Multitactic Preplant Soil Fumigation with Allyl Isothiocyanate in Cut Flowers and Strawberry

Allyl isothiocyanate (AITC) is a glucosinolate produced in cruciferous plant species. AITC is known to act as a pesticide on microorganisms, insects, and weeds. Synthetic AITC is registered as a biopesticide for agricultural soil treatment use in the United States and elsewhere in the world. Although a potent pesticide, reports on the weed and pathogen control efficacy of synthetic AITC applied as soil disinfectant are highly variable. Due to the low vapor pressure of AITC, questions remain as to whether pest and weed control efficacy can be improved by combining it with other chemicals. The objective of this study was to assess the control efficacy of AITC stand-alone applications vs. applications, in which AITC was combined with the standard-fumigants chloropicrin, 1,3-dichloropicrin, and methyl isothiocyanate. Two shank-applied on-farm field trials were conducted in cut flower [delphinium (Delphinium elatum), ranunculus (Ranunculus asiaticus)] fields, and two drip tape applied field trials in strawberry (Fragaria ×ananassa) fields in California. Weed pressure, weed seed viability, nematode survival, and pathogen survival of Pythium ultimum, fusarium wilt (Fusarium oxysporum), and verticillium wilt (Verticillium dahliae) were assessed. Cumulative yearly yield of marketable fruit was assessed in the strawberry field trials. The results of this study show that the use of AITC as a stand-alone treatment provided no consistent weed or pathogen control efficacy. However, our results also indicate that shank and drip applied multitactic fumigation approaches with AITC can efficiently control soil-borne diseases and weeds. These findings have potential implications, especially in those areas where certain fumigants are restricted due to regulations and/or availability.

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(244) Interspecificic Hybridization of a White-flowered, Cold-hardy Alstroemeria

HortScience ◽

10.21273/hortsci.40.4.1003e ◽

2005 ◽

Vol 40 (4) ◽

pp. 1003E-1004

Author(s):

Elizabeth L. Kollman ◽

Mark P. Bridgen

Keyword(s):

United States ◽

Embryo Rescue ◽

Morphological Characteristics ◽

The United States ◽

Field Trials ◽

Ms Medium ◽

Cut Flowers ◽

Hand Pollination ◽

Cold Hardy

Alstroemeria, the Inca Lily or Lily-of-the-Incas, is becoming a popular garden plant in the United States. In past years, the primary interest in Alstroemeria has been for its cut flowers. However, recent cold-hardy introductions (USDA hardiness zone 5) have expanded the interest of this colorful plant as a garden perennial throughout the United States. Previously, garden interests were restricted to warmer zones in the southern United States where Alstroemeria could overwinter. This research describes a breeding procedure that has been used with the objective to develop a cold-hardy, white-flowered Alstroemeria. The interspecific hybrids were bred with the use of in ovulo embryo rescue. Reciprocal crosses were made between several white-flowered cultivars and the cold-hardy Chilean species Alstroemeriaaurea during Summer 2004. Ovaries were collected 10–23 days after hand pollination and their ovules were aseptically excised. Ovules were placed in vitro on 25% Murashige and Skoog (MS) medium under dark conditions until germination. Three weeks after germination, they were then placed on 100% MS medium, and subcultured every 3–4 weeks thereafter until they were large enough for rooting. After rooting and acclimation, plants were transferred to the greenhouse. Successful hybrids that were produced in 2004 were evaluated under greenhouse and field trials during 2005, and the number of plants with white-colored flowers was noted. Although certain morphological characteristics indicate if plants are coldhardy, the hybrids will be overwintered outside in Ithaca, N.Y. (USDA zone 5), during the next several years to determine winter hardiness.

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Allyl Isothiocyanate: A Methyl Bromide Replacement in Polyethylene-Mulched Bell Pepper

Weed Technology ◽

10.1614/wt-d-10-00076.1 ◽

2011 ◽

Vol 25 (1) ◽

pp. 90-96 ◽

Cited By ~ 13

Author(s):

Sanjeev K. Bangarwa ◽

Jason K. Norsworthy ◽

Edward E. Gbur ◽

Jingying Zhang ◽

Tsehaye Habtom

Keyword(s):

