Physiological characteristics of recent Canada Western Red Spring wheat cultivars: Components of grain nitrogen yield

2003 ◽  
Vol 83 (4) ◽  
pp. 699-707 ◽  
Author(s):  
H. Wang ◽  
T. N. McCaig ◽  
R. M. DePauw ◽  
F. R. Clarke ◽  
J. M. Clarke

Genetic yield gains have been difficult to achieve within the Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) class, partially because of the requirement for high protein concentration. A previous study indicated that four newer, high-yield CWRS cultivars (registered 1994–1997) also had higher protein yields. The objective of the present study was to determine if the increase in grain nitrogen (protein) yield of the four newer wheat cultivars, relative to two older cultivars, Neepawa (registered in 1969) and Marquis (introduced in 1909), resulted from increased plant nitrogen uptake, more efficient utilization of nitrogen, or a combination of these factors. The higher nitrogen yields were primarily attributed to more efficient utilization and redistribution of the nitrogen rather than increased uptake of soil nitrogen. The nitrogen harvest index (NHI) of the new cultivars, considered as a group, was higher than the NHI of Neepawa, which in turn was higher than that of the much older cultivar Marquis. The NHI of each of the new cultivars was higher than that of Marquis. The nitrogen concentration in the non-grain tissue at maturity (NGNCM) of the new cultivars, considered as a group, was lower than that of Neepawa, which in turn was lower than the NGNCM of Marquis. At maturity, all five tissues (leaf blade, stem plus sheath, peduncle, glume, and rachis) for the new cultivars and Neepawa had lower nitrogen concentrations than for the corresponding tissues of Marquis. The nitrogen concentration of the peduncle and leaf-blade tissues of the new cultivars, as a group, were also lower at maturity than the corresponding nitrogen concentrations for Neepawa. The results suggest that low non-grain nitrogen concentration at harvest is associated with improved NHI and grain nitrogen yield in CWRS wheat. This information may improve our understanding of the higher protein yields that have been achieved within this class, and assist in the selection of future parents. Key words: Nitrogen harvest index, nitrogen uptake, nitrogen yield, protein, remobilization, Triticum aestivum

2001 ◽  
Vol 41 (4) ◽  
pp. 533 ◽  
Author(s):  
R. G. Flood ◽  
P. J. Martin

Plant nitrogen relationships were studied in 10 wheat cultivars sown at 3 sites (Horsham, Boort and Walpeup) in north-western Victoria by determining the nitrogen concentration and nitrogen content of plant components at anthesis and maturity. While the concentration of nitrogen varied in different plant components, whole plants at anthesis had a nitrogen concentration below the value required for maximum growth. The time to anthesis had an influence only on grain yield and grain nitrogen percentage at Horsham. Total assimilation of nitrogen at both anthesis and maturity was more strongly correlated to plant dry matter than plant nitrogen concentration. There was a significant negative correlation between grain nitrogen percentage and both nitrogen harvest index and harvest index. Grain yield was strongly correlated with total nitrogen accumulated at anthesis and more strongly correlated with total nitrogen accumulated at maturity. Grain yield was significantly correlated with nitrogen harvest index and more strongly correlated with harvest index. Grain yield was negatively correlated with grain nitrogen percentage. The negative association between grain nitrogen percentage and harvest index has important implications for the breeding of wheat with higher grain nitrogen percentage while maintaining or increasing grain yield. The results indicated that none of the measured parameters could be used for indirect selection aimed at improving grain nitrogen percentage.


1988 ◽  
Vol 68 (2) ◽  
pp. 311-322 ◽  
Author(s):  
PATRICK M. McMULLAN ◽  
PETER B. E. McVETTY ◽  
AILEEN A. URQUHART

Dry matter and nitrogen (nitrate and reduced) accumulation and redistribution in four different spring wheat (Triticum aestivum L.) genotypes grown at field density were studied on a plant part and whole plant basis over the growing season for 2 yr. The four cultivars displayed significant differences in plant part and total plant dry matter, harvest index, nitrogen content, nitrogen concentration, nitrogen harvest index and nitrogen translocated values at most sample dates in both years. Grain yield was highly correlated with dry matter accumulation (r = 0.88**), while grain nitrogen content was highly correlated with plant nitrogen content (r = 0.95**). Nitrogen harvest index and plant nitrogen content were correlated at anthesis (r = 0.61**), while, as a consequence of this, the amount of nitrogen translocated was highly correlated with plant nitrogen content at anthesis (r = 0.87**). Nitrogen harvest index and harvest index were highly correlated (r = 0.83**), indicating that they may be related processes. Since plant dry matter and plant nitrogen content were not significantly correlated, it should be possible to select simultaneously for these traits to effect grain yield and grain nitrogen content increases on a per-plant basis. Further research will have to be done to determine how these changes will relate to grain nitrogen concentrations and grain yield per unit area.Key words: Wheat, dry matter, nitrogen, yield, protein, Triticum aestivum L.


