scholarly journals (92) Preplant Practices to Manage Armillaria Root Rot Disease and Other Soil Pathogens on a Commercial Peach Replant Site

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1028D-1029
Author(s):  
Desmond R. Layne ◽  
Guido Schnabel
Keyword(s):  
South Carolina ◽  
Tree Growth ◽  
Methyl Bromide ◽  
Root Rot ◽  
Mycorrhizal Fungi ◽  
Tree Mortality ◽  
Long Term Effects ◽  
Soil Pathogens ◽  
Armillaria Root Rot

In 2003, a replicated long-term research trial was established on a commercial peach replant site with a history of Armillaria root rot and other soilborne diseases. The objectives of the trial were to determine the short- and long-term effects of preplant fumigation, rootstock, and preplant root dipping with mycorrhizal fungi and beneficial bacteria on tree growth, productivity, and survival. Preplant fumigants included none (control), methyl bromide, Telone II, or Enzone. Rootstocks tested included Guardian, Lovell, and Halford. Root dipping (or not) was with MycorTree. The scion cultivar was Big Red. There were a total of 24 experimental treatment combinations and the trial site comprised more than 1500 trees on 11.5 acres. By 2 years after planting, fumigation with Enzone was disadvantageous when compared with no treatment at all. Enzone-treated blocks had higher tree mortality or were significantly reduced in growth compared to other treatments. Preplant fumigation with Telone II or methyl bromide, however, resulted in reduced tree stunting and phytotoxicity and increased tree growth when compared to the untreated control. After 2 years, 10% of the total trees planted were dead. Half of these were from the Enzone treatment. Enzone does not appear to be a viable preplant fumigation product for South Carolina peach growers, based on this preliminary data. Both Guardian and Halford rootstocks had performance superior to Lovell during the first 2 years. Although Guardian trees were smaller than Halford at the time of planting, by the end of the second growing season, their TCA was not significantly different. There was no benefit to preplant root dipping with MycorTree. Experimental results were not influenced by the location of trees on the site.

scholarly journals Field Testing Peach Rootstocks for Resistance to Armillaria Root Rot

HortScience ◽  
2001 ◽  
Vol 36 (1) ◽  
pp. 101-103 ◽  
Author(s):  
T.G. Beckman ◽  
P.L. Pusey
Keyword(s):  
United States ◽  
Root Rot ◽  
Tree Mortality ◽  
Prunus Persica ◽  
Infected Plant ◽  
Field Testing ◽  
The United States ◽  
Peach Tree ◽  
Armillaria Root Rot ◽  
Peach Rootstocks

Armillaria root rot is the second leading cause of peach tree mortality (after peach tree short life) in the southeastern United States. Currently, there are no commercially available rootstocks for peach with proven resistance to this pathogen in the United States. Since 1983, we have been screening rootstock candidates for resistance to Armillaria utilizing naturally infected field sites. Inoculation of peach [Prunus persica (L.) Batsch], plum (P. cerasifera J.F. Ehrh., P. munsoniana F.W. Wight & Hedr., P. salicina Lindl. or P. angustifolia Marsh.) × peach and plum × plum hybrid rootstocks with infected plant tissue (such as acorns, Quercus sp.) prior to planting has provided a significantly increased infection and mortality of candidate rootstock lines in comparison with sole reliance on natural inoculum on an infested site.

scholarly journals Long-term watershed management is an effective strategy to reduce organic matter export and disinfection by-product precursors in source water

2019 ◽  
Vol 28 (10) ◽  
pp. 804 ◽  
Author(s):  
Hamed Majidzadeh ◽  
Huan Chen ◽  
T. Adam Coates ◽  
Kuo-Pei Tsai ◽  
Christopher I. Olivares ◽  
...  
Keyword(s):  
Organic Matter ◽  
South Carolina ◽  
Watershed Management ◽  
Management Practices ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Long Term Effects ◽  
Pyrolysis Gas ◽  
Water Extracts

