Evaluating faba beans for resistance to ascochyta blight using detached organs

2000 ◽  
Vol 40 (5) ◽  
pp. 707 ◽  
Author(s):  
S. Kohpina ◽  
R. Knight ◽  
F. L. Stoddard
Keyword(s):  
Ascochyta Blight ◽  
Good Condition ◽  
Field Trials ◽  
Experimental Conditions ◽  
Susceptible Population ◽  
Disease Symptoms ◽  
Plant Parts ◽  
Cultural Conditions ◽  
Faba Beans ◽  
Moderately Resistant

Detached-organ techniques were developed, using either individual leaves or stem segments with attached leaves, for use in genetic studies on resistance to ascochyta blight in faba beans. A single isolate of Ascochyta fabae, A26, was used to infect the highly resistant population ILB 752, moderately resistant cultivar Fiord and highly susceptible population NEB 463. Cultural conditions were established that maintained the detached organs in good condition for more than the 10 days required for disease symptoms to be expressed. Detached organs were scored for presence, number and size of lesions and also for number of lesions bearing pycnidia. Spore suspensions of 5 x 102 to 2 x 106 per mL were used, with 5 x 104 providing as much infection as greater concentrations. Leaves and stems were taken from 3-, 5- or 7-week-old plants. Younger plant parts were more susceptible than older ones and plants aged 3–5 weeks provided adequate material for the tests. The susceptibility of the 3 accessions in these experimental conditions followed the order expected from field trials.

scholarly journals Susceptibility of Maize Inbreds and Incidence of Symptomless Infection by the Head Smut Pathogen, Sphacelotheca reiliana

2016 ◽  
Vol 17 (1) ◽  
pp. 1-5 ◽  
Author(s):  
S. J. Anderson ◽  
H. E. Simmons ◽  
R. D. French-Monar ◽  
G. P. Munkvold
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Field Trials ◽  
Growth Stages ◽  
High Susceptibility ◽  
Head Smut ◽  
Pcr Assay ◽  
Disease Symptoms ◽  
The Real ◽  
Seedling Infection

A real-time PCR assay was used to compare seedling infection by Sphacelotheca reiliana, the causal agent of head smut, among five inbred genotypes representing low, moderate, and high susceptibility to the disease. Seeds were coated with teliospores and planted in autoclaved field soil in a growth chamber. Incidence of seedling infection at growth stage V3 differed between an inbred genotype of low susceptibility and those of moderate and high susceptibility, but did not differ between the high and moderately susceptible groups (P < 0.05). The real-time PCR assay was also used to compare infection status at early and late vegetative stages with observable symptoms in the field. We detected infection via real-time PCR in maize at both growth stages during field trials conducted in Texas and California but observed no disease symptoms (smutted ears or tassels). Notably, the fungus was present in up to 31% of the ear shoots in plots without disease symptoms. The real-time assay can be a useful tool for screening seedling-stage host resistance, and for better understanding the progress of infection in different maize genotypes. The field data suggest that asymptomatic infection is much more common than previously thought, and may have important implications for the epidemiology of this fungus under diverse plant resistance and growing conditions. Accepted for publication 11 December 2015. Published 5 January 2016.

Compatibility of Palm Biodiesel Blends on the Existing Elastomer Fuel Hose in Diesel Engine with Approach of Dynamic Test Rig: A Concept Study

2020 ◽  
Vol 1010 ◽  
pp. 172-177
Author(s):  
Narisa Sa'at ◽  
Ariffin Samsuri ◽  
Noradila Abdul Latif ◽  
Nurul Fitriah Nasir ◽  
Rais Hanizam Madon ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Dynamic Testing ◽  
Dynamic Test ◽  
Field Trials ◽  
Biodiesel Fuel ◽  
Compatibility Study ◽  
Fuel System ◽  
Experimental Conditions

