Leaf development in relation to infection by Stagonospora nodorum and Septoria tritici in wheat

1996 ◽  
Vol 47 (7) ◽  
pp. 1169
Author(s):  
BA Peters ◽  
R Loughman ◽  
Pdi Prinzio ◽  
Prinzio P Di
Keyword(s):  
Leaf Development ◽  
Flag Leaf ◽  
Sowing Date ◽  
Thermal Time ◽  
Septoria Tritici ◽  
Stagonospora Nodorum ◽  
Wheat Cultivars ◽  
Leaf Production ◽  
Leaf Emergence ◽  
Sowing Dates

Disease and phenology were compared in 2 wheat cultivars (Aroona and Spear) differing in disease resistance and maturity, at early (April-May) to late (June) sowing dates in 1991 and 1992. The cultivars had similar rates of leaf development but the longer season cultivar Spear averaged up to one leaf more on the main stem than the midseason cultivar Aroona, depending on sowing date. The extra leaf production which delayed flag leaf emergence on Spear compared to Aroona at early sowings was associated with lower disease levels in 1991. The occurrence of leaf rust may have diminished this advantage in 1992. Resistance to Septoria tritici in Aroona did not affect disease progress compared to Spear. A comparison of disease over a segment of accumulated thermal time revealed that in 1991, under average seasonal conditions, the earliest sowing experienced the most disease. In 1992, above average late spring rainfall occurred and time of sowing had little influence on disease over the same segment of thermal time. We conclude that a cultivar appropriate for early sowing on the south coast should exhibit increasing leaf production in response to early sowing. This can result in a reduction of disease severity on the upper leaves through disease escape.

Plant development of triticale cv. Lasko at different sowing dates

1998 ◽  
Vol 130 (3) ◽  
pp. 297-306 ◽  
Author(s):  
R. E. L. NAYLOR ◽  
J. SU
Keyword(s):  
Stem Elongation ◽  
Seedling Emergence ◽  
Sowing Date ◽  
Thermal Time ◽  
Development Stages ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Time Requirements ◽  
Leaf Appearance ◽  
Double Ridge

The progress of leaf emergence, external morphology and apical development stages were recorded in sowings of triticale (cv. Lasko) made from February to November 1990 at Aberdeen (57° N). Leaf appearance and the number of primordia were related to thermal time (above a base of 0°C) except when photoperiods were <c. 11 h. The thermal time per phyllochron varied between leaves and the combined times for all the phyllochrons at a particular sowing accounted for the apparent response of average phyllochron to sowing date. The thermal time requirements for progression to the double ridge stage, terminal spikelet stage, onset of stem elongation and anthesis were similar except where photoperiods of <11 h occurred. The rate of grain primordium production was constant when photoperiod had been increasing at seedling emergence but the rate was reduced when the seedling experienced shortening photoperiods at emergence.

A field study of the number of main shoot leaves in wheat in relation to vernalization and photoperiod

1992 ◽  
Vol 118 (3) ◽  
pp. 271-278 ◽  
Author(s):  
E. J. M. Kirby
Keyword(s):  
Field Experiments ◽  
Seedling Emergence ◽  
Wheat Plant ◽  
Sowing Date ◽  
Thermal Time ◽  
Model Function ◽  
Main Shoot ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Developmental Feature

SUMMARYThe number of leaves formed on the main shoot of a wheat plant is an important developmental feature, and a method of predicting this is essential for computer simulation of development.A model function was used to estimate vernalization from simulated sowing dates throughout a season. When expressed in terms of thermal time, it was estimated that a plant might be fully vernalized soon after seedling emergence or take up to about 1000 °Cd, depending on sowing date. When the simulated progress of vernalization was related to main shoot development (primordium initiation and leaf emergence) it was found that there were substantial differences between sowings in the rate of vernalization at comparable stages of apex development.A number of field experiments done in Britain from 1980 to 1984 with prominent commercial varieties, sown at various times from September to March, were analysed in terms of the thermal time to full vernalization and the photoperiod at the time of full vernalization, with vernalization simulated by the model function. In both winter and spring varieties, both of these variables significantly affected the number of main shoot leaves. Multiple linear regression using these two variables accounted for between 70 and 90% of the variance in leaf number, depending on variety.

scholarly journals Examining the latent period of Septoria tritici blotch in a field trial of winter wheat