Watershed management practices such as prescribed fire, harvesting and understory mastication can alter the chemical composition and thickness of forest detritus, thus affecting the quantity and quality of riverine dissolved organic matter (DOM). Long-term effects of watershed management on DOM composition were examined through parallel field and extraction-based laboratory studies. The laboratory study was conducted using detritus samples collected from a pair of managed and unmanaged watersheds in South Carolina, USA. Results showed that dissolved organic carbon (DOC), total dissolved nitrogen (TDN) and ammonium (NH4+-N) concentrations were higher in water extracts from the unmanaged watershed than from the managed watershed (P<0.01). Pyrolysis gas chromatography–mass spectrometry analysis showed that water extracts from the unmanaged watershed contained more aromatic compounds than extracts from the managed watershed. For the field study, monthly water samples were collected for 1 year (2015) from the paired watersheds. DOC and TDN concentrations, as well as DOM aromaticity, were significantly higher in the unmanaged watershed than in the managed watershed for most of the year (P<0.05) and were linked to detrital thickness, precipitation and flow patterns. The formation potential of two regulated disinfection by-products was lower in the unmanaged watershed for most of 2015 (P<0.05). From this study, it appears that long-term watershed management practices may alter detrital mass and chemistry in ways that improve water quality.

Field Evaluation of Trichoderma spp. for Control of Armillaria Root Rot of Peach

2011 ◽  
Vol 12 (1) ◽  
pp. 3 ◽  
Author(s):  
G. Schnabel ◽  
A. P. Rollins ◽  
G. W. Henderson
Keyword(s):  
South Carolina ◽  
Root Rot ◽  
Statistical Significance ◽  
Field Evaluation ◽  
Integrated Approach ◽  
Trichoderma Spp ◽  
Trunk Diameter ◽  
Armillaria Root Rot ◽  
Tree Survival ◽  
Peach Trees

Management of Armillaria root rot (ARR) of perennial crops is challenging and requires an integrated approach. In this study, Trichoderma asperellum and T. gamsii formulated as Remedier WP were drenched onto peach trees 3 to 12 days after planting (2007), and biannually thereafter in spring and fall for a total of three years in two commercial replant sites of South Carolina. All trees were planted in spots where a tree had declined from ARR the previous season to maximize disease pressure. Tree survival and trunk diameter were determined each year in the control and Remedier WP treatments. Four years after planting (2011), about 50% of all control trees and Remedier WP-treated trees had died from ARR in both locations. There was no statistical significance in survival between the treatments in either location. However, three and four years after planting, surviving Remedier WP-treated trees had significantly larger tree trunks compared to control trees in the Campobello location. Not enough trees survived in the other location for meaningful analysis of tree trunk diameter data. Our results show that in soils with heavy ARR inoculum levels, biannual drenches of Trichoderma spp. formulated as Remedier WP starting at planting are ineffective for ARR control of peach. Accepted for publication 27 October 2011. Published 29 November 2011.

scholarly journals Long-term effects of grazing and topography on extra-radical hyphae of arbuscular mycorrhizal fungi in semi-arid grasslands

Mycorrhiza ◽  
2017 ◽  
Vol 28 (2) ◽  
pp. 117-127 ◽  
Author(s):  
Haiyan Ren ◽  
Weiyang Gui ◽  
Yongfei Bai ◽  
Claudia Stein ◽  
Jorge L. M. Rodrigues ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Long Term Effects ◽  
Arid Grasslands ◽  
Semi Arid

scholarly journals Preventative Root-Collar Excavation Reduces Peach Tree Mortality Caused By Armillaria Root Rot On Replant Sites

Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1274-1279 ◽  
Author(s):  
Sarah. B. Miller ◽  
Ksenija Gasic ◽  
Gregory L. Reighard ◽  
William G. Henderson ◽  
Phillip A. Rollins ◽  
...  
Keyword(s):  
Root Rot ◽  
Tree Mortality ◽  
Net Present Value ◽  
Standard Treatment ◽  
Premature Mortality ◽  
Negative Effects ◽  
Management Options ◽  
Armillaria Root Rot ◽  
Disease Pressure ◽  
Root Collar