Elastomer is one of the important material for the hoses, sealants and tubes in the components of fuel delivery system in diesel engine vehicles due to the factor of compatibility with diesel fuel. However, concern were arise that presence of alcohol, fatty acid component and other factors such as water content in the alternative fuels which is blended biodiesel fuel and different chemical composition from the diesel fuel may increase further uncertainty to the consumer of diesel engine or diesel engine manufacturers in terms of compatibility issue. Thus this paper intends to assess current and typical test standards on their efficacy of representing the fuel system of diesel engine vehicles. Respectively, ASTM D471 are based on laboratory immersion studies and the experimental conditions are differ from the real service conditions in the fuel system of diesel engine vehicles. Even though number of previous studies regarding to the compatibility of elastomer components has been reported, there is a need to set up the exact material that present in the fuel system of diesel engine vehicles. This is especially right for elastomers since their resistance is mainly depends on their elemental compositions. As such, introduction of the dynamic testing approach that may be applied when assessing the compatibility study between blended biodiesel fuel that simulate the actual fuel system of a diesel engine vehicles before carrying out in the field trials.

Chemical control of loose smut (Ustilago segetum var. tritici) of barley and the effects of cultivar and environment on disease incidence

1991 ◽  
Vol 31 (3) ◽  
pp. 373
Author(s):  
R Loughman ◽  
EJ Speijers ◽  
GJ Thomas ◽  
DJ Ballinger
Keyword(s):  
Western Australia ◽  
Chemical Control ◽  
Disease Incidence ◽  
Field Trials ◽  
Loose Smut ◽  
High Rainfall ◽  
Barley Cultivars ◽  
Control Disease ◽  
Moderately Resistant ◽  
Very High

The reasons for an increase in barley loose smut in high rainfall areas of Western Australia were investigated in field trials from 1986 to 1988 by examining the effects of environment, cultivar and adequacy of chemical control. Disease was 4-18 times greater in 2 seed lines produced in very high rainfall areas (>750 mm/year) compared with that produced in high (450-750 mm/year) or low (<325 mm/year) rainfall areas. The effectiveness of 5 fungicide seed treatments was assessed. No fungicide seed treatment controlled disease completely. Triadimenol at 225 mg a.i./kg and carboxin at 940 mg a.i./kg were most effective, providing 93-96% disease control. Treatments were significantly (P<0.01) less effective in high rainfall areas of Western Australia. Barley cultivars released recently in Western Australia were found to be susceptible to loose smut; we suggest that the replacement of the moderately resistant Dampier with these cultivars has contributed to an increased incidence of disease.

scholarly journals Game browse and its impact on selected grain crops

2009 ◽  
Vol 55 (No. 5) ◽  
pp. 181-186 ◽  
Author(s):  
R. Cerkal ◽  
K. Vejražka ◽  
J. Kamler ◽  
J. Dvořák
Keyword(s):  
Leaf Area ◽  
Significant Influence ◽  
Spring Barley ◽  
Field Trials ◽  
Growth Stages ◽  
Plant Parts ◽  
Area Reduction ◽  
Mechanical Removal ◽  
The Impact ◽  
Leaf Area Reduction

This work presents the results of a survey that studied simulated plant browsing by herbivores. In 2004–2006, winter wheat, spring barley, and maize field trials were founded in order to monitor the impact of different levels of defoliation (leaf area reduction) on the yield and grain quality. The defoliation was carried out by means of mechanical removal of plant parts in the early growth stages. Selected qualitative parameters were determined in the harvested grain of wheat and barley. Statistically significant influence of leaf area reduction (LAR) on grain yield (decrease by 4–14%) was found only in maize in 2004. No statistically significant influence of the leaf area reduction on thousand grain weight (TGW) was found in any of the studied crops. The leaf area reduction in barley did not affect grain characteristics; however, it had a statistically significant influence on the quality of wheat grain. Moreover, wheat reduction statistically significantly increased the falling number (by 29–39 s) and decreased SDS test values (by 8–9 ml).

