Integrated control of Fusarium damping-off in red pine seedlings with the ectomycorrhizal fungus Paxillusinvolutus and fungicides

1990 ◽  
Vol 20 (9) ◽  
pp. 1283-1288 ◽  
Author(s):  
P. Chakravarty ◽  
R. L. Peterson ◽  
B. E. Ellis
Keyword(s):  
Integrated Control ◽  
Mycorrhizal Fungus ◽  
Ectomycorrhizal Fungus ◽  
Red Pine ◽  
The Other ◽  
Tube Length ◽  
Damping Off ◽  
Seedling Mortality ◽  
Other Hand ◽  
Pine Seedlings

Damping-off caused by Fusariumoxysporum Schlecht. in red pine (Pinusresinosa Ait.) was significantly reduced when seedlings were treated with either of two fungicides (benomyl or oxine benzoate) concomitantly with the ectomycorrhizal fungus Paxillusinvolutus (Batsch.) Fr. compared with inoculation with P. involutus alone. Both fungicides at concentrations of 10 ppm and above significantly reduced spore germination and germ-tube length of F. oxysporuminvitro. On the other hand, invitro growth of P. involutus mycelium was not affected by the fungicides at concentrations up to 1000 ppm. The growth of P. involutus was, however, significantly reduced by the two fungicides at 5000 and 10 000 ppm. Inoculation of red pine seedlings with P. involutus was effective under growth chamber and greenhouse conditions in reducing the incidence of damping-off induced by F. oxysporum. When benomyl and oxine benzoate were applied in combination with P. involutus, seedling mortality was not observed. Oxine benzoate was phytotoxic and inhibited mycorrhiza formation by P. involutus at the recommended dose. Benomyl, on the other hand, had no inhibitory effect on seedling growth and stimulated ectomycorrhiza formation either by a naturally occurring mycorrhizal fungus or P. involutus in the greenhouse. The concept of incorporating integrated biological and chemical treatment for controlling Fusarium damping-off of red pine seedlings is suggested.

scholarly journals Response of the Leek (Allium porrum)-Mycorrhizal Fungus Symbiosis to Cutting Levels, Light Exposure and Seedling Density

2021 ◽  
Vol 2 (3) ◽  
pp. 1-6
Author(s):  
G. Nowo Nekou ◽  
A.-M. Sontsa-Donhoung ◽  
. Hawaou ◽  
M. Bahdjolbe ◽  
R. Tobolbaï ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Light Exposure ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
The Other ◽  
Allium Porrum ◽  
Seedling Density ◽  
Positive Effects ◽  
Other Hand ◽  
The Impact

This work aims to assess the leek-arbuscular fungus symbiosis response to the effect of cutting and light exposure on the one hand, and the impact of seedling density on this symbiosis on the other hand. Allium Porrum was grown in a container in two different trials. Four species of arbuscular mycorrhizal fungi, Glomus hoi, Scutellospora gregaria, Rhizophagus intraradices and Gigaspora margarita were used to constitute the mycorrhizal inoculum. After 150 days of growth and inoculation, a series of cuts were made on the aerial part (0% = zero cut, 50% = half cut, 100% = whole cut). Plants that had undergone these treatments were placed in shade and sun for 30 days. The leek density per bag was varied by the order of 1, 2, 3 and 4 plant (s) by the pocket density test. Results showed that for 0% of cut in the shade, the vesicle occurrence decreases from 83.33% to 52.22%, and from 90% to 25.5% for 50% of cut in the shade. On the other hand, there is a significant increase in intra-root spores for a complete cut compared to other levels of cuts. For extra-root sporulation, under light, cuts have a negative and weak effect (from -11 to -3%) while in the absence of light, cuts have significant positive effects (from +16 to +61%). Regarding seedling density, the best root colonization (90%) and biomass production (14 g) are obtained with three plants per pot, but it is rather with a density of two plants per pot that extra-root sporulation is higher (153 spores/g). Variation in light, cut level and density significantly affects the development of mycorrhizal fungi.

Effects of Hebeloma arenosa on growth and survival of container-grown red pine seedlings (Pinus resinosa)

1991 ◽  
Vol 21 (10) ◽  
pp. 1459-1465 ◽  
Author(s):  
J. S. MacFall ◽  
S. A. Slack
Keyword(s):  
Seedling Survival ◽  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Commercial Production ◽  
Red Pine ◽  
Shoot Height ◽  
Growth And Survival ◽  
Fungal Inoculum ◽  
Pine Seedlings ◽  
Production Conditions

The ability of the ectomycorrhizal fungus Hebelomaarenosa Burdsall, MacFall & Albers to enhance growth and survival of container-grown red pine seedlings (Pinusresinosa Ait.) was investigated. Shoot height of H. arenosa inoculated seedlings was 28% greater than noninoculated seedlings when grown without fertilizer applications. Eight-week-old seedlings transplanted into a Ball mix (a mixture of peat, bark, and perlite) containing up to a 1:64 dilution of fungal inoculum had significantly greater root dry weights and root/shoot ratios than noninoculated seedlings when grown for an additional 14 weeks. Under experimental greenhouse conditions, root and shoot dry weights of container-grown red pine seedlings that had been directly seeded into Ball mix containing up to a 1:256 dilution of fungal inoculum were significantly greater than weights measured for noninoculated seedlings. Root and shoot dry weights of container-grown seedlings seeded directly into a 1:5 dilution of H. arenosa inoculum and Ball mix and then grown under commercial production conditions were greater than comparable weights of noninoculated seedlings. Hebelomaarenosa inoculation significantly increased seedling survival following outplanting, but did not increase seedling growth. Hebelomaarenosa did not colonize roots growing from the root plug into the surrounding soil.

