scholarly journals Ecology and control of grapevine root diseases in New Zealand a review

2015 ◽  
Vol 68 ◽  
pp. 396-404
Author(s):  
D.C. Mundy
Keyword(s):  
New Zealand ◽  
Root Rot ◽  
Economic Loss ◽  
Foot Rot ◽  
Phytophthora Root Rot ◽  
Root Rots ◽  
Root Diseases ◽  
Armillaria Root Rot ◽  
Verticillium Dahlia ◽  
Black Foot

Grapevine root diseases can result in economic loss during vineyard establishment Symptoms may not be noticed in vineyards until vines die The death of young vines as a result of root rots can be a point of contention between the grower and the nursery supplying the plants In New Zealand root diseases include black foot rot (caused by Cylindrocarpon spp) verticillium wilt (caused by Verticillium dahlia) phytophthora root rot (caused by various Phytophthora spp) and armillaria root rot (caused in New Zealand by Armillaria novaezelandiae and A limonea) Of these diseases black foot rot is the most commonly observed in the field in New Zealand and has received the most study This review provides information on symptoms causal organisms disease cycles and where available control of grapevine root rots under New Zealand conditions

Simulated soil and plant management effects on root rots of subterranean clover

1986 ◽  
Vol 37 (6) ◽  
pp. 633 ◽  
Author(s):  
RW Smiley ◽  
PA Taylor ◽  
RG Clarke ◽  
FC Greenhalgh ◽  
P Trutmann
Keyword(s):  
Root Rot ◽  
Subterranean Clover ◽  
Plant Management ◽  
Root Rots ◽  
Root Diseases ◽  
Organic Debris ◽  
Pasture Soil ◽  
Management Procedures ◽  
Controlled Environments ◽  
Management Effects

Pasture productivity in southern Australia is often limited by root diseases of complex etiology. The influences of simulated plant and soil management procedures on subterranean clover (Trifolium subterranean cv. Woogenellup) root rots were evaluated in controlled environments, using a soil from an irrigated and from a dryland pasture. Root rot incidence and severity were high in soils collected and used as intact cores, and low to moderate in soils disturbed while being collected. Simulated cultivation of soil in cores also reduced root rots in the dryland pasture soil that had little surface litter, but not in the irrigated pasture soil which had high levels of organic debris (and pathogen inocula) distributed through the surface 0-11 cm. Root rot was mild on plants in continually moist cores at 10�C, and severe in cyclically wetted and dried cores at 10, 15 and 20�C, and in continually moist cores at 15 and 20�C. Root rots were reduced by treatment of seeds with Rhizobium, fungicides, or both, by drenching soils with fungicides, and by planting the resistant T. yanninicum cvv. Larisa, Meteora and Trikkala. Removal of seedling leaves, to simulate grazing, accentuated root rot severity. The identified pathogens included species of Pythium, Fusarium, Rhizoctonia, and nematodes. Integrated strategies for controlling root rots of subterranean clover are considered promising in view of these studies with cores of pasture soils.

scholarly journals Management of pathogens in seed orchards and nurseries

1991 ◽  
Vol 67 (5) ◽  
pp. 481-485 ◽  
Author(s):  
Jack R. Sutherland
Keyword(s):  
Root Rot ◽  
Seed Orchard ◽  
Forest Nursery ◽  
Damping Off ◽  
Seed Orchards ◽  
Root Rots ◽  
Armillaria Root Rot ◽  
Cylindrocladium Floridanum ◽  
Gray Mould ◽  
And Storage

The biology, damage and impact, and recent innovations in management of the major diseases affecting seed orchard trees and cones and forest nursery seedlings across Canada are discussed. Specific diseases covered are Armillaria root rot (A. ostoyae) and inland spruce cone rust (Chrysomyxa pirolata) in seed orchards, and damping-off and root rots, especially Cylindrocladium floridanum, and gray (Botrytis cinerea) and storage moulds of forest nursery seedlings. Areas needing research are also mentioned. Key words: Root rots, cone rust, damping-off, gray mould, storage moulds

scholarly journals Fate of mycelial and conidial propagules of Ilyonectria and Dactylonectria species in soil

2019 ◽  
Vol 72 ◽  
pp. 27-35 ◽  
Author(s):  
Chantal Probst ◽  
Dudley Crabbe ◽  
Hayley Ridgway ◽  
Marlene V. Jaspers ◽  
E. Eirian Jones
Keyword(s):  
New Zealand ◽  
Economic Loss ◽  
Nylon Mesh ◽  
Rapid Formation ◽  
Mesh Bags ◽  
Novel Method ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease ◽  
Significant Economic Loss

