scholarly journals The effect of nitrogen fertilization on flag leaf and ear photosynthesis and grain yield of spring wheat

2014 ◽  
Vol 60 (No. 12) ◽  
pp. 531-536 ◽  
Author(s):  
J. Olszewski ◽  
M. Makowska ◽  
A. Pszczółkowska ◽  
A. Okorski ◽  
T. Bieniaszewski

In a three-year field experiment the assessment of leaves and ears photosynthesis rate in spring wheat was made using a LI-COR 6400 portable photosynthesis system. The photosynthetic rate of spring wheat was affected by cultivars, nitrogen fertilization and weather conditions. We generally found a negative correlation between the yield of spring wheat and the rate of photosynthesis in flag leaves in phases 39–55 BBCH (the strength of this effect depended on the level of nitrogen fertilization). Strong negative correlation occurred for cv. Bryza in phases:  39–51 BBCH in treatment fertilized with lower dose of nitrogen and in phase 39–41 BBCH for dose 120 kg/ha. There was a significant negative correlation for cv. Tybald only in phase 39–41 BBCH for higher dose of nitrogen and 52–55 BBCH for lower dose. Our studies show that the photosynthetic activity of flag leaves decreased from the booting (39–41 BBCH) to heading stage (52–55 BBCH), and their function was taken over by ears. Contrary to flag leaf, in wheat ears the intensity of photosynthesis correlated positively with grain yield for most of the studied period (52–65 BBCH, with highly significant correlation at 56–57 BBCH and – only for high nitrogen treatments – at 59–61 BBCH; a negative correlation was generally observed at a later phase, i.e. at 65–69 BBCH). Contrary to flag leaf photosynthesis, the intensity of this process in wheat ears (at the heading and flowering stages) seems highly relevant for grain yield. High positive correlation was noted in 56–57 BBCH and 61–65 BBCH. However, the study was done in field conditions and for definitive conclusions observations over a longer period would be desirable.

2019 ◽  
Author(s):  
Victoria Larweh ◽  
Richard Akromah ◽  
Stephen Amoah ◽  
James Yaw Asibuo ◽  
Francis Kusi ◽  
...  

Abstract Background: The parasitic plant Striga gesnerioides (Willd) Vatke is becoming a threat to cowpea production in the three northern regions of Ghana (Derived Savanna, Southern Guinea Savanna and Northern Guinea Savanna. The objective of this study was to determine the extent of yield loss due to Striga in F3 progenies and their parental lines. A total of twelve cowpea genotypes were evaluated to ascertain the level of damage by S. gesnerioides. Results: The results indicated varietal differences with respect to Striga susceptibility in the genotypes studied. The susceptible varieties (Asomdwee and Hewale) showed an array of emerged Striga shoots. The F3 progenies (s52, s37, s147, s272) also exhibited the same trend. The resistance genotypes (IT99K-573-1-1 and GH3684), however, were totally devoid of Striga shoots. Similarly, some of the F3 progenies (r246, r286, r282 and r69) were completely without Striga shoot. Striga height was higher on susceptible genotypes than those that are moderately resistance. The results obtained from this study revealed a percentage reduction in pods per plant range between 45.12 and 49.53 %; grain yield reduction ranged between 78.22 and 87.17% on susceptible genotypes which indicated that Striga had greater influence on yield. Fodder yield was also significantly reduced between 70.59 and 73.03% in susceptible genotypes. There was a strong negative correlation (r = -0.724) between grain yield and days to Striga emergence. A significant negative correlation (r = -0.762) was also found between Striga shoot per plant and grain yield. Conclusion: Striga infestation reduced pods per plant to 49%, grain yield loss to 87% and fodder yield loss to 73%. This study has revealed potential F3 genotypes resistant to S. gesnerioides under pot experiment. The implication is that if susceptible genotypes are grown the farmer stand the chance of loosen everything to the parasite.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ajeet Kumar Pandey ◽  
Vinod Kumar Mishra ◽  
Ramesh Chand ◽  
Sudhir Navathe ◽  
Neeraj Budhlakoti ◽  
...  

AbstractSpot blotch and terminal heat are two of the most important stresses for wheat in South Asia. A study was initiated to explore the use of spelt (Triticum spelta) to improve tolerance to these stresses in spring wheat (T. aestivum). We assessed 185 recombinant inbred lines (RILs) from the cross T. spelta (H + 26) × T. aestivum (cv. HUW234), under the individual stresses and their combination. H + 26 showed better tolerance to the single stresses and also their combination; grain yield in RILs was reduced by 21.9%, 27.7% and 39.0% under spot blotch, terminal heat and their combined effect, respectively. However, phenological and plant architectural traits were not affected by spot blotch itself. Multivariate analysis demonstrated a strong negative correlation between spikelet sterility and grain yield under spot blotch, terminal heat and their combination. However, four recombinant lines demonstrated high performance under both stresses and also under their combined stress. The four lines were significantly superior in grain yield and showed significantly lower AUDPC than the better parent. This study demonstrates the potential of spelt wheat in enhancing tolerance to spot blotch and terminal heat stresses. It also provides comprehensive evidence about the expression of yield and phenological traits under these stresses.


