Short-term impact of thinning and fertilizer application on Armillaria root disease in regrowth karri (Eucalyptus diversicolor F. Muell.) in Western Australia

2003 ◽  
Vol 176 (1-3) ◽  
pp. 417-426 ◽  
Author(s):  
Richard M Robinson
Keyword(s):  
Western Australia ◽  
Fertilizer Application ◽  
Root Disease ◽  
Short Term ◽  
Armillaria Root Disease ◽  
Eucalyptus Diversicolor

scholarly journals Short-term effects of fertilizer application on soil respiration in red pine stands

2012 ◽  
Vol 35 (4) ◽  
pp. 307-311 ◽  
Author(s):  
Choonsig Kim ◽  
Jaeyeob Jeong ◽  
Nanthi S. Bolan ◽  
Ravi Naidu
Keyword(s):  
Soil Respiration ◽  
Fertilizer Application ◽  
Red Pine ◽  
Short Term ◽  
Pine Stands ◽  
Short Term Effects

scholarly journals Armillaria Root Disease Inoculum Remaining in Young Ontario Conifer Plantations Following Root Raking or Madge Rotoclearing

1998 ◽  
Vol 15 (4) ◽  
pp. 191-196 ◽  
Author(s):  
Johann N. Bruhn ◽  
Jeanne D. Mihail ◽  
Timothy R. Meyer
Keyword(s):  
Woody Debris ◽  
Site Preparation ◽  
Root Disease ◽  
Northern Ontario ◽  
Fallow Period ◽  
Disease Mortality ◽  
Lethal Infection ◽  
Woody Root ◽  
Armillaria Root Disease ◽  
Apparently Healthy

Abstract Armillaria ostoyae causes a destructive root disease in northern conifers. Most infections result from root invasions by rhizomorphs growing through the soil from previously colonized stump and woody root debris. Armillaria longevity in woody debris is related to the colonized volume. Stump and root removal by root raking alone often does not satisfactorily reduce subsequent root disease mortality. This investigation characterized residual woody debris volumes in three conifer seed orchards in northern Ontario. Site preparation for stump and root removal in two of the orchards consisted of root raking alone, vs. Madge Rotoclear™ treatment ("rotoclearing") in the third orchard. Fallow periods between site preparation and planting were 1, 5, and 8 yr in the three orchards, respectively. Mortality related to colonized residual woody debris is continuing in the raked orchards, but appears to have ended in the rotocleared orchard. Root systems of 32 orchard trees recently killed by Armillaria root disease and 9 apparently healthy (otherwise comparable) trees were excavated. Regardless of site preparation method, Armillaria-killed trees were associated with greater total volumes of residual woody debris (comprising larger pieces on average) than were healthy trees. Also, healthy trees in the rotocleared orchard were associated with smaller debris pieces on average than were healthy trees in the root-raked orchard. Size of individual woody debris pieces which contained viable A. ostoyae was highly variable. Even small pieces of colonized debris close to a root crown were apparently capable of causing lethal infection. Nevertheless, compared to root raking, rotoclearing apparently breaks A. ostoyae-colonized woody debris into smaller pieces resulting in more rapid displacement of A. ostoyae. We conclude that rotoclearing followed by a fallow period of 8 yr before planting merits consideration as an inoculum reduction treatment for site preparation. A 10 yr fallow period might have prevented nearly all root disease mortality under the conditions of this study. North. J. Appl. For. 15(4):191-196.

Severity of root rot in mature subterranean clover and associated fungal pathogens in the wheatbelt of Western Australia

2009 ◽  
Vol 60 (1) ◽  
pp. 43 ◽  
Author(s):  
Tiernan A. O'Rourke ◽  
Tim T. Scanlon ◽  
Megan H. Ryan ◽  
Len J. Wade ◽  
Alan C. McKay ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
Fungal Pathogens ◽  
Lateral Roots ◽  
Subterranean Clover ◽  
Growing Season ◽  
Root Diameter ◽  
Root Disease ◽  
Soil Dna ◽  
Tap Root

Pasture decline is considered to be a serious challenge to agricultural productivity of subterranean clover across southern Australia. Root disease is a significant contributing factor to pasture decline. However, root disease assessments are generally carried out in the early part of the growing season and in areas predominantly sown to permanent pastures. For this reason, in spring 2004, a survey was undertaken to determine the severity of root disease in mature subterranean clover plants in pastures located in the wheatbelt of Western Australia. DNA-based soil assays were used to estimate population density in the soil of a variety of soil-borne pathogens known to commonly occur in the Mediterranean-type environments of southern Australia. The relationships between severity of disease on tap and lateral roots and root diameter, root length, nodulation, and total rainfall were determined. The survey showed, for the first time, that severe root disease is widespread in spring across the wheatbelt of Western Australia. There was a positive correlation between rainfall and tap root disease, and between tap root disease and average root diameter of the entire root system. Despite the high levels of root disease present across the sites, the DNA of most root disease pathogens assayed was detected in trace concentrations. Only Pythium Clade F showed high DNA concentrations in the soil. DNA concentrations in the soil, in particular for Phytophthora clandestina and Rhizoctonia solani AG 2.1 and AG 2.2, were higher in the smaller autumn sampling in 2006. This study suggests that the productivity of subterranean clover-based pastures is severely compromised by root rot diseases throughout the growing season in the wheatbelt of Western Australia.

scholarly journals Inoculum Reduction Measures to Manage Armillaria Root Disease in a Severely Infected Stand of Ponderosa Pine in South-Central Washington: 35-Year Results

2012 ◽  
Vol 27 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Charles G. Shaw ◽  
D.W. Omdal ◽  
A. Ramsey-Kroll ◽  
L.F. Roth
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Root Disease ◽  
Intensive Treatment ◽  
Control Treatment ◽  
No Removal ◽  
South Central ◽  
Armillaria Root Disease ◽  
Different Levels ◽  
Maximum Removal

Abstract A stand of ponderosa pine (Pinus ponderosa) severely affected by Armillaria root disease was treated with five different levels of sanitation by root removal to reduce root disease losses in the regenerating stand. Treatments included the following: (1) all trees pushed over by machine, maximum removal of roots by machine ripping, and visible remaining roots removed by hand; (2) all trees pushed over by machine and maximum removal of roots by machine ripping; (3) all trees pushed over by machine with no further removal of roots; (4) smaller trees pushed over by machine but large stumps left, otherwise maximum removal of roots by machine ripping; and (5) all trees felled and removed by skidding, area cleared of slash, sod scalped, and no removal of roots. After 35 years, we found that the more intense and thorough root-removal treatments were generally more effective in reducing the occurrence of Armillaria root disease. However, even the most intensive treatment (treatment 1), which experienced significantly less disease than most other treatments, had 23% of the area expressing mortality. The only operationally feasible treatment (treatment 3) also reduced levels of mortality, but not significantly (40% mortality versus 52% in the control, treatment 5). Although these results support the concept that inoculum removal can reduce root disease levels, the treatment necessary to provide a meaningful reduction in disease loss does not seem to warrant its cost.

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