scholarly journals Field evaluation of Fusarium tumidum as a bioherbicide against gorse and broom

2000 ◽  
Vol 53 ◽  
pp. 59-65 ◽  
Author(s):  
J. Fr?hlich ◽  
J.A. Zabkiewicz ◽  
A.F. Gianotti ◽  
J.W. Ray ◽  
A.L. Vanner ◽  
...  
Keyword(s):  
Plant Species ◽  
Pinus Radiata ◽  
Severe Disease ◽  
Field Evaluation ◽  
Application Rate ◽  
Field Conditions ◽  
Spore Concentration ◽  
Ulex Europaeus ◽  
Invert Emulsion ◽  
Disease Epidemics

Fusarium tumidum spores formulated in water and three invert emulsions were tested under field conditions as a potential bioherbicide against gorse (Ulex europaeus) and broom (Cytisus scoparius) Inundation with F tumidum spores failed to induce severe disease epidemics The invert emulsion formulants demonstrated some phytotoxicity towards gorse and Pinus radiata Plant species and age spore concentration and application rate all influenced the performance of the bioherbicide formulations It will be necessary to develop further formulations that will better enhance the activity of F tumidum in the field

Native plant species field evaluation in salt desert: good materials, bad situation

2015 ◽  
Vol 16 (2) ◽  
pp. 87-95 ◽  
Author(s):  
N. Grant-Hoffman ◽  
S. Parr ◽  
T. Blanke
Keyword(s):  
Plant Species ◽  
Field Evaluation ◽  
Native Plant ◽  
Native Plant Species ◽  
Salt Desert

Field evaluation of the performance of alternative deicers for winter maintenance of transportation facilities

2015 ◽  
Vol 42 (7) ◽  
pp. 437-448 ◽  
Author(s):  
S.M. Kamal Hossain ◽  
Liping Fu ◽  
Roberto Lake
Keyword(s):  
Field Evaluation ◽  
Application Rate ◽  
Relative Advantage ◽  
Comparative Performance ◽  
Winter Maintenance ◽  
Application Rates ◽  
Extensive Field ◽  
Alternative Materials ◽  
Adjustment Factors ◽  
Transportation Facilities

This paper presents the results of an extensive field study on the comparative performance of alternative materials for snow and ice control of transportation facilities. Approximately 300 tests were conducted in a real-world environment, covering four alternative materials, and 21 snow events. Each of the alternatives tested were compared to regular rock salt in terms of snow melting performance — bare-pavement regain time. The study confirmed the relative advantage of these alternatives over the regular salt, but also showed that their performance varied largely depending on some external conditions. Performance models were calibrated and then used for developing application rate adjustment factors that can be applied by maintenance operations for determining the optimal application rates for specific weather events and pavement conditions. The applicability of the results is limited to parking lots and sidewalks without the traffic effects, and as such cannot be easily applied to winter roadways maintenance.

Field evaluation of plaster-based temephos pellets for residual control of midge larvae (Diptera: Chironomidae) in establishing rice crops

1994 ◽  
Vol 34 (5) ◽  
pp. 659 ◽  
Author(s):  
MM Stevens ◽  
GN Warren
Keyword(s):  
Water Column ◽  
Water Samples ◽  
Field Evaluation ◽  
Application Rate ◽  
Control Agent ◽  
Fourth Instar ◽  
Soil Core ◽  
Potential Control ◽  
Core Samples ◽  
Application Rates

A pelletised formulation of temephos (5% a.i.) was evaluated as a potential control agent for chironomid midge larvae in establishing rice crops. Four application rates between 0.03 and 0.53 mg a.i./L (42-732 g a.i./ha) were applied to 80 m2 experimental rice bays immediately after flooding. Water samples and soil core samples were taken at regular intervals until 29 days post-treatment. Larvae were extracted from core samples using magnesium sulfate (MgSO4) flotation, whilst laboratory-reared fourth instar Chironomus tepperi Skuse larvae were used in bioassays with field-collected water samples to determine pesticide activity in the water column. All treatments significantly suppressed C. tepperi-type larvae in the field for at least 13 days. Some suppression of non-C. tepperi-type larvae was obtained at 0.27 mg a.i./L, whilst at 0.53 mg a.i./L all chironomids were reduced to negligible levels for the full period of the trial. In bioassays, significant levels of water column toxicity to fourth instar C. tepperi larvae were only recorded for 2 days after treatment at the highest application rate. Our results indicate that plaster-based temephos pellets have the potential to provide effective, single application control of chironomid larvae in establishing rice crops without the risk of spray drift inherent in the aerial application of liquid insecticides.

