Evaluating the contribution of take-all control to the break-crop effect in wheat

2013 ◽  
Vol 64 (6) ◽  
pp. 563 ◽  
Author(s):  
R. A. Lawes ◽  
V. V. S. R. Gupta ◽  
J. A. Kirkegaard ◽  
D. K. Roget

Break-crops such as legumes and oilseeds increase the yield of subsequent cereal crops by reducing the level of diseases and weeds that build in continuous cereal crops, and can also improve water and nitrogen supply. Although the term ‘break-crop’ originates from their role in breaking disease cycles of soil-borne diseases such as take-all (caused by Gaeumannomyces graminis var. tritici), the contribution of take-all control to the overall break-crop effect has not been separated in most studies. We re-analysed a range of medium- and short-term crop-sequencing experiments comprising 18 year × site combinations in diverse environments in southern Australia. An analysis using linear mixed effects models was conducted to: (i) define the agro-environments that lead to increases in take-all incidence in continuous wheat crop sequences, (ii) quantify the effect of take-all on wheat yield, and (iii) ascertain the contribution of the reduction in take-all following break-crops to the size of the total break-crop effect on wheat crop yield. Break-crop effects on wheat yield averaged 0.7 t/ha and ranged from 0 to 2.1 t/ha. On 14 of 18 occasions, take-all contributed to reduced wheat yield in continuous wheat rotations, although the estimated effect exceeded 0.1 t/ha on just six of those occasions. As a result, reduced take-all by break-crops contributed to <20% of the total break-crop effect in all but one instance, where the suppression accounted for 80% of the break-crop effect. In summary, although the break-crops improved wheat yield by 0.7 t/ha, the contribution from take-all control in the 14 locations where it could be quantified was just 0.1 t/ha. Correlation analysis revealed that take-all incidence in wheat was most likely to proliferate in colder, wetter environments. Take-all can severely damage crop yield, and the reduction contributes to the break-crop effect, but the average impact on wheat yield is small and poorly correlated with the potential yield of the wheat crop. The analytical approach helped to quantify the effect of take-all damage on crop yield, to provide further insight into the agro-environment that contributes to high levels of take-all incidence, and to demonstrate that take-all, like many other processes, operates in an episodic manner that is rare but, on occasions, severe.

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Rafia Mumtaz ◽  
Shahbaz Baig ◽  
Iram Fatima

Land management for crop production is an essential human activity that supports life on Earth. The main challenge to be faced by the agriculture sector in coming years is to feed the rapidly growing population while maintaining the key resources such as soil fertility, efficient land use, and water. Climate change is also a critical factor that impacts agricultural production. Among others, a major effect of climate change is the potential alterations in the growth cycle of crops which would likely lead to a decline in the agricultural output. Due to the increasing demand for proper agricultural management, this study explores the effects of meteorological variation on wheat yield in Chakwal and Faisalabad districts of Punjab, Pakistan and used normalised difference vegetation index (NDVI) as a predictor for yield estimates. For NDVI data (2001-14), the NDVI product of Moderate Resolution Imaging spectrometer (MODIS) 16-day composites data has been used. The crop area mapping has been realised by classifying the satellite data into different land use/land covers using iterative self-organising (ISO) data clustering. The land cover for the wheat crop was mapped using a crop calendar. The relation of crop yield with NDVI and the impact of meteorological parameters on wheat growth and its yield has been analysed at various development stages. A strong correlation of rainfall and temperature was found with NDVI data, which determined NDVI as a strong predictor of yield estimation. The wheat yield estimates were obtained by linearly regressing the reported crop yield against the time series of MODIS NDVI profiles. The wheat NDVI profiles have shown a parabolic pattern across the growing season, therefore parabolic least square fit (LSF) has been applied prior to linear regression. The coefficients of determination (<em>R</em><sup>2</sup>) between the reported and estimated yield was found to be 0.88 and 0.73, respectively, for Chakwal and Faisalabad. This indicates that the method is capable of providing yield estimates with competitive accuracies prior to crop harvest, which can significantly aid the policy guidance and contributes to better and timely decisions.


2002 ◽  
Vol 42 (8) ◽  
pp. 1087 ◽  
Author(s):  
C. R. Kidd ◽  
G. M. Murray ◽  
J. E. Pratley ◽  
A. R. Leys

Winter cleaning is the removal of grasses from pasture using selective herbicides applied during winter. We compared the effectiveness of an early (June) and late (July) winter cleaning with an early spring herbicide fallow (September), spring (October) herbicide and no disturbance of the pasture on development of the root disease take-all in the subsequent wheat crop. Experiments were done at 5 sites in the eastern Riverina of New South Wales in 1990 and 1991. The winter clean treatments reduced soil inoculum of Gaeumannomyces graminis var. tritici (Ggt) compared with the other treatments at all sites as measured by a bioassay, with reductions from the undisturbed treatments of 52–79% over 5 sites. The winter clean treatments also significantly reduced the amount of take-all that developed in the subsequent wheat crop by between 52 and 83%. The early and late winter clean treatments increased the number of heads/m2 at 3 and 1 sites, respectively. Dry matter at anthesis was increased by the winter clean treatments at 3 sites. Grain yield was increased by the winter cleaning treatments over the other treatments at the 4 sites harvested, with yield increases of the early winter clean over the undisturbed treatment from 13 to 56%. The autumn bioassay of Ggt was positively correlated with spring take-all and negatively correlated with grain yield of the subsequent wheat crop at each site. However, there was a significant site and site × bioassay interaction so that the autumn bioassay could not be used to predict the amount of take-all that would develop.


