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

Agronomy ◽  
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.

scholarly journals Seasonal Fluctuations and Management of Sucking Insect Pests on Bitter Gourd (Momordica charantia L.)

2020 ◽  
Author(s):  
M.M. Mawtham ◽  
C. Gailce Leo Justin ◽  
S. Sheeba Joyce Roseleen
Keyword(s):  
Tamil Nadu ◽  
Field Experiments ◽  
Insect Pests ◽  
Block Design ◽  
Insect Pest ◽  
Bitter Gourd ◽  
Maximum Temperature ◽  
Seasonal Fluctuations ◽  
Pest Population ◽  
Field Efficacy

Background: Bitter gourd, an important tropical and sub-tropical vegetable which occupies a predominant position in Indian vegetables. The aphids and leafhoppers are more serious agricultural insect pests and aphids indirectly transmit plant virus diseases like, Cucumber Mosaic Virus (CMV) in cucurbit crops. Our study aimed to noticed seasonal fluctuations and bio-inputs using management of sucking pests in bitter gourd.Methods: Field experiments were conducted during 2017-19 in a farmer’s field at Ellamanam village, Tiruchirappalli district, Tamil Nadu in insect pest population was monitored at weekly intervals from ten randomly selected plants in three plots. In field efficacy studies conducted Randomised Block Design with eight treatments and three replications. Result: Our results showed in the maximum aphid and leafhopper populations were recorded in September 2018 during 39th SMW (Standard Meteorological Week). In Rabi, the aphids and leaf hopper population were maximum in 9th and 10th SMW in February and March. The population of aphids and leafhopper were positively correlated with maximum temperature, minimum temperature, wind speed and wind direction. Rainfall and relative humidity were negatively associated to aphids and leafhopper infestation. In Kharif and Rabi, high reduction of aphid and leafhopper pest population were noticed in chlorantraniliprole 18.5 SC and spinosad 45 SC compared to control. Among the bio-inputs agniastram recorded higher reduction of pest population followed by karpurakaraisal, NSKE, fish acid and ten leaf extract.

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

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.

scholarly journals Effect of Application Frequency and Reduced Rates of Acibenzolar-S-Methyl on the Field Efficacy of Induced Resistance Against Bacterial Spot on Tomato

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Cheng-Hua Huang ◽  
Gary E. Vallad ◽  
Shouan Zhang ◽  
Amin Wen ◽  
Botond Balogh ◽  
...  
Keyword(s):  
Disease Severity ◽  
Untreated Control ◽  
Systemic Acquired Resistance ◽  
Field Experiments ◽  
Acquired Resistance ◽  
Foliar Spray ◽  
Field Trials ◽  
Plant Diseases ◽  
Bacterial Spot ◽  
Field Efficacy

Acibenzolar-S-methyl (ASM), a plant activator known to induce systemic acquired resistance, has demonstrated an ability to manage a number of plant diseases, including bacterial spot on tomato caused by four distinct Xanthomonas spp. The aim of this study was to evaluate application rate and frequency of ASM in order to optimize field efficacy against bacterial spot in Florida, while minimizing its impact on marketable yields. ASM was applied biweekly (once every 2 weeks) as a foliar spray at a constant concentration of 12.9, 64.5, and 129 μM throughout four field experiments during 2007–08. A standard copper program and an untreated control were also included. Overall, biweekly applications of ASM did not significantly reduce disease development or the final disease severity of bacterial spot compared with the copper-mancozeb standard or the untreated control. Only one experiment showed a significant reduction in the final disease severity on plants treated with ASM at 129 μM compared with the untreated control. Three additional field trials conducted during 2009–10 to evaluate the effects of weekly and biweekly applications of ASM at concentrations of 30.3 to 200 μM found that weekly applications provided significantly better disease control than biweekly applications. The tomato yields were not statistically improved with the use of ASM relative to the untreated control and standard copper program. Weekly ASM applications at rates as low as 75 μM (equivalent to 1.58 g a.i./ha in 100 liters of water or 0.21 oz. a.i./acre in 100 gallons of water) to 200 μM (equivalent to 4.20 g a.i./ha in 100 liters of water or 0.56 oz. a.i./acre in 100 gallons of water) were statistically equivalent in managing bacterial spot of tomato without significantly reducing yield compared with the untreated control.

scholarly journals Bioactive Metabolites from the Endophytic Fungus Aspergillus sp. SPH2

2021 ◽  
Vol 7 (2) ◽  
pp. 109
Author(s):  
Viridiana Morales-Sánchez ◽  
Carmen E. Díaz ◽  
Elena Trujillo ◽  
Sonia A. Olmeda ◽  
Felix Valcarcel ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Plant Pathogens ◽  
Insect Pests ◽  
Ethyl Acetate Extract ◽  
Rhopalosiphum Padi ◽  
Fungal Growth ◽  
Bioactive Metabolites ◽  
Endemic Plant ◽  
Antifungal Effects ◽  
Aspergillus Sp

