scholarly journals Occurrence of Dactylaria higginsii on Purple Nutsedge in Florida

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 588-588 ◽  
Author(s):  
J. B. Kadir ◽  
R. Charudattan
Keyword(s):  
Biological Control Agent ◽  
Severe Disease ◽  
First Record ◽  
The United States ◽  
Control Agent ◽  
Cyperus Rotundus ◽  
Commonwealth Mycological Institute ◽  
Purple Nutsedge ◽  
Small Water ◽  
Yellow Nutsedge

In September 1994, a population of severely diseased purple nutsedge (Cyperus rotundus L.) was found in Gainesville, FL. The symptoms were characterized by necrotic leaf spots, blotches, and foliar blighting. A fungal isolate was consistently recovered from symptomatic leaves and grown in pure culture. Based on the characteristics of conidia (28.6 × 6.6 μm) and conidiophores (45.2 × 7.0 μm at the broadest base), the fungus was identified as Dactylaria higginsii (Luttrell) M.B. Ellis. This fungus was first described as Piricularia [sic] higginsii from Georgia (4) and later redescribed as D. higginsii (2). A Pyricularia sp. and P. grisea (Cooke) Sacc. have been recorded on C. alternifolius L., C. papyrus L., and other Cyperus spp. from Florida, but species of Pyricularia or Dactylaria have not been reported from this state on purple nutsedge (1). Proof of pathogenicity (Koch's postulates) was established in repeated trials in a greenhouse; the disease symptoms were reproduced, and the fungus was reisolated from inoculated plants and confirmed to be the same organism used for inoculations. Four- to six-leaf-stage purple nutsedge and yellow nutsedge (C. esculentus L.) plants were sprayed with a suspension of 1 × 106 conidia per ml amended with 0.02% Silwet L-77 (vol/vol). Control plants were sprayed with 0.02% Silwet L-77 only. Small, water-soaked lesions developed 4 days after inoculation. The lesions coalesced into larger necrotic blotches with grayish centers 8 days after inoculation. Most of the inoculated foliage was blighted within 15 days after inoculation. The disease did not kill nutsedge bulbs or tubers, but reduced shoot and tuber yields. None of the control plants developed any symptoms. The ability of D. higginsii to cause severe disease and reduce the yields of vegetative organs indicates that it has potential as a biological control agent for purple nutsedge and yellow nutsedge, two of the world's worst weeds. This is the first record of occurrence of D. higginsii outside of its original distribution in Georgia (3). References: (1) S. A. Alfieri, Jr., et al. 1994. Diseases and Disorders of Plants in Florida. Bull. No. 14. Division of Plant Industry, Gainesville, FL. (2) M. B. Ellis. 1976. More Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, Surrey, England. (3) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN. (4) E. S. Luttrell. Mycologia 46:810, 1954.

Description of Purple and Yellow Nutsedge (Cyperus rotundusandC. esculentus)

1987 ◽  
Vol 1 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Gene D. Wills
Keyword(s):  
United States ◽  
North Carolina ◽  
Southern California ◽  
The United States ◽  
Southern Region ◽  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
The World

Both purple nutsedge (Cyperus rotundusL. # CYPRO) and yellow nutsedge (C. esculentusL. # CYPES) are problem weeds in crops in many parts of the world. Yellow nutsedge is found in all U.S. states. Purple nutsedge is confined to the southern region of the United States, ranging from North Carolina across southern Arkansas and into southern California.

Worldwide Distribution of Purple and Yellow Nutsedge (Cyperus rotundusandC. esculentus)

1987 ◽  
Vol 1 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Leo E. Bendixen ◽  
U. B. Nandihalli
Keyword(s):  
United States ◽  
The United States ◽  
Cyperus Rotundus ◽  
Weed Competition ◽  
Cyperus Esculentus ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Worldwide Distribution ◽  
The Family

The family Cyperaceae includes approximately 3000 species, of which about 220 species are identified as weeds (Table 1). Nearly 42% of these weeds are in the genusCyperus. An additional 43% are in three other genera,Eleocharis,Scirpus, andFimbristylis. The remaining 15% are found in six other genera,Scleria,Kyllinga,Rhynchospora,Bulbostylis,Fuira, andDichromena. Purple nutsedge (Cyperus rotundusL. # CYPRO) was identified as the world's worst weed based on the number of countries where it was reported as a serious, principal, or common weed. Competition with crops was the major factor in determining weediness. From the same report, yellow nutsedge (Cyperus esculentusL. # CYPES) ranked sixteenth. This contrasts with relative rankings of these two species in the United States where yellow nutsedge is more widespread than purple nutsedge.

