Increases in wheat yield on limed soil after reduction of take-all by fungicide application and crop rotation

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.

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1161-1166 ◽  
Author(s):  
Barry M. Cunfer ◽  
G. David Buntin ◽  
Daniel V. Phillips

Take-all of wheat (Triticum aestivum), caused by Gaeumannomyces graminis var. tritici, became a serious problem with the widespread adoption of wheat:soybean double-cropping and minimum tillage farming systems in the southeastern United States during the past 30 years. A long-term crop rotation study was initiated in 1994 with 12 double-cropping sequences incorporating wheat, rye, or canola as the fall-planted crop and soybean or grain pearl millet as the summer crop. Cotton and fallow were included in some summer rotations during the last 2 years of the study. The purpose was to identify sustainable alternatives to the continuous wheat:soybean system that would provide acceptable management of take-all. G. graminis var. tritici cultured on autoclaved oats was incorporated into soil prior to planting the first season's crop. Take-all was severe in rotations with continuous wheat each year. Pearl millet was compatible with the cropping system but did not affect incidence or severity of take-all in a following wheat crop. Soybean or pearl millet had little effect on yield loss due to take-all in a subsequent wheat crop. A 1-year rotation with canola significantly reduced take-all incidence and severity. At the end of the second and third seasons, in those rotations where wheat followed 1 year of canola, wheat grain yield was the same as that in control plots that had little or no take-all. Two consecutive years of canola did not suppress take-all or improve wheat yields any more than a single year of canola between wheat crops. Seedling assays for take-all incidence and severity in growth chambers were conducted using soil collected twice each year near the end of each crop's growing season. Results were similar to those observed in the field. However, canola in the rotation had a greater effect in suppressing disease severity than disease incidence. Canola can be a valuable rotational crop for management of take-all in wheat in the southeastern United States.


1989 ◽  
Vol 29 (2) ◽  
pp. 247 ◽  
Author(s):  
RF Brennan

Wheat was grown in soil amended with 5 levels of superphosphate with or without 4 levels of flutriafol at 3 sites naturally infested with Gaeumannomyces graminis var. tritici. The severity of take-all was related to the rates of superphosphate and flutriafol. At all sites, the disease incidence and severity were high, with values for the moderate plus severe category (i.e. >25% of the root system discoloured by the takeall fungus) exceeding 80% for untreated plots. As plants responded to increasing levels of superphosphate and flutriafol, the percentage of infected roots declined. There was no further decline in the severity of take-all with increasing levels of flutriafol above 50 g/ha. The lowest severity of take-all was observed at the highest superphosphate level (200 kg/ha) and a fungicide level of 50 g/ha. Take-all severity for this treatment varied with the site location, being 52% at Condingup while the Mt Ridley and Neridup sites had 60% infection of take-all on the roots. There was a 25-30% increase in grain yield in response to added flutriafol at the highest superphosphate level. There were also corresponding increases in dry matter production and 1000-grain weights with superphosphate and fungicide application.


1991 ◽  
Vol 31 (5) ◽  
pp. 645 ◽  
Author(s):  
GM Murray ◽  
DP Heenan ◽  
AC Taylor

The incidence of take-all of wheat, caused by Gaeumannomyces graminis var. tritici (Ggt), and eyespot, caused by Tapesia yallundae, was examined in a long-term rotation-tillage experiment at Wagga Wagga, N.S.W. Take-all occurred in years of higher August-October rainfall from 1979 to 1984. In years with take-all, soil water in the upper 20 cm was estimated to be above permanent wilting point for the growing season. Eyespot was associated with above-average rainfall during winter and spring and was more prevalent where residues of wheat or grasses were retained. After the severe drought of 1982, take-all developed to high levels in 1983 in wheat that followed wheat, lupins or pasture when stubble was retained, but was reduced in 1984 after lupins. Take-all was reduced in the lupin-wheat rotations by removing stubble through burning or by early incorporation of stubble. Take-all incidence was less in wheat that followed grazed pasture than after mown pasture. Where stubble was retained, Ggt survived on stubble from wheat in 1981, through the drought of 1982, to infect wheat in 1983, but inoculum did not survive on stubble through the wet season of 1983 to infect wheat in 1984. Regression analysis indicated that take-all was negatively correlated with yield but eyespot was not. Take-all reduced yield by reducing kernel mass in 1 year and by reducing kernels per cm2 in 2 other years. Soil water conditions that were associated with take-all development from 1979 to 1984 occurred in 50% of years from 1960 to 1989.


1990 ◽  
Vol 4 (3) ◽  
pp. 478-481
Author(s):  
Ray M. Geddens ◽  
Arnold P. Appleby ◽  
Robert L. Powelson

Experiments were conducted in each of two seasons to determine possible effects of diclofop, difenzoquat, dinoseb, and mecoprop on the incidence of take-all disease and grain yield of winter wheat. All of the herbicides, especially mecoprop, reduced incidence of take-all. Treatments increased grain yields the first year but not the second, compared to the inoculated weed-free control. None of the herbicides tested increased incidence or severity of take-all disease in either of the two seasons. The technique of inoculating disease-free soil was successful in obtaining uniform and reproducible incidence of disease.


