Diversity for resistance to a moderately virulent bluegreen aphid (Acyrthosiphon kondoi Shinji) population in Trifolium species

The resistance of a diverse range of Trifolium species (clovers) to a highly virulent bluegreen aphid (BGA, Acyrthosiphon kondoi Shinji) population (Urrbrae 2011) collected in South Australia was assessed in greenhouse and field experiments, with the aims of determining the potential impact of this insect pest on biomass and identifying resistant genotypes for future plant-breeding activities. Resistance to BGA was found in populations of clovers that show some level of outcrossing—white clover (T. repens L.), rose clover (T. hirtum All.), crimson clover (T. incarnatum L.) and red clover (T. pratense L.)—and in one entry of the inbreeding subspecies of subterranean clover, T. subterraneum L. subsp. subterraneum (Katzn. and Morley). Resistance was not found in T. s. brachycalycinum (Katzn. and Morley) or T. s. yanninicum (Katzn. and Morley). In a greenhouse experiment, damage from BGA resulted in forage yield penalties of 72–100% when aphids were inoculated at 14 days after sowing and 13−74% when inoculated at 42 days after sowing, showing that in optimum conditions BGA can be a serious pest of clovers. Observations of severe damage caused by BGA in two regenerating field trials in southern New South Wales confirmed that field damage could occur in seasons favourable to aphid growth and reproduction. The severe damage that BGA can cause to clovers, and the sources of resistance we found, suggest that breeding for BGA resistance in clovers is warranted and feasible.

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Effect of glyphosate on the establishment, growth and nodulation of 14 pasture legume cultivars

Australian Journal of Experimental Agriculture ◽

10.1071/ea9850347 ◽

1985 ◽

Vol 25 (2) ◽

pp. 347 ◽

Cited By ~ 2

Author(s):

WM Blowes ◽

KJ Schmalzl ◽

SM Jones

Keyword(s):

Adverse Effect ◽

Adverse Effects ◽

South Australia ◽

Subterranean Clover ◽

Field Trials ◽

High Rate ◽

Rapid Absorption ◽

Seed Placement ◽

Pasture Legume ◽

Topsoil Layer

In field trials carried our in 1983 at Gama and Horsham (Victoria), Hart (South Australia) and York (Western Australia), the effect of two rates of glyphosate (0.54 and 1.08 kg/ha active ingredient), applied 1-8 days before sowing, on the establishment, growth and nodulation of four cultivars of subterranean clover and 10 medic cultivars was investigated. No significant adverse effects were observed on establishment, growth or nodulation even at the high rate (2x field rate) of glyphosate. The absence of any adverse effect was attributed to rapid absorption and inactivation of glyphosate in soil and possibly also the manner of seed placement below the glyphosate-treated topsoil layer.

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Tarnished Plant Bug (Hemiptera: Miridae) on Selected Cool-Season Leguminous Cover Crops

Journal of Entomological Science ◽

10.18474/0749-8004-25.3.463 ◽

1990 ◽

Vol 25 (3) ◽

pp. 463-474 ◽

Cited By ~ 13

Author(s):

Robert L. Bugg ◽

Felix L. Wäckers ◽

Kathryn E Brunson ◽

Sharad C. Phatak ◽

James D. Dutcher

Keyword(s):

Cover Crops ◽

Subterranean Clover ◽

Trifolium Subterraneum ◽

Field Trials ◽

Lygus Lineolaris ◽

Cool Season ◽

Tarnished Plant Bug ◽

Trifolium Incarnatum ◽

Crimson Clover ◽

Late Instar

Replicated field trials indicated that tarnished plant bug (TPB), Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) attained relatively-high densities on hybrid vetches, Vicia sativa L. X V. cordata Wulf cv ‘Cahaba White’ and ‘Vantage’, lower densities on crimson clover, Trifolium incarnatum L. cv ‘Dixie,’ and particularly-low densities on subterranean clover, Trifolium subterraneum L. cv ‘Mt. Barker’. Densities of TPB were also relatively low on an additional 10 types of subterranean clover, including 7 cultivars representing T. subterraneum, 1 cultivar of T. brachycalycinum Katznelson and Morley, and 3 of T. yanninicum Katznelson and Morley. Field longevity trials indicated that late-instar and adult TPB lived longer when caged on crimson clover than on hybrid vetch, which in turn supported better survival than did subterranean clover. When adult TPB were caged on hybrid vetch or subterranean clover with or without floral and fruiting structures, there was no evidence that the presence of these structures prolonged TPB survival on either crop. In laboratory choice tests with flowering and fruiting shoots of three cover crops, TPB preferred crimson clover over hybrid vetch, which in turn was more attractive than subterranean clover. When shoots were presented after reproductive structures had been excised, there was no statistically-significant preference by TPB.

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Regression Analyses for Evaluating the Influence of Bacillus cereus on Alfalfa Yield Under Variable Disease Intensity

Phytopathology ◽

10.1094/phyto.2000.90.6.657 ◽

2000 ◽

Vol 90 (6) ◽

pp. 657-665 ◽

Cited By ~ 12

Author(s):

Elizabeth R. Kazmar ◽

Robert M. Goodman ◽

Craig R. Grau ◽

David W. Johnson ◽

Erik V. Nordheim ◽

...