Breakdown and Movement of 2,4-D in the Soil Under Field Conditions

Weed Science ◽  
1976 ◽  
Vol 24 (5) ◽  
pp. 461-466 ◽  
Author(s):  
R. G. Wilson ◽  
H. H. Cheng
Keyword(s):  
Triticum Aestivum ◽  
Acetic Acid ◽  
Soil Profile ◽  
Soil Surface ◽  
Application Rate ◽  
Soil Samples ◽  
Field Conditions ◽  
Herbicide Application ◽  
Eastern Washington ◽  
Dichlorophenoxy Acetic Acid

The fate of 2,4-D [(2,4-dichlorophenoxy)acetic acid] in the soil under winter wheat (Triticum aestivumL. ‘Nugaines’) and fallow cropping schemes was studied under the field conditions of eastern Washington in 1973 and 1974 using formulated dimethylamine salt and isooctyl ester of 2,4-D. Soil samples taken 1 hour after herbicide application showed that amine-treated plots retained considerably more applied 2,4-D than ester-treated plots. The rapidity of 2,4-D breakdown decreased gradually with time, and at the end of 6 months, an average of 0.04 ppm of 2,4-D remained in the sampled soil profile regardless of formulation, application rate, or cropping scheme. Loss of 2,4-D from the soil surface in runoff occurred when the plots were irrigated heavily one day after the herbicide application. The herbicide was also leached into the soil profile by both irrigation and natural precipitation. Herbicide concentrations in the sampled portion of the upper soil profile decreased during the summer and then increased slightly in the fall.

scholarly journals Effective Biomass Reduction of the Invasive Weed Species Banana Poka by Septoria Leaf Spot

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 357-361 ◽  
Author(s):  
Eduardo E. Trujillo ◽  
Chris Kadooka ◽  
Victor Tanimoto ◽  
Steve Bergfeld ◽  
Glenn Shishido ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Severe Disease ◽  
Disease Spread ◽  
Leaf Spot Disease ◽  
Native Forest ◽  
Invasive Weed ◽  
Disease Epidemics ◽  
Biomass Reduction ◽  
Septoria Leaf Spot

Inoculations of Septoria passiflorae for biological control of banana poka (Passiflora tripartita var. tripartita) at different forest sites in Hawaii, Kauai, and Maui resulted in successful establishment of the Septoria leaf spot disease at all sites during 1996. Semi-annual monitoring of sites in 1997 revealed low disease incidence and no disease spread to adjacent non-inoculated plants. Site inspections in March 1998 revealed light disease epidemics causing visible defoliation at inoculated sites on Kauai and Maui. Banana poka biomass reduction at sites with light epidemics of the disease in Kauai and Maui were estimated to be less than 10% in 1998, whereas in 1999 biomass reduction ranged from 50 to 95%. Five of 11 inoculation sites in 1996 on the island of Hawaii showed no disease. These five sites on Kaloko had frequent acid rainfall averaging 3.2 pH, which inhibited spore germination and infection. Six sites, free of acid rain, three at Hilo Forest Reserve and three at Puuwaawaa Wildlife Sanctuary, had severe disease epidemics by 1998, and vine defoliation was >90%. Widespread epidemics of the disease occurred in 1999, resulting in estimated 80 to 95% biomass reductions in more than 2,000 hectares of native forest infested with banana poka.

FIELD EVALUATION OF INSECTICIDES FOR THE CONTROL OF THE EUROPEAN SKIPPER, THYMELICUS LINEOLA (LEPIDOPTERA: HESPERIIDAE), IN QUEBEC

1979 ◽  
Vol 111 (12) ◽  
pp. 1313-1317 ◽  
Author(s):  
Michel Letendre ◽  
Jeremy N. McNeil
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Mortality ◽  
Field Evaluation ◽  
Field Conditions ◽  
Target Effects

AbstractThe efficacy of seven chemical insecticides, five commercial preparations of Bacillus thuringiensis, and two preparations containing diatom dust were tested against the European skipper, Thymelicus lineola (Ochs.), under field conditions. Satisfactory control was obtained with carbaryl, carbofuran, methomyl, permethrin, trichlorfon, Dipel 45B(=Dipel SC), Dipel WP, Thuricide 26B, Thuricide HPC, and Novabac 3 while dimethoate, chlorpyrifos, and the diatom dusts afforded little or no foliage protection. While larval mortality occurred less rapidly when B. thuringiensis preparations were applied, their use is strongly recommended as they afford the same degree of foliage protection as chemical insecticides and diminish possible undesirable off-target effects.

Thermotolerance of Photosystem 2 of Three Alpine Plant Species Under Field Conditions

2002 ◽  
Vol 40 (4) ◽  
pp. 587-595 ◽  
Author(s):  
V. Braun ◽  
O. Buchner ◽  
G. Neuner
Keyword(s):  
Plant Species ◽  
Photosystem 2 ◽  
Field Conditions ◽  
Alpine Plant

scholarly journals Infection Courts in Watermelon Plants Leading to Seed Infestation by Fusarium oxysporum f. sp. niveum

2017 ◽  
Vol 107 (7) ◽  
pp. 828-833 ◽  
Author(s):  
Aparna Petkar ◽  
Pingsheng Ji
Keyword(s):  
Fusarium Oxysporum ◽  
Real Time ◽  
Field Experiments ◽  
Severe Disease ◽  
Transmitted Disease ◽  
Field Conditions ◽  
Pcr Analysis ◽  
Immature Fruit ◽  
Significant Yield ◽  
Seed Infestation

