Fungicidal control in pineapple and avocado of diseases caused by Phytophthora cinnamomi

1980 ◽  
Vol 20 (102) ◽  
pp. 119 ◽  
Author(s):  
RN Allen ◽  
KG Pegg ◽  
LI Forsberg ◽  
DJ Firth
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Soil Surface ◽  
Soil Drench ◽  
Old Trees ◽  
Better Than

Root and heart rot diseases of pineapples and root rot of avocado caused by P. cinnamomi were controlled with fungicides. In pineapples, treatments were applied at planting and again after one and two months. Ridomil (0.8 kg a.i. ha-1) and Aliette (8 kg a.i. ha-1) controlled P. cinnamomi better than the standard Difolatan treatment (11 kg a.i. ha-1). In avocado nursery plants, Ridomil mixed with the soil before planting (1 g a.i. per 10 l soil) or drenched onto the soil surface around established plants (1 g a.i, per 10 1 container) controlled root rot for at least four months after treatment. Two applications of Ridomil, applied at a rate of 5 g a.i. m-2 as a soil drench beneath the canopy of 7 year old trees affected by root rot, controlled P. cinnamomi without affecting its biological antagonists and permitted trees to recover over a 12-month period.

scholarly journals Incidence of Phytophthora Root Rot of Fraser Fir in North Carolina and Sensitivity of Isolates of Phytophthora cinnamomi to Metalaxyl

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 661-664 ◽  
Author(s):  
D. M. Benson ◽  
L. F. Grand
Keyword(s):  
North Carolina ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Disease Incidence ◽  
The State ◽  
Systematic Sampling ◽  
Phytophthora Root Rot ◽  
Fraser Fir ◽  
Phytophthora Spp ◽  
Old Trees

A survey of Fraser fir Christmas trees in North Carolina for incidence of Phytophthora root rot was conducted during 1997 and 1998. Field sites (7- to 13-year-old trees) and nursery transplant beds (4- to 5-year-old trees) selected at random were surveyed based on foliar symptoms of Phytophthora root rot. Field sites were surveyed with a random transect method (>3,000 trees/field) or by counting all trees (<3,000 trees/field). Overall, incidence of Phytophthora root rot averaged 9% over the 58 field sites sampled, with a range of 0 to 75%. No relationship was found between number of years Fraser fir had been planted in the field site and disease incidence. Disease incidence did not increase as field sites were rotated through second or third crops of Fraser fir. Phytophthora spp. were recovered from 1.8% of asymptomatic trees sampled from 58 field sites across the state. P. cinnamomi accounted for 91% of the Phytophthora isolates recovered. In nursery transplant beds where a systematic sampling procedure was used, incidence of diseased trees averaged 2%, with a range of 0 to 12% across 16 locations. Recovery of Phytophthora spp. averaged 1.2% from root samples collected from 50 asymptomatic seedlings at each location. Isolates collected from the field and nursery transplant beds were grown on cornmeal agar incorporated with 0, 1, 1.25, 10, or 100 μg a.i. metalaxyl/ml. All 166 isolates of P. cinnamomi tested were sensitive to metalaxyl at 1 or 1.25 μg a.i. metalaxyl/ml. Although incidence of Phytophthora root rot has not increased in the state compared to a survey done in 1976 to 1977, the disease continues to limit production of Fraser fir in North Carolina.

scholarly journals Control of Phytophthora Root Rot of Rhododendron chapmanii A. Gray with Subdue

1989 ◽  
Vol 7 (2) ◽  
pp. 73-75
Author(s):  
D. M. Benson ◽  
Frank A. Blazich
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Rooted Cuttings ◽  
Phytophthora Root Rot ◽  
Soil Drench ◽  
The One

Abstract Rooted cuttings of Chapman's rhododendron (Rhododendron chapmanii) in soilless medium were challenged with inoculum of the soi1borne fungus, Phytophthora cinnamomi (Rands). A portion of the plants received a soil drench of Subdue 2EC (metalaxyl) at 0.16 ml/L (2.0 oz/100 gal) at 2 month intervals. Chapman's rhododendron was highly susceptible to P. cinnamomi, but five of six plants treated with Subdue did not develop symptoms of Phytophthora root rot. In the one plant which developed root rot symptoms, P. cinnamomi was recovered in culture.

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 Phytophthora mediterranea sp. nov., a New Species Closely Related to Phytophthora cinnamomi from Nursery Plants of Myrtus communis in Italy

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 682
Author(s):  
Carlo Bregant ◽  
Antonio A. Mulas ◽  
Giovanni Rossetto ◽  
Antonio Deidda ◽  
Lucia Maddau ◽  
...  
Keyword(s):  
New Species ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Colony Growth ◽  
Phytophthora Species ◽  
Maximum Temperature ◽  
Pathogenicity Test ◽  
Forest Nurseries ◽  
Collar And Root Rot ◽  
A New Species

Monitoring surveys of Phytophthora related diseases in four forest nurseries in Italy revealed the occurrence of fourteen Phytophthora species to be associated with collar and root rot on fourteen plants typical of Mediterranean and alpine regions. In addition, a multilocus phylogeny analysis based on nuclear ITS and ß-tubulin and mitochondrial cox1 sequences, as well as micromorphological features, supported the description of a new species belonging to the phylogenetic clade 7c, Phytophthora mediterranea sp. nov. Phytophthora mediterranea was shown to be associated with collar and root rot symptoms on myrtle seedlings. Phylogenetically, P. mediterranea is closely related to P. cinnamomi but the two species differ in 87 nucleotides in the three studied DNA regions. Morphologically P. mediterranea can be easily distinguished from P. cinnamomi on the basis of its smaller sporangia, colony growth pattern and higher optimum and maximum temperature values. Data from the pathogenicity test showed that P. mediterranea has the potential to threaten the native Mediterranean maquis vegetation. Finally, the discovery of P. cinnamomi in alpine nurseries, confirms the progressive expansion of this species towards cold environments, probably driven by climate change.