RECENT ADVANCES IN DISPERSANT EFFECTIVENESS EVALUATION: EXPERIMENTAL AND FIELD ASPECTS

1985 ◽  
Vol 1985 (1) ◽  
pp. 445-452 ◽  
Author(s):  
J. P. Desmarquest ◽  
J. Croquette ◽  
F. Merlin ◽  
C. Bocard ◽  
G. Castaing ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Oil Spills ◽  
Practical Interest ◽  
Field Tests ◽  
Field Trials ◽  
Large Field ◽  
Experimental Program ◽  
Experimental Conditions ◽  
Good Accord ◽  
Dispersant Effectiveness

ABSTRACT Although dispersants are used in different countries, it appeared from recent international meetings that more knowledge concerning dispersant effectiveness is still needed for a better response to oil spills. Large field trials which were conducted during the past two years raised some questions as to how dispersants work at sea. Even though the results obtained in different laboratory tests are generally in good accord, significant discrepancies of practical interest may be observed because of variations in the experimental conditions. With EEC support, an experimental program has been conducted by CEDRE and Institut Français du Pétrole (IFP), both with the already-described French middle scale field test and with different laboratory tests (U.K. and French standard tests and the recently developed dilution test). With the objective of correlating the results obtained in field tests and in laboratory tests, several parameters were investigated at sea with different dispersants: the type and viscosity of the oil, slick thickness, and oil to dispersant ratio. Based mainly on the results obtained in the laboratory with dilution tests, new aspects of dispersant behavior have been identified, relating to the nature of the oil and the energy input.

scholarly journals Evaluation of different fungicides applied as seed tuber treatments for the control of potato silver scurf

2005 ◽  
Vol 82 (2) ◽  
pp. 41-48 ◽  
Author(s):  
V. Hervieux ◽  
R. Chabot ◽  
J. Arul ◽  
R.J. Tweddell
Keyword(s):  
Solanum Tuberosum ◽  
Seed Tuber ◽  
Field Trials ◽  
Potato Seed ◽  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Potato Tubers ◽  
Experimental Conditions ◽  
Soil Inoculum ◽  
Seed Tubers

Silver scurf of potatoes (Solanum tuberosum), caused by the fungus Helminthosporium solani, is an important surface-blemishing disease of potato tubers. The objective of the study was to evaluate the efficacy of different fungicides applied to potato seed tubers for control of silver scurf. Field trials were conducted in Québec province in 1998 and 1999. Potato seed tubers infected with H. solani were treated with either talc, fludioxonil, mancozeb, iprodione, thiabendazole, imazalil or azoxystrobin, and planted at three locations in 1998 and two locations in 1999. The results showed that, under our experimental conditions, the fungicides tested, applied as seed treatments, did not significantly influence total and marketable yields as well as silver scurf severity on daughter tubers at harvest and after different storage periods. In addition, this study showed the influence of the experimental locations on silver scurf development and suggests that soil inoculum plays a role in the epidemiology of the disease.

scholarly journals SUSCEPTIBILITY OF CHILLI LINES / VARIETIES TOWARDS CHILLI LEAF CURL VIRUS AND ITS MANAGEMENT THROUGH VECTOR CONTROL

2017 ◽  
Vol 29 (1) ◽  
pp. 17 ◽  
Author(s):  
Muhammad S. Hussain ◽  
Khalid Naveed ◽  
Muhammad Atiq
Keyword(s):  
Disease Incidence ◽  
Field Trials ◽  
Local Germplasm ◽  
Moderately Resistant ◽  
Leaf Curl Virus ◽  
Chilli Leaf Curl Virus ◽  
Leaf Curl Disease ◽  
Whitefly Vector ◽  
Susceptible Response ◽  
Leaf Curl

                                                                  Chilli leaf curl virus (ChiLCV) is a serious problem for chilli production in Pakistan and India. In this study, fourteen different chilli lines / varieties were screened for their resistance/susceptibility towards ChiLCV in open field trials. Data of disease severity and disease incidence was recorded on weekly basis. Out of all varieties screened, Tatapuri Chilli and CH111 showed high susceptibility towards the chilli leaf curl disease. Talhari, CH 99, CH103, CH 106, CH107, CH108, CH109, GSL111 showed susceptible response whereas CBS1292 showed moderately susceptible response towards the disease. Only two cultivars Hybrid-46 and Hot Queen were found as moderately resistant. The screening experiment showed that most of the chilli varieties are susceptible to chilli leaf curl disease and resistance is lacking in local germplasm. Furthermore, three insecticides: Imidacloprid, Polo and Emamectin were tested for their efficacy for the management of disease and whitefly vector in field conditions at weekly intervals. Out of three insecticides, Polo gave best results as compared to Emamectin and Imidacloprid against chilli leaf curl disease and whitefly vector.

