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

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.


2004 ◽  
Vol 55 (8) ◽  
pp. 863 ◽  
Author(s):  
Imma Farré ◽  
Michael J. Robertson ◽  
Senthold Asseng ◽  
Robert J. French ◽  
Miles Dracup

Simulation of narrow-leafed lupin (Lupinus angustifolius L.) production would be a useful tool for assessing agronomic and management options for the crop. This paper reports on the development and testing of a model of lupin development and growth, designed for use in the cropping systems simulator, APSIM (Agricultural Production Systems Simulator). Parameters describing leaf area expansion, phenology, radiation interception, biomass accumulation and partitioning, water use, and nitrogen accumulation were obtained from the literature or derived from field experiments. The model was developed and tested using data from experiments including different locations, cultivars, sowing dates, soil types, and water supplies. Flowering dates ranged from 71 to 109 days after sowing and were predicted by the model with a root mean square deviation (RMSD) of 4–5 days. Observed grain yields ranged from 0.5 to 2.7 t/ha and were simulated by the model with a RMSD of 0.5 t/ha. Simulation of a waterlogging effect on photosynthesis improved the model performance for leaf area index (LAI), biomass, and yield. The effect of variable rainfall in Western Australia and sowing date on yield was analysed using the model and historical weather data. Yield reductions were found with delay in sowing, particularly in water-limited environments. The model can be used for assessing some agronomic and management options and quantifying potential yields for specific locations, soil types, and sowing dates in Western Australia.



2002 ◽  
Vol 42 (2) ◽  
pp. 149 ◽  
Author(s):  
M. D. A. Bolland ◽  
W. J. Cox ◽  
B. J. Codling

Dairy and beef pastures in the high (>800 mm annual average) rainfall areas of south-western Australia, based on subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum), grow on acidic to neutral deep (>40 cm) sands, up to 40 cm sand over loam or clay, or where loam or clay occur at the surface. Potassium deficiency is common, particularly for the sandy soils, requiring regular applications of fertiliser potassium for profitable pasture production. A large study was undertaken to assess 6 soil-test procedures, and tissue testing of dried herbage, as predictors of when fertiliser potassium was required for these pastures. The 100 field experiments, each conducted for 1 year, measured dried-herbage production separately for clover and ryegrass in response to applied fertiliser potassium (potassium chloride). Significant (P<0.05) increases in yield to applied potassium (yield response) were obtained in 42 experiments for clover and 6 experiments for ryegrass, indicating that grass roots were more able to access potassium from the soil than clover roots. When percentage of the maximum (relative) yield was related to soil-test potassium values for the top 10 cm of soil, the best relationships were obtained for the exchangeable (1 mol/L NH4Cl) and Colwell (0.5 mol/L NaHCO3-extracted) soil-test procedures for potassium. Both procedures accounted for about 42% of the variation for clover, 15% for ryegrass, and 32% for clover + grass. The Colwell procedure for the top 10 cm of soil is now the standard soil-test method for potassium used in Western Australia. No increases in clover yields to applied potassium were obtained for Colwell potassium at >100 mg/kg soil. There was always a clover-yield increase to applied potassium for Colwell potassium at <30 mg/kg soil. Corresponding potassium concentrations for ryegrass were >50 and <30 mg/kg soil. At potassium concentrations 30–100 mg/kg soil for clover and 30–50 mg/kg soil for ryegrass, the Colwell procedure did not reliably predict yield response, because from nil to large yield responses to applied potassium occurred. The Colwell procedure appears to extract the most labile potassium in the soil, including soluble potassium in soil solution and potassium balancing negative charge sites on soil constituents. In some soils, Colwell potassium was low indicating deficiency, yet plant roots may have accessed potassum deeper in the soil profile. Where the Colwell procedure does not reliably predict soil potassium status, tissue testing may help. The relationship between relative yield and tissue-test potassium varied markedly for different harvests in each year of the experiments, and for different experiments. For clover, the concentration of potassium in dried herbage that was related to 90% of the maximum, potassium non-limiting yield (critical potassium) was at the concentration of about 15 g/kg dried herbage for plants up to 8 weeks old, and at <10 g/kg dried herbage for plants older than 10–12 weeks. For ryegrass, there were insufficient data to provide reliable estimates of critical potassium.



Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 167 ◽  
Author(s):  
ICR Holford ◽  
JM Morgan ◽  
J Bradley ◽  
BR Cullis

In a study using data from 57 wheat field experiments on the central-western slopes of New South Wales, eight soil phosphate tests (Bray,, Bray,, alkaline fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. The results showed that, regardless of how well correlated a soil test is with yield responsiveness, it cannot give a satisfactory estimate of fertilizer requirement unless yield response curvature is also taken into account. The tendency of soil test values, especially of the Colwell test, to be negatively related to response curvature, and hence inversely related to fertilizer effectiveness, compounded the problem of directly relating soil test values to fertilizer requirement. The best test (lactate) accounted for only 28% of the variance in fertilizer requirement, compared with 50% of the variance in responsiveness, and the worst test (Colwell) was completely unrelated to fertilizer requirements. When fertilizer requirement was estimated from the lactate test value and the actual response curvature for each experiment, 68% of the variance (from the actual fertilizer requirement) was accounted for. Thirteen experiments were subject to drier conditions than the others, and these were less responsive and had lower fertilizer requirements relative to soil test values. In relation to yield responsiveness, the Colwell test was most sensitive (P < 0.001) to dry conditions, while the two best tests (lactate and Bray,) were the least sensitive (P > 0.05). The results demonstrated the superiority of acidic anionic extractants over alkaline bicarbonate extractants on moderately acid to alkaline wheat-growing soils.



1998 ◽  
Vol 49 (7) ◽  
pp. 1111 ◽  
Author(s):  
D. J. Stephens ◽  
T. J. Lyons

As sowing dates are critical for appropriate yield forecasting, a national survey of Australian wheat farmers was undertaken. This revealed that wheat sowing generally takes 2-4 weeks to complete between the middle of May and the middle of June. Distinct regional differences occur in the way sowing is completed and these are related to soil and climatic effects. In Western Australia, sowing follows a more distinct `break in the season" and the midpoint of farm sowing is fairly uniform across cropping areas. As one progresses into south-eastern and then north-eastern cropping areas the spatial variability in sowing increases. The combination of fallowing practices, unreliable autumn rainfall, and heavier soils (that delay operations when conditions are wet or dry), all add to the variability in sowing date and sowing duration in north-eastern areas. The range of midpoint in sowing (between years) generally decreases as the progression is made from a farm, to a State, to a national scale. Reduced variability at a national scale is enhanced by broad-scale weather patterns causing sowing opportunities to contrast markedly on different sides of the country. During the 1980s, sowing progressed a day earlier per year at a national scale. The most pronounced changes occurred in Queensland and Western Australia, where a 2-3-week shift to earlier sowing was recorded. Coinciding with this was a trend in all areas to reduced or minimum tillage techniques. Late opening rains in South Australia restricted early sowing opportunities during this time.



1992 ◽  
Vol 118 (3) ◽  
pp. 279-287 ◽  
Author(s):  
M. J. Conry ◽  
A. Hegarty

SUMMARYAn experiment, carried out over a 5-year period (1984–88) on medium–heavy textured soil at Athy (Ireland), tested the effect of five sowing dates (early September–early December) and four seed rates (c. 100, 150, 200 and 250 kg/ha) on the grain yield and protein content of winter barley (cv. Panda).September-sown plots gave the greatest yields in all years. Plots sown in mid-October and later gave significantly reduced yields. Yield reductions over the 5-year period averaged 15, 24 and 34% for the mid-October, November and December sowing dates, respectively. Significant differences in yield between the smaller and larger seed rates were obtained, with the latter giving the greatest yields at all sowing dates from late September to December. Increasing the seed rate, however, did not compensate for the yield reduction due to delayed sowing. In the early September-sown plots, the higher seed rates gave reduced yields in four of the five years (1984–87) with the opposite result in 1988. In 1988 the early September-sown plots gave greater yields than the late September-sown plots.Regression analysis showed a strong relationship between yield and log(ears/m2) in four of the five years (1984–87) but the relationship was poor in 1988 primarily due to the inexplicably low ear population of the early-sown plots. The inclusion of 1000-grain weight in the model gave a better fit and accounted for a high proportion (62–80%) of the yield variation.The late September sowing date and the higher seed rates gave slightly lower protein levels in four of the five years. There was an inverse relationship between grain yield and protein for the same four years (1984–87).



2001 ◽  
Vol 52 (2) ◽  
pp. 295 ◽  
Author(s):  
R. A. Latta ◽  
L. J. Blacklow ◽  
P. S. Cocks