Weed Control ◽

Methyl Bromide ◽

Standard Treatment ◽

Allyl Isothiocyanate ◽

Field Trials ◽

Bell Pepper ◽

Marketable Yield ◽

Control Efficacy ◽

Yellow Nutsedge ◽

Potential Alternative

Methyl bromide has been a key fumigant for broad-spectrum weed control in polyethylene-mulched bell pepper. However, the ozone-depleting nature of methyl bromide has led to its scheduled phaseout from U.S. agriculture. Thus, an effective alternative to methyl bromide is needed. Field trials were conducted in 2007 and 2009 to evaluate the crop response and weed control efficacy of allyl isothiocyanate (ITC) in polyethylene-mulched bell pepper. The experiment included various combinations of two mulch types (low density polyethylene [LDPE] and virtually impermeable film [VIF] mulch) and six rates of allyl isothiocyanate (0, 15, 75, 150, 750, 1,500 kg ha−1). Additionally, a standard treatment of methyl bromide/chloropicrin (67 : 33%) at 390 kg ha−1 under LDPE mulch was included for comparison. Bell pepper injury was < 3% in all treatments, except 11% injury at 1,500 kg ha−1 allyl isothiocyanate under VIF mulch at 2 wk after transplanting (WATP). VIF mulch did not provide additional weed control and marketable pepper yield over LDPE mulch. Allyl isothiocyanate at 932 (± 127) kg ha−1 controlled yellow nutsedge (90%), Palmer amaranth (97%), and large crabgrass (92%) through 6 WATP and maintained the marketable yield equivalent to methyl bromide treatment. This research demonstrates that allyl ITC under an LDPE mulch can serve as a potential alternative to methyl bromide for weed control in polyethylene-mulched bell pepper.

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Inhibition of Fungal Growth by Macerated Plant Tissues in a Closed Environment

HortScience ◽

10.21273/hortsci.33.3.476e ◽

1998 ◽

Vol 33 (3) ◽

pp. 476e-476

Author(s):

Craig S. Charron ◽

Catherine O. Chardonnet ◽

Carl E. Sams

Keyword(s):

Radial Growth ◽

Fungal Pathogens ◽

Solid Phase ◽

Indian Mustard ◽

Fungal Growth ◽

Allyl Isothiocyanate ◽

Pythium Ultimum ◽

Alternative Methods ◽

Gas Chromatography Mass Spectrometry ◽

Clean Air

The U.S. Clean Air Act bans the use of methyl bromide after 2001. Consequently, the development of alternative methods for control of soilborne pathogens is imperative. One alternative is to exploit the pesticidal properties of macerated tissues of Brassica spp. This study tested the potential of several Brassica spp. for control of fungal pathogens. Pythium ultimum Trow or Rhizoctonia solani Kühn plugs on potato-dextrose agar on petri dishes were sealed in 500-ml glass jars (at 22 °C) containing macerated leaves (10 g) from one of six Brassica spp. Radial growth was measured 24, 48, and 72 h after inoculation. Indian mustard (B. juncea) was the most suppressive, followed by `Florida Broadleaf' mustard (B. juncea). Volatile compounds in the jars were sampled with a solid-phase microextraction device (SPME) and identified by gas chromatography-mass spectrometry (GC-MS). Allyl isothiocyanate (AITC) comprised over 90% of the total volatiles measured from Indian mustard and `Florida Broadleaf' mustard. Isothiocyanates were detected in jars with all plants except broccoli. (Z)-3-hexenyl acetate was emitted by all plants and was the predominant volatile of `Premium Crop' broccoli (B. oleracea L. var. italica), `Michihili Jade Pagoda' Chinese cabbage (B. pekinensis), `Charmant' cabbage (B. oleracea L. var. capitata), and `Blue Scotch Curled' kale (B. oleracea L. var. viridis). To assess the influence of AITC on radial growth of P. ultimum and R. solani, AITC was added to jars to give headspace concentrations of 0.10, 0.20, and 0.30 mg·L–1 (mass of AITC per volume of headspace). Growth of both fungi was inhibited by 0.10 mg·L–1 AITC. 0.20 mg·L–1 AITC was fungicidal to P. ultimum although the highest AITC level tested (0.30 mg·L–1) did not terminate R. solani growth. These results indicate that residues from some Brassica spp. may be a viable part of a soilborne pest control strategy.

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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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Efficacy of five herbicide treatments for control of Pyrus calleryana

Invasive Plant Science and Management ◽

10.1017/inp.2020.36 ◽

2020 ◽

pp. 1-6

Author(s):

James T. Vogt ◽

David R. Coyle ◽

David Jenkins ◽

Chris Barnes ◽

Christopher Crowe ◽

...

Keyword(s):

Loblolly Pine ◽

Foliar Application ◽

The United States ◽

Invasive Pest ◽

Active Ingredients ◽

Old Field ◽

Control Efficacy ◽

Pyrus Calleryana ◽

Callery Pear ◽

Cut Stump

Abstract Callery pear (Pyrus calleryana Decne.) is rapidly spreading in the United States, gaining attention in the last two decades as a serious invasive pest. Recommended control methods include foliar, basal bark, cut stump, and hack-and-squirt application of herbicides, but there are few published studies with replicated data on efficacy. Four readily available herbicidal active ingredients and a combination of two active ingredients were tested for control efficacy against P. calleryana in old-field areas and loblolly pine (Pinus taeda L.) understory. Basal bark applications (triclopyr, triclopyr + aminopyralid), foliar applications (glyphosate, imazapyr), and a soil application (hexazinone) effectively killed P. calleryana with the exception of hexazinone at one site, where rainfall may not have been optimal. Foliar application of glyphosate provided the most consistent control. Our results demonstrate efficacy of registered herbicide formulations for P. calleryana control in two geographic locations and two habitat types. The need for development of integrated pest management programs for P. calleryana is discussed.

