Towards Practical Application of Verticillium isaacii Vt305 to Control Verticillium Wilt of Cauliflower: Exploring Complementary Biocontrol Strategies

Verticillium wilt is one of the most important diseases of cauliflower and can lead to serious economic losses. In this study, two complementary strategies were explored to employ the antagonistic capacity of Verticillium isaacii towards Verticillium wilt of cauliflower. The first strategy focused on introducing V. isaacii Vt305 by artificial inoculation of cauliflower plantlets at the nursery stage. Two inoculum types (spores and microsclerotia of V. isaacii Vt305) and different concentrations of microsclerotia were tested in greenhouse and field trials. Seed treatment with 500 microsclerotia seed−1 led to a satisfying biocontrol level of Verticillium wilt. In addition, the PHYTO-DRIP® system was successful in delivering the microsclerotia to cauliflower seeds. The second strategy relied on the stimulation of the natural V. isaacii populations by rotating cauliflower with green manures and potato. Four green manure crops and potato were tested during multiple field experiments. Although these crops seemed to stimulate the V. isaacii soil population, this increase did not result in a control effect on Verticillium wilt of cauliflower in the short term. Importantly, our results indicate that the use of green manures is compatible with the application of V. isaacii Vt305 as biocontrol agent of Verticillium wilt in cauliflower.

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Exploring the use of residues from the invasive Acacia sp. for weed control

Renewable Agriculture and Food Systems ◽

10.1017/s1742170518000170 ◽

2018 ◽

Vol 35 (1) ◽

pp. 26-37 ◽

Cited By ~ 2

Author(s):

Pablo Souza-Alonso ◽

Carolina G. Puig ◽

Nuria Pedrol ◽

Helena Freitas ◽

Susana Rodríguez-Echeverría ◽

...

Keyword(s):

Weed Control ◽

Cropping Systems ◽

Crop Protection ◽

Field Trials ◽

Green Manures ◽

Short Term ◽

Physiological Profile ◽

Acacia Dealbata ◽

Weed Emergence ◽

Different Doses

AbstractA sustainable practice for weed control and crop protection is the incorporation of green manures with phytotoxic potential. It is gaining attention as a way to reduce the use of synthetic herbicides in agriculture and so pot experiments and field trials were conducted to explore the possible use of residues of Acacia species to alleviate weed emergence. We assessed, under greenhouse conditions, the herbicidal effect of phytotoxic manures from Acacia dealbata and Acacia longifolia applied to soil at different doses (1.5 and 3% w/w) on maize growth, some accompanying weeds, and the physiological profile of soil microbes. Applied at a higher dose, A. dealbata residues reduced the emergence of dicotyledons in the short-term (P < 0.05) and, after 30 days, there was a decrease in total weed emergence (P < 0.005) and a mild effect on weed composition, while total weed biomass remained unaffected. Regardless of the inclusion of Acacia residues, the physiological profile of the soil bacterial community did not show significant alterations. Additionally, we tested A. dealbata residues as a mulch or a green manure at the field scale. Although the effects of manures were site-dependent and affected monocot and dicot weeds differentially, dicots were more sensitive. The herbicide potential of acacia residues was only evident for dicots at sites with low-weed density in the seed bank. Nevertheless, due to the absence of phytotoxic effects on maize and minor modifications in the functional profile of bacterial communities, residues of acacia could be used as a complementary tool used together with other practices to reduce the reliance on synthetic herbicides in maize-based cropping systems.

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Effect of Beauveria bassiana-Seed Treatment on Zea mays L. Response against Spodoptera frugiperda

Applied Sciences ◽

10.3390/app11072887 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2887

Author(s):

Laiju Kuzhuppillymyal-Prabhakarankutty ◽

Fernando H. Ferrara-Rivero ◽

Patricia Tamez-Guerra ◽

Ricardo Gomez-Flores ◽

María Cristina Rodríguez-Padilla ◽

...

