ABSTRACT Pinus radiata (Monterey pine), a tree native to coastal California and Mexico, is widely planted worldwide for timber production. A major threat Monterey pine plantations the fungal disease pitch canker, caused by Fusarium circinatum ( Hypocreales ). We present novel trapping approach using filter paper in combination with rapid molecular method detect presence of inoculum air. The assay also useful diagnosing pathogen on plants. test based F. specific primer pair CIRC1A-CIRC4A,...

Patterns of spore deposition by Fusarium circinatum, the causal agent pine pitch canker (PPC) Monterey (Pinus radiata) and other conifers, were studied between May 2003 April 2004 at two sites in Northern California using a novel trapping method combined with real-time polymerase chain reaction (PCR) approach. At each study site, plots sampled placing traps 100 m intervals along transects 600 length. The air was continuously exchanging every 2 weeks. rate (DR), ranged from 0 to 1.3 × 10 5...

Phylogenetic relationships between species from the genera Kluyveromyces and Saccharomyces representatives of Metschnikowiaceae (Holleya, Metschnikowia, Nematospora) including two filamentous phytopathogenic fungi Ashbya gossypii Eremothecium ashbyii were studied by comparing monosaccharide pattern purified cell walls, ubiquinone system, presence dityrosine in ascospore nucleotide sequences ribosomal DNA (complete 18S rDNA, ITS1 ITS2 region). Based on sequence information both ITS regions,...

Black-stain root disease is a threat to conifer forests in western North America. The caused by the ophiostomatoid fungus Leptographium wageneri (W.B. Kendr.) M.J. Wingf., which associated with number of bark beetle (Coleoptera: Scolytidae) and weevil species Curculionidae). We developed polymerase chain reaction test identify quantify fungal DNA directly from insects. was detected on 142 384 samples (37%) collected Lassen National Forest, northeastern California, during years 2001 2002....

Nursery trade plays a major role in the long-distance spread of Phytophthora ramorum, causal agent Sudden Oak Death (SOD) and ramorum blight ornamental plants. Under federal regulations, nurseries found positive for P. must destroy infected plants treat infested soils. The use steam is an effective method to thermally inactivate from nursery soils as demonstrated at National Ornamental Research Site Dominican University (NORSDUC) one commercial Central Valley California. Heating up top soil...

Abstract Phylogenetic relationships of several strains within the Fusarium oxysporum species complex and two related from maize were used to test whether phylogenies inferred nuclear‐encoded translation elongation factor EF‐1 α mitochondrial small subunit (mtSSU) ribosomal RNA gene sequences are concordant with one derived random amplified polymorphic DNA (RAPD) characters. Results a partition‐homogeneity (PHT) indicated that mtSSU rDNA data‐sets highly homogeneous (P ≥ 0.99) could be...

The Sudden Oak Death (SOD) Blitzes consist of yearly surveys led by citizen scientists designed to map the distribution Phytophthora ramorum, cause forest disease called SOD, across northern California. During 2017 Santa Cruz County SOD Blitz, six rare or endangered Arctostaphylos (manzanita) species were found be possibly symptomatic for first time. Symptoms included branch cankers and associated canopy mortality, affected multiple individuals per species. Isolates P. ramorum obtained from...

Bois noir (BN) is a grapevine yellows disease caused by phytoplasma of the Stolbur group (16SrXII-A). The planthopper Hyalesthes obsoletus known to be principal vector and can accidentally transmit from its herbaceous host plants ( Vitis vinifera ). Due increasing incidence BN over last decade, monitoring study was conducted in South Tyrol (Northern Italy). Over period up four years, 659 insect samples, 516 41 potential plant species as well 56 samples BN-affected vineyards were tested for...

The potential aerial spread of Phytophthora ramorum, causal agent sudden oak death and Ramorum blight, from infected plants in a quarantine research nursery at the National Ornamentals Research Site Dominican University California (NORS-DUC) to environment was monitored weekly for five years (2011 2016) using sentinel system. ramorum never detected on any (Rhododendron, Viburnum, Loropetalum spp), indicating very limited under suboptimal meteorological environmental conditions. An infection...

A major concern for plant nurseries and land stewards is managing pathogens that induce soilborne diseases. Plant diseases cost millions of dollars in lost revenue spread into the environment from nursery soil used out-plantings. Recent research shows steaming at high temperatures can effectively kill pathogens; however, few studies have investigated influence on microbiome, an essential component health. We conducted a controlled experiment where underwent event within rectangular mesocosm...

A rapid decline of Aleppo pines was observed in the parking lot Legoland amusement park San Diego Co., CA. Although pine is a known host for Fusarium circinatum, this first report describing resin-soaked sapwood lesions roots mature trees. Previous reports on root infections regarded seedlings. The infestation location may have begun with infected planted saplings. persistent at represents significant source inoculum pathogen exotic to California. Accepted publication 7 June 2006. Published...

Phytophthora ramorum, the causal agent of Sudden Oak Death (SOD) and ramorum blight, infects a wide range hardwood nursery ornamental species. Chlamydospores P. can survive for extended periods time in soils. Two studies were conducted, including: 1) laboratory study to evaluate two liquid disinfectants controlling chlamydospores, 2) field novel soil fumigation treatment as an alternative steaming or methyl bromide fumigation. The ElectroBiocide Oxidate 2.0. resulted complete inactivation...

A field study was conducted at the National Ornamental Research Site Dominican University California (NORS-DUC). The goal to evaluate three chemical inducers applied as foliar treatments for controlling Phytophthora ramorum, on Rhododendron x ‘Cunningham’s White’ nursery plants. were chlorine dioxide (ElectroBiocide), hydrogen peroxide (OxiDate 2.0), and acibenzolar-s methyl (Actigard). Water samples from electrostatic sprayer measured physicochemical water properties. Visual assessment of...

For many nurseries it is difficult to diagnose Phytophthora-infected plants in time prevent disease incursion and spread, especially if the infection occurs on roots causes no or limited symptoms aerial plant parts. Rapid, accurate, specific diagnostic methods can facilitate identification removal of infected plants. This study was conducted investigate nursery types within California are more likely have different Phytopthora species which hosts test positive for a Phytophthora using...