Glasshouse and field experiments on the control of tobacco blue mould

A simple procedure is described for the testing of chemicals against blue mould (Peronospora tabacina Adam) on tobacco seedlings in the glasshouse. Of approximate/y 500 chemicals tested, 17 gave mould control comparable to that of the standard (0.1 per cent w/v zineb), but a number of these were phytotoxic. In two field trials, zineb and ethylenethiuram monosulphide as dispersible powders or suspensions in white spraying oil base and N-p-tolyl dichloromaleimide as a dispersible powder, gave highly effective control early in the season, but later in the season, only zineb at 0.1 and 0.2per cent w/v gave effective control. Maneb, which was not tested in the field, later proved consistently superior to zineb in extensive glasshouse trials, and appeared to be the most promising compound for further investigation.

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The role of temperature in the development of blue mould (Peronospora tabacina Adam) disease in tobacco seedlings. I. In leaves

Australian Journal of Agricultural Research ◽

10.1071/ar9650597 ◽

1965 ◽

Vol 16 (4) ◽

pp. 597 ◽

Cited By ~ 2

Author(s):

AV Hill ◽

S Green

Keyword(s):

Narrow Range ◽

Peronospora Tabacina ◽

Progressive Development ◽

Blue Mould ◽

Temperature Conditions ◽

Strong Trend ◽

Slow Development ◽

Wide Range ◽

Tobacco Seedlings

In tests over a wide range of temperature conditions the number of days from inoculation of plants of cv. Virginia Gold with conidia of Peronospora tabacina to appearance of blue mould symptoms in leaves varied from 4 to 12 days with conidia of strain APT1 and from 5 to 15 days with strain APT2. It was 4 to 14 days with strain APT2 on plants of cv. SO1. Initial death of leaves of cv. Virginia Gold occurred at 5–6 days after inoculation with APT1 but 3–4 days later when similar plants or cv. SO1 were inoculated with APT2. For each strain there was a strong trend toward similar leaf loss, and similar progressive development of leaf loss in treatments with the same night temperatures. For both strains, leaf losses developed most rapidly and were most severe at night temperatures of 16–24°C. The relatively slow development of APT2, except over a narrow range of temperatures, would limit its capacity for competing with APT1 and for producing epiphytotics.

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Herbicide Programs for Control of Waterhemp (Amaranthus tuberculatus) Resistant to Three Distinct Herbicide Sites of Action in Corn

Weed Technology ◽

10.1017/wet.2020.140 ◽

2020 ◽

pp. 1-28

Author(s):

Christian Willemse ◽

Nader Soltani ◽

Lauren Benoit ◽

David C. Hooker ◽

Amit J. Jhala ◽

...

Keyword(s):

Field Experiments ◽

Field Trials ◽

Effective Control ◽

High Fecundity ◽

Field Corn ◽

Amaranthus Tuberculatus ◽

Excellent Control ◽

Density And Biomass ◽

Sites Of Action ◽

Herbicide Programs

Abstract Control of waterhemp is becoming more difficult in Ontario as biotypes have evolved resistance to four herbicide sites of action (SOA) including groups 2, 5, 9, and 14. The objective of this study was to compare PRE, POST, and PRE followed by (fb) POST herbicide programs and their effect on control, density, and biomass of multiple herbicide-resistant (MHR) waterhemp as well as corn injury and grain yield. Two separate field experiments, each consisting of five field trials, were conducted over a two-year period (2018 and 2019) in corn in Ontario, Canada. The first experiment evaluated MHR waterhemp control with 4-hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitor containing programs applied PRE, HPPD-inhibitor containing programs applied PRE fb glufosinate applied POST, and glufosinate applied POST. The second experiment evaluated MHR waterhemp control with non-HPPD inhibitor containing programs applied PRE, non-HPPD inhibitor containing programs applied PRE fb atrazine + mesotrione applied POST, and atrazine + mesotrione applied POST. Atrazine + isoxaflutole caused 3 to 5% corn injury at E1; no corn injury was observed with PRE and POST herbicide programs at other environments. In general, atrazine/bicyclopyrone/mesotrione/S-metolachlor and dimethenamid-P/saflufenacil, applied PRE, controlled MHR waterhemp ≥ 95% 12 weeks after POST application (WAA). A POST application of glufosinate following atrazine + tolpyralate PRE, and a POST application of atrazine + mesotrione following atrazine/dicamba or atrazine/S-metolachlor PRE, improved control at 4, 8, and 12 WAA in most environments. In general, PRE fb POST applications resulted in better control of MHR waterhemp throughout the growing season than PRE and POST applications (P<0.05). It is concluded that herbicide programs based on multiple effective SOA are available for effective control of MHR waterhemp in field corn and it is advisable that when choosing a herbicide program, excellent control of MHR waterhemp should be the goal given its high fecundity and competitive ability.