Black foot disease of grapevines causes significant economic loss to the viticulture industry worldwide. A novel method was developed to investigate the fate of propagules of three species associated with black foot disease in New Zealand, Dactylonectria macrodidyma, Ilyonectria europaea and I. liriodendri, in soil. Conidia or mycelium of one isolate each of the three species were buried in soil in nylon mesh bags, and conidia/chlamydospore numbers were determined microscopically after 2 and 3 weeks. Conidia and chlamydospores were produced by mycelial inocula of all isolates, with greater numbers of chlamydospores after 3 weeks. Conidial inocula of all isolates also produced chlamydospores. Chlamydospores were formed at either the terminus or side of a hypha, and single and multiple conidia formed chlamydospores by combining their cellular protoplasm. Chlamydospores were produced from conidia, and conidia from mycelium faster for the I. europaea isolate than the D. macrodidyma and I. liriodendri isolates. The rapid formation of chlamydospores as survival propagules will facilitate the ability of these pathogens to persist in soil in the absence of a host.

scholarly journals First Report of Phytophthora Root Rot Caused by Phytophthora cryptogea on Spinach in California

Plant Disease ◽  
2010 ◽  
Vol 94 (1) ◽  
pp. 131-131 ◽  
Author(s):  
S. T. Koike ◽  
Frank N. Martin
Keyword(s):  
Root Rot ◽  
Spinacia Oleracea ◽  
Root Zone ◽  
Sequence Data ◽  
Soil Extract ◽  
Phytophthora Root Rot ◽  
Phytophthora Cryptogea ◽  
First Report ◽  
Root Rots ◽  
Zoospore Release

In 2006 and 2007, commercially grown spinach (Spinacia oleracea) in California's coastal Salinas Valley (Monterey County) was affected by an unreported root rot disease. Disease was limited to patches along the edges of fields. Affected plants were stunted with chlorotic older leaves. As disease progressed, most of the older foliage first wilted and then turned tan and dry; youngest leaves remained green but were stunted and leathery in texture. Plants most severely affected died. Symptoms on roots were mostly restricted to the distal portion of the root system, where feeder roots and the main taproot turned black. Isolations from root lesions consistently resulted in the recovery of a Phytophthora sp. The isolates were heterothallic, and on the basis of morphological and cytochrome oxidase 2 gene sequence data (GenBank Accession No. GQ984233), the pathogen was identified as Phytophthora cryptogea. To evaluate pathogenicity, individual inocula of four isolates were prepared by incubating colonized 6-mm-diameter V8 agar plugs in filtered soil extract for 2 days at 20°C to induce sporangia production. These cultures were then chilled at 4°C for 20 min and returned to room temperature for 1 h to induce zoospore release (4). Four-week-old spinach plants (cv. Bolero) were uprooted, soaked in suspensions of 1.0 × 105 zoospores/ml for 10 min, and repotted. After treatment, pots were placed in shallow trays of water for 24 h to saturate the root zone, then were removed from trays and incubated in a greenhouse. After 9 days, inoculated plants showed foliar wilting and chlorosis similar to that observed in the field; after 13 days, roots were examined and found to show the black necrosis as seen in the field. P. cryptogea was isolated from all inoculated plants. Control spinach plants, treated with soil extract only, did not develop disease. This experiment was completed two times and the results were similar. To our knowledge, this is the first report of Phytophthora root rot of spinach caused by P. cryptogea in California. This finding is significant because spinach in California is subject to root rots caused by three other pathogens (Fusarium oxysporum, Pythium spp., and Rhizoctonia solani) (1); symptoms from these root rots are very similar to those caused by P. cryptogea, thereby complicating diagnosis. This pathogen has been documented on spinach in Germany and Sweden (2,3). References: (1) S. T. Koike et al. Vegetable Diseases: A Color Handbook. Manson Publishing LtD. London, 2007. (2) H. Krober and E.-O. Beckmann. Phytopathol. Z. 78:160, 1973. (3) M. Larsson and J. Olofsson. Plant Pathol. 43:251, 1994. (4) S. A. Tjosvold et al. Plant Dis. 93:371, 2009.

scholarly journals Armillaria root rot

2003 ◽  
Vol 24 (3) ◽  
pp. 31
Author(s):  
J L Smith-White ◽  
B A Summerell
Keyword(s):  
Root Rot ◽  
Economic Loss ◽  
Tissue Necrosis ◽  
Successful Management ◽  
Management Procedure ◽  
Armillaria Root Rot ◽  
Wide Range ◽  
Fungal Phytopathogen ◽  
Infected Material ◽  
Considerable Economic Loss

Armillaria luteobubalina is a fungal phytopathogen endemic to Australia. First described by Podger et al, this species affects a wide range of plants in horticultural and native environments of temperate regions within Australia, colonising root and trunk tissue. This colonisation causes tissue necrosis and ultimately death of the host, giving it the disease name of Armillaria root rot. This disease has brought about considerable economic loss to horticultural, forestry and amenity plantings. To date, control options are limited, with removal of the infected material as the only proven successful management procedure.

scholarly journals Cellulase Activity as a Mechanism for Suppression of Phytophthora Root Rot in Mulches

2011 ◽  
Vol 101 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Brantlee Spakes Richter ◽  
Kelly Ivors ◽  
Wei Shi ◽  
D. M. Benson
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Cellulase Activity ◽  
Enzyme Concentration ◽  
Disease Suppression ◽  
In Vitro Assays ◽  
Infested Soil ◽  
Phytophthora Root Rot ◽  
Standard Curve

