scholarly journals Utilization of Soil Solarization for Eliminating Viable Tilletia indica Teliospores from Arizona Wheat Fields

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1604-1610 ◽  
Author(s):  
G. L. Peterson ◽  
K. L. Kosta ◽  
D. L. Glenn ◽  
J. G. Phillips
Keyword(s):  
Management Strategies ◽  
Soil Solarization ◽  
Karnal Bunt ◽  
Daily Maximum ◽  
Rapid Decline ◽  
United States Department ◽  
Tilletia Indica ◽  
Wheat Field ◽  
Soil Temperatures ◽  
Clear Plastic

Studies were conducted in Arizona to determine the efficacy of soil solarization for killing teliospores of the soilborne fungal wheat pathogen Tilletia indica. In a replicated study conducted in each of 3 years, T. indica teliospores and bunted wheat kernels were buried in a Karnal bunt-infested wheat field at depths of 5, 10, and 20 cm. Replicate samples were removed from under a clear plastic solarization cover at 7-day intervals and the number of viable teliospores determined. A rapid decline in teliospore viability occurred at all treatment depths over 38 days, with efficacy comparable with methyl bromide protocols using clear plastic sheeting. Initial viability rates of 43, 71, and 82% germination were reduced to 0.1, 7.7, and 0.2% after 38 days (across all depths) in 2003, 2005, and 2006, respectively. Mean daily maximum soil temperatures at 5 and 20 cm under clear plastic in 2003, 2005, and 2006 were 67, 53 and 60°C and 43, 38, and 43°C, respectively. Under current United States Department of Agriculture disease management strategies, the method may be useful for the rapid deregulation of Karnal bunt-affected fields.

scholarly journals Tilletia walkeri on Annual Ryegrass in Wheat Fields in the Southeastern United States

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 685-689 ◽  
Author(s):  
Barry M. Cunfer ◽  
Lisa A. Castlebury
Keyword(s):  
United States ◽  
Lolium Multiflorum ◽  
Southeastern United States ◽  
Karnal Bunt ◽  
Annual Ryegrass ◽  
Wheat Seed ◽  
Tilletia Indica ◽  
Wheat Field ◽  
South Central ◽  
Low Levels

Surveys for Tilletia walkeri on annual ryegrass (Lolium multiflorum) were conducted during 1997 and 1998 in the southeastern United States, where suspect teliospores of the Karnal bunt fungus, Tilletia indica, were found in USDA-APHIS surveys of wheat (Triticum aestivum) seed in 1996. T. walkeri is morphologically similar to T. indica. Annual ryegrass is a common weed in wheat fields in the southeastern United States. Between April and June 1997, ryegrass seed samples were collected from 190 fields of wheat in 47 counties in Georgia and from 26 fields in 17 counties in Alabama and south-central Tennessee. In 1998, 70 samples were collected from 40 counties in the same regions of the three states. The teliospores from these samples were 23 to 45 μm in diameter (average about 33 μm) and ranged from light brown to dark reddish brown. They had coarse, widely spaced cerebriform ridges on the surface and were surrounded by a gelatinous sheath. The ryegrass bunt was identified as the recently described species T. walkeri, occurring on ryegrass seed from Australia and Oregon. In 1997, teliospores of T. walkeri were found in 13 samples from eight counties in central Georgia and from one field in Tennessee. In 1998, more teliospores and bunted seeds were found, possibly due to frequent rain in the region throughout the flowering period for ryegrass. Teliospores were found in 26/70 of the samples, and among these, only a small number of bunted seed were found in 12 of 13/70 samples. In one wheat field in Morgan County, Georgia, about 50% of the ryegrass seed collected was partially bunted, and a small percentage was completely bunted. Fields with teliospores were widely distributed and generally matched the locations where teliospores were found in APHIS wheat seed surveys in 1996 to 1998. T. walkeri occurs at very low levels on ryegrass in the Southeast and is the source of teliospores, initially identified as those of T. indica, associated with wheat seed in APHIS surveys. No bunted wheat seeds or teliospores of T. indica were found in the survey.

scholarly journals 285 CONTROL OF SOILBORNE ONION DISEASES WITH SOIL SOLARIZATION, FUMIGATION AND RESISTANT VARIETIES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 471a-471
Author(s):  
Michael K. Thornton ◽  
S. Krishna Mohan
Keyword(s):  
Disease Incidence ◽  
Soil Solarization ◽  
Disease Development ◽  
Disease Resistant ◽  
Resistant Varieties ◽  
Soil Temperatures ◽  
Clear Plastic ◽  
Pathogen Populations ◽  
Metham Sodium