Keyword(s):

Beauveria Bassiana ◽

Spodoptera Frugiperda ◽

Field Trial ◽

Seed Treatment ◽

Insect Pest ◽

Field Trials ◽

Negative Control ◽

Economic Losses ◽

Native Strain ◽

Symbiotic Associations

Spodoptera frugiperda is a widely distributed insect pest that causes major economic losses in various crops, particularly maize. On the other hand, Beauveria bassiana is an entomopathogenic fungus that establishes symbiotic associations with many plants and contributes to tolerance against biotic and abiotic stresses. In the present work, in laboratory experiments, the effects of the B. bassiana strain GHA, in addition to a native strain (PTG4), delivered via seed treatment in maize seedlings, were evaluated on S. frugiperda growth, development, and mortality. We inoculated maize seeds with 1 × 106B. bassiana blastospores; then these seeds were germinated and grown to seedlings under growth chamber conditions. Third-instar S. frugiperda larvae were allowed to feed on B. bassiana-treated and -untreated (negative control) seedlings until reaching the sixth instar and transferred to an artificial diet until reaching adult stage. Results showed that larvae feeding on B. bassiana strain PTG4-treated plants prolonged their larval stage. Furthermore, feeding on plants treated with B. bassiana strains yielded fewer S. frugiperda male moths compared with feeding with the untreated control plants. Under field conditions, 1 × 106 (first trial) and 1 × 108 (second trial) of B. bassiana (GHA strain) blastospores were used for corn seed inoculation. In the first field trial, there were a higher number of larvae in the negative control plants compared to those in the plants treated with B. bassiana. No larvae were found in negative control and B. bassiana-treated plants in the second field trial. In conclusion, seed treatment with B. bassiana in maize reduced S. frugiperda infestation of maize plants in field trials. S. frugiperda development was also affected in laboratory trials.

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Insecticide Seed Treatments Partially Safen Rice to Low Rates of Glyphosate and Imazethapyr

Weed Technology ◽

10.1017/wet.2018.67 ◽

2018 ◽

Vol 32 (5) ◽

pp. 520-525

Author(s):

Steven M. Martin ◽

Jason K. Norsworthy ◽

Robert C. Scott ◽

Jarrod Hardke ◽

Gus M. Lorenz ◽

...

Keyword(s):

Seed Treatment ◽

Field Experiments ◽

Rice Yield ◽

Leaf Growth ◽

Rice Cultivar ◽

Yield Potential ◽

Seed Treatments ◽

Herbicide Treatments ◽

Added Benefit ◽

Multiple Field

AbstractEach year there are multiple reports of drift occurrences, and the majority of drift complaints in rice are from imazethapyr or glyphosate. In 2014 and 2015, multiple field experiments were conducted near Stuttgart, AR, and near Lonoke, AR, to evaluate whether insecticide seed treatments would reduce injury from glyphosate or imazethapyr drift or decrease the recovery time following exposure to a low rate of these herbicides. Study I was referred to as the “seed treatment study,” and Study II was the “drift timing study.” In the seed treatment study the conventional rice cultivar ‘Roy J’ was planted, and herbicide treatments included imazethapyr at 10.5 g ai ha–1, glyphosate at 126 g ae ha–1, or no herbicide. Each plot had either a seed treatment of thiamethoxam, clothianidin, chlorantraniliprole, or no insecticide seed treatment. The herbicides were applied at the two- to three-leaf growth stage. Crop injury was assessed 1, 3, and 5 wk after application. Averaged over site-years, thiamethoxam-treated rice had less injury than rice with no insecticide seed treatment at each rating, along with an increased yield. Clothianidin-treated rice had an increased yield over no insecticide seed treatment, but the reduction in injury for both herbicides was less pronounced than in the thiamethoxam-treated plots. Overall, chlorantraniliprole was generally the least effective of the three insecticides in reducing injury from either herbicide and in protecting rice yield potential. A second experiment conducted at Stuttgart, AR, was meant to determine whether damage to rice from glyphosate and imazethapyr was influenced by the timing (15, 30, and 45 d after planting) of exposure to herbicides for thiamethoxam-treated and nontreated rice. There was an overall reduction in injury with the use of thiamethoxam, but the reduction in injury was not dependent on the timing of the drift event. Reduction in damage from physical drift of glyphosate and imazethapyr as well as increased yields over the absence of an insecticide seed treatment appear to be an added benefit.

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Effect of Zea Mays-Beauveria Bassiana Seed Treatment on Spodoptera Frugiperda

10.20944/preprints202101.0094.v1 ◽

2021 ◽

Author(s):

Laiju Kuzhuppillymyal-Prabhakarankutty ◽

Fernando H. Ferrara-Rivero ◽

Patricia Tamez-Guerra ◽

Ricardo Gomez-Flores ◽

María Cristina Rodríguez-Padilla ◽

...