2004 ◽  
Vol 55 (6) ◽  
pp. 599 ◽  
Author(s):  
Victor O. Sadras ◽  
Jeff A. Baldock ◽  
Jim W. Cox ◽  
W. D. Bellotti

Theoretically, growth of stressed plants is maximised when all resources are equally limiting. The concept of co-limitation could be used to integrate key factors affected by crop rotation. This paper tested the hypothesis that the effect of crop rotation on the yield of wheat is partially mediated by changes in the degree of co-limitation between nitrogen and water. Four rotations were established on a sodic, supracalcic, red chromosol in a Mediterranean-type environment of southern Australia. Rotations included wheat grown after (a) faba bean harvested for grain, (b) faba bean incorporated as green manure, (c) ryegrass pasture, or (d) medic pasture; barley was grown after wheat in all cases. The response of wheat to the rotations during 3 growing seasons was analysed in terms of nitrogen and water co-limitation, and the response of barley was taken as a measure of the persistence of rotation effects. Daily scalars quantifying water and nitrogen stress effects on tissue expansion were calculated with a crop simulation model. These scalars were integrated in a series of seasonal indices to quantify the intensity of water (SW ) and nitrogen stress (SN ), the aggregated intensity of water and nitrogen stress (SWN ), the degree of water and nitrogen co-limitation (CWN ), and the integrated effect of stress and co-limitation (SCWN 25 CWN/SWN ). The expectation is that grain yield should be inversely proportional to stress intensity and directly proportional to degree of co-limitation, thus proportional to SCWN . Combination of rotations and seasons generated a wide variation in the amount of water and inorganic nitrogen in the 1-m soil profile at the time of wheat sowing. Plant-available water ranged from 33 to 107 mm, and inorganic nitrogen from 47 to 253 kg N/ha. Larger amounts of nitrogen were found after green-manured faba bean, and smaller after grass pasture. There was a consistent effect of rotation on wheat yield and grain protein content, which persisted in subsequent barley crops. Measured grain yield of wheat crops ranged from 2.5 to 4.8 t/ha. It was unrelated to water or nitrogen stresses taken individually, inversely related to the aggregated stress index SWN , and directly related to the CWN index of co-limitation. The combination of stress and co-limitation in a single index SCWN accounted for 65% of the variation in measured crop yield. This is a substantial improvement with respect to the stress effect quantified with SWN , which accounted for 43% of yield variation. It is concluded that rotation effects mediated by changes in the relative availability of water and nitrogen can be partially accounted for by degree of resource co-limitation.


1988 ◽  
Vol 39 (1) ◽  
pp. 1 ◽  
Author(s):  
NS Wilhelm ◽  
RD Graham ◽  
AD Rovira

Two experiments tested the effectiveness of manganese (Mn) decreasing take-all of wheat. The first experiment was conducted under controlled environmental conditions. Mn sulfate was mixed through the soil at sowing or 2 weeks before, or applied to the seed or leaves, and manganese dioxide (MnO2) was mixed through the soil at sowing or 2 weeks before. Mixing manganese sulfate (MnSO4) through the soil was the most effective treatment at decreasing take-all, followed by seed applied Mn. MnO2 and foliar applied Mn had little effect on take-all. All Mn treatments, except foliar Mn, completely eliminated Mn deficiency in the plants. In the second experiment, which was conducted in the field at a Mn deficient site, Mn sulfate and MnO2 were applied to the soil at sowing. MnSO4 decreased take-all and increased grain yields in take-all inoculated plots nearly threefold, but increased yields only slightly in uninoculated plots. MnO2 was not effective in decreasing take-all or increasing grain yield. This is the first report of take-all infection being suppressed by MnSO4in the field. The results of these experiments support the hypothesis that Mn may be acting through the physiology of the wheat plant to decrease take-all.


1991 ◽  
Vol 117 (3) ◽  
pp. 287-297 ◽  
Author(s):  
J. F. Jenkyn ◽  
R. J. Gutteridge ◽  
A. D. Todd

SUMMARYExperiments in 1985 and 1986, at Woburn Experimental Farm in Bedfordshire, tested the effects of fungicides, applied in autumn, and a growth regulator, applied at GS3O–31 or GS32–33 in spring, on winter barley grown on two contrasting soil types in each year. Leaf diseases did not become severe in any of the experiments but take-all (Gaeumannomyces graminis var. tritici) was prevalent in 1985. Triadimenol (‘Baytan’) was more effective than flutriafol (‘Ferrax’) in decreasing the severity of takeall and its activity against the disease was related to earliness of sowing.Mean responses in grain yield to the fungicide treatments were mostly small and not significant but did not conflict with the hypothesis that crops on lighter soils benefit more from autumn fungicides than those on heavier soils. Mean effects of the growth regulator sprays were also small but they interacted with both soil type and season. Over the 2 years the later spray applied to crops on the heavier soil gave the largest mean response. Sprays applied to crops on lighter soils were often detrimental to yield, especially in 1985.


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.


1987 ◽  
Vol 27 (3) ◽  
pp. 411 ◽  
Author(s):  
GM Murray ◽  
BJ Scott ◽  
Z Hochman ◽  
BJ Butler

Lime was applied at rates from 0 to 5.0 t ha-1 at 4 sites in southern and central New South Wales. A root and crown disease characterised by basal stem blackening affected up to 60% of wheat plants and 80% of triticale plants when the soil pH in 0.01 mol L-1 CaCl2 was above 5.0 at all 4 sites. Below pH 4.8, incidence was less than 5%. The take-all fungus, Gaeumannomyces graminis var. tritici, was consistently associated with this symptom. Losses in grain yield from the disease ranged from 26 to 77% depending on site. Regression analysis indicates that each 10% increase in plants with basal stem blackening decreased yield by 0.76%. These results demonstrate that the disease can reverse the expected increase in yield after liming, and that progressive acidification of the soils in the region may have caused the present reduced amount of take-all.


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