The effects of combined nitrogen on growth, nodulation, and nitrogen fixation of black locust seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1251-1254 ◽  
Author(s):  
Dane R. Roberts ◽  
Richard W. Zimmerman ◽  
Jeff W. Stringer ◽  
Stanley B. Carpenter
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Black Locust ◽  
Nitrogen Deficiency ◽  
Biomass Accumulation ◽  
Leaf Nitrogen ◽  
Sand Culture ◽  
Leaf Nitrogen Content ◽  
Fixation Rate ◽  
Relative Growth

Black locust (Robiniapseudoacacia L.) seedlings grown for 50 days in sand culture with 5 mM NH4NO3-supplemented nutrient solution had 74% lower nitrogen-fixation rates (acetylene reduction) than seedlings grown without nitrogen. Nodule activity was not affected by treatment, and differences in nitrogen fixation between treatments reflected decreased nodulation in seedlings grown with NH4NO3. Relative growth rate was approximately 3 times greater in seedlings supplied with NH4NO3, indicating maximum biomass accumulation cannot be supported by nitrogen fixation alone. Growth was positively correlated with the nitrogen-fixation rate in seedlings grown without nitrogen, but this correlation was not found in NH4NO3-treated seedlings. Leaf nitrogen content was less for seedlings grown in the nitrogen-free sand culture and observations suggested that a nitrogen deficiency in these seedlings restricted their growth.

The contribution of lateral rooting to phosphorus acquisition efficiency in maize (Zea mays) seedlings

2004 ◽  
Vol 31 (10) ◽  
pp. 949 ◽  
Author(s):  
Jinming Zhu ◽  
Jonathan P. Lynch
Keyword(s):  
Growth Rate ◽  
Lateral Root ◽  
Root Respiration ◽  
Lateral Roots ◽  
Biomass Accumulation ◽  
Phosphorus Availability ◽  
Phosphorus Acquisition ◽  
Relative Growth ◽  
Phosphorus Stress ◽  
Low Phosphorus

Low soil phosphorus availability is a primary constraint for plant growth in many terrestrial ecosystems. Lateral root initiation and elongation may play an important role in the uptake of immobile nutrients, such as phosphorus, by increasing soil exploration and phosphorus solubilisation. The overall objective of this study was to assess the value of lateral rooting for phosphorus acquisition through assessment of the ‘benefit’ of lateral rooting for phosphorus uptake and the ‘cost’ of lateral roots in terms of root respiration and phosphorus investment at low and high phosphorus availability. Five recombinant inbred lines (RILs) of maize derived from a cross between B73 and Mo17 with contrasting lateral rooting were grown in sand culture in a controlled environment. Genotypes with enhanced or sustained lateral rooting at low phosphorus availability had greater phosphorus acquisition, biomass accumulation, and relative growth rate (RGR) than genotypes with reduced lateral rooting at low phosphorus availability. The association of lateral root development and plant biomass accumulation under phosphorus stress was not caused by allometry. Genotypes varied in the phosphorus investment required for lateral root elongation, owing to genetic differences in specific root length (SRL, which was correlated with root diameter) and phosphorus concentration of lateral roots. Lateral root extension required less biomass and phosphorus investment than the extension of other root types. Relative growth rate was negatively correlated with specific root respiration, supporting the hypothesis that root carbon costs are an important aspect of adaptation to low phosphorus availability. Two distinct cost–benefit analyses, one with phosphorus acquisition rate as a benefit and root respiration as a cost, the other with plant phosphorus accumulation as a benefit and phosphorus allocation to lateral roots as a cost, both showed that lateral rooting was advantageous under conditions of low phosphorus availability. Our data suggest that enhanced lateral rooting under phosphorus stress may be harnessed as a useful trait for the selection and breeding of more phosphorus-efficient maize genotypes.

Does the routine heat treatment of sugarcane stem pieces for xylem pathogen control affect the nitrogenase activity of an N2-fixing endophyte in the cane?