Keyword(s):

Beauveria Bassiana ◽

Spodoptera Frugiperda ◽

Field Trial ◽

Seed Treatment ◽

Insect Pest ◽

Field Trials ◽

Negative Control ◽

Economic Losses ◽

Native Strain ◽

Symbiotic Associations

Spodoptera frugiperda is a widely distributed insect pest that causes major economic losses in various crops, particularly maize. On the other hand, Beauveria bassiana is an entomopathogenic fungus that establishes symbiotic associations with many plants and contributes to tolerance against biotic and abiotic stresses. In the present work, under field conditions, 1x106 (first trial) and 1x10⁸ (second trial) of B. bassiana (GHA strain) blastospores were used for corn’s seed inoculation. In the first field trial, a higher number of larvae were present in the negative control plants in comparison with those in B. bassiana-treated plants. No larvae were found in negative control and B. bassiana-treated plants in the second field trial. In further laboratory experiments, the effects of the B. bassiana strains GHA, in addition to a native strain (PTG4) also delivered via seed treatment in maize seedlings, on S. frugiperda growth, development, and mortality were evaluated. 1x10⁶ B. bassiana blastospores were used to inoculate maize seeds, which were germinated and grown to seedlings under growth chamber conditions. Third-instar S. frugiperda larvae were allowed to feed on B. bassiana-treated and -untreated (negative control) seedlings until reaching 6th instar and transferred to artificial diet until reaching adult stage. Results showed that larvae feeding on B. bassiana strain PTG4 prolonged their larval stage. Furthermore, feeding with plants treated with B. bassiana strains yielded fewer S. frugiperda male moths and the female moths emerged with altered wings, compared with the untreated control. In conclusion, seed treatment with B. bassiana in maize reduced S. frugiperda infestation of maize plants in field trials. Besides S. frugiperda development was affected in laboratory trials.

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Non-overwintering cover crops: a significant source of N

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v45i2.515 ◽

1997 ◽

Vol 45 (2) ◽

pp. 231-248 ◽

Cited By ~ 2

Author(s):

J.J. Schroder ◽

L. Ten Holte ◽

B.H. Janssen

Keyword(s):

Winter Wheat ◽

Cover Crops ◽

Green Manure ◽

Field Experiments ◽

Fertilizer N ◽

Green Manures ◽

Marketable Yield ◽

Green Manure Crop ◽

Plant Parts ◽

Green Manure Crops

In field experiments in 1982-89 at 2 sites in the Netherlands, potatoes cv. Bintje and sugarbeet cv. Monohil or Ovatio in a wheat/potatoes/wheat/sugarbeet rotation were preceded during winter by fallow or a green manure crop of Lolium multiflorum cv. Tetila with 0 (G0), 100 (G100) or 200 kg N/ha (G200) or Trifolium pratense cv. Rotra with no N (RC). Green manure crops were undersown to winter wheat cv. Durin and ploughed in in the first half of November. On average, G0, G100, G200 and RC had then accumulated 22, 93, 125 and 57 kg N/ha, respectively, in the above-ground plant parts. G0 crops tended to immobilize soil mineral N in spring and generally had non-significant effects on the yields of potatoes and sugarbeet, whereas G100, G200 and RC increased the N yields and marketable yields significantly. Effects were mainly attributable to the release of N by the green manures. The fertilizer value of the green manures was evaluated by their effect on economic optimum N rates, the marketable yield and the N yield when no mineral fertilizer N was supplied. The last two methods appeared to be most appropriate for the present experiments. Fertilizer values ranged from -21 to 108 kg N/ha, depending on the type of green manure crop and the calculation method. About half of the N accumulated in above-ground parts of the green manure crop was available to potatoes and sugarbeet from G100 when evaluated by its effect on N yields. From G200 this was even greater, although this may partly have resulted from the transfer of fertilizer N that had not been taken up by the green manure crop. Due to a high content of N in roots and stubble, RC provided, on average, almost double the amount of N accumulated in the above-ground plant parts. Green manure crops also had a minor positive effect on grain yields of winter wheat following potatoes and sugarbeet. At least 35% of the above-ground N in L. multiflorum green manure crops was not utilized within the first 18 months after their incorporation.

