scholarly journals Effect of Foliarly Applied Spirotetramat on Reproduction of Heterodera avenae on Wheat Roots

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 983-989 ◽  
Author(s):  
R. W. Smiley ◽  
J. M. Marshall ◽  
G. P. Yan

The cereal cyst nematode, Heterodera avenae, has the potential to reduce yields of cereal crops in the Pacific Northwest. Spirotetramat (Movento) is a foliar-applied insecticide with ambimobile translocation that reduces fecundity of sucking insects which feed on roots as well as foliage. Spirotetramat (88 g/ha) was applied to foliage during 2010 in two wheat fields infested by H. avenae near St. Anthony, ID and Palouse, WA. In Idaho, two applications at 2-week intervals during late spring to plants already exhibiting swollen white females reduced the postharvest density of H. avenae eggs plus juveniles by 35% (P = 0.03) compared to the nontreated control. In Washington, a single application before white females became apparent reduced the nematode density by 78% (P = 0.01). Grain yields and test weights were not significantly affected by application of spirotetramat at either location. In addition, symptomatic plants from the Idaho field were transplanted into greenhouse pots and treated with spirotetramat. One application (110 g/ha) reduced numbers of eggs plus juveniles/plant by 78% (P = 0.02). Spirotetramat effectively reduced H. avenae populations and warrants further evaluation as a substitute for crop rotations or long fallow periods that reduce nematode population densities in infested fields.

Nematology ◽  
2011 ◽  
Vol 13 (5) ◽  
pp. 539-552 ◽  
Author(s):  
Richard W. Smiley ◽  
Guiping Yan ◽  
John N. Pinkerton

Abstract The cereal cyst nematode, Heterodera avenae, occurs in at least seven western states of the USA and reduces grain yield in localised regions and in selected crop management systems. Virulence phenotypes for H. avenae populations in North America have not been reported. Nine individual assays in six experiments were conducted to determine the reactions of barley, oat and wheat cultivars to five H. avenae populations in the Pacific Northwest (PNW) states of Idaho, Oregon and Washington. Three populations were evaluated for virulence to 23 entries of the 'International Test Assortment for Defining Cereal Cyst Nematode Pathotypes', plus selected local cultivars and entries representing a greater diversity of resistance genes. The virulence phenotype(s) for populations of H. avenae in the PNW did not correspond to any of the 11 pathotypes defined by the Test Assortment. Five PNW populations exhibited affinities with Group 2 but were not defined by pathotypes Ha12 and Ha22. Reproduction was prevented or greatly inhibited by barley carrying the Rha3 resistance gene and by most carriers of Rha2 resistance, and by selected oat cultivars with multigenic resistance. Wheat cultivars carrying the Cre1 resistance gene were highly effective in suppressing H. avenae reproduction. Current PNW wheat cultivars do not carry the Cre1 resistance gene. Crosses between Ouyen, an Australian bread wheat with Cre1 resistance, and several PNW wheat cultivars were resistant. The CreR gene also prevented H. avenae reproduction in the trial where it was tested. Intermediate levels of reproduction occurred on wheat cultivars carrying the Cre5, Cre7 and Cre8 resistance genes, each of which was considered useful for pyramiding into cultivars with Cre1 resistance. This research identified genetic resources of value in PNW cereal crop breeding programmes.


Plant Disease ◽  
2013 ◽  
Vol 97 (5) ◽  
pp. 590-600 ◽  
Author(s):  
Richard W. Smiley ◽  
Juliet M. Marshall ◽  
Jennifer A. Gourlie ◽  
Timothy C. Paulitz ◽  
Shyam L. Kandel ◽  
...  