1988 ◽  
Vol 68 (4) ◽  
pp. 983-993 ◽  
Author(s):  
PATRICK M. McMULLAN ◽  
PETER B. E. McVETTY ◽  
AILEEN A. URQUHART

Dry matter and nitrogen (nitrate and reduced) accumulation and redistribution in four different spring oat (Avena sativa L.) genotypes grown at commercial field density were studied on a plant part and whole plant basis over the growing season for 2 yr. The four cultivars displayed significant differences in plant part and total plant dry matter, harvest index, nitrogen content, nitrogen concentration, nitrogen harvest index, and nitrogen translocated values at most sample dates in both years. Grain yield per plant was correlated with dry matter accumulation (r = 0.80*). Harvest index was highly correlated with grain yield per plant (r = 0.88**). Grain nitrogen content was highly correlated with plant nitrogen content (r = 0.94**). Nitrogen harvest index and harvest index were highly correlated (r = 0.86**), indicating that they may be related processes. Since plant dry matter and plant nitrogen content were not significantly correlated, it should be possible to select simultaneously for these traits to effect grain yield and grain nitrogen content increases on a per plant basis. Further research will have to be done to determine how these changes will relate to grain nitrogen concentrations and grain yield per unit area.Key words: Avena sativa L., oat, dry matter, nitrogen, yield, protein


2020 ◽  
Author(s):  
Prabin Ghimire

Abstract Unsuitable nitrogen management and low soil fertility are major constraints of wheat production in Nepal. Limited information is available on optimum nitrogen rates and use efficiencies. So a field experiment was conducted on the inner terai to determine the effect nitrogen on yield and improving the nitrogen use efficiency of wheat. Level of five doses of nitrogen, 0kg ha-1 (Control), 60kg ha-1,80kg ha-1,100kg ha-1 and 120kg ha-1 were laid out in Randomized Completely Block Design (RCBD) with four replication. Observation on the various parameters of yield attributing characters like plant height(cm), tiller m-2 thousand grain weight(Kg), spike length(cm), grain spike-1was found highest on Nitrogen dose 120 kg ha-1. Similarly, nitrogen at 120kg ha-1 increases the grain yield by increasing the biological yield and harvest index. Grain nitrogen concentration at 120 kg ha-1 is statistically similar with 100 kg ha-1 and 80 kg ha-1 while nitrogen uptake is highest (114.833kg ha-1) in 120kg ha-1 and lowest in control. Agronomic use efficiency is highest observed in 100kg ha-1 and lowest on 60 kg ha-1. Apparent fertilizer N recovery ratio obtained high (49.62%) in 120 kg ha-1 which is statistically similar to 100kg ha-1 (46.97%) and lowest (31.76%) in 60 kg ha-1. While observing agro physiological efficiency and Nitrogen harvest index did not show any significant difference among any treatments. The application of nitrogen at 120kg ha-1 was required to produce the optimum yield and increasing the nitrogen use efficiency traits.


2014 ◽  
Vol 155 ◽  
pp. 213-223 ◽  
Author(s):  
Oorbessy Gaju ◽  
Vincent Allard ◽  
Pierre Martre ◽  
Jacques Le Gouis ◽  
Delphine Moreau ◽  
...  