Interactions betweenBactra verutanaand the Development of Purple Nutsedge(Cyperus rotundus)Grown Under Three Temperature Regimes

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 550-553 ◽  
Author(s):  
K. E. Frick ◽  
R. D. Williams ◽  
R. F. Wilson
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Dry Matter ◽  
Biological Control Agent ◽  
Natural Populations ◽  
Control Agent ◽  
Cyperus Rotundus ◽  
Larval Feeding ◽  
Purple Nutsedge ◽  
Temperature Regimes

For effective biological control through augmentation,Bactra verutanaZeller, would have to be released against purple nutsedge(Cyperus rotundusL.) in May and June when temperatures are cooler than they are from late July through September when maximal natural populations of this biological control agent occur.Bactralarvae exposed to simulated mid-May (24/13 C) and mid-June (29/18 C) temperature regimes developed more slowly than larvae exposed to the mid-July (32/26 C) temperature regime, but nutsedge plant growth was also slower. Thus, the relative amounts of feeding injury were similar at all three regimes. Larval feeding generally increased the number of shoots slightly, but not significantly, reduced significantly the production of inflorescences, and reduced the weight of total dry matter produced between 28 and 49%.

Effect of Selected Pesticides on Conidial Germination and Mycelial Growth ofDactylaria higginsii, a Potential Bioherbicide for Purple Nutsedge (Cyperus rotundus)

2006 ◽  
Vol 20 (1) ◽  
pp. 255-260 ◽  
Author(s):  
Camilla B. Yandoc ◽  
E. N. Rosskopf ◽  
R.L.C.M. Pitelli ◽  
R. Charudattan
Keyword(s):  
Weed Management ◽  
Mycelial Growth ◽  
Biological Control Agent ◽  
Control Agent ◽  
Management Program ◽  
Conidial Germination ◽  
Cyperus Rotundus ◽  
Control Measures ◽  
Integrated Weed Management ◽  
Purple Nutsedge

The suitability of a bioherbicide as a component of an integrated weed management program not only relies on its field efficacy, but also on its compatibility with other pest control measures that may be employed during the cropping season. The effects of selected pesticides applied according to label rates onDactylaria higginsii, a biological control agent for purple nutsedge, were determined using mycelial growth on pesticide-amended potato dextrose agar (PDA) and conidial germination as indicators of pesticide sensitivity. Among the pesticides tested, the herbicides oxyfluorfen and sethoxydim and the fungicides fosetyl-Al and thiophanate methyl inhibitedD. higginsiimycelial growth and reduced or completely inhibited conidial germination; the herbicide diuron, the fungicides metalaxyl and copper hydroxide, and the insecticide cyromazine reduced mycelial growth but did not reduce conidial germination. The miticide dicofol reduced mycelial growth and completely inhibited conidial germination while the herbicide imazapyr had no adverse effect on either the mycelial growth or conidial germination ofD. higginsii.

scholarly journals Behavior of a Wild-Type and Two Mutant Strains of Colletotrichum gloeosporioides f. sp. aeschynomene on Northern Jointvetch in the Field

Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 374-379 ◽  
Author(s):  
Y. Luo ◽  
D. O. TeBeest
Keyword(s):  
Population Density ◽  
Wild Type Strain ◽  
Colletotrichum Gloeosporioides ◽  
Biological Control Agent ◽  
Field Tests ◽  
The United States ◽  
Control Agent ◽  
Sampling Time ◽  
Wild Type ◽  
Mutant Strains

The fungus Colletotrichum gloeosporioides f. sp. aeschynomene causes an anthracnose on Aeschynomene virginica and has been used as a biological control agent to control this weed in the United States. The population dynamics of a wild-type strain (3-1-3) and two mutant strains of 3-1-3 of C. gloeosporioides f. sp. aeschynomene, a benomyl-resistant strain (B21) and nitrate-nonutilizing strain (Nit A), were studied in field tests on northern jointvetch in 1994 and 1995 to determine how the strains interacted on infected plants under field conditions. Plants were co-inoculated with strains 3-1-3 and B21, strains 3-1-3 and Nit A, and strains 3-1-3, B21, and Nit A at equal and unequal initial proportions. Plants were grown and maintained under flooded conditions in small wading pools. In co-inoculation of plants with 3-1-3 and B21 from equal initial proportions, the population of 3-1-3 increased slightly until it reached a proportion of 60 to 70%, whereas the population density of B21 reached 30 to 40% at the end of growing season. From unequal initial proportions, the population density of B21 decreased from 90 to about 50%, whereas the 3-1-3 increased from 10 to 50%. The population density of 3-1-3 increased from an equal initial proportion and was significantly greater than that of Nit A on every sampling time. From unequal initial proportions, the population density of 3-1-3 increased from 10 to 90%, whereas that of Nit A declined. In co-inoculation of plants with the three strains, the population density of 3-1-3 was significantly greater than those of the mutant strains at every sampling time. The proportions of mutant strains within the total population of C. gloeosporioides f. sp. aeschynomene on plants varied according to the test conditions and the number and types of strains co-inoculated.

Is Phasmarhabditis papillosa (Nematoda: Rhabditidae) a possible biological control agent against the Spanish slug, Arion vulgaris (Gastropoda: Arionidae)?