2004 ◽  
Vol 57 ◽  
pp. 116-120 ◽  
Author(s):  
T. Armour ◽  
S.L.H. Viljanen-Rollinson ◽  
S.F. Chng ◽  
R.C. Butler ◽  
P.D. Jamieson ◽  
...  
Keyword(s):  
New Zealand ◽  
Latent Period ◽  
Environmental Conditions ◽  
Wheat Cultivar ◽  
Flag Leaf ◽  
Sowing Date ◽  
Septoria Tritici ◽  
Sowing Dates ◽  
Forecasting System ◽  
The Mean

The wheat cultivar Consort was artificially inoculated with Septoria tritici in an experiment to determine the latent period of the pathogen in New Zealand Three individual leaf layers (leaf three leaf two or the flag leaf) were inoculated over three sowing dates to provide a range of different environmental conditions following inoculation The mean latent period was 21 to 27 days (291372C days) The length of the latent period increased slightly with delays in sowing date The implications for producing a simple forecasting system to assist farmers with timing of fungicide applications are discussed

scholarly journals Effect of sowing Dates of some bread wheat cultivars on Disease response toward the fungal pathogen Wheat leaf rust

2004 ◽  
Vol 1 (2) ◽  
pp. 207-214
Author(s):  
Baghdad Science Journal
Keyword(s):  
Leaf Rust ◽  
Flag Leaf ◽  
Natural Infection ◽  
Soluble Sugar ◽  
Sowing Date ◽  
Abu Ghraib ◽  
Wheat Cultivars ◽  
Rust Disease ◽  
Disease Response ◽  
Sowing Dates

Disease responses of eight wheat cultivars , Saber Beg. , Abu-Ghraib 3, Mexipak , Tamoz 2,Tamoz 3 , IPA 95 ,IPA 99 and Tahadi which were grown in four different sowing date , 25 th October , 19th September , 14th December and 8 January , to leaf rust disease caused by Puccinia recondita were investigated under natural infection conditions at the experimental farm , College of Agriculture , Abu-Ghraib, during the growing season of 1997-1998.Results of this study revealed that IPA 95, IPA 99 and Tahadi showed moderate resistant reaction, while Tamuz 3 was moderateley susceptable . Abu-Ghraib , Saber Beg, Tamuz 2 and Mexipak showed susceptible yeaction to the causal agent . The first sowing date was not suitable for disease progress in comparsion to the fourth date where the highest disease severity were observed . The results also showed some correlation between disease response of each cultivar and the amount of chlorophyll, starch, soluble sugar in the flag leaf , and the Yield of each cultivare at the sowing dates were also obtained.

Leaf emergence rates of wheat in a mediterranean environment

1987 ◽  
Vol 38 (2) ◽  
pp. 455 ◽  
Author(s):  
EJM Kirby ◽  
MW Perry
Keyword(s):  
Field Experiments ◽  
Sowing Date ◽  
Rate Of Change ◽  
Main Stem ◽  
Thermal Time ◽  
Wheat Varieties ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Zero Rate ◽  
Leaf Appearance

Rates of leaf appearance on the main stem were measured for various wheat varieties for five to ten sowing dates in three field experiments in Western Australia.Rate of leaf appearance was constant in relation to thermal time for any given variety and sowing date, and ranged from 0.0064 to 0.0132 leaves (�C day)-1. Most of this variation could be accounted for as a response to sowing date or rate of change of daylength, although the response was complicated by interactions with variety and year.Because successive measurements were made on the same plants, it was possible to estimate directly the effects of temperature on the rate of leaf emergence. In the three years, mean rates of leaf emergence were 0.008, 0.008 and 0.011 leaves day-1 �C-1 with base temperatures (temperatures at zero rate) of 0.08, -1.2 and 0.4�C respectively. Contrary to expectation, rate of leaf emergence decreased as temperatures increased in late sowings due probably to depression of leaf emergence as daytime temperatures exceeded 25�C.For Gamenya, the only variety common to the three years, the rate of leaf emergence (RLE) on the main stem was related to the rate of change of daylength (-DL, min day-1 negative when daylength shortening) by the equationRLE = 0.00949 + 0.000988 (-DL).For crops emerging in late June (-DL approximately zero) in southern Australia, this implies a constant thermal time for leaf appearance of 105�C day leaf-1.

scholarly journals Accurate Assessment of Wheat and Triticale Cultivar Resistance to Septoria tritici and Stagonospora nodorum Infection by Biotin/Avidin ELISA