scholarly journals Performance and Resistance to Phytophthora Crown and Root Rot in Squash Lines

2020 ◽  
Vol 30 (5) ◽  
pp. 608-618 ◽  
Author(s):  
Kyle E. LaPlant ◽  
Gregory Vogel ◽  
Ella Reeves ◽  
Christine D. Smart ◽  
Michael Mazourek
Keyword(s):  
Root Rot ◽  
Cucurbita Pepo ◽  
Field Experiments ◽  
Phytophthora Capsici ◽  
Severe Disease ◽  
Field Trials ◽  
Disease Symptoms ◽  
Resistant Lines ◽  
Oomycete Pathogen ◽  
Crown And Root Rot

Phytophthora crown and root rot, caused by the oomycete pathogen Phytophthora capsici, is a devastating disease of squash and pumpkin (Cucurbita pepo). No currently available cultivars provide complete resistance to this disease. Three newly developed squash lines and four hybrids were evaluated in greenhouse and field experiments for their resistance to phytophthora crown and root rot as well as for their horticultural performance. The three newly developed lines ranked among the most resistant entries included in 2 years of field trials. In addition, in a separate greenhouse experiment, one of the lines was shown to display the least severe disease symptoms among a group of accessions previously reported to possess partial resistance to phytophthora crown and root. Furthermore, the resistance was observed to be robust to several isolates of P. capsici. However, the phytophthora-resistant lines had reduced yield relative to standard squash cultivars. These lines are useful for continued breeding efforts toward a phytophthora crown and root rot-resistant cultivar.

scholarly journals Evidence of recent increased pathogenicity within the Australian Ascochyta rabiei population

2020 ◽  
Author(s):  
P Sambasivam ◽  
Y Mehmood ◽  
I Bar ◽  
J Davidson ◽  
K Hobson ◽  
...  
Keyword(s):  
Control Strategies ◽  
Severe Disease ◽  
Ascochyta Blight ◽  
Resistant Cultivar ◽  
Ascochyta Rabiei ◽  
Application Timing ◽  
Defence Responses ◽  
Moderately Resistant ◽  
Resistant Genotypes ◽  
Resistance Rating

AbstractAscochyta Blight (AB), caused by Ascochyta rabiei (syn Phoma rabiei), is the major endemic foliar fungal disease affecting the Australian chickpea industry, resulting with potential crop loss and management costs. This study was conducted to better understand the risk posed by the Australian A. rabiei population to current resistance sources and to provide informed decision support for chemical control strategies. Recent changes in the pathogenicity of the population were proposed based on disease severity and histopathological observations on a host set. Controlled environment disease screening of 201 isolates on the host set revealed distinct pathogenicity groups, with 41% of all isolates assessed as highly aggressive and a significant increase in the proportion of isolates able to cause severe damage on resistant and moderately resistant cultivars since 2013. In particular, the frequency of highly aggressive isolates on the widely adopted PBA HatTrick cultivar rose from 18% in 2013 to 68% in 2017. In addition, isolates collected since 2016 caused severe disease on Genesis 090, another widely adopted moderately resistant cultivar and on ICC3996, a commonly used resistance source. Of immediate concern was the 10% of highly aggressive isolates able to severely damage the recently released resistant cultivar PBA Seamer (2016). Histopathology studies revealed that the most aggressive isolates were able to germinate, develop appressoria and invade directly through the epidermis faster than lower aggressive isolates on all hosts assessed, including ICC3996. The fungal invasion triggered a common reactive oxygen species (ROS) and hypersensitive response (HR) on all assessed resistant genotypes with initial biochemical and subsequent structural defence responses initiated within 24 hours of inoculation by the most highly aggressive isolates. These responses were much faster on the less resistant and fastest on the susceptible check host, indicating that speed of recognition was correlated with resistance rating. This will inform fungicide application timing so that infected crops are sprayed with prophylactic chemistries prior to invasion and with systemic chemistries after the pathogen has invaded.

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