Effect of fungicide seed treatments on root pathogens of cereal crops under field conditions

2010 ◽  
Vol 90 (6) ◽  
pp. 905-917 ◽  
Author(s):  
M.R. Fernandez ◽  
W.E. May ◽  
G.P. Lafond

It is of importance to reduce the spread of Fusarium graminearum to western regions of the Canadian prairies where Fusarium head blight has so far occurred to a limited extent. Determining the effectiveness of fungicides against F. graminearum in infected seed under various growing conditions will help design a comprehensive strategy for preventing the spread of this pathogen. Field trials at various locations in eastern Saskatchewan were conducted (2003-2005) to examine the performance of registered and experimental fungicides on Fusarium colonization of subcrown internodes (SIs) of plants derived from Fusarium-infected barley (Hordeum vulgare L.), common (Triticum aestivum L.) and durum [T. turgidum L. ssp. durum (Desf.) Husn.] wheat seed, and on SI discoloration. Among the fungi isolated from discolored SIs were Fusarium spp., including F. graminearum, and Cochliobolus sativus. Fusarium graminearum infections were mostly seed-borne whereas infection by other fungi appeared to be mostly soil-borne. Compared with the untreated infected control, the combined seed treatments reduced discoloration of SIs, but no single fungicide reduced discoloration consistently across site-years or crops. Similarly, no product consistently reduced the isolation of F. graminearum or other Fusarium pathogens, although some fungicides appeared to be more effective than others in reducing isolation of F. graminearum or C. sativus. Our observations agree with results from a controlled-environment study of effects of seed treatments on F. graminearum colonization of plants derived from infected common and durum wheat seed, thus confirming that treatment of F. graminearum-infected seed with fungicides will not likely prevent the spread of this pathogen.

2009 ◽  
Vol 89 (4) ◽  
pp. 811-821 ◽  
Author(s):  
M R Fernandez ◽  
T K Turkington ◽  
W E May

Fusarium head blight (FHB) is well established in the eastern prairies, but for the most part it has been absent from western regions, especially under dryland conditions. This has been largely attributed to dry and hot conditions during some years, and the limited occurrence of F. graminearum in the western prairies. It is of importance to prevent the movement of F. graminearum, the most important FHB pathogen in North America, to areas where this pathogen is not commonly found. Three controlled-environment studies, using different Fusarium-infected common and durum wheat seed lots, were conducted to determine the effectiveness of currently registered fungicide seed treatments in improving seedling emergence and plant development, and preventing the growth of F. graminearum from infected seed to plant tissue. Fungicide treatments improved seedling emergence from the most infected seed over the untreated infected control, but most treatments did not improve emergence in the other experiments. Plant growth in the fungicide treatments was either similar to or slower than in the untreated controls. Fusarium graminearum was isolated from discoloured tissue in all treatments and was generally more common in crowns than in subcrown internodes. No fungicide treatment reduced discolouration of plant tissue or percentage isolation of F. graminearum or other Fusarium spp. consistently. We conclude that while currently registered seed treatments might be effective in improving seedling emergence in some infected wheat seed lots, they do not prevent the growth of F. graminearum from seeds to plant tissue. For the western prairies, the use of fungicide seed treatments as a strategy in the prevention of spread of FHB would require that they be effective primarily against F. graminearum. Performance of fungicide seed treatments against Fusarium-infected wheat seed should also be determined under typical growing conditions across the western prairies.Key words: Seed treatments, fungicides, wheat, root rot, crown rot, Fusarium graminearum, Fusarium avenaceum


1994 ◽  
Vol 74 (4) ◽  
pp. 703-711 ◽  
Author(s):  
G. P. Lafond

Adopting water-conserving tillage practices on the Canadian prairies will protect the soil against erosion while conserving soil water. The use of tall-standing stubble to conserve water creates a dilemma for producers because maximum yields can only be obtained with narrow rows, and tall stubble may limit the use of narrow row spacings. A 4-yr study on a thin Black clay soil investigated the effects of three row spacings (10, 20 and 30 cm), six seeding rates (34, 67, 100, 134, 168 and 202 kg ha−1 for wheat and 27, 54, 81, 108, 134 and 161 kg ha−1 for barley) and two rates of N (low and high) in hard red wheat (Triticum aestivum L.), durum (Triticum durum L.) and barley (Hordeum vulgare L.) using a continuous cropping, zero-till production system. The yields of cereals were maintained with 30-cm row spacing over a wide range of growing conditions under zero-till management. Durum had a 5.8% yield advantage and barley a 2.4% advantage for the 30-cm row spacing over the 10-cm row spacing. The number of plants established and the number of spikes produced decreased as row spacing increased for all crops. But wider row spacing resulted in more kernels produced per spike, which, in the case of barley and durum, more than compensated for the lower number of spikes. Increasing seeding rates significantly improved grain yield in all crops and years because more spikes were produced. Grain yield was related to the reciprocal of seeding rate. The few row spacing × seeding rate interactions observed in 2 of 12 cases suggest that seeding rates need not be adjusted for changes in row spacing. The results obtained have important implications for equipment design and the ability to more easily handle high-crop-residue situations. Key words: Yield components, seeding rate, row spacing, yield compensation