1992 ◽  
Vol 118 (2) ◽  
pp. 157-163 ◽  
Author(s):  
H. E. Echeverría ◽  
C. A. Navarro ◽  
F. H. Andrade

SUMMARYA trial using a split-plot with blocks design was carried out at the INTA Balcarce Experimental Station, Argentina on a typic argiudol soil to evaluate N nutrition in wheat after different preceding crops and using two rates of N fertilization (0 and 90 kg N/ha).Wheat (Triticum aestivum), soyabean (Glycine max), sunflower (Helianthus annuus) and maize (Zea mays) were grown in different combinations for two successive years (1984/85 and 1985/86).No water stress was detected during either growing season. Nitrogen availability was altered by the previous crops grown, but the effect lasted only for one season. Wheat following maize yielded least with no N and responded most to N fertilization. The highest yields of wheat without N and the lowest response by wheat to N fertilization were found after crops of soyabean and sunflower.Wheat after a fertilized wheat crop did not respond to N fertilization because of a serious attack of take-all (Gaeumannomyces graminis tritici).The nitrate concentration in wheat stem bases was found to be a good estimator of the availability of soil N.


2009 ◽  
Vol 57 (1) ◽  
pp. 26-39 ◽  
Author(s):  
Nadezhda Shumova

Crop Water Supply and its Relation to Yield of Spring Wheat in the South of Russian Plain The proposed method to estimate water supply of spring wheat crop is based on the ratio of the water amount extracted by plants under actual conditions of growth (transpiration) to cover needs for maximum (potential) yield (potential transpiration). Estimates of spatial, inter- and intra-annual water supply variability of the spring wheat crop in basic agricultural zones are given. Dependence of the spring wheat yield on water supply is presented.


1998 ◽  
Vol 78 (1) ◽  
pp. 145-150 ◽  
Author(s):  
K. L. Bailey ◽  
Guy P. Lafond ◽  
Daryl Domitruk

Changes in tillage and other agronomic practices have shown benefits of increased grain yield for many crops, but these changes may alter the micro-environment resulting in changes to populations of disease-causing agents and other micro-organisms. This study examined the effects of row spacing (10, 20, 30 cm), seeding rate (54, 108, 161 kg ha−1 for barley; 67, 134, 202 kg ha−1 for spring wheat) and seed-placed phosphorus (0, 8, 16 kg ha−1) on root diseases in spring wheat and barley using a zero-tillage production system in four environments. Root rot severity was assessed by visual ratings and the causal agents were identified. Analyses of variance indicated significant differences in root rot severity and the incidence of some causal agents for the main treatment effects (i.e. row spacing, seeding rate, seed-placed phosphorus) and no significant interactions between locations, years, and cultural practices. Contrasts of treatment means showed that higher rates of seeding decreased root rot severity and the incidence of Fusarium in wheat but these effects were small (less than 6%). The higher rates of monoammonium phosphate fertilizer reduced root rot severity in barley by 7% and the incidence of Gaeumannomyces graminis var. tritici in wheat by greater than 40%. Wider row spacings showed a small reduction of 6% in root rot severity in wheat but mostly had no effect on root diseases. Wheat yields were negatively associated with root rot severity in three of four environments. Fertility, root rot severity, and seeding rate had the greatest impact on wheat yield. Root diseases did not affect barley yields. Therefore, the use of wider row spacings and higher seeding rates with zero tillage practices will not lead to adverse effects on root diseases in wheat and barley. Phosphorus fertilizer should be used to reduce losses resulting from take-all disease in wheat. Key words: Zero tillage, cultural practices, common root rot, take-all, cereals


1989 ◽  
Vol 29 (1) ◽  
pp. 85 ◽  
Author(s):  
DR Coventry ◽  
HD Brooke ◽  
JF Kollmorgen ◽  
DJ Ballinger

The severity of take-all, caused by Gaeumannomyces graminis var. tritici, was measured with lime, rotation and flutriafol treatments in a long-term field experiment. The incidence of eyespot lesions caused by Pseudocercosporella herpotrichoides was also measured. Flutriafol reduced the number of plants with deadheads or no heads and resulted in 12-60% more grain yield. However flutriafol had no effect on the number of plants with eyespot lesions. The number of plants with deadheads or no heads was highest (50-53%) on the wheat which was a third consecutive crop and on soil which had been amended with 2.5 and 5.0 t/ha lime. Sowing wheat after a subterranean clover based pasture considerably reduced the number of deadheads. Control of annual grasses in the pasture by spray-topping further reduced deadheads and with this treatment and at nil and low lime there were 2-7% deadheads. The percentage of plants with eyespot lesions was higher with the continuous cropped wheat. Lime increased grain yield only where the disease incidence was low but had no effect on the percentage of eyespot lesions. This work demonstrates the importance of crop rotation for disease control, particularly where soils are limed to amend severe soil acidity; the value of controlling annual grasses in pasture in the year preceding wheat cropping; and the potential of fungicide treatment as a practical means for controlling take-all in field grown wheat.


