effects of salinity on growth and post-harvest of lettuce. A completely randomized design with four replicates was performed in a 3 × 2 factorial, consisting of three salinity levels (1.65, 3.65, 7.65 dS m-1) and two levels of silicon (0.0 and 2.0 mM). Salinity reduced all variables related to plant growth. For shoot fresh and dry mass, it was observed that NaCl caused a reduction of 79.80 and 80%, respectively, in comparison to the control. However, parameters related to post-harvest such as titratable acidity, soluble solids and vitamin C increased with salinity. Although not effective in reducing saline stress on plant growth, Si provided improvements in the variables related to lettuce post-harvest. Salinity significantly reduced plant growth in the presence and absence of Si, but provided better post-harvest quality with Si.


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