2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.


Author(s):  
Andrew James Burt ◽  
D.G. Humphreys ◽  
J. Mitchell Fetch ◽  
Denis Green ◽  
Thomas Fetch ◽  
...  

AAC Redstar is an early maturing, high yielding hard red spring wheat (Triticum aestivum L.) cultivar that is well adapted to the northern Canadian Prairies and eligible for grades of Canada Western Red Spring (CWRS) wheat. Over three years (2016-2018) of testing in the Parkland Wheat Cooperative registration trials, AAC Redstar was 11% higher yielding than AC Splendor, 6% higher than Parata, and 4% higher than Glenn and Carberry. AAC Redstar matured 3 days earlier than Glenn, 2 days earlier than Carberry and had similar maturity to Parata. AAC Redstar was shorter than all checks except Carberry and had better lodging resistance compared to all the check cultivars in the registration trial. The test weight and thousand kernel weight of AAC Redstar were similar to Carberry. The grain protein concentration of AAC Redstar was 0.2% lower than Carberry. AAC Redstar was rated moderately resistant to Fusarium head blight, leaf rust, stripe rust and common bunt. AAC Redstar had resistant reactions to loose smut, and stem rust. AAC Redstar was registered under the CWRS market class.


2014 ◽  
Vol 94 (7) ◽  
pp. 1297-1302 ◽  
Author(s):  
D. G. Humphreys ◽  
T. F. Townley-Smith ◽  
O. M. Lukow ◽  
B. D. McCallum ◽  
T. G. Fetch ◽  
...  

Humphreys, D. G., Townley-Smith, T. F., Lukow, O. M., McCallum, B. D., Fetch, T. G., Gilbert, J. A., Menzies, J. G., Tkachuk, V., Brown, P. D. and Fox, S. L. 2014. Peace hard red spring wheat. Can. J. Plant Sci. 94: 1297–1302. Peace is a hard red spring wheat (Triticum aestivum L.) adapted to the shorter-season wheat-growing regions of the Canadian prairies. Peace was evaluated in the Parkland Wheat Cooperative Test in 1999, 2000 and 2001. Peace exhibited grain yield similar to the check cultivars over 2 yr (1999–2000; Neepawa and Roblin) and over 3 yr (1999–2001; AC Barrie and AC Splendor) Peace matured a day earlier than AC Barrie but was 2 d later than AC Splendor over 3 yr of testing (1999–2001) and was a day later than Neepawa and Roblin over 2 yr of testing (1999–2000). Peace had test weight similar to the check cultivars. Peace was moderately resistant to leaf rust and loose smut and resistant to stem rust including the highly virulent Ug99 race of stem rust and common bunt. Peace was moderately susceptible to Fusarium head blight. Peace meets the end-use quality specifications of the Canada Western Red Spring wheat class.


1974 ◽  
Vol 54 (1) ◽  
pp. 17-22 ◽  
Author(s):  
J. HARWIG ◽  
Y.-K. CHEN

Wheat, ground wheat, barley, and heat-treated wheat and barley were inoculated with different strains of Penicillium viridicatum Westling and incubated under different conditions of moisture content, relative humidity, temperature, and time. An important factor for production of ochratoxin A and citrinin was humidity. A water activity (aw) of 0.90–0.93 produced high concentrations of the mycotoxins. Below this aw, the native mycoflora developed along with P. viridicatum and concentrations of the mycotoxins were significantly lower. A temperature of 5 C did not prevent production of the toxins under conditions of high aw and extended storage. Viable barley (Hordeum vulgare L.) and wheat seed (Triticum aestivum L.) were less prone to mycotoxin production than nonviable seed. Samples exposed for short periods to conditions most favorable for P. viridicatum were not visibly moldy but contained ochratoxin A. Such material, if used, may present a hazard to farm animals and man.