Fusarium wilt incited by Fusarium oxysporum f. sp. niveum is a seed-transmitted disease that causes significant yield loss in watermelon production. The pathogen may infect watermelon seeds latently, which can be an important inoculum source and contribute to severe disease outbreak. However, information regarding infection courts of F. oxysporum f. sp. niveum leading to infestation of watermelon seeds is limited. To determine how seeds in watermelon fruit can be infested by F. oxysporum f. sp. niveum during the watermelon growing season, greenhouse and field experiments were conducted in 2014 and 2015 where watermelon flowers and immature fruit were inoculated with F. oxysporum f. sp. niveum. Seeds were extracted from mature watermelon fruit, and infestation of watermelon seeds was determined by isolation of F. oxysporum f. sp. niveum and further confirmed by real-time polymerase chain reaction (PCR) analysis. Inoculation of the pericarp of immature fruit resulted in 17.8 to 54.4% of infested seeds under field conditions and 0.6 to 12.8% of infested seeds under greenhouse conditions when seeds were not surface disinfested prior to isolation. Seed infestation was also detected in 0 to 4.5% of the seeds when seeds were surface disinfested prior to isolation. Inoculation of pistil resulted in 0 to 7.2% and 0 to 18.3% of infested seeds under greenhouse and field conditions when seeds were surface disinfested or not disinfested before isolation, respectively. Inoculation of peduncle resulted in 0.6 to 6.1% and 0 to 10.0% of infested seeds in the greenhouse and field experiments when seeds were surface disinfested or not disinfested before isolation, respectively. Seed infestation was also detected in all the experiments using real-time PCR assay when pericarp or pistil was inoculated, and in three of four experiments when peduncle was inoculated, regardless of whether seeds were surface disinfested or not disinfested. Pericarp and peduncle of immature watermelon fruit and pistil of watermelon flowers could be potential infection courts for F. oxysporum f. sp. niveum leading to infestation of seeds in asymptomatic watermelon fruit.

scholarly journals Sub-Specific Populations of Verticillium dahliae and their Roles in Vascular Wilt Pathogsystems

1996 ◽  
Author(s):  
Randall C. Rowe ◽  
Jaacov Katan ◽  
Talma Katan ◽  
Leah Tsror
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Verticillium Dahliae ◽  
Severe Disease ◽  
Vegetative Compatibility ◽  
Phenotypic Traits ◽  
Potato Seed ◽  
Vascular Wilt ◽  
Large Collection ◽  
Pathogenic Potential

Verticillium dahliae is an economically important pathogen causing vascular wilt on over 160 plant species. In North America, potato early dying is a significant disease of potato, especially in the midwest and Pacific northwest states. This disease is caused by the fungus Verticillium dahliae and in some cases involves a synergistic interaction with root-lesion nematodes, primarily Pratylenchus penetrans. In Israel, Verticillium wilt occurs in many regions and inflicts serious losses in potato, cotton, and other crops. Objectives of this project were to establish a large collection of isolates of Verticillium dahliae from potato (USA) and several host plants (Israel) and to characterize and compare the isolates with regard to morphology, vegetative compatibility group (VCG), and pathogenic capabilities on several hosts. Isolations were made from 224 commercial lots of certified potato seed tubers from across N. America and 87 potato fields located in the Columbia Basin of Oregon and Washington. A large collection of isolates from central U.S. states already existed. In Israel, 47 field sites were sampled and isolates of Verticillium dahliae were recovered from 13 host plant species and from soil. Potato isolates from N. America were tested for vegetative compatibility and all found to be in VCG 4 with about 2/3 in VCG 4A and the rest in VCG 4B. VCG 4A isolates were significantly more aggressive on potato than VCG 4B isolates and were more likely to interact synergistically with P. penetrans. The Israeli isolates fell into three vegetative compatibility groups. Nearly all (> 90%) VCG2B and VCG 4B isolates were recovered from the northern and southern parts of Israel, respectively, with some overlap in central areas. Several pathotypes were defined in cotton, using cotton and eggplant together as differentials. All VCG 2B isolates from cotton caused severe disease in cotton, while VCG 2A and VCG 4B isolates from several crops were much less aggressive to cotton. When Israeli isolates of VCGs 2A, 2B and 4B were inoculated to potato and tomato, VCG 4B isolates caused much more severe disease on potato and VCG 2A isolates caused much more severe disease in tomato. Differential patterns of pathogenicity and aggressiveness of these VCGs on potato and tomato were consistent regardless of the host plant of origin. Isolates of the same VCG resembled one another more than isolates from different VCGs based on colony and microsclerotial morphology, temperature responses and, partially, in pathogenicity. Vegetative compatibility grouping of V. dahliae in Israel appears closely associated with specific pathogenicity and other phenotypic traits. The absence of VCG 4A in Israel is significant. VCG patterns among Verficillium populations are useful to predict relatedness and pathogenic potential in both countries.  

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