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Relative Abundance and Field Efficacy of Insecticides and Bio-control Agents Against Stem Borer Species in Rice (Oryza sativa L.)

Indian Journal of Agricultural Research ◽

10.18805/ijare.a-5619 ◽

2021 ◽

Author(s):

T. Sharmitha ◽

C. Gailce Leo Justin ◽

S. Sheeba Joyce Roseleen

Keyword(s):

Field Experiments ◽

Insect Pests ◽

Oryza Sativa L ◽

Stem Borer ◽

Field Trials ◽

Control Agent ◽

High Yield ◽

Seasonal Incidence ◽

Yellow Stem Borer ◽

Highly Effective

Background: In India, out of the total loss incurred by different insect pests of paddy, 25 to 30 per cent damage is done by stem borer alone. Many conventional insecticides though have been evaluated against stem borers, yet, most of the chemicals have failed to provide adequate control. Hence, the present study aimed to evaluate the efficacy of some newer molecules of insecticides and bio-control agents.Methods: Field trials were conducted to record the seasonal incidence and to evaluate the efficacy of insecticides and bio-control agents against the stem borer species in rice during Kharif and Rabi. Result: Field experiments revealed that during Kharif 2018, chlorantraniliprole 18.5 SC was highly effective with 92.98 and 91.24 per cent reduction of stem borer infestation over control at vegetative and reproductive stages, respectively and recorded a high yield of 5720 kg/ha followed by spinetoram 11.7 SC with 83.16 and 80.82 per cent reduction of stem borer over control at vegetative and reproductive stages, respectively. During Rabi 2019, spinetoram 11.7 SC was highly effective with 92.36 and 93.73 per cent reduction of stem borer infestation over control at vegetative and reproductive stages respectively and recorded a high yield of 4570 kg/ ha, followed by chlorantraniliprole 18.5 SC with 84.60 and 91.48 per cent reduction of stem borer at vegetative and reproductive stages, respectively. The difference in the efficacy of insecticides during Khaif, 2018 and Rabi, 2019, might be due to shift in the species occurrence of stem borer, with a dominant occurrence of yellow stem borer (80.61%) in Kharif 2018 and pink stem borer (70.00%) in Rabi, 2019. The bio-control agent Trichogramma japonicum exerted minimum reduction of stem borer with a low grain yield of 3946.6 kg/ha.

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Fruit Volatiles to Control Postharvest Rot of Stone Fruits and Pears

HortScience ◽

10.21273/hortsci.33.3.469a ◽

1998 ◽

Vol 33 (3) ◽

pp. 469a-469

Author(s):

L.J. Skog ◽

D.P. Murr ◽

B.E. Digweed

Keyword(s):