Pathogen populations, disease development and onion yield were compared in solarized, fumigated and non-treated plots during 1992 and 1993. Soil solarization was accomplished by covering plots with clear plastic for six weeks beginning in mid-August, prior to the year of onion production. Solarization was also combined with metham sodium, a plied prior to covering with plastic. Soil temperatures reached a maximum of 48°C at the 10 cm depth in solarized plots, and were consistently 10 to 15°C higher than in non-solarized plots. Disease resistant (Bravo) and susceptible (Valdez) onion cultivars were planted the following spring. Only the solarization + metham sodium treatment significantly controlled pink root and plate rot in 1992. In 1993, all solarization and fumigation treatments controlled pink root. Solarization and fumigation did not significantly increase yield in comparison to the check, except for the solarization + metham sodium treatment in 1992. Bravo exhibited lower disease incidence than Valdez in both years of the study. Bravo produced 32.7 t/ha and 6.2 t/ha higher yield than Valdez in 1992 and 1993, respectively.

scholarly journals Soil Solarization in High Tunnels in the Semiarid Southwestern United States

HortScience ◽  
2014 ◽  
Vol 49 (9) ◽  
pp. 1165-1170 ◽  
Author(s):  
Kristen Hanson ◽  
Tilak Mahato ◽  
Ursula K. Schuch
Keyword(s):  
United States ◽  
Soil Surface ◽  
Soil Solarization ◽  
Daily Maximum ◽  
Base Temperature ◽  
Southwestern United States ◽  
High Tunnel ◽  
Adverse Weather ◽  
High Tunnels ◽  
Soil Temperatures

High tunnels are unheated structures covered with polyethylene (PE) glazing to protect high-value crops from adverse weather. The objective of this study was to raise soil temperatures to determine the efficacy of soil solarization using clear mulch on the soil surface and glazing or no glazing on a high tunnel during the hottest months of the year in the semiarid southwestern United States. Solarization trials were conducted in May and June 2013 in two high tunnels in southern Arizona. Highest soil temperatures were reached with the combination of a high tunnel covered with glazing and the soil covered with PE mulch. Average daily soil temperatures were 48 and 47 °C and average degree hours (DH) per day (base temperature 45 °C) were over 14 at soil depths of 5 and 15 cm. The average daily maximum soil temperature at 5- and 15-cm depth was 63.4 and 52 °C, respectively. The second highest soil temperatures were reached when the soil was covered with PE mulch without high tunnel glazing, which resulted per day in 5.2 DH above 45 °C at 5 cm and less than one DH at 15-cm depth. Glazing on the high tunnel without covering the soil surface raised soil temperatures only at the 5-cm depth above 45 °C, but not further down. High tunnel producers in the low desert areas in the southwestern United States can complete solarization in less than 1 week, depending on the organism to be controlled, when the soil is fallow during the summer months with glazing on the high tunnel and on the soil surface.

scholarly journals RESPONSE OF OKRA TRANSPLANTS GROWS ON SOIL SOLARIZING PLOTS DURING THE ACTIVE PERIOD OF SOIL SOLARIZATION

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 733e-733
Author(s):  
V.A. Khan ◽  
C. Stevens ◽  
J. Y. Lu ◽  
D. I. Collins ◽  
M. A. Wilson ◽  
...  
Keyword(s):  
Cover Crop ◽  
Plant Density ◽  
Soil Solarization ◽  
Marketable Yield ◽  
Affected Plant ◽  
Winter Cover Crop ◽  
Soil Temperatures ◽  
Clear Plastic ◽  
Complete Fertilizer ◽  
Field Plots

A study was conducted in 1991 to determine the effect high soil temperatures would have on `Clemson Spineless' okra plants transplanted into field plots during 60 days of active soil solarization (solar heating of the soil using clear plastic during the summer period). Solarized plots were planted to a winter cover crop which served as an organic amendment, which was rototilled into the top 15 cm of the soil before solarizing. Okra transplants were planted on the outer edges of the plots one month after the solarization process commenced and drip irrigated. Three weeks (wk) after transplanting, a complete fertilizer at the rate of 200 parts per million was applied to the plots giving the following treatment combinations: solarized non-fertilized control (SNF), non-solarized non-fertilized control (NSNF), solar fertilized (SF). and non-solarized fertilized (NSF). Results showed that the increased soil temperature did not have any deleterious effect on the okra plants grown in SNF or SF plots. However, plants grown in SF plots suffered severe fertilizer bums which affected plant density and yield. This indicated a rapid breakdown of soil organic matter provided sufficient nutrients to sustain a late-season crop of okra. Plant height, marketable yield vegetative branching and income generated were greater in SNF compared to SF, NSF and NSNF plots, respectively.