2001 ◽  
Vol 28 (9) ◽  
pp. 907 ◽  
Author(s):  
Eduardo Ortega ◽  
Rosa Rodés ◽  
Enrique de la Fuente ◽  
Loiret Fernández
Keyword(s):  
Heat Treatment ◽  
Nitrogen Fixation ◽  
International Symposium ◽  
Nitrogenase Activity ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Content ◽  
Gluconacetobacter Diazotrophicus ◽  
Pathogen Control ◽  
Sugarcane Stem ◽  
Poor Soil

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 In sugarcane propagation the sett pieces are routinely heated at 50˚C before planting to control the xylem pathogen Leifsonia xyli ssp. xyli. To determine whether this treatment also affects the diazotrophic endophyte, Gluconacetobacter diazotrophicus, found in the intercellular solution of cane parenchyma, cultures of this bacterium were similarly heated. The nitrogenase activity of the heated cultures was monitored by measurement of hydrogen evolution. Activity was destroyed in cultures heated directly at 45 or 50˚C for 2 h. In contrast, when sett pieces were first heated for 2 h at 50˚C, G. diazotrophicus could still be isolated from the intercellular fluid, and these cultures showed considerable nitrogenase activity. There was no difference in leaf nitrogen content of plants grown in nitrogen-poor soil from setts either heated or unheated. It is concluded that the routine heat treatment of sugarcane setts for pathogen control does not totally destroy the nitrogenase activity of the diazotrophic endophyte G. diazotrophicus.

scholarly journals Biomass Accumulation in the Fern Asplenium nidus avis (L) under Root Restriction

2020 ◽  
pp. 1-9
Author(s):  
A. Pagani ◽  
J. Molinari ◽  
E. Giardina ◽  
A. Di Benedetto
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Parameters ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Point Of View ◽  
Relative Growth ◽  
Net Assimilation ◽  
Root Restriction ◽  
Asplenium Nidus

Pot ornamental plant productivity is related to the environmental growth facilities but negatively affected by the pot root restriction syndrome. Most ferns showed a lower relative growth rate and long production cycles (24 months or more) for which growers use small pots to increase yield per unit area of greenhouse. The aim of this work was to analyze growth changes in response to different pot volume in plants of A. nidus avis spore-propagated under the hypothesis that it would play a role as an abiotic stress which decrease commercial productivity. Our results showed that the use of big pots increased fresh and dry weight and frond area (the main aesthetic trait). When growth parameters were performed, a higher the frond appearance rate (RLA), the frond area expansion (RLAE) and the frond thickness (SLA) were found in 1500 cm3 pot as well as the relative growth rate (RGR) and the net assimilation rate. The use of biggest pot for fern cropping stimulated biomass accumulation through a higher capacity to initiate and expand fronds, to increase photosynthetic rates and change photo assimilate partitioning which favor shoots. From the grower´s point of view, our results suggested that higher yields of A. nidus avis fern would be reached decreasing root restriction, that is, to use the biggest pot volume from the early transplant from plug trays.

Competitive ability of cowpea genotypes with different growth habit

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 775-782 ◽  
Author(s):  
Guangyao Wang ◽  
Milton E. McGiffen ◽  
Jeff D. Ehlers ◽  
Edilene C. S. Marchi
Keyword(s):  
Growth Rate ◽  
Competitive Ability ◽  
Growth Habit ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Similar Reduction ◽  
Relative Growth ◽  
Use Efficiency ◽  
Common Purslane ◽  
Prostrate Growth

Growth habit is an important determinant of competitive ability in legume crops. Erect ‘Iron-Clay’ (IC), semi-erect ‘IT89KD-288’ (288), and prostrate ‘UCR 779’ (779) cowpea genotypes were planted with four densities of common sunflower or common purslane to determine which cowpea growth habit is more competitive to these weeds having markedly different statures. Both sunflower and purslane reduced cowpea relative growth rate (RGR) but at different phases of the growing season. Low-growing purslane had an effect in the earlier part of the season, and sunflower decreased cowpea RGR in the middle of growing season. RGR of genotype IC was the least affected and genotype 779 the most reduced by sunflower. Cowpea apparently compensated for early season purslane competition by increasing RGR after purslane flowering, with RGR for the IC genotype increasing the most and 779 increasing the least. All cowpea genotypes caused a similar reduction in sunflower biomass accumulation; but purslane biomass was most reduced by genotype IC and least affected by genotype 288. Erect genotype IC is more competitive due to its taller stature, greater height growth rate, and higher position of maximal leaf area density, despite a lower photosynthetic rate and light use efficiency than the other cowpea genotypes. Our results suggest that erect cowpea growth habit may be generally more competitive with weeds compared to semi-erect or prostrate growth habit.