Volatile Compounds ◽

Isoamyl Acetate ◽

Penicillium Expansum ◽

Effective Control ◽

In Vitro Tests ◽

Stone Fruits ◽

In Situ Tests ◽

Highly Effective ◽

Postharvest Rot

Volatile compounds are ubiquitous in plants, giving fruits their characteristic aroma and flavor. There is increasing evidence that these compounds can protect plants from pathogenic organisms. In this trial ≈25 volatile compounds were tested for efficacy against Monilinia fructicola and Penicillium expansum. Both in vitro tests on agar plugs of actively growing pathogens and in situ tests on inoculated stone fruits and pears were conducted. The volatile compounds were grouped into three categories based upon fungicidal activity in vitro: highly effective (fungicidal concentration ≤100 M), moderately effective (fungicidal concentration between 100–200 M) and ineffective (fungicidal concentration >200 M). Highly effective compounds included: acetaldehyde, citral, 2-ethyl-1-hexanol, 2,exadienal, E-2-hexenal, 4-hexen-3-one, linalool, (E,E)2,4-nonadienal, E-2-nonenal, E-3-none-2-one, salicylaldehyde, and valeraldehyde. Moderately effective compounds included: (E,Z) 2,6-nonadienal, propionaldehyde, terpinene, butyl acetate, E-cinnamaldehde, hexanal, E-2-hexen-1-ol, Z-3-hexen-1-ol and isoamyl acetate. Ineffective compounds included: butyrolactone, ethanol, ethyl acetate, and methyl acetate. Effectiveness of the compounds varied with both strain and type of microorganism tested. Concentraions required for effective control were much higher when the compounds were tested on inoculated fruit. Phytotoxicity was a problem with some compounds.

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COR/LEA Proteins as Indicators of Frost Tolerance in Triticeae: A Comparison of Controlled versus Field Conditions

Plants ◽

10.3390/plants10040789 ◽

2021 ◽

Vol 10 (4) ◽

pp. 789

Author(s):

Klára Kosová ◽

Miroslav Klíma ◽

Ilja Tom Prášil ◽

Pavel Vítámvás

Keyword(s):

Cold Acclimation ◽

Field Experiments ◽

Quantitative Relationship ◽

Field Trials ◽

Frost Tolerance ◽

Late Embryogenesis Abundant ◽

Field Conditions ◽

Lea Proteins ◽

Winter Cereals ◽

Vernalisation Requirement

Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and field conditions. The impacts of cold acclimation and vernalisation processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter survival in field-grown winter cereals but only in plant prior to the fulfilment of vernalisation requirement.

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Exploiting Thrips Aggregation Pheromones to Develop a Lure-and-Kill Strategy for the Management of the Bean Flower Thrips

Agronomy ◽

10.3390/agronomy11071269 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1269

Author(s):

David K. Mfuti ◽

Amanuel Tamiru ◽

William D. J. Kirk ◽

Adeyemi O. Akinyemi ◽

Heather Campbell ◽

...

Keyword(s):

Field Experiments ◽

Insect Pests ◽

Field Trials ◽

Aggregation Pheromones ◽

Megalurothrips Sjostedti ◽

Flower Thrips ◽

Antifungal Effects ◽

Field Efficacy ◽

Management Alternative ◽

Trap Catches

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.

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Synergistic Effect of Combined Application of a New Fungicide Fluopimomide with a Biocontrol Agent Bacillus methylotrophicus TA-1 for Management of Gray Mold in Tomato

Plant Disease ◽

10.1094/pdis-01-19-0143-re ◽

2019 ◽

Vol 103 (8) ◽

pp. 1991-1997 ◽

Cited By ~ 3

Author(s):

Xiaoxue Ji ◽

Jingjing Li ◽

Zhen Meng ◽

Shouan Zhang ◽

Bei Dong ◽

...

Keyword(s):

Field Experiments ◽

Biocontrol Agent ◽

Severe Disease ◽

Combined Treatment ◽

Field Trials ◽

Antimicrobial Activities ◽

Gray Mold ◽

Control Efficacy ◽

Bacillus Methylotrophicus

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.

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The use of light spectrum blocking films to reduce populations of Drosophila suzukii Matsumura in fruit crops

Scientific Reports ◽

10.1038/s41598-020-72074-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Michelle T. Fountain ◽

Amir Badiee ◽

Sebastian Hemer ◽

Alvaro Delgado ◽

Michael Mangan ◽

...

