Yield of wheat and canola in the high rainfall zone of south-western Australia in years with and without a transient perched water table

2004 ◽  
Vol 55 (4) ◽  
pp. 461 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Western Australia ◽  
Crop Production ◽  
Dry Matter ◽  
Unit Area ◽  
Wheat Yield ◽  
Soil Surface ◽  
Wheat Roots ◽  
Area Index ◽  
High Rainfall ◽  
Perched Water Table

The yields of wheat and canola in 2 successive years with and without the development of a perched watertable were compared in the high rainfall zone of south-western Australia. In 2001, no perched watertable was observed and wheat and canola yields were close to their estimated potentials. In 2002, a perched watertable developed at less than 30 cm below the soil surface for more than 8 days and at less than 50 cm below the soil surface for at least 30 days at the tillering stage of wheat and at the rosette stage of canola. The air-filled porosity of the soil fell below the critical value of 10% at 10 and 30 cm depth for about 40 days. This reduced the maximum leaf area index of canola by 46% and of wheat by 30%, and reduced the shoot dry matter of wheat at flowering by 27% and by 40% at podding in canola compared with those in 2001. The growth of the wheat roots was constrained at depths from 50-90 cm from the soil surface in 2002 compared with 2001. However, the roots of canola and wheat were able to grow to at least 1.4 m in both 2001 and 2002. In both years, a much higher proportion (>10%) of roots was present in the clay subsoil compared with previous reports in south-western Australia and enabled the crops to utilise a greater amount of water from the clay subsoil. The wheat yield in 2002 was 37% lower than in 2001 and well below the potential, largely as a result of a reduced tiller number per plant and ears per unit area. Despite the greater reduction in dry matter in canola than in wheat in 2002, the seed yield of canola was 17% higher in 2002 than in 2001. Canola, an indeterminate crop, was able to respond to the late rain that occurred in 2002 compared with 2001 and produced a significantly higher seed number per unit area. In 2002, grain size in wheat was 25% larger than in 2001, but this increase was insufficient to compensate for the yield loss resulting from the fewer ears per unit area. It is concluded that early transient perched watertable induced subsurface waterlogging, and that the subsurface waterlogging can be a major constraint to crop growth in the high rainfall region of southwestern Australia, and that reducing waterlogging could be a key to achieving higher crop production.

High ear number is key to achieving high wheat yields in the high-rainfall zone of south-western Australia

2007 ◽  
Vol 58 (1) ◽  
pp. 21 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole ◽  
Senthold Asseng
Keyword(s):  
Western Australia ◽  
Spring Wheat ◽  
Harvest Index ◽  
Dry Matter ◽  
Growing Season ◽  
Growth And Yield ◽  
Yield Potential ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Sink Capacity

The growth and yield of spring wheat (Triticum aestivum L.) were examined to determine the actual and potential yields of wheat at a site in the high rainfall zone (HRZ) of south-western Australia. Spring wheat achieved yields of 5.5−5.9 t/ha in 2001 and 2003 when subsurface waterlogging was absent or minimal. These yields were close to the estimated potential, indicating that a high yield potential is achievable. In 2002 when subsurface waterlogging occurred early in the growing season, the yield of spring wheat was 40% lower than the estimated potential. The yield of wheat was significantly correlated with the number of ears per m2 (r2 = 0.81) and dry matter at anthesis (r2 = 0.73). To achieve 5–6 t/ha of yield of wheat in the HRZ, 450–550 ears per m2 and 10–11 t/ha dry matter at anthesis should be targetted. Attaining such a level of dry matter at anthesis did not have a negative effect on dry-matter accumulation during the post-anthesis period. The harvest index (0.36−0.38) of spring wheat was comparable with that in drier parts of south-western Australia, but relatively low given the high rainfall and the long growing season. This relatively low harvest index indicates that the selected cultivar bred for the low- and medium-rainfall zone in this study, when grown in the HRZ, may have genetic limitations in sink capacity arising from the low grain number per ear. We suggest that the yield of wheat in the HRZ may be increased further by increasing the sink capacity by increasing the number of grains per ear.