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1229-1234 ◽  
Author(s):  
Shimin Tian ◽  
Gerhard A. Wolf ◽  
Joachim Weinert
Keyword(s):  
Early Stage ◽  
Flag Leaf ◽  
Infected Plant ◽  
Visual Assessment ◽  
Field Trials ◽  
Septoria Tritici ◽  
Stagonospora Nodorum ◽  
Wheat Cultivars ◽  
Breeding Lines ◽  
Leaf Blotch

Specific and quantitative biotin/avidin-enzyme-linked immunosorbent assays (BA-ELISA) were evaluated for their ability to assess resistance of wheat and triticale cultivars to Septoria tritici (leaf blotch) and Stagonospora nodorum (leaf and glume blotch) in field trials. Using BA-ELISAs, the antigen amounts of S. tritici and of Stagonospora nodorum were measured in the flag leaf (F) and the first leaf below it (F-1) of five cultivars of triticale at Zadok's growth stage (GS) 75–80 and in 11 cultivars of wheat at GS 73–75 in 2001 and 2002. The presence of the pathogens was found to be specific to parts of the plants, cultivar, and plant species. Stagonospora nodorum was the dominant leaf blotch pathogen in triticale, while both Septoria tritici and Stagonospora nodorum occurred commonly in wheat. Close correlations were obtained between the pathogen amount measured by BA-ELISA and the percentage of necrotic leaf area in the tested cultivars. The BA-ELISA values for the tested triticale and wheat cultivars were ranked, and they correlated well with the susceptibility ratings given in the cultivar list recommended by Bundessortenamt (German Federal Office of Plant Variety), which is based on visual assessment of the leaf blotch complex caused by S. tritici and Stagonospora nodorum. The relative susceptibilities of individual wheat cultivars to both pathogens were similar. In conclusion, BA-ELISA provided for an accurate diagnosis and quantification of S. tritici and Stagonospora nodorum in infected plant tissue, and therefore can be used to assess resistance to these fungi in a disease complex in both early-stage breeding lines and field trials.

scholarly journals Pre-anthesis development of winter wheat and barley and relationships with grain yield

2018 ◽  
Vol 64 (No. 7) ◽  
pp. 310-316 ◽  
Author(s):  
Mirosavljevic Milan ◽  
Momcolovic Vojislava ◽  
Maksimovic Ivana ◽  
Putnik-Delic Marina ◽  
Pržulj Novo ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Sowing Date ◽  
Wheat Cultivars ◽  
Growing Seasons ◽  
Sowing Dates ◽  
Winter Wheat Cultivars ◽  
Leaf Appearance ◽  
Relationship Of ◽  
The Relationship

The aim of this study was to improve understanding of (1) the effect of genotypic and environmental factors on pre-anthesis development and leaf appearance traits of barley and wheat; (2) the relationship of these factors with grain yield, and (3) the differences between these two crops across different environments/sowing dates. Therefore, trials with six two-row winter barley and six winter wheat cultivars were carried out in two successive growing seasons on four sowing dates. Our study showed that the observed traits varied between species, cultivars and sowing dates. In both growing seasons, biomass at anthesis and grain yield declined almost linearly by delaying the sowing date. There was no clear advantage in grain yield of wheat over barley under conditions of later sowing dates. Generally, barley produced more leaf and had shorter phyllochron than wheat. Both wheat and barley showed a similar relationship between grain yield and different pre-anthesis traits.

Changes in Leaf Photosynthesis With Plant Ontogeny and Relationships With Yield Per Ear in Wheat Cultivars and 120 Progeny

1983 ◽  
Vol 10 (6) ◽  
pp. 503 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh ◽  
RA Fischer ◽  
YM Stockman
Keyword(s):  
Carbon Fixation ◽  
Flag Leaf ◽  
Wheat Cultivars ◽  
Leaf Photosynthesis ◽  
Negative Effects ◽  
Photosynthetic Rates ◽  
Leaf Emergence ◽  
Plant Ontogeny ◽  
Rate Of Decline ◽  
Linear Decline

