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.

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.

Sowing date and photoperiod effects on leaf appearance in field-grown wheat

1997 ◽  
Vol 77 (1) ◽  
pp. 23-31 ◽  
Author(s):  
G. K. Hotsonyame ◽  
L. A. Hunt
Keyword(s):  
Air Temperature ◽  
Sowing Date ◽  
Rate Of Change ◽  
Wheat Field ◽  
Sowing Dates ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Supported Work ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Rate of leaf appearance is a characteristic that can impact on the rate of development of a crop canopy. For wheat (Triticum aestivum L.), it is generally thought to be constant within a sowing date, but to vary among sowing dates. Such variation has been variously attributed to differences in the rate of change of photoperiod, the absolute photoperiod, or the mean air temperature. This study was undertaken to provide further information on the photoperiod and temperature effects on rate of leaf appearance in wheat. Field studies were conducted at Elora, Ontario at five sowing dates under natural and extended (20 h) photoperiod conditions. Two genotypes each of spring and winter wheat were grown under 0 and 150 kg ha−1 nitrogen fertilization. The results indicated that variations in rate of leaf appearance were not due to rate of change in photoperiod or absolute photoperiod at emergence. The change in rate of leaf appearance during a growth cycle was constant when mean air temperature during growth varied in a narrow range (less than 10 °C), but varied when there were wider ranges (over 10 °C) of temperature variation. Rate of leaf appearance was lower for the September seeding, at which time temperatures were around 5 °C, but were quite similar for May, June, July and August seedings even though temperatures ranged from approximately 15 °C (May) to 23 °C (June). The results suggested that the leaf appearance rate–temperature response curve is curvilinear, as found in some growth room studies, and supported work indicating that the phyllochron would depend on the temperature at the time of measurement. Key words: Wheat, photoperiod, temperature, nitrogen, sowing date, leaf appearance rate

Comparative rates of emergence and leaf appearance in wild oats (Avena fatua), winter barley (Hordeum sativum) and winter wheat (Triticum aestivum)

1992 ◽  
Vol 118 (2) ◽  
pp. 149-156 ◽  
Author(s):  
R. D. Cousens ◽  
M. P. Johnson ◽  
S. E. Weaver ◽  
T. D. Martin ◽  
A. M. Blair
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Field Studies ◽  
Sowing Date ◽  
Avena Fatua ◽  
Winter Barley ◽  
Rate Of Change ◽  
Wild Oats ◽  
Underlying Mechanisms ◽  
Leaf Appearance

SUMMARYWinter barley cv. Igri, winter wheat cv. Avalon and spring wild oats (Avena fatua) were studied in monocultures in pots and in the field. The field experiments were located near Bristol and Bury St Edmunds in 1988/89. Pot sowings were monthly, whereas there was a single sowing date for each of the two field locations. Base temperatures for emergence in pots were 2·2, 1·3 and 2·3 °C for barley, wheat and A. fatua respectively. Barley was consistently the fastest to emerge. Leaf number was strongly correlated with photothermal time from emergence, with barley producing leaves at the greatest rate. Base temperatures for leaf appearance were −6, −5 and −3 °C for barley, wheat and A. fatua respectively. The field studies confirmed the ranking of the species based on the pot experiments. Both a model based on photothermal time and one based on rate of change of daylength at emergence gave good descriptions of the data. It is argued that correlations of rates of development with individual environmental variables are not sufficient to deduce the underlying mechanisms.

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.

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.