EFFECTS OF CUTTING ON THE NITROGEN ECONOMY AND DRY MATTER YIELD OF LABLAB GROWN UNDER MONOCULTURE AND INTERCROPPED WITH MAIZE IN NORTHERN THAILAND

2000 ◽  
Vol 36 (4) ◽  
pp. 459-468 ◽  
Author(s):  
N. R. DEVKOTA ◽  
B. RERKASEM
Keyword(s):  
Dry Matter ◽  
Cropping System ◽  
Soil Surface ◽  
Yield Component ◽  
N Fixation ◽  
Lablab Purpureus ◽  
Area Index ◽  
Total N ◽  
Equivalent Ratio ◽  
N Yield

A study was conducted to examine the effects of the time and severity of cutting lablab (Lablab purpureus), both in sole crops and intercropped with maize (Zea mays). The effects of cutting management on the dry matter (DM) yield, leaf area index (LAI), nodulation, the nitrogen (N) yield, and N fixation by lablab were measured, as were the total DM yield, grain yield, and a yield component of maize.Two dates of lablab cutting (40 and 60 d after sowing (DAS)), and two heights of cutting (30 and 20 cm above the soil surface) were applied in factorial combinations as well as a no-cutting treatment. Maize was not cut either in monoculture or intercrops.Intercropping lablab with maize increased the grain yields of maize from 3.2 t ha−1 to 3.8 t ha−1 if lablab was cut at 40 DAS, but delaying cutting until 60 DAS had no effect, while uncut lablab reduced the yield of maize by 10%. Intercropping lablab with maize reduced the total N yield of lablab by over 50%, from 302 to 132 kg N ha−1. Regardless of cropping system, the total N yield of lablab at 130 DAS was 24% less when lablab was cut at 60 DAS compared with 40 DAS. Cutting height did not significantly affect the total N yield of lablab. Although both cropping system and cutting time significantly affected the total N fixation by lablab at 130 DAS, there were no significant effects of cropping system, cutting time or severity of cutting on the proportion of N in lablab derived from N fixation.Values of Land Equivalent Ratio (LER) which ranged between 1.2 and 1.6, and of Area Time Equivalent Ratio (ATER) which ranged between 1.0 and 1.4 for intercrops of maize with lablab indicated a definite advantage of intercropping. LER and ATER values were greatest when lablab was uncut, and least when lablab was cut at 60 DAS.

Water use of wheat, barley, canola, and lucerne in the high rainfall zone of south-western Australia

2005 ◽  
Vol 56 (7) ◽  
pp. 743 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Dry Matter ◽  
Grain Filling ◽  
Rooting Depth ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Annual Crops ◽  
Significant Difference

Water use of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), canola (Brassica napus L.), and lucerne (Medicago sativa L.) was measured on a duplex soil in the high rainfall zone (HRZ) of south-western Australia from 2001 to 2003. Rainfall exceeded evapotranspiration in all years, resulting in transient perched watertables, subsurface waterlogging in 2002 and 2003, and loss of water by deep drainage and lateral flow in all years. There was no significant difference in water use among wheat, barley, and canola. Lucerne used water at a similar rate to annual crops during the winter and spring, but continued to extract 80−100 mm more water than the annual crops over the summer and autumn fallow period. This resulted in about 50 mm less drainage past the root-zone than for annual crops in the second and third years after the establishment of the lucerne. Crop water use was fully met by rainfall from sowing to anthesis and a significant amount of water (120−220 mm) was used during the post-anthesis period, resulting in a ratio of pre- to post-anthesis water use (ETa : ETpa) of 1 : 1 to 2 : 1. These ratios were lower than the indicative value of 2 : 1 for limited water supply for grain filling. High water use during the post-anthesis period was attributed to high available soil water at anthesis, a large rooting depth (≥1.4 m), a high proportion (15%) of roots in the clay subsoil, and regular rainfall during grain filling. The pattern of seasonal water use by crops suggested that high dry matter at anthesis did not prematurely exhaust soil water for grain filling and that it is unlikely to affect dry matter accumulation during grain filling and final grain yield under these conditions.

scholarly journals Predicting Cereal Root Disease in Western Australia Using Soil DNA and Environmental Parameters

2015 ◽  
Vol 105 (8) ◽  
pp. 1069-1079 ◽  
Author(s):  
Grant J. Poole ◽  
Martin Harries ◽  
D. Hüberli ◽  
S. Miyan ◽  
W. J. MacLeod ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Western Australia ◽  
Crop Production ◽  
Environmental Parameters ◽  
Gaeumannomyces Graminis ◽  
Wheat Roots ◽  
Soil Dna ◽  
Root Diseases ◽  
Pathogen Dna ◽  
Root Health