Variability and inheritance in macadamia progenies to Phytophthora cinnamomi and P. multivora the causal agents of root rot and stem canker

2021 ◽  
Author(s):  
Olumide S. Jeff-Ego ◽  
Andre Drenth ◽  
Bruce Topp ◽  
Juliane Henderson ◽  
Olufemi A. Akinsanmi
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Stem Canker

Efficacy of Clonostachys rosea strain ACM941 and fungicide seed treatments for controlling the root rot complex of field pea

2003 ◽  
Vol 83 (3) ◽  
pp. 519-524 ◽  
Author(s):  
A. G. Xue
Keyword(s):  
Root Rot ◽  
Untreated Control ◽  
Seedling Emergence ◽  
Field Trials ◽  
Field Pea ◽  
Seed Treatments ◽  
Clonostachys Rosea ◽  
Pea Root ◽  
Pea Root Rot ◽  
Better Than

The efficacy of seed treatments with bioagent ACM941 (a strain of Clonostachys rosea), its formulated products GB116 and ACM941-Pro, and common fungicides for the control of pea root rot complex were examined in six field trials in western Canada from 1996 to 2000. The effects on seedling emergence, root rot severity, and yield varied among years. In trials 1 and 2 (1996–1997), none of the treatments significantly reduced root rot severity or increased yield. ACM941 + Thiram 75WP was the most effective treatment, increasing emergence by 17.4% and was significantly better than that of the untreated controls. In trials 3 and 4 (1997–1998), Apron FL alone and ACM941 + Apron FL were significantly better than the untreated control, increasing emergence by 6.2 and 7.7%, and yield by 10.8 and 11.5%, respectively. In trials 5 and 6 (1999–2000), AC M 941 and GB116 were equally the most effective treatments, increasing emergence by 11.5 and 12.2%, and yield by 8.2 and 6.3%, respectively. These effects were significantly greater than that of the untreated control, but not significantly different from those of Apron FL or Vitaflo-280. ACM941-Pro was developed and tested in 2000 only, and it increased emergence by 17.1% and reduced root rot severity by 29.6%. Key words: Bioagent, Clonostachys rosea, field pea, Pisum sativum, pea root rot complex (PRRC), seed treatment, fungicide

Influence of diet on development and oviposition of Forficula auricularia (Dermaptera: Forficulidae)

2001 ◽  
Vol 133 (5) ◽  
pp. 705-708 ◽  
Author(s):  
Ghislain Berleur ◽  
Jean Gingras ◽  
Jean-Claude Tourneur
Keyword(s):  
Food Preference ◽  
Rhopalosiphum Padi ◽  
Soil Surface ◽  
Cold Weather ◽  
Forficula Auricularia ◽  
Content Analyses ◽  
European Earwig ◽  
Preference Tests ◽  
Daylight Period ◽  
Better Than

In North America, the life cycle of the European earwig (Forficula auricularia L.) can be divided into a nesting phase (hypogean phase) and a free-foraging phase (epigean phase) (Crumb et al. 1941; Behura 1956; Lamb and Wellington 1975). Adults spend the nesting phase in the soil; females burrow into the ground at the onset of the cold weather, lay eggs, and then care for the eggs. Hatching occurs in spring; first- or second-instar nymphs move to the soil surface for the free-foraging period. The earwig, a nocturnal insect, spends the entire daylight period of hiding under trash or in dark crevices. Where two broods occur, females reenter the ground a second time (Lamb and Wellington 1975). Stomach content analyses (Crumb et al. 1941; Sunderland and Vickerman 1980) and food preference tests (McLeod and Chant 1952; Buxton and Madge 1976) revealed that the European earwig is omnivorous. Under laboratory conditions, nymphs fed freshly frozen aphids, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), survive better than those fed green algae or carrots, develop faster, and produce heavier females (Phillips 1981; Carrillo 1985).

Cylindrocladium clavatum. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
A. Peerally
Keyword(s):  
Geographical Distribution ◽  
Camellia Sinensis ◽  
Root Rot ◽  
Araucaria Angustifolia ◽  
Eucalyptus Saligna ◽  
Bright Yellow ◽  
Cylindrocladium Floridanum ◽  
Old Trees ◽  
Brown Root Rot ◽  
Phellinus Noxius

Abstract A description is provided for Cylindrocladium clavatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Araucaria angustifolia, Camellia sinensis, Eucalyptus saligna and Pinus. DISEASE: Occasionally associated with Cylindrocladium floridanum[Calonectria kyotensis] and Cylindrocarpon tenue on rotting roots of unthrifty tea bushes in Mauritius. Associated with a root disease of dying 10-15 year old trees of Araucaria angustifolia (Hodges & May, 1972). Roots of such trees are pitch-soaked and copiously exude resin, causing large quantities of soil to stick to the roots, thus resembling in symptomatology the brown root rot caused by Phellinus noxius. Also isolated from the roots of dying trees of several species of Pinus (Hodges & May, 1972). The pine needles on affected trees turn bright yellow, droop and finally turn brick red. Roots were pitch-soaked but resin exudation was slight. Also isolated from seedlings of Eucalyptus saligna (Hodges & May, 1972). GEOGRAPHICAL DISTRIBUTION: Brazil, Mauritius. TRANSMISSION: The pathogen is soil-borne.

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