The emergence of maize from field sowings in Great Britain: I. The effect of date of sowing on the extent and speed of emergence of different varieties

1957 ◽  
Vol 48 (4) ◽  
pp. 447-456 ◽  
Author(s):  
E. S. Bunting ◽  
L. A. Willey
Keyword(s):  
Great Britain ◽  
Western Europe ◽  
Field Experiments ◽  
Field Capacity ◽  
Sowing Date ◽  
Cold Test ◽  
Soil Pathogen ◽  
Sowing Dates ◽  
Soil Temperatures ◽  
North Western

Between 1953 and 1955 a series of field experiments have been carried out in Great Britain to assess the effect of sowing date on the extent and the rate of emergence of a number of varieties of maize.The range of sowing dates was from late March till May. Records were kept of the soil temperatures, these will be reported later, and in certain experiments the water content of the soil was maintained at field capacity. In all experiments a northern flint variety and a southern dent variety were sown, in the first year only flint × dent hybrids were also grown.There was an increase in final emergence with the later sowing dates. The northern flint varieties were superior to the southern dent varieties, while the flint × dent hybrids occupied an intermediate position. The lower final emergence of the southern dent variety was most marked at the earlier sowing dates.Differences between varieties in the speed of emergence, taken as the number of days from sowing until half of the surviving seedlings had emerged, was observed at several centres. The open-pollinated varieties usually emerged more slowly than the flint × dent hybrids. There was a very marked difference between early- and late-sowing dates in speed of emergence.It was possible in the second year to compare seed of high quality with that of low quality as determined by the ‘cold test’ of germination capacity. The lowquality seed gave greatly reduced final emergence, the experiments stressing the need for the adoption of a standard ‘cold test’ for maize seed, especially of that intended for sowing in north-western Europe.The high final emergence of the northern flint varieties suggest that a gene source for resistance to soil pathogen attack is readily available. The possibilities in north-western Europe for expansion of growing grain maize would be greatly strengthened by development of varieties capable of growth at low temperatures. The experiments suggest that until such varieties are available little advantage in time of emergence will be gained by sowing maize before late April in Britain.

Relationships between the responses of spring wheat genotypes to temperature and photoperiodic treatments and their performance in the field

1981 ◽  
Vol 96 (3) ◽  
pp. 623-634 ◽  
Author(s):  
Margaret A. Ford ◽  
R. B. Austin ◽  
W. J. Angus ◽  
G. C. M. Sage
Keyword(s):  
Spring Wheat ◽  
Field Experiments ◽  
Sowing Date ◽  
Photoperiodic Response ◽  
Low Latitude ◽  
Wheat Varieties ◽  
Wheat Genotypes ◽  
The North ◽  
Controlled Environments ◽  
Late Sowing

SUMMARYThirty-eight spring wheat genotypes of north temperate or low latitude origin, all reasonably well adapted to the English environment, were grown in controlled environments providing the four combinations of 10 and 14 h photoperiods and temperatures of 8 and 16 °C for 6 weeks. They were then transferred to a glasshouse to assess their responses to these treatments. In separate experiments the responses of the genotypes to vernalization for 2 and 4 weeks at 2 and 8 °C were compared with unvernalized controls. The genotypes were also compared in field experiments from early, intermediate or late sowing over 3 years.Both high temperatures and long days hastened ear emergence. At the higher temperature more leaves and spikelets were produced on the main stem while in long days the plants had fewer leaves and spikelets.Most genotypes of north temperate and low latitude origin were responsive to photoperiod but not to the vernalization treatments. As a group, the low latitude ones were as responsive as the north temperate group. Five genotypes of north temperate origin were responsive to vernalization but not to photoperiod and were designated as ‘winter’ ones. Pitic 62 and Hork, from low latitudes, were responsive to vernalization and Hork was unique in also being responsive to photoperiod. The main difference between the north temperate and low latitude genotypes was in time to ear emergence and it is suggested that these differences were due to the effects of earliness genes as distinct from those determining photoperiodic response.Taking all genotypes individually there were no correlations between yield or its sensitivity to sowing date and any of the attributes measured in controlled environments. However, considering class means, the winter genotypes were the latest to reach ear emergence in the field, and their yields, while greatest from the earliest sowings, were proportionally more depressed by late sowing than the others of the north temperate origin. Thus, it may be unwise for plant breeders to incorporate a vernalization response in spring wheat varieties unless genes for ‘earliness’ are also included. The low latitude class gave only slightly lower yields than the north temperate class.It is concluded that genes other than those controlling responses to photoperiod, temperature and vernalization were more important determinants of the differences in yield among this set of genotypes.