Root diseases have long been prevalent in Australian grain-growing regions, and most management decisions to reduce the risk of yield loss need to be implemented before the crop is sown. The levels of pathogens that cause the major root diseases can be measured using DNA-based services such as PreDicta B. Although these pathogens are often studied individually, in the field they often occur as mixed populations and their combined effect on crop production is likely to vary across diverse cropping environments. A 3-year survey was conducted covering most cropping regions in Western Australia, utilizing PreDicta B to determine soilborne pathogen levels and visual assessments to score root health and incidence of individual crop root diseases caused by the major root pathogens, including Rhizoctonia solani (anastomosis group [AG]-8), Gaeumannomyces graminis var. tritici (take-all), Fusarium pseudograminearum, and Pratylenchus spp. (root-lesion nematodes) on wheat roots for 115, 50, and 94 fields during 2010, 2011, and 2012, respectively. A predictive model was developed for root health utilizing autumn and summer rainfall and soil temperature parameters. The model showed that pathogen DNA explained 16, 5, and 2% of the variation in root health whereas environmental parameters explained 22, 11, and 1% of the variation in 2010, 2011, and 2012, respectively. Results showed that R. solani AG-8 soil pathogen DNA, environmental soil temperature, and rainfall parameters explained most of the variation in the root health. This research shows that interactions between environment and pathogen levels before seeding can be utilized in predictive models to improve assessment of risk from root diseases to assist growers to plan more profitable cropping programs.

The growth of two maize varieties in farmers' plots located at two contiguous ecological zones in Nigeria

1981 ◽  
Vol 97 (1) ◽  
pp. 125-134 ◽  
Author(s):  
E. O. Lucas
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Unit Area ◽  
Statistical Significance ◽  
Planting Density ◽  
Area Index ◽  
Ecological Zones ◽  
Maize Varieties ◽  
Net Assimilation ◽  
The Relationship

SUMMARYThe growth and development of two new maize hybrids (FARZ 27 and FARZ 23) were studied in density experiments located at two contiguous ecological zones in Nigeria. The range of planting density used was from 2·6 to 6·6 plants/m2. Within this range, the relationship between dry-matter yield and density was asymptotic at final harvest. At the forest location of Jago (7·3 °N, 4·2 °E), both varieties attained optimum grain yield at planting density of 4·4 plants/m2, while at the derived savannah location of Alagunmu (7·8 °N, 4 °E), FARZ 23 attained optimum grain yield at 4·4 plants/m2and FARZ 27 attained its optimum grain yield at 6·6 plants/ma2. This response of the new maize varieties to density treatments indicates that they could be planted at higher densities than are now used in the country.Differences between varieties did not quite reach statistical significance but, at both locations, FARZ 27 produced more dry matter and grain per unit area than FARZ 23. FARZ 27 gave its higher grain yield mainly by producing more seeds per unit area than FARZ 23. Physiological measurements like net assimilation rate, crop growth rate and leaf area index were also higher for FARZ 27, although there were no significant differences between the varieties at most sampling dates. The partition of dry matter was identical in both varieties, although FARZ 27 showed a slightly better balance by partitioning more assimilates to the grain. Also, there was an indication of remobilization of stored assimilates from the stem to the grain in both varieties. Both varieties produced more dry matter and grain at the derived savannah location of Alagunmu than at the forest location of Jago. Physiological measurements were also higher at the derived savannah location.

Economic value of grazing vegetative wheat (Triticum aestivum L.) crops in mixed-farming systems of Western Australia

2009 ◽  
Vol 49 (10) ◽  
pp. 807 ◽  
Author(s):  
Graeme J. Doole ◽  
Andrew D. Bathgate ◽  
Michael J. Robertson
Keyword(s):  
Western Australia ◽  
Crop Production ◽  
Economic Value ◽  
Farming Systems ◽  
Triticum Aestivum L ◽  
Grazing Pressure ◽  
Relative Advantage ◽  
High Rainfall ◽  
Mixed Farming ◽  
Short Period