Author(s):  
Jindřiška Kučerová

The results of three-year trials (1999 to 2001) conducted with six winter wheat varieties in which was studied the grain yield and parameters of technological quality. Varieties of wheat come from four different localities of the Czech Republic. The most favourable weather conditions, a lot of precipitation and high temperature in the course of ripening from three years were proved in the year 2000. The best grain yield were in 2001 (average of sites 8.84 t/ha) and variety Semper, worst quality, had the highest grain yield of 9.17 t/ha, the least grain yield had Sulamit, best quality (7.94 t/ha). The laboratory analysis revealed negative correlation between grain yield and baking quality. The number of statistically highly significant correlations among bread-making quality parameters too.The negative correlation was of grain yield and grain volume mass (P < 0.05), Zeleny test and protein content taken as a whole for three years (P < 0.01). The correlation of loaf volume, which is the traits of baking quality and Zeleny test (r = 0.6016**), protein content (r = 0.5932**), dough stability (r = 0.2898**) and flour water absorption (r = 0.3632**) was positive (P < 0.01).


2008 ◽  
Vol 110 (3) ◽  
pp. 366-375 ◽  
Author(s):  
Johanna Gelang ◽  
Håkan Pleijel ◽  
Ebe Sild ◽  
Helena Danielsson ◽  
Suhaila Younis ◽  
...  

1982 ◽  
Vol 60 (12) ◽  
pp. 2741-2744 ◽  
Author(s):  
R. Frossard ◽  
N. J. Fokkema

Green flag leaves of spring wheat grown with low or high nitrogen supply in the form of Ca(NO3)2 were inoculated with Sporobolomyces roseus. Growth of the yeast in a controlled environment was followed for several days by culturing techniques. No consistent differences were found between the development of S. roseus on leaves from low or high nitrogen treated plants, suggesting that leaf exudates from low nitrogen treated plants still contain enough nitrogen compounds to support growth of S. roseus. Nitrogen fertilization obviously seems not to be an appropriate means to manipulate the phyllosphere mycoflora.


Author(s):  
V. V. Liubych ◽  

Aim. To study the selection value of new spring triticale varieties according to the main economic and valuable properties (duration of the growing season, plant height, lodging resistance, resistance to diseases, tillering coefficient, grain weight from one ear, grain yield). Methods. Laboratory, mathematical and statistical, physical. Results. The duration of the growing season of spring triticale was longer compared to wheat. Thus, it was the longest in 2015–122 days, in 2014–112, and in 2013–102 days or 3–9 days more compared to wheat, except for 2014 in which the duration of the growing season of spring wheat was 117 days. This figure did not change depending on the variety of spring triticale over the years of research. The shorter growing season of spring triticale in 2013 was apparently due to the later sowing period. On average, over three years of research, the height of spring triticale plants varied from 99 to 105 cm depending on the variety. Triticale spring exceeded soft spring wheat by 2–8 %. However, Heritage durum wheat plants were the highest. This figure has changed significantly over the years of research. Thus, the highest plants were in the favourable 2014 – 108–129 cm, the shortest in the less favourable 2013 – 85–92 cm, and in 2015 – 100–106 cm. Spring triticale plants had the highest resistance to pathogens of leaf spot in 2015. In 2014, the intensity of their defeat was at the level of 4.0–4.5% with the resistance of 9 points. Triticale spring significantly exceeded the plants of both types of wheat in this respect. On the average for three years of researches, the coefficient of general spring triticale tillering made 1.56–1.65 depending on the variety. This indicator was at the level of durum wheat and 9–14 % lower than that of soft wheat. The productive tillering coefficient was 10–15 % lower than that of soft wheat. Of the five varieties of spring triticale, the highest grain yield was obtained for the cultivation of Kharkiv Oberih variety – 6.12 t/ha. Yields of Kharkiv Lebid, Kharkiv Sontsedar and Kharkiv Korovai varieties were 18–22 % higher compared to soft wheat and 7–11 % higher than durum wheat. Conclusions. Indicators of growth and development of spring triticale plants and grain yield change significantly depending on the variety and weather conditions of the growing season. The duration of the growing seasom of spring triticale is 102–122 days. Plants can be medium and very tall, lodging resistance varies from 5 to 9 points. Triticale spring has a very high resistance to main fungal diseases. Grain yield is 4.93–6.12 t/ha depending on the genotype. To obtain a high and stable grain yield, it is necessary to grow Kharkiv Korovai and Kharkiv Oberih spring triticale varieties.