Six wheat cultivars, and 120 random progeny derived from composite crosses among these cultivars and 10 others, were grown in a glasshouse and changes in photosynthesis of the main-shoot leaves determined throughout ontogeny. Photosynthetic rates for each leaf generally showed a short-term rise after ligule emergence, a plateau, and then a linear decline as the leaf aged. Both peak photosynthesis, and the rates of reduction in photosynthesis with aging, increased with successive leaves, and then either stabilized or declined in the upper leaf positions. Leaves also increased in area in a power progression with plant ontogeny. The combined effect of these factors was that successive leaves fixed progressively more carbon during their lives. Leaf emergence was essentially linear with time. Fast leaf emergence was linked with small leaves and a greater final leaf number. Whilst there was a negative correlation between area per leaf and photosynthetic rate, in terms of carbon fixation per leaf the benefits of larger leaves far outweighed the negative effects of reduced rates. Rates of aging of leaves and areas of leaves accounted for the major differences in carbon fixation per leaf among cultivars. There was no correlation between peak photosynthetic rates of leaf 3 and the flag leaf so that any screening for high rates could not be done on seedling leaves. In any event, this could be of doubtful benefit because yield per ear was unrelated to peak photosynthetic rates of the flag leaf. However, yield per ear was correlated with flag leaf area (P<0.05), rate of decline of flag leaf photosynthesis with age (P<0.001, inverse), and most closely with cumulative carbon production by the flag leaf during its life (P<0.001).

Effects of sowing date and cultivar on spike weight and kernel number in durum wheat

2010 ◽  
Vol 61 (4) ◽  
pp. 287 ◽  
Author(s):  
Simona Bassu ◽  
Francesco Giunta ◽  
Rosella Motzo
Keyword(s):  
Durum Wheat ◽  
Environmental Conditions ◽  
Sowing Date ◽  
Field Trials ◽  
Combined Effects ◽  
Wheat Cultivars ◽  
Kernel Number ◽  
Sowing Dates ◽  
Intercepted Radiation ◽  
Wheat Spike

In wheat, spike weight is associated with kernel number. The response of spike weight to photoperiod and the amount of radiation available during the period of spike growth and the associated changes in spike : stem ratio were investigated through field trials involving three durum wheat cultivars with different flowering time over two seasons and three sowing dates. Across the three cultivars spike and stem weight differed in response to the photoperiod and to the photothermal quotient, i.e. the ratio between intercepted radiation and temperature; this reflected the sensitivity of the spike : stem ratio to the environmental conditions induced by sowing date, which affected the allometry of the ratio. The photothermal quotient (0.14–1.70 MJ m–2 day–1 °C–1) explained most of the variation in both spike weight (83–270 g m–2) and kernel number per m2 (2638–13 993), across all the environments sampled. The phenology explained a significant portion of the variation in spike weight, but its influence was minor compared with the combined effects of the quantity of intercepted radiation and the temperature. Therefore, the correlation between kernel number and the photothermal quotient before anthesis was more sensible to the environmental variation induced by sowing date beyond its conventional window.

Prediction of leaf and internode development in wheat

1997 ◽  
Vol 129 (4) ◽  
pp. 385-396 ◽  
Author(s):  
R. M. WEIGHTMAN ◽  
E. J. M. KIRBY ◽  
R. SYLVESTER-BRADLEY ◽  
R. K. SCOTT ◽  
R. W. CLARE ◽  
...  
Keyword(s):  
Flag Leaf ◽  
Sowing Date ◽  
Leaf Length ◽  
Growth Stages ◽  
Factors Affecting ◽  
Final Number ◽  
Leaf Emergence ◽  
Basal Internode ◽  
Number Of Leaves ◽  
The Difference

Functions which predict rate of leaf emergence and final number of leaves, used in a model to predict the date at which growth stages occur, were tested in an experiment on winter wheat cv. Mercia grown with standardized husbandry at six sites in 1992/93, 1993/94 and 1994/95. A study of the number of detectable nodes on the culm and leaf length was also made.The predicted rate of leaf emergence was mostly within 5% of the observed value. The difference between observed and predicted final number of leaves was mostly less than half a leaf but suspected errors in leaf counts resulted in some differences of more than two leaves.Variable extension of the basal internode impaired confidence in the detection of nodes. The mean number of detectable nodes differed significantly among sites and between seasons from 3·7 to 4·8 but could not be related to sowing date or final number of leaves. Further information on factors affecting extension of the basal internode is desirable to standardize node detection and improve prediction of culm leaf appearance.Culm leaves showed successively longer laminae up to the penultimate leaf. There was a significant relationship between length of the flag leaf and the final number of leaves, but it was positive in 1993/94 and negative in 1994/95. This may have been due to greater water stress in 1994/95.

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