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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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Evaluating the Sensitivity and Efficacy of Fungicides with Different Modes of Action Against Botryosphaeria dothidea

Plant Disease ◽

10.1094/pdis-01-18-0118-re ◽

2018 ◽

Vol 102 (9) ◽

pp. 1785-1793 ◽

Cited By ~ 2

Author(s):

Yingying Song ◽

Lili Li ◽

Chao Li ◽

Zengbin Lu ◽

Xingyuan Men ◽

...

Keyword(s):

Field Trials ◽

Apple Fruit ◽

Effective Concentration ◽

Botryosphaeria Dothidea ◽

Control Efficacy ◽

Frequency Distributions ◽

Considerable Potential ◽

Ring Rot ◽

Fungal Plant Pathogen ◽

The Mean

Botryosphaeria dothidea, the causal agent of apple ring rot, is an important fungal plant pathogen that can cause serious reductions in crop yield, and fungicides still play a crucial role in management. In the present study, the sensitivity of B. dothidea to fludioxonil, fluazinam, and pyrisoxazole was assessed in 162 isolates. Moreover, the protective and curative activity of the three fungicides on detached apple fruit as well as the control efficacy in the field were determined. The results showed that the mean 50% effective concentration (EC50) values (± standard deviation) were 0.01 ± 0.008, 0.04 ± 0.03, and 0.02 ± 0.01 μg ml−1, with individual EC50 values of 0.002 to 0.05, 0.003 to 0.19, and 0.005 to 0.26 μg ml−1 for fludioxonil, fluazinam, and pyrisoxazole, respectively. In addition, the frequency distributions of EC50 values were both unimodal curves. However, significant correlations (P < 0.05) were found between fludioxonil and iprodione, between fluazinam and iprodione, as well as between pyrisoxazole and difenoconazole. In field trials conducted during 2016 and 2017, the control efficacy ranged from 75.91 to 87.41% when fludioxonil was applied at 100 to 150 mg active ingredient (a.i.) kg−1, 81.90 to 85.13% when fluazinam was applied at 400 mg a.i. kg−1, and 77.43 to 80.97% when pyrisoxazole was applied at 400 mg a.i. kg−1. The control efficacy of the fungicides in storage was higher than 60%, with the exception of fluazinam. These results demonstrated that fludioxonil, fluazinam, and pyrisoxazole have considerable potential to control apple ring rot.

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Comparison of the Effect of Insecticides on Bumble Bees (Bombus impatiens) and Mosquitoes (Aedes aegypti and Culex quinquefasciatus) by Standard Mosquito Research Methods

Journal of Economic Entomology ◽

10.1093/jee/toaa282 ◽

2020 ◽

Author(s):

Bethany L McGregor ◽

Bryan V Giordano ◽

Alfred E Runkel ◽

Herbert N Nigg ◽

H Lee Nigg ◽

...

Keyword(s):

Aedes Aegypti ◽

Culex Quinquefasciatus ◽

Mosquito Control ◽

The United States ◽

Field Trials ◽

Bombus Impatiens ◽

Acute Effects ◽

Nontarget Effects ◽

Native North American ◽

Significant Mortality

Abstract Mosquito control districts in the United States are limited to two main classes of adulticides, pyrethroids and organophosphates, to control mosquitoes. Two adulticides used to control domestic mosquitoes are Fyfanon EW (malathion, organophosphate) and DeltaGard (deltamethrin, pyrethroid). While the effect of these pesticides on European honeybees (Apis mellifera L., Hymenoptera: Apidae) has been investigated, effects on native pollinators need additional research. The purpose of this study was to investigate the acute nontarget effects of these pesticides on Bombus impatiens Cresson (Hymenoptera: Apidae), a native North American bumble bee species, and compare these effects to wild and laboratory strains of mosquitoes (Aedes aegypti (L.) and Culex quinquefasciatus Say, Diptera: Culicidae) through field and laboratory assays. Bombus impatiens was found to be resistant to Fyfanon EW (x̅ = 6.7% mortality at 50-µg malathion per bottle) at levels that caused significant mortality to study mosquitoes (86.2 ≥ x̅ ≥ 100% mortality) in laboratory bottle bioassays. Comparatively, B. impatiens demonstrated greater mortality to DeltaGard (93.3%) at 2.5-µg deltamethrin/bottle than any mosquito colony assayed (14.1 ≥ x̅ ≥ 87.0% mortality). Only DeltaGard was tested in field applications. In the field, we observed acute effects of DeltaGard on mosquitoes and B. impatiens at 25- and 75-m distance from a truck-mounted ultra-low volume fogger, although treatment effects were not significant for B. impatiens. Additional wild-caught nontarget mortality to DeltaGard field trials was also evaluated. This study indicated that common mosquito control adulticides do cause nontarget mortality to B. impatiens but that impacts are variable depending on pesticide and further studies are needed.

