Stump injections with soil fumigants to eradicate Armillariellamellea from young-growth ponderosa pine killed by root rot

1977 ◽  
Vol 7 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Gregory M. Filip ◽  
Lewis F. Roth

Root rot caused by Armillariellamellea (Vahl ex Fr.) Karst. creates unproductive disease centers in young-growth ponderosa pine (Pinusponderosa Laws.) after removal of the old-growth timber. The fungus persists in stumps in these centers keeping the land unproductive indefinitely. Armillariellamellea was effectively eradicated from infected stumps by insitu fumigation with methyl bromide, Vorlex, chloropicrin, carbon disulfide, and Vapam. The fungal antagonist Trichoderma appeared to be unaffected by the fumigants except for methyl bromide, which resulted in a significant increase in the incidence of Trichoderma over control stumps.

1992 ◽  
Vol 22 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Stephen C. Hart ◽  
Mary K. Firestone ◽  
Eldor A. Paul

A litter-bag technique was used to measure decay rates and assess changes in organic and inorganic constituents of ponderosa pine (Pinusponderosa Laws.) needle litter during decomposition over a 2-year period in old- and young-growth forests in the Sierra Nevada of California. Rates of mass loss were among the lowest reported for temperate and boreal forests, with annual decomposition constants of about 0.08 and 0.18 year−1 for the old- and young-growth forests, respectively. Apparently, the temporal separation of warm temperatures and moist conditions found in Mediterranean-type climates severely limits decomposition in these coniferous forests. In the old-growth forest, comparison of estimates of tree nutrient uptake with net releases of nutrients from fine litter during their 1st year of decomposition suggests that recent litter fall potentially acts as a significant source of P, Mg, and K for tree uptake in this forest; in contrast, recently fallen litter acts as a net sink for N, S, and Ca. Despite initially lower indices of litter quality for litter originating from the old–growth relative to the young–growth forest, no significant difference in decomposition rates of these two litter age-classes was found when placed at either site. This result does not support the hypothesis that decreases in decomposition rates during forest development are driven by decreases in the quality of litter fall.


Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Aida Zveibil ◽  
Neta Mor ◽  
Nabeel Gnayem ◽  
Stanley Freeman

Crown and root rot of strawberry, caused by Macrophomina phaseolina, have become predominant soilborne diseases of strawberry in Israel over the past 5 years. In total, 151 isolates of the pathogen were isolated from infected strawberry plants of commercially grown cultivars in Israel onto a modified agar medium for the genus Macrophomina. Sclerotia viability declined more rapidly in soil maintained at 25°C or at soil temperatures fluctuating from 18 to 32°C under greenhouse conditions, compared with sclerotia viability in soil kept at 30°C. After 30 to 40 weeks of exposure in soil, inocula maintained at 25 or 30°C or at fluctuating temperatures in a greenhouse declined to negligible levels. A significant increase in plant mortality was observed in infested soils maintained at 30 versus 25°C, whereas water stress at 25 or 30°C did not affect plant mortality in M. phaseolina-infested soils. This demonstrated the importance of elevated soil temperature, not moisture stress, on plant mortality caused by M. phaseolina. Host specificity was not evident when strawberry plants were inoculated with each of seven Israeli isolates of M. phaseolina obtained from six other plant species, suggesting the importance of keeping strawberry crops out of rotation with other host crops of the pathogen. The soil fumigants methyl bromide (applied at 500 kg/ha) and metam sodium (730 liter/ha) caused 90 and 95% pathogen mortality in field experiments, respectively, indicating that fumigation may be an effective method of managing this pathogen in infested soils. The increase in prevalence of crown and root rot caused by M. phaseolina in strawberry crops in Israel may be related to the phase-out of methyl bromide.


1991 ◽  
Vol 31 (6) ◽  
pp. 843 ◽  
Author(s):  
IJ Porter ◽  
PR Merriman ◽  
PJ Keane

The effect of solarisation combined with low rates of soil fumigants on the severity of clubroot and yield of cauliflowers was determined at 2 locations in southern Victoria. The effectiveness of treatments was shown to be dependent on location; on the type, water content and temperature of soil; and on the population density of Plasmodiophora brassicae. Yields were reduced depending upon the disease severity, usually within 60 days after transplanting. Propagules of P. brassicae could survive for more than 28 days in ovens at 45�C when in dry soil but died within 14 days at 40�C in moist soil. At Werribee in 1985 on a red brown earth, solarisation combined with dazomet (100 kg dazomet/ha) gave significantly better control than either treatment alone. This treatment reduced P. brassicae in the 0-10 cm layer, reduced the disease rating from 2.7 to 0.9 (0-3), and increased yield from 2.4 to 47 t/ha compared with controls. In 1986, solarisation combined with 98% methyl bromide-2% chloropicrin (100 and 250 kg/ha) reduced the population density of P. brassicae in the 0-10 and 10-20 cm layers of soil, reduced the disease rating from 3 to 1.8, and increased yield from 0 to 22 t/ha. These treatments were more effective than solarisation and dazomet used alone or in combination. At Keysborough in 1985 on a grey sand, separate treatments of solarisation or dazomet (100 and 250 kg dazometha) were as effective as combined treatments and significantly reduced disease and increased yields compared to controls. Solarisation combined with either fumigant significantly reduced the distribution and total number of weeds at all sites and was generally more effective than separate treatments.