Nematology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Žiga Laznik ◽  
Ivana Majić ◽  
Stanislav Trdan ◽  
Antoinette P. Malan ◽  
Annika Pieterse ◽  
...  
Keyword(s):  
Biological Control ◽  
Laboratory Experiments ◽  
Biological Control Agent ◽  
First Record ◽  
Control Agent ◽  
Molecular Techniques ◽  
Parasitic Nematodes ◽  
Arion Vulgaris ◽  
Potential Use

Summary In the period from August to October 2018, 140 specimens of the Spanish slug, Arion vulgaris, were collected from Podbrezje, Slovenia. Slugs were dissected and examined for the presence of parasitic nematodes within the cadavers. Identification of the nematodes was conducted using morphological and molecular techniques and confirmed the presence of Phasmarhabditis papillosa. This is the first record of P. papillosa from the mollusc host, A. vulgaris. Laboratory experiments aimed at testing the efficacy of P. papillosa against A. vulgaris were conducted using nematodes grown in vivo. Nematodes were applied at concentration rates of 50, 100 and 200 nematodes slug−1, respectively. Three weeks following treatment, the mortality of slugs was confirmed in all treatments (50 nematodes slug−1, 37.4 ± 2.7%; 100 nematodes slug−1, 48.4 ± 2.7%; 200 nematodes slug−1, 50.6 ± 2.7%). However, the pathogenesis of P. papillosa was observed first in the treatments with the lowest nematode dose at 4 days after treatments, while a decrease in the feeding behaviour of slugs was noted first in the treatments with the highest nematode dose. Future opportunities for the potential use of P. papillosa as a biological control agent against slugs are discussed. This is the first report of P. papillosa from Slovenia, and of its virulence against A. vulgaris.

Response of Purple and Yellow Nutsedge to Dichlobenil

Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 339-340 ◽  
Author(s):  
W. S. Hardcastle ◽  
R. E. Wilkinson
Keyword(s):  
Cyperus Rotundus ◽  
Cyperus Esculentus ◽  
Purple Nutsedge ◽  
Yellow Nutsedge

Purple nutsedge (Cyperus rotundus L.) and yellow nutsedge (Cyperus esculentus L.) tubers were stored at 5 C in soil treated at 0, 2, 3, 4, 6, 8, or 10 lb/A 2,6-dichlorobenzontrile (dichlobenil) for 2, 4, 6, 8, 10, or 12 weeks. Respiration of dormant tubers differed with species, unaffected by period of storage or dichlobenil concentration. Sprouting of untreated tubers decreased from 90% after 2 weeks storage to 43% after 12 weeks. Yellow nutsedge sprout production was uniform in time; purple nutsedge sprouting progressed to an 8-week high. Increased concentrations of dichlobenil progressively inhibited sprouting.

Reactions of Several Crops to Dichlobenil

Weed Science ◽  
1971 ◽  
Vol 19 (6) ◽  
pp. 655-658 ◽  
Author(s):  
W. S. Hardcastle ◽  
R. E. Wilkinson
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Brassica Rapa ◽  
Clay Content ◽  
Cyperus Rotundus ◽  
Sorghum Halepense ◽  
Clay Loam ◽  
Purple Nutsedge ◽  
Crop Tolerance ◽  
Yellow Nutsedge

Tolerance of corn (Zea maysL. ‘B’), cotton (Gossypium hirsutumL. ‘coker 413’), soybean (Glycine maxMerr. ‘Hardee’), turnip (Brassica rapaL. ‘Tendergreen’), sorghum (Sorghum bicolor(L.) Moench. ‘Georgia 615’), purple nutsedge (Cyperus rotundusL.), yellow nutsedge (C. esculentusL.), and johnsongrass (Sorghum halepense(L.) Pers.) to 2,6-dichlorobenzonitrile (dichlobenil) at 0, 0.14, 0.28, 0.56, 1.12, and 2.24 kg/ha in four Georgia soils was determined. Equivalent rates of dichlobenil generally were more toxic in Davidson clay loam which had the highest clay content. Crop tolerance was corn > sorghum > cotton > turnip. Purple and yellow nutsedge tolerance to dichlobenil was intermediate to that of the crops tested. Johnsongrass response was equivalent to that shown by sorghum.

Control of Nutsedge with Organic Arsenical Herbicides

Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 601-606 ◽  
Author(s):  
P. E. Keeley ◽  
R. J. Thullen
Keyword(s):  
Cyperus Rotundus ◽  
Growth Chamber ◽  
Cyperus Esculentus ◽  
Purple Nutsedge ◽  
Yellow Nutsedge

Nonradioactive and14C-labeled arsenical herbicides were applied to foliage of purple nutsedge (Cyperus rotundusL.) and yellow nutsedge (Cyperus esculentusL.) grown under greenhouse and growth chamber conditions. Disodium methanearsonate (DSMA) controlled purple nutsedge better at 20 and 29 C than at 13 C. Monosodium methanearsonate (MSMA) was as effective in controlling this weed at 13 C as at 20 and 29 C. DSMA and MSMA provided 80% or greater control of yellow nutsedge grown at the three temperatures. When plants were treated with14C-DSMA and14C-MSMA, greater radioactivity was detected in yellow nutsedge than in purple nutsedge. The apparent differential herbicide penetration of purple and yellow nutsedge leaves is believed to have contributed substantially to the control of nutsedge observed in this study.

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