1996 ◽  
Vol 76 (2) ◽  
pp. 223-228 ◽  
Author(s):  
S. A. Brandt

A number of alternative options to summerfallow are feasible on the Dark Brown soils of the Canadian prairies. These include recropping to cereal or pulse crops, as well as use of summerfallow substitute crops, such as legume green manures. The objective of this study was to evaluate these options for their impact on the productivity of subsequent crops. Green-manure lentil (Lens culinaris Medic.), incorporated at either the bud or full-bloom stage of growth, field pew (Pisum sativum L.), grain lentil, and wheat (Triticum aestivum L.) grown as grain were compared with conventional summerfallow for their impact on yield of a succeeding wheat crop and of barley (Hordeum vulgare L.) grown the year after wheat on a Dark Brown Chernozemic soil at Scott, Saskatchewan. During the 5-yr period, 1984–1988, above-ground dry-matter production of green-manure lentil averaged 500 kg ha−1 at the bud stage of growth but more than doubled to 3170 kg ha−1, by full bloom. Grain yield of field pea averaged 1470 kg ha−1, while that of grain lentil, unfertilized wheat, and N-fertilized wheat averaged 1220, 1290 and 1490 kg ha−1, respectively. Considerable year-to-year yield variation occurred with all crops, variability being greatest for lentil. Yield of wheat grown after lentil green manure was similar to yield of wheat on summerfallow (2340 kg ha−1) during each of the 5 yr for both early (2360 kg ha−1) and late (2250 kg ha−1) incorporation. Wheat yield after pea (2210 kg ha−1) or grain lentil (2080 kg ha−) was reduced in 1987, but it was equal to wheat yield after summerfallow during the remaining 4 yr. Yield of wheat on wheat stubble, whether fertilized with N (1830 kg ha−1) or not (1610 kg ha−1), was generally lower than on summerfallow. Yield of barley grown the following year was generally unaffected by summerfallow or summerfallow substitute treatments. The higher value and similar productivity of pea and grain lentil, compared with wheat, combined with their favourable impact on subsequent wheat yield, should make these crops attractive alternatives to summerfallow. On fields unsuited to pea or grain lentil production, lentil green manures may be a suitable alternative to summerfallow because they should reduce soil degradation, although lentil green manures leave little residue to protect against soil erosion where through incorporation is practised. Summerfallow or green manure incorporated early or late generally resulted in greater available soil water and N for a succeeding crop than did grain lentil, pea or wheat. Key words: Green manuring, legume effect, recropping, lentil, grain yield, summerfallow alternatives


Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1217-1217 ◽  
Author(s):  
M. Pasquali ◽  
F. Giraud ◽  
C. Brochot ◽  
L. Hoffmann ◽  
T. Bohn

Head blight caused by Fusarium graminearum is one of the major diseases of wheat (Triticum aestivum L.) in Luxembourg (2) and there is concern for mycotoxins in diseased grain. Isolates of F. graminearum have been assigned to chemotypes based on the particular toxins produced. Ten wheat fields representing different topoclimatological areas of Luxembourg were surveyed in 2007 and 2008 to determine the frequency and distribution of chemotypes. Partially blighted wheat heads were collected, and diseased grains were plated on Fusarium-selective agar (dichloran-chloramphenicol-peptone) for 12 days at 22 ± 2°C with a 12-h light period. Monoconidial isolates of F. graminearum (79 in 2007 and 85 in 2008) were obtained by conidia dilution on 2% water agar and needle selection under a microscope. F. graminearum isolates showed rapid growth on potato dextrose agar, dense aerial mycelium with red pigment deposits in the plate, macroconidia with five to six defined septa, and a basal cell with the typical foot shape. Microconidia were absent. To confirm species identification, a PCR reaction was carried out using the F. graminearum species-specific primers Fg16F (5′-CTCCGGATATGTTGCGTCAA-3′) and Fg16R (5′-GGTAGGTATCCGACATGGCAA-3′) according to Demeke et al. (1). Chemotype of each isolate was determined according to Ward et al. (4). In particular, PCR primer 12CON (5′ CATGAGCATGGTGATGTC-3′) coupled with primer 12NF (5′-TCTCCTCGTTGTATCTGG-3′) and primer 3CON (5′-TGGCAAAGACTGGTTCAC-3′) coupled with primer 3NA (5′-GTGCACAGAATATACGAGC-3′) identified the nivalenol chemotype, primer 12CON coupled with primer 12-15F (5′-TACAGCGGTCGCAACTTC-3′) and primer 3CON coupled with primer 3D15A (5′-ACTGACCCAAGCTGCCATC-3′) identified the 15-acetylated deoxynivalenol (DON) chemotype, while primer 12CON coupled with primer 12-3F (5′-CTTTGGCAAGCCCGTGCA-3′) and primer 3CON coupled with primer 3D3A (5′-CGCATTGGCTAACACATG-3′) identified 3-acetylated DON chemotype. Reactions were repeated two times and positive controls (provided by Kerry O'Donnell, NRRL collection, Peoria, IL) and a negative control (water) were used in each reaction. Frequency of the nivalenol chemotype was found to be 2.5% in 2007 and 1% in 2008. Interestingly, the nivalenol chemotype was absent in southern Luxembourg. According to this finding, nivalenol was likely to be present at low levels in grain from Reisdorf and Echternach in 2007 (central Luxembourg) and in 2008 from grain of Troisvierges (northern Luxembourg). The remaining isolates in both years belonged to the 15-acetylated DON chemotype and the 3-acetylated DON chemotype was not detected. Compared with a previous report from the Netherlands (3), the nivalenol chemotype in Luxembourg is less frequent and widespread. To our knowledge, this is the first report of the nivalenol chemotype of F. graminearum causing head blight on wheat in Luxembourg. References:(1) T. Demeke et al. Int. J. Food Microbiol. 103:271, 2005. (2) F. Giraud et al. Plant Dis. 92:1587, 2008. (3) C. Waalwijk et al. Eur. J. Plant Pathol. 109:743, 2003. (4) T. J. Ward et al. Fung. Genet. Biol. 45:473, 2008.