In the current study, an ethyl acetate extract from the endophytic fungus Aspergillus sp. SPH2 isolated from the stem parts of the endemic plant Bethencourtia palmensis was screened for its biocontrol properties against plant pathogens (Fusarium moniliforme, Alternaria alternata, and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi), plant parasites (Meloidogyne javanica), and ticks (Hyalomma lusitanicum). SPH2 gave extracts with strong fungicidal and ixodicidal effects at different fermentation times. The bioguided isolation of these extracts gave compounds 1–3. Mellein (1) showed strong ixodicidal effects and was also fungicidal. This is the first report on the ixodicidal effects of 1. Neoaspergillic acid (2) showed potent antifungal effects. Compound 2 appeared during the exponential phase of the fungal growth while neohydroxyaspergillic acid (3) appeared during the stationary phase, suggesting that 2 is the biosynthetic precursor of 3. The mycotoxin ochratoxin A was not detected under the fermentation conditions used in this work. Therefore, SPH2 could be a potential biotechnological tool for the production of ixodicidal extracts rich in mellein.

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

Plants ◽  
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.

scholarly journals Comparative Experimental Effects of Intercropping and Cypermethrin on Insect Pest Infestation and Yield of Maize, Cowpea and Okra in Two Cameroonian Agro-Ecological Zones

2021 ◽  
Vol 3 (2) ◽  
pp. 383-393
Author(s):  
Patient Farsia Djidjonri ◽  
Nukenine Elias Nchiwan ◽  
Hartmut Koehler
Keyword(s):  
Field Experiments ◽  
Insect Pests ◽  
Cropping Systems ◽  
Insect Pest ◽  
Maize Yield ◽  
Ecological Zones ◽  
Pest Infestation ◽  
Final Yield ◽  
Cropping Seasons ◽  
Agro Ecological Zones

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.

scholarly journals 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 ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1991-1997 ◽  
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.

Effects of irrigation regimes on powdery scab disease and yield of potatoes

1986 ◽  
Vol 26 (6) ◽  
pp. 745 ◽  
Author(s):  
PA Taylor ◽  
SP Flett ◽  
RFde Boer ◽  
D Marshall
Keyword(s):  
Large Scale ◽  
Field Experiments ◽  
Field Trials ◽  
Powdery Scab ◽  
Infested Soil ◽  
Spongospora Subterranea ◽  
Potato Tubers ◽  
Potato Plants ◽  
Tuber Set ◽  
Large Scale Field

The period of susceptibility of potato tubers to powdery scab (Spongospora subterranea) was studied by inoculating potato plants with spores, or by watering plants in infested soil, at different stages of plant development in greenhouse conditions. Maximum susceptibility began about 1 week before the stage when 50% of stolons had swollen to at least 5-mm diameter (tuber set), and ended 3-4 weeks later. With holding irrigation water during this period reduced the severity of powdery scab by 65-75% in field experiments in 1981-82 and 1982-83, but had no apparent effect on disease severity in 3 out of 6 large-scale field trials during 1984-85.

Management strategies to reduce losses caused by fusarium seedling blight of field pea

2013 ◽  
Vol 93 (4) ◽  
pp. 619-625 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
...  
Keyword(s):  
Root Rot ◽  
Field Experiments ◽  
Management Strategies ◽  
Stand Density ◽  
Field Trials ◽  
Field Pea ◽  
Seedling Blight ◽  
Inoculum Level ◽  
Fusarium Seedling Blight ◽  
Disease Pressure

Chang, K. F., Hwang, S. F., Ahmed, H. U., Gossen, B. D., Turnbull, G. D. and Strelkov, S. E. 2013. Management strategies to reduce losses caused by fusarium seedling blight of field pea. Can. J. Plant Sci. 93: 619–625. Fusarium seedling blight can cause substantial reductions in the stand density of field pea in western Canada. In greenhouse experiments, emergence decreased and root rot severity rose with increasing inoculum density. In field trials in 2007 and 2008 near Edmonton, AB, seeding at different depths and seeding dates did not consistently affect emergence or yield in Fusarium-infested soils. In field experiments, emergence declined significantly with each increase in inoculum level. Also, seed yield were reduced at high levels of disease pressure. Treatment of seed with Apron Maxx improved emergence, nodulation and yield of treatments challenged with inoculum of F. avenaceum in both greenhouse and field experiments. This research demonstrates the need to prevent seedling blight and root rot through proper seed treatment.

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