The cereal cyst nematode Heterodera avenae reduces wheat yields in the Pacific Northwest. Previous evaluations of cultivar resistance had been in controlled environments. Cultivar tolerance had not been evaluated. Seven spring wheat trials were conducted in naturally infested fields in three states over 2 years. A split-plot design was used for all trials. Five trials evaluated both tolerance and resistance in 1.8-by-9-m plots treated or not treated with nematicides. Two trials evaluated resistance in 1-m head rows where each wheat entry was paired with an adjacent row of a susceptible cultivar. Cultivars with the Cre1 resistance gene (‘Ouyen’ and ‘Chara’) reduced the postharvest density of H. avenae under field conditions, confirming Cre1 parents as useful for germplasm development. Ouyen was resistant but it was also intolerant, producing significantly lower grain yield in controls than in plots treated with nematicides. Susceptible cultivars varied in tolerance. Undefined resistance was identified in one commercial cultivar (‘WB-Rockland) and four breeding lines (UC1711, SO900163, SY-B041418, and SY-97621-05). This research was the first systematic field demonstration of potential benefits to be derived through development and deployment of cultivars with resistance plus tolerance to cereal cyst nematode in North America.


Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1654-1660 ◽  
Author(s):  
Hai Yan Wu ◽  
Qiong He ◽  
Jing Liu ◽  
Jian Luo ◽  
De Liang Peng

The cereal cyst nematode (CCN), Heterodera aveane, has been found in 16 provinces of China, including the Shandong winter-wheat-growing region. This study investigated the population dynamics of H. avenae in the winter wheat ‘Jimai 22’ and ‘Tainong 18’ for two consecutive years in the field. Soil and root samples were collected during the winter-wheat-growing season and H. avenae population densities and life-stages determined. H. avenae population dynamics in roots and soil of the two winter wheat cultivars were similar over the 2-year period. Second-stage juvenile (J2) population densities in wheat roots were greatest during booting stage (April), when mean soil temperature was between 11.8 and 14.4°C. Cysts in rhizosphere soil increased significantly when new cysts were formed after Zadoks (Z) 47 (booting stage). There was a peak in J2 population densities in soil during Z23 and Z30 (tillering and stem elongation, respectively) whereas J2 population densities were the lowest at Z13 (seedling stage). This research provides important information indicating that J2 populations in roots and soil increased after the wheat winter dormancy period. Knowledge of when different life stages of H. avenae occur in winter wheat in Shandong will provide valuable insights to enable the development of an integrated approach to manage this plant-parasitic nematode.


Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 396-407 ◽  
Author(s):  
Juliet M., Marshall ◽  
Richard W. Smiley

Heterodera avenae is a cereal cyst nematode that reduces wheat yields in the Pacific Northwest of the United States. Barley is also susceptible but there were no previous reports of resistance or tolerance to H. avenae in the United States. Spring barley cultivars were assayed in H. avenae-infested fields over 2 years. Cultivars were planted in plots treated or not treated with aldicarb. Forty-five cultivars were evaluated for the market classes of two- and six-row feed barley cultivars and two- and six-row malt barley cultivars. One two-row feed barley (‘Lenetah’) was ranked as resistant and four were tolerant or very tolerant. In total, 1 two-row malt barley (‘Odyssey’) was very resistant and 10 were tolerant or very tolerant. Two six-row feed and two six-row malt barley cultivars were tolerant or very tolerant but none were resistant. Seven feed barley cultivars were ranked as having a balance of at least moderate resistance plus moderate tolerance: ‘Champion’, Lenetah, ‘Xena’, ‘Idagold II’, ‘Transit’, ‘Millennium’, and ‘Goldeneye’. This is the first report of resistance and tolerance of barley in H. avenae-infested fields in the Pacific Northwest. Barley productivity can be improved by planting resistant plus tolerant cultivars or by using highly resistant and highly tolerant cultivars as parents in barley improvement programs.