1971 ◽  
Vol 19 (4) ◽  
pp. 211-222 ◽  
Author(s):  
J.H.J. Spiertz ◽  
B.A. ten Hag ◽  
L.J.P. Kupers

Spring wheat cv. Opal, Orca and Gaby, sown in 1967-8 on various dates at different seed rates or with different levels of N and chlormequat, were assessed for green area of leaves, internodes and ears. Green-area duration (D) for flag leaf and for peduncle were closely correlated with grain yield, the combined value for the 2 parameters accounting for 81 and 61% of the variance in grain yield in the 2 years, respectively. Including all the values of D in a multiple correlation increased the predictive value to 83 and 74%. D for ears was closely correlated with grain yield in 1968 only. The grain: leaf ratio was higher for Gaby than for the other 2 cv. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1992 ◽  
Vol 67 (03) ◽  
pp. 377-380 ◽  
Author(s):  
S H Ibbotson ◽  
G M Tate ◽  
J A Davies

SummaryThrombotic diseases increase in incidence with advancing years and this might be partly due to an increased propensity for fibrin formation in older individuals. Accordingly we decided to investigate whether the time taken to generate 50% thrombin activity in vitro varied with the age of the plasma donor. Coagulation was initiated in defibrinated, diluted plasma by contact activation and thrombin activity measured using the chromogenic substrate, S2238. The rate of thrombin generation was assessed by measuring the time taken to reach 50% maximal activity (T50/s). There was a highly significant negative correlation between T50 and age, T50 declining from 93 s at 19 years to 71 s at 65 years (r = −0.637, p <0.0001). A strong negative correlation was demonstrated between T50 and FVII level (r = -0.415, p = 0.0007) and FVIII: C level (r = -0.465, p = 0.0001). Although FVII concentration correlated with age (r = 0.307, p = 0.014) no relationship was seen between age and FVIII :C. These data suggest that coagulation rates in plasma accelerate with age.


1985 ◽  
Vol 63 (9) ◽  
pp. 1605-1609 ◽  
Author(s):  
L. A. Hunt ◽  
G. van der Poorten

Postanthesis carbon dioxide exchange and transpiration rates of flag and penultimate leaves of five spring-wheat (Triticum aestivum L. emend. Thell.) cultivars were measured from complete flag-leaf expansion to senescence. Leaf nitrogen contents were determined from anthesis to maturity. Both the absolute level of and the time-related decline of the carbon dioxide exchange rate varied among the cultivars. The flag-leaf carbon dioxide exchange rate decreased steadily throughout for one cultivar and slowly for a varying period and then rapidly for most others. The penultimate-leaf carbon dioxide exchange rate decreased throughout with one cultivar but did not decline in the period from 1 to 3 weeks postanthesis in others. The transpiration rate peaked at or near anthesis for the flag leaves and then either declined or fluctuated around the peak value for 3 weeks. The penultimate-leaf transpiration rate increased to a second peak late in ontogeny for most genotypes. In general, the time course of the transpiration rate matched that of the carbon dioxide exchange rate, but the transpiration rate at a specific carbon dioxide exchange rate was lower for penultimate than for flag leaves. The carbon dioxide exchange rate was linearly related to leaf nitrogen content, with the same regression applying for both flag and penultimate leaves; regressions were similar for all genotypes. There were no marked deviations from the overall carbon dioxide exchange rate – nitrogen regression that could be indicative of a "sink" influence on the activity of photosynthetic enzymes.


1977 ◽  
Vol 88 (2) ◽  
pp. 267-282 ◽  
Author(s):  
H. G. Jones

SUMMARYThis paper describes a field study of the variation in leaf water potential (ѱL), leaf conductance (gL) and other aspects of crop water relations in a set of ten spring wheats. The two main soil moisture regimes used were irrigation and drought; the latter being imposed by placing rainwater gutters between the crop rows to intercept a proportion of any rainfall. The development of plant stresses, the changes in leaf conductances during the growing season and the relationship between these variables and soil moisture depletion are described. Mean daytime leaf water potentials declined during much of the season even in well irrigated plots. There was also evidence that stomata tended to be most open during the period just prior to anthesis. Data on variation of ѱL and gL within the crop are also presented and indicate that most evaporation occurs from the flag leaf in the spring wheat canopy.Although genotypic variation was found for the mean values of ѱL and gL, interactions between variety and water regime were generally non-significant. Although yields were not well correlated with most aspects of crop water relations measured, partly because of the dominance of other factors such as maturity and disease susceptibility, a strong negative correlation was observed between yield and gL for the period 7–14 days before anthesis.Stomatal frequencies were not related to leaf conductances and there was no evidence that the stomatal behaviour adapted to previous drought stress. The growth responses observed, however, could be regarded as adaptations for reducing evaporation. The results are discussed in relation to the breeding of drought tolerant varieties of wheat.


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