2000 ◽  
Vol 80 (4) ◽  
pp. 977-980 ◽  
Author(s):  
H. Campbell ◽  
T. M. Choo ◽  
B. Vigier ◽  
L. Underhill

In Eastern Canada Fusarium species infect barley (Hordeum vulgare L.) and oats (Avena sativa L.) more frequently than wheat (Triticum aestivum L.), yet information on mycotoxin contamination in barley and oats is lacking. Such information is essential to determine the need for control of fusarium head blight in barley and oats. Therefore, data were retrieved from the Mycotoxin Databank of the Canadian Food Inspection Agency to study mycotoxin contamination in Eastern Canada's barley and oats. Of the 116 barley samples collected from 1991 to 1998 crops, 84 (72%) were contaminated with deoxynivalenol (DON). Some samples contained up to 8–9 mg kg−1 of DON. DON contamination was particularly severe in recent years (1996, 1997, and 1998). DON contamination was less frequent and less severe in oats in comparison with barley. Only 34 of the 73 oat samples (47%) contained DON. Thirty-four percent of the barley samples (18/53) and 15% of the oat samples (4/26) contained nivalenol. Zearalenone, ochratoxin A, 3-acetyl DON, 15- acetyl DON, and T-2 were also detected at a low frequency; but HT-2, diacetoxyscirpenol (DAS), fusarenon X, 15-acetoxyscirpenol, and neosolaniol were not detected in these samples. The results suggest that breeding barley for resistance to DON accumulation is warranted in Eastern Canada. Key words: Barley, Hordeum vulgare, oat, Avena sativa, mycotoxins, deoxynivalenol


2014 ◽  
Vol 104 (4) ◽  
pp. 357-364 ◽  
Author(s):  
I. Malbrán ◽  
C. A. Mourelos ◽  
J. R. Girotti ◽  
P. A. Balatti ◽  
G. A. Lori

At least 20 epidemics of Fusarium head blight (FHB) of wheat have been registered in the last 50 years in Argentina, with variable intensity. Damage induced by the disease is further aggravated by the presence of mycotoxins in affected grains that may cause health problems to humans and animals. The trichothecene chemotype was analyzed for 112 isolates of Fusarium graminearum from Argentina by polymerase chain reaction and two field trials were conducted to study the aggressiveness of a subsample of 14 representative isolates and to analyze deoxynivalenol (DON) production in planta and in vitro. All isolates belonged to the 15-acetyl-DON chemotype. Significant differences were observed in both the symptom severity induced in wheat spikes and the in vivo DON production, and a close correlation was found between these two variables. However, in vitro toxigenic potential was not correlated with the capacity of F. graminearum isolates to produce DON under natural conditions. The progress of infection in the rachis of inoculated wheat spikes was analyzed and the pathogen presence verified in both symptomatic and symptomless spikes. Even isolates with a limited capacity to induce symptoms were able to colonize the vascular tissue and to produce considerable amounts of DON in planta.


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