Two field experiments in the Great Southern region of Western Australia compared the soil water content under lucerne (Medicago sativa) with subterranean clover (Trifolium subterranean) and annual medic (Medicago polymorpha) over a 2-year period. Lucerne depleted soil water (10–150 cm) between 40 and 100 mm at Borden and 20 and 60 mm at Pingrup compared with annual pasture. There was also less stored soil water after wheat (Triticum aestivum) and canola (Brassica napus) phases which followed the lucerne and annual pasture treatments, 30 and 48 mm after wheat, 49 and 29 mm after canola at Borden and Pingrup, respectively. Lucerne plant densities declined over 2 seasons from 35 to 25 plants/m2 (Borden) and from 56 to 42 plants/m2 (Pingrup), although it produced herbage quantities similar to or greater than clover/medic pastures. The lucerne pasture also had a reduced weed component. Wheat yield at Borden was higher after lucerne (4.7 t/ha) than after annual pasture (4.0 t/ha), whereas at Pingrup yields were similar (2 t/ha) but grain protein was higher (13.7% compared with 12.6%) . There was no yield response to applied nitrogen after lucerne or annual pasture at either site, but it increased grain protein at both sites. There was no pasture treatment effect on canola yield or oil content at Borden (2 t/ha, 46% oil). However, at Pingrup yield was higher (1.5 t/ha compared to 1.3 t/ha) and oil content was similar (41%) following lucerne–wheat. The results show that lucerne provides an opportunity to develop farming systems with greater water-use in the wheatbelt of Western Australia, and that at least 2 crops can be grown after 3 years of lucerne before soil water returns to the level found after annual pasture.



1957 ◽  
Vol 48 (4) ◽  
pp. 447-456 ◽  
Author(s):  
E. S. Bunting ◽  
L. A. Willey

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.



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 ◽  
...  

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.



Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 358-364 ◽  
Author(s):  
P. M. Rogers ◽  
W. R. Stevenson

Foliar diseases of carrot caused by Alternaria dauci and Cercospora carotae occur every year in Wisconsin, requiring repeated foliar fungicide applications to minimize defoliation and yield reduction. Improved timing of fungicide applications combined with the use of disease resistant cultivars offer growers a means to improve disease control with fewer fungicide inputs compared with the current strategy of weekly fungicide applications to a susceptible cultivar. Field experiments in 2002 to 2004 examined fungicide application schedules indicated by a disease forecasting model that calculated the duration of environmental conditions favorable for A. dauci and C. carotae (adaptation of TOM-CAST) on two carrot cultivars differing in susceptibility to these foliar diseases. All fungicide programs were initiated at a 1% disease severity threshold determined by scouting. Intervals for weather-based spray programs were based on in-canopy leaf wetness and temperature data. Fungicide sprays were applied according to 15 and 20 disease severity value (DSV) application thresholds, and were compared with a weekly spray program and an untreated control. Results of this trial demonstrated that fungicide sprays made according to weather data may reduce fungicide inputs in most years compared with current industry-standard, calendar-based spray programs. Host susceptibility affected the efficacy of weather-based spray programs, resulting in longer spray intervals and fewer fungicide applications on the resistant cultivar Bolero when compared with the susceptible cultivar Fontana. Fungicide spray programs based on TOM-CAST diminished fungicide inputs by 30 to 50%, compared with the weekly spray program, by lengthening intervals between applications without compromising disease control or root yield.



Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 420 ◽  
Author(s):  
Mohamed Ashour ◽  
Ahmed A. El-Shafei ◽  
Hanan M. Khairy ◽  
Doaa Y. Abd-Elkader ◽  
Mohamed A. Mattar ◽  
...  

We performed field experiments to evaluate the influence of two extraction treatments, seaweed (Pterocladia capillacea S.G. Gmelin) water extraction (WE) and ultrasound-assisted water extraction (USWE) at three concentrations (5%, 10%, and 15%), as well as control NPK traditional mineral fertilizer on the growth, yield, minerals, and antioxidants of Jew’s Mallow (Corchorus olitorius L.) during the two seasons of 2016 and 2017 in Egypt. Plant height, number of leaves, and fresh weight of WE10 treatment were the highest (p < 0.05) as 59.67 cm, 10.67 and 2.41 kg m−2 in 2016, respectively, and 57.33 cm, 11.00 and 2.32 kg m−2 in 2017, respectively. WE10 and USWE5 treatments produced the highest dry matter (17.07%) in 2016 and (16.97%) in 2017, respectively. WE10 plants had an increased water productivity of 41.2% relative to control plants in both seasons. The highest chlorophyll ‘a’ was recorded after the WE10 treatment in 2016 and 2017 (17.79 μg g−1 and 17.84 μg g−1, respectively). The highest levels of total antioxidant capacity, total phenolics, and total flavonoids were also recorded after the WE10 treatment. Application of WE10 boosted growth, yield, minerals, and antioxidants of Jew’s Mallow. The CROPWAT model was used to estimate the evapotranspiration, irrigation water requirements, and yield response to irrigation scheduling. Our data showed a yield reduction in the initial growth stage if a limited amount of water was provided. Therefore, irrigation water should be provided during the most important stages of crop development with the choice of effective irrigation practices to avoid water losses, as this helps to maximize yield.



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