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MODELING AND EXPERIMENTAL VERIFICATION OF AIR-THERMAL AND MICROWAVE-CONVECTIVE PRESOWING SEED TREATMENT

Elektrotekhnologii i elektrooborudovanie v APK ◽

10.22314/2658-4859-2020-67-4-35-43 ◽

2020 ◽

Vol 4 (41) ◽

pp. 35-43

Author(s):

ALEKSEY A. VASIL’EV ◽

◽

ALEKSEY N. VASIL’EV ◽

DMITRIY BUDNIKOV ◽

ANTON SHARKO

Keyword(s):

High Frequency ◽

Seed Treatment ◽

Field Experiments ◽

Research Purpose ◽

Dense Layer ◽

Technological Equipment ◽

External Influence ◽

Ultra High Frequency ◽

Grain Processing ◽

Seed Processing

The use of electrophysical influences for pre-sowing treatment of seeds is an effective way to increase their sowing quality. The use of these methods is limited by the fact that their implementation requires new technological equipment in grain processing lines. This problem is solved more easily when pre-sowing processing is performed using installations for active ventilation and grain drying. (Research purpose) The research purpose is in determining the possibility of using active ventilation units and ultra-high-frequency convective grain dryers for pre-sowing grain processing and to evaluating the effectiveness of such processing using computer modeling. (Materials and methods) It is necessary to ensure the uniformity of processing with external influence the seeds placed in a dense layer. Authors carried out pre-sowing treatment of seeds on real installations. Treated seeds were sown in experimental plots and the results of treatment were evaluated. (Results and discussion) The article presents graphs of changes in grain temperature and humidity during processing. To check the feasibility of pre-sowing treatment, authors performed modeling of air-heat and ultra-high-frequency convective seed treatment processes. Based on the results of field experiments, air-heat treatment stimulates the development of secondary plant roots, contributes to an intensive increase in the green mass of plants; ultra-high-frequency convective seed treatment allows increasing the number of productive stems in plants, the number of ears in one plant. (Conclusions) Technological equipment designed for drying and active ventilation of grain can be effectively used for pre-sowing seed processing. In the course of field experiments, it was revealed the possibility of controlling the structure of the crop using different types of external influence on seeds during their pre-sowing processing.

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Separate and combined Hanseniaspora uvarum and Metschnikowia pulcherrima metabolic volatiles are attractive to Drosophila suzukii in the laboratory and field

Scientific Reports ◽

10.1038/s41598-020-79691-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

R. Jones ◽

M. T. Fountain ◽

C. S. Günther ◽

P. E. Eady ◽

M. R. Goddard

Keyword(s):

Yeast Species ◽

Field Trapping ◽

Field Trials ◽

Economic Losses ◽

Drosophila Suzukii ◽

Control Efficacy ◽

Hanseniaspora Uvarum ◽

Metschnikowia Pulcherrima ◽

Rich Diversity ◽

Relative Attractiveness

AbstractDrosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by individual fruit associated yeast isolates, but fruits naturally harbour a rich diversity of yeast species. Here, we report the relative attractiveness of D. suzukii to yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four of 12 single yeast isolates were attractive to D. suzukii, of which Metschnikowia pulcherrima and Hanseniaspora uvarum were also attractive in field trials. Four out of 10 yeast combinations involving Candida zemplinina, Pichia pijperi, M. pulcherrima and H. uvarum were attractive in the laboratory. Whilst a combination of M. pulcherrima + H. uvarum trapped the greatest number of D. suzukii in the field, the efficacy of the M. pulcherrima + H. uvarum combination to trap D. suzukii was not significantly greater than traps primed with volatiles from only H. uvarum. While volatiles from isolates of M. pulcherrima and H. uvarum show promise as baits for D. suzukii, further research is needed to ascertain how and why flies are attracted to certain baits to optimise control efficacy.

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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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Short term fallow and partitioning effects of green manures on wheat systems in East African highlands

Field Crops Research ◽

10.1016/j.fcr.2021.108175 ◽

2021 ◽

Vol 269 ◽

pp. 108175

Author(s):

Tilahun Amede ◽

Gizachew Legesse ◽

Getachew Agegnehu ◽

Tadesse Gashaw ◽

Tulu Degefu ◽

...

Keyword(s):

Green Manures ◽

East African ◽

Short Term ◽

African Highlands ◽

East African Highlands

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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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