Livestock production in Western Australian mixed-farming systems has traditionally been constrained by a profound scarcity of feed in autumn–early winter when crop stubbles and pasture residues from the previous growing season have been exhausted. This study investigates the profitability of partially filling this ‘feed gap’ through the grazing of vegetative wheat crops. Whole-farm bioeconomic modelling is used to provide insight into the relative value of grazing and grain production in both low- and high-rainfall areas of Western Australia. Dual-purpose wheat crops are a valuable source of feed in high-rainfall areas as they provide an affordable alternative to expensive grain supplements for a short period in winter. This also allows annual pastures to establish more vigorously by reducing grazing pressure on young plants. Model output suggests farm profit can increase by over 10% with the grazing of vegetative wheat crops in high-rainfall regions; however, these results are logically shown to be strongly related to the assumed rate of yield loss. In contrast, at the parameter values used in this study, grazing wheats are unlikely to be profitable in low-rainfall environments due to depressed crop production and the extended feed gap experienced in these areas. Higher grain prices unequivocally lower the relative advantage of grazing activity since this elevates the cost of foregone grain yield.

Wild radish (Raphanus raphanistrum) interference in wheat

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 749-756 ◽  
Author(s):  
Seyed V. Eslami ◽  
Gurjeet S. Gill ◽  
Bill Bellotti ◽  
Glenn McDonald
Keyword(s):  
Seed Production ◽  
Dry Matter ◽  
Yield Loss ◽  
Wheat Yield ◽  
Integrated Weed Management ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Area Index ◽  
Crop Density ◽  
Radish Seed

Wild radish is a major weed of field crops in southern Australia. The effects of various densities of wild radish and wheat on the growth and reproductive output of each other were investigated in field studies in 2003 and 2004. The experiments were established as a factorial combination of wheat (0, 100, 200, and 400 plants m−2) and wild radish (0, 15, 30, and 60 plants m−2) densities. The effect of wild radish density on wheat yield loss and wild radish seed production were described with a rectangular hyperbola model. The presence of wild radish in wheat reduced aboveground dry matter, leaf-area index (LAI), and grain yield of wheat, and the magnitude of this reduction was dependent on weed density. Increasing the density of wheat substantially reduced the adverse effects of wild radish on wheat. As crop density increased, wild radish dry matter, LAI, and seed production per unit area decreased. The maximum seed production of wild radish was achieved at its highest density (60 plants m−2), and was 43,300 and 61,200 seeds m−2for the first and second year, respectively. The results indicated that higher densities of wheat were able to suppress seed production of this weed species. From a practical viewpoint, this study shows that increased wheat density in the range of 200 to 400 wheat plants m−2can reduce wild radish seed production and also give some reduction in crop yield loss, and could be an important component of an integrated weed management program.

Source - sink balance and manipulating sink - source relations of wheat indicate that the yield potential of wheat is sink-limited in high-rainfall zones

2010 ◽  
Vol 61 (10) ◽  
pp. 852 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Unit Area ◽  
Grain Filling ◽  
Yield Potential ◽  
Limiting Factor ◽  
Wheat Cultivars ◽  
High Rainfall ◽  
Sink Size ◽  
Source Sink

Grain yield depends on the number of grains per unit area (sink) and the availability of assimilates (source) to fill these grains. The aim of the current work was to determine whether wheat yield in the high-rainfall zone of south-western Australia is limited in current cultivars by the size of the sink or by the assimilates available for grain filling. Three wheat cultivars (Calingiri, Chara and Wyalkatchem) and two breeding lines (HRZ216 and HRZ203) were grown in four replicates in the field from 2005 to 2007. Dry matter and water soluble carbohydrates (WSC) at anthesis and maturity were measured and used to determine the source and sink balance of the crop. In 2007, three further treatments were applied to manipulate the sink–source relationships: (i) spikelets were removed on main stems to increase the source : sink ratio; (ii) incoming solar radiation was reduced by 40% by shading after anthesis to reduce the availability of assimilates to grains; and (iii) supplemental irrigation was used to maintain the capacity for photosynthesis by an improved water supply during grain filling. The source–sink balance of the crops showed that the potential source was 25% greater than the actual grain yield in average and above-average seasons (2005 and 2007), suggesting that sink size, represented by the number of grain per unit area, was a limiting factor to yield potential. However, the source may have become a limiting factor in a drought season (2006). The grain yield increased with increased number of grains/m2 and kernel weight remained relatively stable even when grain number increased from 7000 to 16 000 per m2. The removal of half of the spikelets on the main stem did not increase kernel mass of the remaining grains and an additional 33 mm of irrigation water did not increase grain yield, but significantly (P < 0.05) increased WSC left in stems and leaf sheaths at maturity. Shading after anthesis did not significantly reduce grain yield of the current cultivars Calingiri and Wyalkatchem, but it reduced grain yield by 23–25% (P < 0.05) in Chara and HRZ203. The source–sink balance over three seasons and three independent experiments in 2007 suggested that the yield of the current wheat cultivars is more sink- than source-limited and that breeding wheat with a larger sink size than in the current cultivars may lift the yield potential of wheat in the high-rainfall zone of south-western Australia.