Wood-based mulches are used in avocado production and are being tested on Fraser fir for reduction of Phytophthora root rot, caused by Phytophthora cinnamomi. Research with avocado has suggested a role of microbial cellulase enzymes in pathogen suppression through effects on the cellulosic cell walls of Phytophthora. This work was conducted to determine whether cellulase activity could account for disease suppression in mulch systems. A standard curve was developed to correlate cellulase activity in mulches with concentrations of a cellulase product. Based on this curve, cellulase activity in mulch samples was equivalent to a cellulase enzyme concentration of 25 U ml–1 or greater of product. Sustained exposure of P. cinnamomi to cellulase at 10 to 50 U ml–1 significantly reduced sporangia production, but biomass was only reduced with concentrations over 100 U ml–1. In a lupine bioassay, cellulase was applied to infested soil at 100 or 1,000 U ml–1 with three timings. Cellulase activity diminished by 47% between 1 and 15 days after application. Cellulase applied at 100 U ml–1 2 weeks before planting yielded activity of 20.08 μmol glucose equivalents per gram of soil water (GE g–1 aq) at planting, a level equivalent to mulch samples. Cellulase activity at planting ranged from 3.35 to 48.67 μmol GE g–1 aq, but no treatment significantly affected disease progress. Based on in vitro assays, cellulase activity in mulch was sufficient to impair sporangia production of P. cinnamomi, but not always sufficient to impact vegetative biomass.

scholarly journals First Report of Phytophthora megasperma and Pythium irregulare As Olive Tree Root Pathogens

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1216-1216 ◽  
Author(s):  
M. E. Sánchez-Hernández ◽  
A. Ruiz-Dávila ◽  
A. Trapero-Casas
Keyword(s):  
Root Rot ◽  
Olive Tree ◽  
The United States ◽  
Damping Off ◽  
Phytophthora Megasperma ◽  
Root Rots ◽  
Foliar Symptoms ◽  
Root Pathogens ◽  
Root Necrosis ◽  
Olive Trees

Several species of the genus Phytophthora are associated with root rot and trunk cankers in olive trees (Olea europaea L.). Among them, Phytophthora megasperma has been cited as being associated with olive root rots in Greece (1). Unidentified species of Pythium and Phytophthora have also been associated with olive tree root rots in the United States. However, the status of P. megasperma and Pythium spp. as olive tree root pathogens has remained unclear. Following a 5-year period of severe drought in southern Spain, autumn-winter rainfall rates in 1996 to 1997 steadily increased in both quantity and frequency. Under these unusually wet conditions, olive trees remained waterlogged for several months. During this period, we observed foliar wilting, dieback, and death of young trees, and later found extensive root necrosis. In 46 of 49 affected plantations surveyed, P. megasperma was consistently isolated from the rotted rootlets, particularly in young (<1- to 10-year-old trees) plantations. This fungus was not detected on plant material affected by damping-off from several Spanish olive tree nurseries. The opposite situation occurred with P. irregulare. This species was not associated with rotted rootlets in the field. In contrast, it was consistently isolated from necrotic rootlets from young olive plants affected by damping-off. These plants were grown in a sand-lime-peat soil mixture under greenhouse conditions and showed foliar wilting and extensive necrosis of the root systems. Pathogenicity tests were conducted with several isolates of P. megasperma and P. irregulare on 6-month-old rooted cuttings of olive, under both weekly watering and waterlogged conditions. Under waterlogged conditions, both fungal species produced extensive root necrosis 2 weeks after inoculation that resulted in wilting of the aerial parts and rapid plant death. Waterlogged control plants remained without foliar symptoms but a low degree of root necrosis was recorded. In addition, under weekly watering conditions, plants inoculated with either species showed some degree of root rot but foliar symptoms were not evident. No differences in pathogenicity were observed within the Phytophthora or Pythium isolates. Reference: (1) H. Kouyeas and A. Chitzanidis. Ann. Inst. Phytopathol. Benaki 8:175, 1968.

Pythium intermedium. [Descriptions of Fungi and Bacteria].

1964 ◽  
Author(s):  
G. M. Waterhouse
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Root Rot ◽  
Crop Plants ◽  
Foot Rot ◽  
Damping Off ◽  
Wide Range

Abstract A description is provided for Pythium intermedium. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts represented by the following families: Begoniaceae, Bromeliaceae, Chenopodiaceae, Compositae, Coniferae, Cruciferae, Euphorbiaceae, Geraniaceae, Gramineae, Leguminosae, Liliaceae, Linaceae, Moraceae, Onagraceae, Ranunculaceae, Rosaceae, Solanaceae, Ulmaceae, Violaceae; also in the Equisetales and Filicales. DISEASES: Damping-off of seedlings, foot rot and root rot of ornamentals, occasionally of crop plants and trees. GEOGRAPHICAL DISTRIBUTION: Asia (China); Australia & Oceania (Hawaii); Europe (England, Belgium, France, Germany, Holland, Sweden, U.S.S.R.); North America (U.S.A.); South America (Argentina). TRANSMISSION: A common soil inhabitant.

Sign in / Sign up

Export Citation Format

Share Document