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Activity of A Novel Succinate Dehydrogenase Inhibitor Fungicide Pydiflumetofen against Fusarium fujikuroi causing Rice Bakanae Disease

Plant Disease ◽

10.1094/pdis-10-20-2274-re ◽

2021 ◽

Author(s):

Yang Bai ◽

Chun-Yan Gu ◽

Rui Pan ◽

Muhammad Abid ◽

Hao-Yu Zang ◽

...

Keyword(s):

Cell Membrane ◽

Succinate Dehydrogenase ◽

Field Trials ◽

Cell Membrane Permeability ◽

Cross Resistance ◽

Fusarium Fujikuroi ◽

Control Efficacy ◽

Bakanae Disease ◽

Geographical Regions ◽

Succinate Dehydrogenase Inhibitor

New fungicides are tools to manage fungal diseases and overcome emerging resistance in fugnal pathogens. In this study, a total of 121 isolates of Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), were collected from various geographical regions of China, and their sensitivity to a novel succinate dehydrogenase inhibitor (SDHI)fungicide ‘pydiflumetofen’ was evaluated. The 50% effective concentration (EC50) value of pydiﬂumetofen for mycelial growth suppression ranged from 0.0101 to 0.1012 μg/ml and for conidial germination inhibition ranged from 0.0051to 0.1082 μg/ml. Pydiﬂumetofen treated hyphae showed contortion and increased branching, cell membrane permeability, and glycerol content significantly. The result of electron microscope transmission indicated that pydiﬂumetofen damaged the mycelial cell wall and the cell membrane, and almost broken up the cells, which increased the intracellular plasma leakage. There was no cross-resistance between pydiflumetofen and the widely used fungicides such as carbendazim, prochloraz, and phenamacril. Pydiflumetofen was found safe to seeds and rice seedlings of four rice cultivars, used up to 400 μg/ml. Seed treatment significantly decreased the rate of diseased plants in the greenhouse as well as in field trials in 2017 and 2018. Pydiflumetofen showed superb results against RBD, when used at 10 or 20 g a.i./100 kg of treated seeds, providing over 90% control efficacy (the highest control efficacy was up to 97%), which was significantly higher than that of 25% phenamacril (SC) at 10g or carbendazim at 100 g. Pydiflumetofen is highly effective against F. fujikuroi growth and sporulation as well as RBD in the field.

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Biological activity of Pyraclostrobin against Coniella granati causing pomegranate crown rot

Plant Disease ◽

10.1094/pdis-01-21-0144-re ◽

2021 ◽

Author(s):

Xue Yang ◽

Chun-Yan Gu ◽

Yang Bai ◽

Jia-Zhi Sun ◽

Hao-Yu Zang ◽

...

Keyword(s):

Biological Activity ◽

Mycelial Growth ◽

Field Trials ◽

Crown Rot ◽

Germination Inhibition ◽

Control Efficacy ◽

Intracellular Organelle ◽

Transmission Electron ◽

Excellent Control ◽

Conidium Germination

Pomegranate crown rot caused by Coniellagranati is one of the most severe diseases of pomegranate. To date, no fungicides have been registered for controlling this disease in China. Pyraclostrobin, belonging to strobilurin fungicides, has a broad spectrum of activity against many phytopathogens. In this study, based on the mycelial growth and conidial germination inhibition methods, we investigated the biological activity of pyraclostrobin against C. granati at the presence of 50 μg/mL SHAM using 80 isolates collected from different orchards in China during 2012-2018. The EC50 (50% effective concentration) values ranged from 0.040-0.613 μg/mL for mycelial growth and 0.013-0.110 μg/mL for conidium germination, respectively. Treated with pyraclostrobin, the hyphae morphology changed and conidial production of C. granati decreased significantly. The result of transmission electron microscope showed that treatment of pyraclostrobin could make the cell wall thinner, and lead to ruptured cell membrane and formation of intracellular organelle autophagosomes. The pyraclostrobin showed good protective and curative activities against C. granati on detached pomegranate fruits. In field trials, pyraclostrobin showed excellent control efficacy against this disease in which the treatment of 25% pyraclostrobin EC 1000× provided 92.25% and 92.58% control efficacy in 2019 and 2020, respectively, significantly higher than that of other treatments. Therefore, pyraclostrobin could be a candidate fungicide for the control of pomegranate crown rot.

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