scholarly journals Wheat growth and nutrient uptake after phosphorus and potassium applications in saline-sodic field of semi-arid region

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Zahid Hussain ◽  
Riaz Ahmad Khattak ◽  
Ping An ◽  
Yang Shao ◽  
Muhammad Irshad
Keyword(s):  
Crop Production ◽  
Dry Matter ◽  
Wheat Yield ◽  
Nutrient Deficiency ◽  
Limiting Factor ◽  
Sodic Soils ◽  
Wheat Growth ◽  
Soil P ◽  
Phosphorus And Potassium ◽  
Semi Arid Region

Nutrient deficiency is important limiting factor of saline-sodic soils which results in declining crop production in arid climates. The study investigated wheat response to phosphorus and potassium in saline-sodic field of Kohat, Pakistan. The K2O was applied at 0(K0), 75(K1), 150 (K2) kg ha-1 as K2S04 and P2O5 at (0(P0), 60(P1), 120(P2) kg ha-1 as (NH4)2HPO4 in three replications under two-factorial randomized complete block (RCB) design. Both treatments significantly enhanced wheat grain (118%) and dry matter yield (60%) at P2K2 compared to control. The P treatments significantly affected leaf P, Mg, SO4, Ca:P, SO4:P ratios and soil P, Ca:P, Cl:P and SO4:P ratios, while K on leaf K, Na, Ca, SO4concentration, K:Na, K:Ca, SO4:P,Ca:P ratios and soil pH, Na, K, Ca, SO4 concentrations, SAR, Na:K, Ca:K and Na:Ca ratios. Leaf Na was decreased to 85.3 mmol (+) kg-1 at K2 compared to 105.3 mmol (+) kg-1at P2K0. Negative correlation (R2=0.906) of leaf K:Na was found with Leaf Na concentration. Correlation of dry matter was more positive (R2=0.851) with leaf K:Na than grain yield (R2=0.392). It is concluded that K and P addition might be beneficial for improving crop nutrition and wheat yield in saline-sodic soils.

Features of high-yielding wheats grown at two seed rates and two nitrogen levels

1972 ◽  
Vol 12 (55) ◽  
pp. 165 ◽  
Author(s):  
JR Syme
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Unit Area ◽  
Flag Leaf ◽  
High Yield ◽  
Area Index ◽  
Seed Rate ◽  
Nitrogen Levels ◽  
Leaf Emergence ◽  
Early Effects

Four wheats of similar maturity were compared at two seed rates and two nitrogen levels. The cultivars were two high-yielding Mexican semi-dwarf wheats, Pitic 62 and accession WW 15, one local semidwarf crossbred, HMR, and one Australian variety, Robin. At each of two sites WW 15 yielded most grain and Robin the least. Yield components, growth, development and leaf characters were studied at one site. The semi-dwarf wheats had a higher proportion of ear weight at anthesis and set more grains per ear and per unit area. The high yield of WW 15 was associated with many grains per ear and a dense ear population. There were relatively small differences in total dry matter yield and leaf area index. WW 15 formed the most leaves on the main stem, had the shortest period from flag leaf emergence to anthesis and showed delay in the senescence of its flag leaves. Its leaves were also particularly narrow and small. The early effects of a higher seed rate on crop growth diminished with time in the main experiment but resulted in a small increase in grain yield. Nitrogen stimulated growth throughout the season, but the increased vegetative potential was not fully reflected in grain yield. Both nitrogen and the higher seed rate hastened flag leaf senescence.

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