scholarly journals Response to Phosphorus Availability during Vegetative and Reproductive Growth of Chrysanthemum: II. Biomass and Phosphorus Dynamics

1998 ◽  
Vol 123 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Conny W. Hansen ◽  
Jonathan Lynch
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Production Rate ◽  
Root Length ◽  
Shoot Growth ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Reproductive Growth ◽  
Relative Growth ◽  
Whole Plant

Whole-plant biomass accumulation, P dynamics, and root-shoot interactions during transition from vegetative to reproductive growth of `Coral Charm' chrysanthemum (Dendranthema ×grandiflorum Ramat.) (Zander, 1993) were investigated over a range of P concentrations considered to be deficient (1 μm), adequate (100 μm), and high (5 mm). In nondeficient plants, transition from vegetative to reproductive growth resulted in reduced relative growth rate and root and shoot biomass accumulation. Reproductive plants showed a higher commitment of the whole plant to the production of developing flowers than to leaves and roots, whereas, in vegetative plants, the highest component production rate was in leaves. This indicates changes in the source-sink relationships during transition from vegetative growth making developing flowers stronger sinks for photoassimilates than roots. Phosphorus allocated to developing flowers was predominantly lost from leaves. Phosphorus-deficient plants showed characteristic P-deficiency symptoms and favored root growth over shoot growth regardless of growth stage. Phosphorus availability in nondeficient plants affected root growth more than shoot growth. No substantial differences in shoot biomass production, relative growth rate, and CO2 assimilation rates were observed in adequate-P and high-P plants. However, the root component production rate, root to shoot ratio, root length ratio, specific root length, specific root area, root mass to leaf area ratio, and root respiration increased in adequate-P plants compared with high-P plants, which indicates that high root activity was maintained without affecting shoot biomass in buffered P conditions. Our results suggest that the high P concentrations used in many horticultural systems may have no benefit in terms of shoot growth and may actually be detrimental to root growth.

Growth, Maintenance and Nitrogen Fixation of Nodulated Plants of Subterranean Clover (Trifolium subterraneum L.)

1979 ◽  
Vol 6 (2) ◽  
pp. 165 ◽  
Author(s):  
JH Silsbury
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Dry Matter ◽  
Accumulation Rate ◽  
Close Association ◽  
Co2 Exchange ◽  
Nitrogen Accumulation ◽  
Co2 Efflux ◽  
Fixation Rate

Plants were grown in a nitrogen-free medium in pots to form a closed canopy. Over a 50-day period, the net CO2 exchange of the pot was measured; nitrogen fixation was estimated by acetylene reduction assay; chemical analyses were performed; and dry matter was determined. Growth and maintenance requirements were estimated in terms of CO2. Dry matter growth rate was almost constant with time, the value half-way through the experiment agreeing with an estimate calculated from the daily CO2-exchange rate and 37.4% carbon in the biomass. Nitrogen accumulation rate was nearly constant. The total daytime CO2 influx for thirteen successive pots during the experiment was almost the same. By contrast, the total dark CO2 efflux increased with time. After partitioning into growth and maintenance components, the increase was due to increase in maintenance. The proportion of the dark efflux attributed to growth was constant with increase in biomass over the range 200-600 gm-2 but the maintenance coefficient may have decreased slightly over this range. Nitrogen fixation rate was constant during the growth period and reproducible between pots: 2.86 moles acetylene were concluded to be equivalent to each mole of nitrogen fixed. As CO2 efflux decreased to the maintenance level in a dark period longer than the usual 12 h, acetylene reduction decreased to near zero. This suggests a close association between growth rate and the rate of nitrogen fixation.