scholarly journals Distribution and Recovery of Tilletia indica Teliospores from Regulated Wheat Fields in Texas

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 344-350 ◽  
Author(s):  
T. W. Allen ◽  
H. W. Maples ◽  
F. Workneh ◽  
J. M. Stein ◽  
C. M. Rush
Keyword(s):  
Grid Point ◽  
The United States ◽  
Karnal Bunt ◽  
Tilletia Indica ◽  
Soil Factors ◽  
Wheat Field ◽  
Contour Maps ◽  
Grid Points ◽  
Single Field ◽  
Analyze Data

Eight wheat fields from the Karnal bunt-regulated regions within Texas were grid sampled to gain a better understanding of the ecology and epidemiology of teliospores produced by the causal agent, Tilletia indica. Teliospores from 25-g aliquots of soil from each grid point were extracted using a size-selective sieving sucrose-centrifugation procedure. Teliospores were recovered from all eight fields and, in some cases, from every grid point within a field. Total teliospore numbers ranged from 0 to 1,305 per 25 g of soil. Over 70% of the total grid sampled points contained one or more teliospores. The relation between soil chemical and physical characteristics and teliospore numbers from each field was evaluated. In general, no consistent, significant trend could be made between soil factors and teliospore numbers. Geostatistics were used to analyze data from grid points and create contour maps. Teliospore distribution was aggregated in four of the fields, random in three of the fields, and discontinuous (neither random nor aggregated) in a single field. This is the first report of widespread distribution and high teliospore numbers from wheat field soils in the United States.

scholarly journals Application of the Humid Thermal Index for Relating Bunted Kernel Incidence to Soilborne Tilletia indica Teliospores in an Arizona Durum Wheat Field

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 713-719 ◽  
Author(s):  
T. W. Allen ◽  
D. C. Jones ◽  
T. N. Boratynski ◽  
R. E. Ykema ◽  
C. M. Rush
Keyword(s):  
Durum Wheat ◽  
Disease Incidence ◽  
Karnal Bunt ◽  
Weather Data ◽  
Sample Point ◽  
Tilletia Indica ◽  
Thermal Index ◽  
Wheat Field ◽  
Sample Points ◽  
Conducive Environment

A study was conducted to determine the relationship between soilborne Tilletia indica teliospore density and Karnal bunt incidence in an Arizona durum wheat field in 2005 and 2006. Soil samples were collected from 507 sample points according to a grid marked in a 7.7-ha field. Approximately 500 g of soil from the top 5 cm was collected from each sample point, and teliospores were recovered from 25-g aliquots by a modified size-selective sieving, sucrose centrifugation procedure. Twenty-five and 50 wheat heads were collected from a 1-m2 area around each sample point in May 2005 and June 2006, respectively. Wheat head samples from each sample point were bulked, threshed, and examined for the presence of bunted kernels. Additionally, data for soilborne teliospores and percent bunted kernels from 70 sample points in 2005 and 2006 that corresponded to sample points from a 2004 bunted kernel survey conducted by the USDA and Arizona Department of Agriculture were analyzed. Soilborne teliospore numbers ranged from 6 to 1,000 per 25-g soil sample in the 2-year study. No bunted kernels were recovered in 2005; however, two sample points yielded bunted kernels in 2006. Weather data from three time periods in 2004, 2005, and 2006 were applied to the humid thermal index model and suggested that a conducive environment for disease development existed in 2005. Based on the data from this research, we concluded that even though high numbers of soilborne teliospores were present in the field, and although a conducive environment was present for disease to develop on only one occasion, a direct relationship between soilborne teliospores and disease incidence may not exist.

scholarly journals Induction of MAP Kinase Homologues during Growth and Morphogenetic Development of Karnal Bunt (Tilletia indica) under the Influence of Host Factor(s) from Wheat Spikes

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Atul K. Gupta ◽  
J. M. Seneviratne ◽  
G. K. Joshi ◽  
Anil Kumar
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Fungal Growth ◽  
Host Factor ◽  
Host Factors ◽  
Karnal Bunt ◽  
Dependent Manner ◽  
Tilletia Indica ◽  
Mitogen Activated Protein