Keyword(s):

Control Strategies ◽

Field Trials ◽

Biological Data ◽

Insect Vision ◽

Invasive Pest ◽

Effective Control ◽

Fruit Crops ◽

Light Spectrum ◽

Drosophila Suzukii ◽

The Impact

Abstract Spotted wing drosophila, Drosophila suzukii, is a serious invasive pest impacting the production of multiple fruit crops, including soft and stone fruits such as strawberries, raspberries and cherries. Effective control is challenging and reliant on integrated pest management which includes the use of an ever decreasing number of approved insecticides. New means to reduce the impact of this pest that can be integrated into control strategies are urgently required. In many production regions, including the UK, soft fruit are typically grown inside tunnels clad with polyethylene based materials. These can be modified to filter specific wavebands of light. We investigated whether targeted spectral modifications to cladding materials that disrupt insect vision could reduce the incidence of D. suzukii. We present a novel approach that starts from a neuroscientific investigation of insect sensory systems and ends with infield testing of new cladding materials inspired by the biological data. We show D. suzukii are predominantly sensitive to wavelengths below 405 nm (ultraviolet) and above 565 nm (orange & red) and that targeted blocking of lower wavebands (up to 430 nm) using light restricting materials reduces pest populations up to 73% in field trials.

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KIH-485 and S-metolachlor Efficacy Comparisons in Conventional and No-Tillage Corn

Weed Technology ◽

10.1614/wt-05-048r2.1 ◽

2006 ◽

Vol 20 (3) ◽

pp. 622-626 ◽

Cited By ~ 38

Author(s):

Patrick W. Geier ◽

Phillip W. Stahlman ◽

John C. Frihauf

Keyword(s):

Weed Control ◽

Field Experiments ◽

Conventional Tillage ◽

Palmer Amaranth ◽

Effective Control ◽

No Tillage ◽

Green Foxtail

Field experiments were conducted during 2003 and 2004 to compare the effectiveness of KIH-485 and S-metolachlor for PRE weed control in no-tillage and conventional-tillage corn. Longspine sandbur control increased as KIH-485 or S-metolachlor rates increased in conventional-tillage corn, but control did not exceed 75% when averaged over experiments. Both herbicides controlled at least 87% of green foxtail with the exception of no-tillage corn in 2004, when KIH-485 was more effective than S-metolachlor at lower rates. Palmer amaranth control ranged from 85 to 100% in 2003 and 80 to 100% in 2004, with the exception of only 57 to 76% control at the lowest two S-metolachlor rates in 2004. Puncturevine control exceeded 94% with all treatments in 2003. In 2004, KIH-485 controlled 86 to 96% of the puncturevine, whereas S-metolachlor controlled only 70 to 81%. Mixtures of atrazine with KIH-485 or S-metolachlor generally provided the most effective control of broadleaf weeds studied.

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Fungicidal control of leaf spot (Septoria apiicola) of celery

Australian Journal of Experimental Agriculture ◽

10.1071/ea9890261 ◽

1989 ◽

Vol 29 (2) ◽

pp. 261 ◽

Cited By ~ 2

Author(s):

TJ Wicks

Keyword(s):

Leaf Spot ◽

Field Experiments ◽

Effective Control ◽

Severity Of Disease

Ten fungicides were evaluated and compared in glasshouse and field experiments for the control of celery leaf spot caused by Septoria apiicola. In glasshouse experiments propiconazole (25 mg a.i. L-1) inhibited the development of S. apiicola when applied to celery seedlings 2 days after inoculation and in 1 experiment an application 8 days after inoculation reduced by 10-fold the severity of disease as well as the production of pycnidia. Penconazole (25 mg a.i. L-1), myclobutanil (50 mg a.i. L-1), flusilazole (20 mg a.i. L-1), fenarimol (36 mg a.i. L-1), terbuconazole (25 mg a.i. L-1) and triadimenol(25 mg a.i. L-1) also controlled S. apiicola when applied 2, but not 8 days, after inoculation. Anilazine protected celery seedlings for at least 13 days after application and was the most effective of the fungicides applied before infection. In field experiments, the most effective control of leaf spot was achieved with applications, every 7-10 days, of anilazine (1500 mg a.i. L-1), applied either alone or mixed with propiconazole (25 mg a.i. L-1). Similar applications of propiconazole either alone or mixed with chlorothalonil (150 mg a.i. L-1) also controlled leaf spot, whereas penconazole (25 mg a.i. L-1), flusilazole (20 mg a.i. L-1) and myclobutanil (50 mg a.i. L-1) were not effective.

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