scholarly journals Temperature Response of Chickpea Cultivars to Races of Fusarium oxysporum f. sp. ciceris, Causal Agent of Fusarium Wilt

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Blanca B. Landa ◽  
Juan A. Navas-Cortés ◽  
María del Mar Jiménez-Gasco ◽  
Jaacov Katan ◽  
Baruch Retig ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Field Experiments ◽  
Temperature Response ◽  
Sowing Date ◽  
Effect Of Temperature ◽  
Sowing Dates ◽  
High Level ◽  
Moderately Resistant ◽  
Chickpea Cultivars

Use of resistant cultivars and adjustment of sowing dates are important measures for management of Fusarium wilt in chickpeas (Cicer arietinum). In this study, we examined the effect of temperature on resistance of chickpea cultivars to Fusarium wilt caused by various races of Fusarium oxysporum f. sp. ciceris. Greenhouse experiments indicated that the chickpea cultivar Ayala was moderately resistant to F. oxysporum f. sp. ciceris when inoculated plants were maintained at a day/night temperature regime of 24/21°C but was highly susceptible to the pathogen at 27/25°C. Field experiments in Israel over three consecutive years indicated that the high level of resistance of Ayala to Fusarium wilt when sown in mid- to late January differed from a moderately susceptible reaction under warmer temperatures when sowing was delayed to late February or early March. Experiments in growth chambers showed that a temperature increase of 3°C from 24 to 27°C was sufficient for the resistance reaction of cultivars Ayala and PV-1 to race 1A of the pathogen to shift from moderately or highly resistant at constant 24°C to highly susceptible at 27°C. A similar but less pronounced effect was found when Ayala plants were inoculated with F. oxysporum f. sp. ciceris race 6. Conversely, the reaction of cultivar JG-62 to races 1A and 6 was not influenced by temperature, but less disease developed on JG-62 plants inoculated with a variant of race 5 of F. oxysporum f. sp. ciceris at 27°C compared with plants inoculated at 24°C. These results indicate the importance of appropriate adjustment of temperature in tests for characterizing the resistance reactions of chickpea cultivars to the pathogen, as well as when determining the races of isolates of F. oxysporum f. sp. ciceris. Results from this study may influence choice of sowing date and use of chickpea cultivars for management of Fusarium wilt of chickpea.

Simulating phenology and yield response of canola to sowing date in Western Australia using the APSIM model

2002 ◽  
Vol 53 (10) ◽  
pp. 1155 ◽  
Author(s):  
I. Farré ◽  
M. J. Robertson ◽  
G. H. Walton ◽  
S. Asseng
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Rainfall Variability ◽  
Sowing Date ◽  
Weather Data ◽  
Yield Response ◽  
Yield Reduction ◽  
Sowing Dates ◽  
3.0 T ◽  
Using Data

Canola is a relatively new crop in the Mediterranean environment of Western Australia and growers need information on crop management to maximise profitability. However, local information from field experiments is limited to a few seasons and its interpretation is hampered by seasonal rainfall variability. Under these circumstances, a simulation model can be a useful tool. The APSIM-Canola model was tested using data from Western Australian field experiments. These experiments included different locations, cultivars, and sowing dates. Flowering date was predicted by the model with a root mean squared deviation (RMSD) of 4.7 days. The reduction in the period from sowing to flowering with delay in sowing date was accurately reproduced by the model. Observed yields ranged from 0.1 to 3.2 t/ha and simulated yields from 0.4 to 3.0 t/ha. Yields were predicted with a RMSD of 0.3–0.4 t/ha. The yield reduction with delayed sowing date in the high, medium, and low rainfall region (3.2, 6.1, and 8.6% per week, respectively) was accurately simulated by the model (1.1, 6.7, and 10.3% per week, respectively). It is concluded that the APSIM-Canola model, together with long-term weather data, can be reliably used to quantify yield expectation for different cultivars, sowing dates, and locations in the grainbelt of Western Australia.

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