Keyword(s):

Bacillus Cereus ◽

Untreated Control ◽

Field Experiments ◽

Seedling Emergence ◽

Field Trials ◽

Forage Yield ◽

Regression Methods ◽

Control Response ◽

Treated Seed ◽

Yield Gain

We developed and tested regression methods to exploit the variability in disease inherent in field experiments, and applied the methods to evaluate strains of Bacillus cereus for biocontrol efficacy. Four B. cereus strains were tested for their effect on alfalfa (Medicago sativa) performance in 16 field trials planted during 1993 to 1996 at multiple sites in Wisconsin. To evaluate performance of the strains, we used the ratio of (metalaxyl response)/(untreated control response) as a measure of disease intensity within the experiments. The ratio of (Bacillus response)/(untreated control response) was then regressed as a function of disease intensity. The slope of the resulting line provides a statistical test to compare performance of the Bacillus strain with that of the untreated seed (Ho: slope = 0) and metalaxyl controls (Ho: slope = 1). Under conditions in which disease occurred, forage yield of plots planted with seed treated with B. cereus strain AS4–12 exceeded yield from the untreated control plots (P = 0.002) and was similar to yield of plots planted with metalaxyl-treated seed (P = 0.14). Yield gain associated with AS4–12 and metalaxyl seed treatment averaged 6.1 ± 2.8% (±standard error) and 3.0 ± 2.8%, respectively. In contrast to the regression approach, means analysis by analysis of variance did not detect differences among treatments. Three other B. cereus strains either did not increase alfalfa yield or increased yield less than did AS4–12. Metalaxyl and three of the Bacillus strains increased seedling emergence, but the improved stands were not predictive of increased forage yield. In six additional studies conducted for one season in 1997, AS4–12 enhanced yield of two cultivars at diverse locations in Wisconsin, but there was an apparent cultivar-location interaction. A strong correlation between response to AS4–12 and metalaxyl treatment suggests that these treatments controlled similar pathogens, most likely the oomycete pathogens Phytophthora medicaginis and Pythium spp.

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WINTER COVER CROPS IN LOW-INPUT VEGETABLE PRODUCTION

HortScience ◽

10.21273/hortsci.25.9.1158a ◽

1990 ◽

Vol 25 (9) ◽

pp. 1158a-1158

Author(s):

Kathryn E. Brunson ◽

Sharad C. Phatak

Keyword(s):

Cover Crops ◽

Subterranean Clover ◽

Field Trials ◽

Vegetable Production ◽

Marketable Yield ◽

Crimson Clover ◽

Yield And Quality ◽

Winter Cover Crops ◽

And Control

Cantaloupe (Cucumis melo L., cv. Hiline) were planted following over-wintering cover crops. In replicated field trials, stand development for 7 different cover crops and their effects on incidence of weeds, insects, diseases, and nematodes was assessed. Effects of cover crops on yield and quality of cantaloupe were evaluated. Cover crops evaluated were rye, crimson clover, lentils, subterranean clover, `Vantage' vetch, mustard, a polyculture of all cover crops and control-fallow. No insecticides were applied and only two applications of fungicides were made. Fertilizer applications were significantly reduced. No differences among cover crops for any of pest nematodes were observed. Significant differences in populations of beneficial and pest insects were observed. Polyculture had the highest plant vigor rating. The highest marketable yield occurred following crimson clover.

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High levels of diversity for seed and forage production exist in Cullen australasicum, a potential new perennial forage legume for dry environments in southern Australia

The Rangeland Journal ◽

10.1071/rj13055 ◽

2014 ◽

Vol 36 (1) ◽

pp. 41 ◽

Cited By ~ 4

Author(s):

Alan W. Humphries ◽

Stephen J. Hughes ◽

Ramakrishnan M. Nair ◽

Eric Kobelt ◽

Graeme Sandral

Keyword(s):

Seed Production ◽

Seed Yield ◽

Alfalfa Mosaic Virus ◽

South Australia ◽

Dry Weight ◽

Field Trials ◽

Forage Yield ◽

Production Traits ◽

Forage Legume ◽

Forage Production

The seed and forage production of a diverse group of the perennial forage legume Cullen spp., collected in southern Australia, was assessed with the aim of discovering diversity for exploitation in future breeding programs. Eighty ecotypes were assessed at the Waite Institute in South Australia, using replicated, spaced-plant field trials, between 2008 and 2012. Seed production in collected ecotypes of Cullen (Expt 1) ranged from 0 to 485 kg ha–1 for windrowed seed yield and from 0 to 790 kg ha–1 for total seed yield, which included vacuum-harvested seed from pods that had fallen to the ground. Individual plants were selected for seed production from their original populations, and the seed and fodder production of their progeny was evaluated in a further field experiment (Expt 2). Moderate to high heritability estimates were recorded for seed production traits. Seed production in progeny families ranged from 0 to1 423 kg ha–1 and was highly correlated with the number of seeds per inflorescence (r = 0.85) and forage yield (r = 0.59). Edible biomass, measured using the Adelaide visual appraisal method, ranged from 50 to 906 g dry weight (DW) plant–1 in parent ecotypes and from 404 to 1248 g DW plant–1 in the selected family progenies. Disease infection with anthracnose (Colletotrichum trifolii) caused considerable damage to plants in Expt 1, resulting in the death of all plants of 10 ecotypes, and infection with Alfalfa mosaic virus in Expt 2 was linked to the death of 67 individuals. The results are discussed in relation to breeding C. australasicum for increased seed yield and disease resistance to overcome these deficiencies as barriers to commercial adoption.

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

AgriEngineering ◽

10.3390/agriengineering3020025 ◽

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.

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

Australian Journal of Experimental Agriculture ◽

10.1071/ea9860745 ◽

1986 ◽

Vol 26 (6) ◽

pp. 745 ◽

Cited By ~ 10

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.

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