1987 ◽  
Vol 38 (6) ◽  
pp. 1011 ◽  
Author(s):  
GC MacNish ◽  
DA Nicholas

The relationship between grass production in subterranean clover pastures with two different rotation histories and take-all in a subsequent wheat crop following barley was studied. Grass production in the pastures ranged from 0 to 1700 kg ha-1. The incidence of take-all in the wheat crop ranged from 10 to l00%, while the take-all severity percentage ranged from 4 to 99.In one rotation series (pasture 9 years; barley, barley, pasture, wheat), each kilogram increase in grass production in the last pasture year caused a 0.087% increase in the take-all severity rating. In the second series (pasture 7 years; oats, pasture 3 years; barley, wheat), each kilogram increase in grass production caused a 0.040% increase in severity. These figures are significantly different (P < 0.05). Thus the field history ranging back at least four seasons influenced the effects that grass level in the last pasture year had on take-all severity. Reductions in wheat yields ranged from 8.6 to 10.5 kg ha-1 for each 1% increase in take-all severity rating.


Author(s):  
A. Kolotii ◽  
N. Kussul ◽  
A. Shelestov ◽  
S. Skakun ◽  
B. Yailymov ◽  
...  

Winter wheat crop yield forecasting at national, regional and local scales is an extremely important task. This paper aims at assessing the efficiency (in terms of prediction error minimization) of satellite and biophysical model based predictors assimilation into winter wheat crop yield forecasting models at different scales (region, county and field) for one of the regions in central part of Ukraine. Vegetation index NDVI, as well as different biophysical parameters (LAI and fAPAR) derived from satellite data and WOFOST crop growth model are considered as predictors of winter wheat crop yield forecasting model. Due to very short time series of reliable statistics (since 2000) we consider single factor linear regression. It is shown that biophysical parameters (fAPAR and LAI) are more preferable to be used as predictors in crop yield forecasting regression models at each scale. Correspondent models possess much better statistical properties and are more reliable than NDVI based model. The most accurate result in current study has been obtained for LAI values derived from SPOT-VGT (at 1 km resolution) on county level. At field level, a regression model based on satellite derived LAI significantly outperforms the one based on LAI simulated with WOFOST.


2000 ◽  
Vol 51 (4) ◽  
pp. 445 ◽  
Author(s):  
J. A. Kirkegaard ◽  
M. Sarwar ◽  
P. T. W. Wong ◽  
A. Mead ◽  
G. Howe ◽  
...  

Biofumigation refers to the suppression of soil-borne pathogens and pests by biocidal compounds released by Brassica crops when glucosinolates (GSL) in their residues decay in soil. We conducted field studies at 2 sites to investigate the hypothesis that biofumigation by Brassica break crops would reduce inoculum of the take-all fungus Gaeumannomyces graminis var. tritici (Ggt) to lower levels than non-Brassica break crops, and thereby reduce Ggt infection and associated yield loss in subsequent wheat crops. High and uniform levels of Ggt were established at the sites in the first year of the experiments by sowing wheat with sterilised ryegrass seed infested with Ggt. Ggt inoculum declined more rapidly under Brassica crops than under linola and this reduction coincided with the period of root decay and reduced root glucosinolate concentrations around crop maturity. There was no consistent difference in inoculum reduction between canola (Brassica napus) and Indian mustard (Brassica juncea), nor between cultivars with high and low root GSL within each species. Despite significant inoculum reduction attributable to biofumigation, there were no differences in the expression of disease and associated impacts on the yield of subsequent wheat crops across the sites. Seasonal conditions, in particular the distribution of rainfall in both the summer–autumn fallow following the break crops and during the subsequent wheat crop, influenced inoculum survival and subsequent disease development. In wet summers, inoculum declined to low levels following all break crops and no extra benefit from biofumigation was evident. In dry summers the lower inoculum levels following brassicas persisted until the following wheat crops were sown but subsequent development of the disease was influenced more by seasonal conditions than by initial inoculum levels. Significant extra benefits of biofumigation were observed in one experiment where wheat was sown within the break crops to simulate grass weed hosts of Ggt. Under these circumstances there was greater reduction in Ggt inoculum under canola than linseed and an associated decrease in disease development. For host-dependent pathogens such as Ggt, we hypothesise that the benefits of biofumigation to subsequent wheat crops will therefore be restricted to specific circumstances in which inoculum is preserved during and after the break crops (i.e. dry conditions, grass hosts present) and where conditions in the following wheat crop lead to significant disease development (early sowing, wet autumn and spring, dry periods during grain filling).


Sign in / Sign up

Export Citation Format

Share Document