scholarly journals Biomass association in specimens and interspecific hybrids of tomatoes

2019 ◽  
Vol 42 ◽  
pp. e42806
Author(s):  
André Ricardo Zeist ◽  
Marcos Ventura Faria ◽  
Juliano Tadeu Vilela Resende ◽  
André Gabriel ◽  
Julio José Nonato ◽  
...  
Keyword(s):  
Growth Rate ◽  
Interspecific Hybrids ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
F1 Hybrids ◽  
Wild Type ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

The objective of this study is to analyze the growth of wild species of tomato, of the cultivar Redenção and of the respective F1 hybrids of interspecific crossings. We evaluated six wild-type accessions (Solanum pimpinellifolium ‘AF 26970’, S. galapagense ‘LA-1401’, S. peruvianum ‘AF 19684’, S. habrochaites var. hirsutum ‘PI-127826’, S. habrochaites var. glabratum ‘PI-134417’, and S. pennellii ‘LA-716’) and the commercial cultivar Redenção (S. lycopersicum) together with their respective interspecific hybrids. In completely randomized blocks and plots subdivided by time (16, 28, 42, 56, 70, and 84 days after transplanting), we evaluated leaf area (LA), total dry matter (TDM), absolute growth rate (AGR), relative growth rate (RGR) and net assimilation rate (NAR). The distribution of assimilates in the different organs followed different patterns according to genotype. There was a greater accumulation of LA and TDM in the accessions ‘PI-127826’ and ‘PI-134417’ and in the hybrids ‘Redenção’ x ‘PI-127826’ and ‘Redenção’ x ‘PI-134417’. Due to a heterotrophic effect provided by the crossings, there were higher LA, TDM, AGR, RGR and NAR in hybrids than in parent plants. The accessions ‘PI-127826’ and ‘PI-134417’ presented a potential to be donor parents for obtaining tomatoes with a greater capacity of net assimilation and biomass accumulation.

scholarly journals Effect of Nitrogen, shading and intercropping on alfalfa-ziziphus agroforestry system under arid land conditions

2016 ◽  
Vol 2 ◽  
pp. 13
Author(s):  
Saleh Mohammed Al-Zamanan ◽  
Fathy Saad El-Nakhlawy ◽  
Abdullah Elfeil
Keyword(s):  
Plant Height ◽  
Nitrogen Fertilizer ◽  
Agricultural Research ◽  
Biomass Accumulation ◽  
Agroforestry System ◽  
Leaf Nitrogen ◽  
Maximum Effect ◽  
Research Station ◽  
Leaf Nitrogen Content ◽  
Planting Distance

<p>To assess the arid lands agroforestry potential, a field experiment was performed at the Agricultural Research Station of King Abdulaziz University, located at Hada Al-Sham during the 2013 and 2014 seasons. Alfalfa was evaluated in a <em>Ziziphus</em> agroforestry system at a distance of 1 m, 2 m and 4 m from the ziziphus tree and were supplied with three different levels of nitrogen fertilizer 0 kg/ha, 200 kg/ha and 400 kg/ha in the form of commercial Urea. The fertilizer were subdivided into split doses and applied as manual broadcasting after each cutting. A split-split plot design was used with three replications. Forage growth rate and biomass accumulation were measured at ten different intervals approximately at a period of 30-40 days. Forage was harvested in 10 different cuts and all this data consisting of plant height, fresh biomass accumulation and dry biomass accumulation and leaf nitrogen content were also measured. Statistical analysis described significant impact for intercropping, planting distance and nitrogen fertilizer on all studied traits. The maximum effect of urea fertilizer was documented for the highest dose of 400 kg/ha but it was statistically non-significant to 200 kg/ha. Distance of planting from the Ziziphus tree produced variable trend for all forages at different cut numbers but 2 m produced maximum plant height and biomass accumulation for most of the cut numbers. The interaction of 200 kg N/ha, intercropping and 2 m distance produced optimum forage growth and biomass accumulation as compared to the sole plantation under no fertilization.  </p>

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