1961 ◽  
Vol 7 (5) ◽  
pp. 785-792 ◽  
Author(s):  
W. B. Bollen ◽  
Ernest Wright

Penicillium spp. predominated in samples of forest soils except occasionally at depths of more than three inches, when Mucor and Aspergillus spp. sometimes were more abundant. Incubation for 30 days at 28 °C and 50 per cent water-holding capacity frequently increased the percentage of Mucor spp. as well as Penicillium spp. Mucor spp. were consistently more prominent in soils associated with alder than for other coastal soils. Mucor and Aspergillus spp. also appeared often in soil from stands of ponderosa pine growing east of the Cascades.The greatest concentration of nitrogen as NO3− in unincubated soils was found in a young red alder stand. Samples of soil from stands of virgin coastal redwood showed no nitrate nitrogen. Soils from stands of virgin Sitka spruce, however, showed considerable nitrate content, which increased markedly with incubation.With few exceptions, bacteria and actinomycetes were most numerous in F layers of soil. Incubation greatly increased these populations in most soils.


2019 ◽  
Vol 450 ◽  
pp. 117502 ◽  
Author(s):  
Jose M. Iniguez ◽  
James F. Fowler ◽  
W. Keith Moser ◽  
Carolyn H. Sieg ◽  
L. Scott Baggett ◽  
...  

1993 ◽  
Vol 8 (2) ◽  
pp. 67-70 ◽  
Author(s):  
E. E. Nelson ◽  
Rona N. Sturrock

Abstract Several species of conifers were outplanted around infected stumps in Oregon and British Columbia to measure their susceptibility to laminated root rot caused by Phellinus weirii. Grand fir (Abies grandis) experienced nearly 30% mortality caused by P. weirii. Douglas-fir (Pseudotsuga menziesii) mortality exceeded 20%. Noble fir (A. procera), Sitka spruce (Picea sitchensis), giant sequoia (Sequoiadendron giganteum), western hemlock (Tsuga heterophylla), and ponderosa pine (Pinus ponderosa) mortality averaged less than 10%. Western white pine (P. monticola) and lodgepole pine (P. contorta) mortality was less than 1%. Phellinus weirii did not cause mortality of western redcedar (Thuja plicata) or redwood (Sequoia sempervirens). Apparent susceptibility, based on mortality over 17-20 growing seasons, was similar to that recorded in past field observations. West. J. Appl. For. 8(2):67-70.


1989 ◽  
Vol 19 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Stephen C. Hart ◽  
Mary K. Firestone

Three indices of nitrogen (N) availability were compared in the field over a 1-year period in an old-growth and a young-growth mixed-conifer forest. The indices utilized were ion exchange resin (IER) bags, buried bags, and a core-IER method employing intact soil cores enclosed in tubes capped at both ends by IER bags. The results from all three methods indicated that in the surface mineral soil, N availability was higher in the young-growth stand than in the old-growth stand. However, seasonal patterns of N availability were generally not well correlated among the methods (correlation coefficients ranged from 0.32 to 0.62). For a given amount of net N mineralized in buried bags, more N accumulated on IER bags placed in the young-growth stand than in those placed in the old-growth stand. This was the result of greater net nitrification in the young-growth stand coupled with the greater mobility of [Formula: see text] relative to [Formula: see text] in soil. Ten-month estimates of net N mineralization measured by the core-IER and buried-bag methods were similar in the young-growth stand (about 42 mg•kg soil−1), but the core-IER estimate was almost twice that of the buried-bag estimate in the old-growth stand (31.7 and 16.8 mg•kg soil−1, respectively). The different sensitivities of the core-IER and buried-bag methods to changes in soil moisture and leaching probably account for much of the difference in their N availability estimates. Results from the core-IER method did reflect the effects of leaching; however, soil water content within the core did not follow changes in soil water content effectively. Because of the greater labor involved in using the core-IER method, its use may be most efficacious in high-precipitation environments, or when in-field soil incubations must be conducted for extended periods of time.


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