2020 ◽  
Vol 177 ◽  
pp. 102709 ◽  
Author(s):  
Rachel A. Wieme ◽  
Lynne A. Carpenter-Boggs ◽  
David W. Crowder ◽  
Kevin M. Murphy ◽  
John P. Reganold

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1611-1619 ◽  
Author(s):  
Guiping Yan ◽  
Richard W. Smiley ◽  
Patricia A. Okubara ◽  
Andrea M. Skantar

Heterodera avenae and H. filipjevi are economically important cyst nematodes that restrict production of cereal crops in the Pacific Northwest United States and elsewhere in the world. Identification of these two species is critical for recommending and implementing effective management practices. Primers were designed from the internal transcribed spacer (ITS) regions of H. avenae and H. filipjevi ribosomal DNA. The primers were highly specific when examined on target isolates but did not amplify DNA from nontarget Heterodera, Globodera, Meloidogyne, Pratylenchus, and other nematode species tested. Polymerase chain reaction (PCR) and amplification conditions were established, and H. avenae and H. filipjevi were clearly distinguished by PCR fragments of 242 and 170 bp, respectively. Robust PCR amplification was achieved with DNA extracted from a single egg or second-stage juvenile (J2) using a laboratory-made worm lysis buffer, and DNA from 0.5 egg or J2 using a commercial kit. The PCR assays were successfully employed for differentiation of H. filipjevi and H. avenae populations collected from eight locations in three Pacific Northwest states. This is the first report of a species-specific ITS PCR assay to detect and identify H. filipjevi. The assays for both species will enhance diagnosis of cereal cyst nematode species in infested fields.


Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 958-968 ◽  
Author(s):  
Richard W. Smiley ◽  
Ruth G. Whittaker ◽  
Jennifer A. Gourlie ◽  
Sandra A. Easley

Many wheat (Triticum aestivum) fields planted annually in the Pacific Northwest are infested by high populations of the lesion nematode, Pratylenchus neglectus. Spring wheat cultivars varying in tolerance and resistance to P. neglectus were treated or not treated with aldicarb to examine relationships between the nematode and growth and yield of annual direct-seeded (no-till) wheat. Increasing initial density of P. neglectus in soil was more strongly associated with declining growth and yield of intolerant (Machete and Spear) than moderately tolerant (Frame and Krichauff) cultivars. Yield suppression by P. neglectus was generally 8 to 36% for intolerant cultivars, but reached 71% in soil also harboring Heterodera avenae, Rhizoctonia solani AG-8, and Gaeumannomyces graminis var. tritici. Intolerant cultivars had lower yields than Krichauff in rainfed but not in irrigated experiments. Density of P. neglectus in mature roots was generally lower for moderately resistant Krichauff than for susceptible Machete and Spear. Aldicarb improved yields in irrigated but not in rainfed experiments, and increased plant height and reduced variability in tiller height, canopy temperature, and density of P. neglectus in roots. This is the first report of damage to wheat by P. neglectus in the Pacific Northwest. Breeding wheat for tolerance and resistance to P. neglectus is suggested.


2019 ◽  
Vol 20 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Inga A. Zasada ◽  
Megan Kitner ◽  
Catherine Wram ◽  
Nadine Wade ◽  
Russell E. Ingham ◽  
...  

The Pacific Northwest (PNW) of the United States (Idaho, Oregon, and Washington) is a diverse agricultural production area with over 400 different commodities grown in the region. Plant-parasitic nematodes are a constraint to the production of many of these commodities. Soil sample data from 2012 to 2016 were obtained from nematode diagnostic laboratories in the region to assess trends in occurrence, population densities, and distribution of plant-parasitic nematodes in the PNW. A total of 38,022 unique data points were analyzed. The number of plant-parasitic nematode samples processed in the PNW by diagnostic laboratories has significantly increased from 2012 to 2016. Fifteen genera of plant-parasitic nematodes were identified by diagnostic laboratories, with 86% of the samples in the PNW containing at least one plant-parasitic nematode genus. These laboratories provide a valuable service to agriculture in the PNW. Additionally, they serve as a rich source of information on plant-parasitic nematode distribution, occurrence, and abundance that, when analyzed, provides an empirical basis upon which to interpret individual grower reports and make management recommendations.


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