2008 ◽  
Vol 54 (No. 7) ◽  
pp. 304-312 ◽  
Author(s):  
J. Haberle ◽  
P. Svoboda ◽  
I. Raimanová

The effect of water supply during grain growth on grain nitrogen concentration (GNC) and grain nitrogen yield (GNY) of winter wheat (<I>Triticum aestivum</I> L.) was studied in the field experiment on fertile loamy-clay soil in years 2004–2007. The water regime was differentiated using mobile rain shelter (water shortage, treatment S) and drip irrigation (ample water supply, treatment W); rain-fed crop served as the control treatment (R). Wheat was grown without addition of nitrogen and with 200 kg N/ha (N0 and N1, resp.). The effect of water supply on GNC was highly significant (<I>P</I> < 0.001) in fertilized wheat and not significant in N0. Drought significantly increased GNC in comparison with irrigated and rain-fed crop in N1. Average grain nitrogen concentrations in respective treatments S, R and W were 1.52, 1.54 and 1.56% in N0 and 2.50, 2.24 and 2.07% in N1. Water availability also significantly affected grain nitrogen yield (<I>P</I> < 0.01). The GNY of fertilized wheat under water shortage was significantly lower (139 kg/ha) than GNY in treatments R (174 kg/ha) and W (182 kg/ha) while under N0 the differences were not significant. Unlike GNC, the GNY was positively associated with mineral N supply (N<sub>min</sub>) in 0–90 cm depth in early spring (<I>r </I> = 0.98–0.99 and 0.83–0.97 for N0 and N1, resp.). Several weather and related characteristics showed relations to GNY and GNC, often opposite under N0 and N1. N<sub>min</sub> together with nitrogen fertilization rate, indicators of water regime and temperature during grain growth period explained 78–97% of observed variability of GNC and GNY in the experiment.


Author(s):  
Wellington F. Roque ◽  
Salomão L. Guimarães ◽  
Edna M. Bonfim-Silva

ABSTRACT This study aimed to evaluate the efficiency of diaztrophic bacteria coinoculation in wheat cultivars grown in Cerrado Oxisol. A randomized block design was used, with a 13 x 3 factorial scheme and four replicates. The treatments consisted of inoculation with Azospirillum brasilense (strains AbV5 and AbV6 strains combined) and coinoculation with Bradyrhizobium japonicum (strains SEMIA 5079 and SEMIA 5080 combined, and strain BR3267), as well as Rhizobium tropici (strains MT08 and MT15) and R. leguminosarum (strain MT16) combined or in isolation, tested in wheat cultivars BRS 394, BRS 264 and BRS 254. The variables analyzed were grain nitrogen concentration and accumulation and crude protein content, 100-grain weight and total grain mass. The treatment containing the commercial cowpea inoculant showed a higher total grain mass (5.8766 g). Interaction was observed for grain nitrogen concentration, particularly for A. brasilense + MT 15 (R. tropici) and MT 15 in wheat cultivar BRS 264. Coinoculation with diazotrophic bacteria isolated from leguminous plants shows potential for use in wheat cultivars.


2007 ◽  
Vol 146 (1) ◽  
pp. 35-47 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
S. MUURINEN ◽  
A. RAJALA ◽  
L. JAUHIAINEN

SUMMARYIncreased harvest index (HI) has been one of the principal factors contributing to genetic yield improvements in spring barley (Hordeum vulgare L.), oat (Avena sativa L.) and wheat (Triticum aestivum L.) cultivars. Although high HI demonstrates high-yielding ability when cultivars are compared, it can also indicate challenges to yield formation when comparisons are made across differing growing conditions. The present study was designed to investigate variation in HI among modern cereal cultivars relative to that brought about by a northern environment, to assess whether HI still explains the majority of the differences in grain yield when only modern cereal cultivars are compared, and to monitor key traits contributing to HI. Stability of HI was also investigated with reference to the role of tillers. Twelve experiments (3 years, two locations, two nitrogen fertilizer regimes) were carried out in southern Finland to evaluate 12 two-row spring barley, 10 six-row barley, 10 oat and 11 wheat cultivars. In addition to HI, days to heading and maturity, length of grain filling period, grain yield, test weight and 13 traits characterizing plant stand structure were measured and analysed with principal component analysis (PCA) to detect traits associated with HI and those contributing to stability of HI. Although only modern cereals were studied, differences among cultivars were significant both in mean HI and stability of HI, and HI was associated with short plant stature in all modern cereal species. Also, single grain weight was associated with HI in all species. Differences between, but not within, species in HI were partly attributable to differences in tiller performance. Grain yield was associated closely with HI except in two-row barley. It may be possible to further increase HI of wheat, as it still was relatively low. High HI did, however, not indicate the degree of success in yield determination when environments are compared.


1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.


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