In the southeastern United States, Armillaria root rot (ARR) is caused by Desarmillaria tabescens and has become the primary cause of premature mortality in peach orchards. Most rootstocks used in commercial orchards are susceptible and management options are limited. A postinfection practice known as root-collar excavation (RCE), which involves permanent removal of the soil from the base of the trunk, has been shown to improve yields and prolong the productive life of symptomatic trees. However, symptomatic trees already have an advanced infection at the base of the trunk. This study evaluated the efficacy of preventative RCE on the progression of tree mortality in two orchards that were planted in infested replant sites. To provide convincing data for growers, the study was carried out in a commercial orchard and an experimental orchard for 8 years. Furthermore, representative enterprise budgets and net present value (NPV) analysis were utilized to compare the profitability of the two approaches. Trees were planted shallow on berms (45 by 90 cm) to facilitate RCE with hoes and AirSpade 2 years later. Tree mortality in the RCE treatment of the experimental orchard was first observed in year 6 and increased 8% on average per year thereafter. In contrast, tree mortality in the “Grower Standard” treatment was first observed in year 4 and increased 12.7% on average per year thereafter. At the commercial orchard, tree mortality in the RCE treatment was first observed in year 7 and increased 1.9% on average thereafter, while tree mortality in the Grower Standard treatment first appeared in year 5 and increased 4.3% on average thereafter. The delayed onset of ARR-associated tree mortality and the lower annual tree mortality rate in the RCE treatment led to higher NPVs in both locations. There were no negative effects on yield or fruit quality. However, the new planting system can create horticultural challenges, including the formation of a proper berm, uneven ground around the tree interfering with tree care and harvest, increased erosion due to channeling of rainwater, and increased rootstock suckering. The RCE is a valid option for southeastern growers needing to manage high ARR disease pressure on replant sites or on sites only recently cleared from ARR-infected forest land.

scholarly journals First Report of Armillaria gallica Causing Armillaria Root Rot in Daylily in South Carolina

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 683-683 ◽  
Author(s):  
G. Schnabel ◽  
K. E. Bussey ◽  
P. K. Bryson
Keyword(s):  
South Carolina ◽  
Root Rot ◽  
Intergenic Spacer ◽  
Selective Medium ◽  
Sodium Hypochlorite Solution ◽  
First Report ◽  
Intergenic Spacer Region ◽  
Hardwood Trees ◽  
Armillaria Root Rot ◽  
Armillaria Gallica

Daylily (Hemerocallis sp.) plants declined in a homeowner's backyard in Walhalla, SC in June 2004. The backyard in northwestern South Carolina contained multiple, hardwood tree stumps, was surrounded by mature hardwood trees, and contained a dogwood tree showing symptoms of Armillaria root rot. Daylily plants were stunted and necrosis of leaves began at the leaf tips. A cross section through the crown of the wilting plants revealed necrotic areas with the presence of white mycelial fans. Rhizomorphs were found in the direct vicinity of the daylily root system, on the roots of the dogwood, and throughout surrounding soil. Diseased daylily crowns, rhizomorphs, and dogwood bark containing mycelial fans were collected. Small sections of white mycelial fans from daylily crowns and the dogwood sample were transferred to benomyl dichloran streptomycin (BDS) selective medium. Rhizomorph pieces were surface sterilized in a 0.6% sodium hypochlorite solution for 10 min and rinsed with sterile water before being transferred to BDS selective medium. Fungal cultures from all three sources looked similar on BDS medium and developed mainly crustose mycelium with some parts being aerial. After 1 week of incubation at room temperature in the dark, all cultures developed nonmelanized, mycelial fans that initiated from the center of the colony. The nucleotide sequences of internal transcribed spacer regions 1 and 2 and the intergenic spacer region 1 were identical for all isolates, and a BLAST search in GenBank of these sequences confirmed the identity of the pathogen as A. gallica (Marxmueller & Romagnesi) for both loci. To our knowledge, this is the first report of A. gallica causing disease on Hemerocallis spp. Our findings indicate that daylilies might be at risk for infection and should not be cultivated in soils containing rhizomorphs from pathogenic Armillaria species.

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