Signaling pathways that activate different mitogen-activated protein kinases (MAPKs) in response to certain environmental conditions, play important role in mating type switching (Fus3) and pathogenicity (Pmk1) in many fungi. In order to determine the roles of such regulatory genes inTilletia indica, the causal pathogen of Karnal bunt (KB) of wheat, semi-quantitative and quantitative RT-PCR was carried out to isolate and determine the expression of MAP kinase homologues during fungal growth and development underin vitroculture. Maximum expression of TiFus3 and TiPmk1 genes were observed at 14th and 21st days of culture and decreased thereafter. To investigate whether the fungus alters the expression levels of same kinases upon interaction with plants, cultures were treated with 1% of host factors (extracted from S-2 stage of wheat spikes). Such treatment induced the expression of MAPks in time dependent manner compared to the absence of host factors. These results suggest that host factor(s) provide certain signal(s) which activate TiFus3 and TiPmk1 during morphogenetic development ofT. indica. The results also provides a clue about the role of host factors in enhancing the disease potential due to induction of MAP kinases involved in fungal development and pathogenecity.

Effect of biofumigation with volatiles from Muscodor albus on the viability of Tilletia spp. teliospores

2009 ◽  
Vol 55 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Blair J. Goates ◽  
Julien Mercier
Keyword(s):  
Organic Compounds ◽  
Seedling Emergence ◽  
Karnal Bunt ◽  
Smut Fungi ◽  
Tilletia Indica ◽  
Common Bunt ◽  
Volatile Organic ◽  
Petri Dishes ◽  
Postharvest Control ◽  
Muscodor Albus

Volatile organic compounds produced by the fungus Muscodor albus inhibit or kill numerous fungi. The effect of these volatiles was tested on dormant and physiologically active teliospores of the smut fungi Tilletia horrida , Tilletia indica , and Tilletia tritici , which cause kernel smut of rice, Karnal bunt of wheat, and common bunt of wheat, respectively. Reactivated rye grain culture of M. albus was used to fumigate dormant teliospores in dry Petri dishes and physiologically active teliospores on water agar for up to 5 days at 22 °C. Teliospores of all 3 species were incapable of germination when fumigated on agar for 5 days. When T. tritici on agar was fumigated only during the initial 48 h of incubation, viability was reduced by 73%–99%. Fumigation of dry loose teliospores of T. tritici caused a 69%–97% loss in viability, whereas teliospores within intact sori were not affected. Dormant teliospores of T. horrida and T. indica were not affected by M. albus volatiles. It appears that M. albus has potential as a seed or soil treatment for controlling seedling-infecting smuts where infection is initiated by germinating teliospores prior to seedling emergence. The volatiles were not effective for postharvest control of teliospores under conditions used in these experiments.

scholarly journals Centenary of Soil and Air Borne Wheat Karnal Bunt Disease Research: A Review

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1152
Author(s):  
Mir Asif Iquebal ◽  
Pallavi Mishra ◽  
Ranjeet Maurya ◽  
Sarika Jaiswal ◽  
Anil Rai ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Association Studies ◽  
Farmyard Manure ◽  
Wheat Breeding ◽  
Karnal Bunt ◽  
Farm Income ◽  
Resistance Locus ◽  
Genome Wide Association Studies ◽  
Tilletia Indica ◽  
Causal Pathogen

Karnal bunt (KB) of wheat (Triticum aestivum L.), known as partial bunt has its origin in Karnal, India and is caused by Tilletia indica (Ti). Its incidence had grown drastically since late 1960s from northwestern India to northern India in early 1970s. It is a seed, air and soil borne pathogen mainly affecting common wheat, durum wheat, triticale and other related species. The seeds become inedible, inviable and infertile with the precedence of trimethylamine secreted by teliospores in the infected seeds. Initially the causal pathogen was named Tilletia indica but was later renamed Neovossia indica. The black powdered smelly spores remain viable for years in soil, wheat straw and farmyard manure as primary sources of inoculum. The losses reported were as high as 40% in India and also the cumulative reduction of national farm income in USA was USD 5.3 billion due to KB. The present review utilizes information from literature of the past 100 years, since 1909, to provide a comprehensive and updated understanding of KB, its causal pathogen, biology, epidemiology, pathogenesis, etc. Next generation sequencing (NGS) is gaining popularity in revolutionizing KB genomics for understanding and improving agronomic traits like yield, disease tolerance and disease resistance. Genetic resistance is the best way to manage KB, which may be achieved through detection of genes/quantitative trait loci (QTLs). The genome-wide association studies can be applied to reveal the association mapping panel for understanding and obtaining the KB resistance locus on the wheat genome, which can be crossed with elite wheat cultivars globally for a diverse wheat breeding program. The review discusses the current NGS-based genomic studies, assembly, annotations, resistant QTLs, GWAS, technology landscape of diagnostics and management of KB. The compiled exhaustive information can be beneficial to the wheat breeders for better understanding of incidence of disease in endeavor of quality production of the crop.

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