scholarly journals THE EFFECT OF CHLORDANE AND THIRAM ON DAMPING-OFF AND SEEDLING GROWTH

1961 ◽  
Vol 37 (3) ◽  
pp. 211-216 ◽  
Author(s):  
J. Cockerill
Keyword(s):  
Adverse Effect ◽  
Seedling Growth ◽  
Root Development ◽  
Red Pine ◽  
Damping Off ◽  
White Grub ◽  
Seedling Mortality ◽  
Apparent Adverse Effect

Chlordane, applied to seed beds of red pine to control white grub infestation, increased seedling mortality due to damping-off in these beds. Losses were significantly reduced when the seed was pelleted with thiram prior to sowing. Neither chlordane nor thiram, alone or in combination, had any apparent adverse effect on seedling growth, root development, or the formation of mycorrhiza.

Later events in suppression of Fusarium root rot of red pine seedlings by the ectomycorrhizal fungus Paxillus involutus

1991 ◽  
Vol 69 (6) ◽  
pp. 1372-1383 ◽  
Author(s):  
M. L. Farquhar ◽  
R. L. Peterson
Keyword(s):  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Red Pine ◽  
Disease Suppression ◽  
Host Cells ◽  
Paxillus Involutus ◽  
Free System ◽  
Primary Roots ◽  
Pine Seedlings ◽  
Rooting Medium

Colonization of primary roots of red pine (Pinus resinosa Ait.) seedlings by two isolates of the fungal pathogen Fusarium oxysporum Schlecht. emend Snyd. & Hans. f.sp. pini in a sterile, soil-free system and a nonsterile rooting medium was suppressed for 2 months if the roots were exposed to the ectomycorrhizal fungus Paxillus involutus (Batsch.) Fr. for 1 week before being inoculated with the pathogen. Roots of protected seedlings harboured only a few hyphae of the pathogen. These were either vacuolated or filled with slightly electron-dense substances and did not penetrate host cells. In contrast, roots of seedlings not inoculated by P. involutus were extensively colonized by F. oxysporum, and host tissue vacuolation and disorganization occurred. Papillae, consisting of either small protuberances or elongate projections, were infrequently formed in response to infection. Chlamydospores of F. oxysporum that formed in the sterile system had numerous lipid deposits and amorphous thick walls but few mitochondria and little endoplasmic reticulum. Key words: biological control, ectomycorrhiza, Fusarium, Pinus resinosa, disease suppression.

The effect of sonication on the growth of some tree seeds

1981 ◽  
Vol 11 (4) ◽  
pp. 840-844 ◽  
Author(s):  
Pearl Weinberger ◽  
C. Burton
Keyword(s):  
Tree Species ◽  
Peak Velocity ◽  
Jack Pine ◽  
Red Pine ◽  
The Other ◽  
Pine Seedlings ◽  
Length Range ◽  
Percent Germination ◽  
Tree Seeds ◽  
All Treatment

Air-dry seeds of jack pine (Pinusbanksiana Lamb.), red pine (P. resinosa Ait.), tamarack (Larixeuropaea L.), and white spruce (Piceaglauca (Moench) Voss) were subjected for 30 min to 1 MHz ultrasound at one of three intensities of ultrasound ranging from 0.5 to 6.0 W/cm2. Subsequent germination was assessed in terms of percent germination, mean daily germination (MDG), and peak velocity of germination (PV). From these, germination values (GV) were obtained. Only jack pine responded to the ultrasonic treatments by giving rise to higher MDG and GV values. The seeds were equally stimulated by all the intensities used. The rates and percent germination of the other tree species were unaffected by any of the sonication treatments. Seeds of jack pine were also sonicated at 25, 50, 100, 250, and 750 kHz at an intensity in the range of 0.5–1.0 W/cm2. None of these treatments affected the course of germination.Subsequent seedling growth of all the seeds in all treatment sets was also monitored by summing the total length of all the seedlings following 8 and 14 days of growth. The seedlings were divided into five length-range categories. The jack pine seedlings alone, sonicated at 1 MHz, had significantly more seedlings in the larger size group than the untreated seedlings.

Damping-off disease of pine seedlings on soils treated with simulated acidic rain

1995 ◽  
Vol 25 (5) ◽  
pp. 838-844 ◽  
Author(s):  
George A. Schier ◽  
Roy L. Patton
Keyword(s):  
Seedling Emergence ◽  
Fungal Species ◽  
Pine Barrens ◽  
Damping Off ◽  
Seedling Mortality ◽  
Solution Ph ◽  
Pine Seedlings ◽  
Early Seedling ◽  
Acidic Rain ◽  
Solution Acidity

Damping-off during seed germination and early seedling growth of Pinusrigida Mill., Pinusechinata Mill., Pinustaeda L., and Pinusstrobus L. were observed for 28 days on three New Jersey (U.S.A.) Pine Barrens soils (Atsion, Downer, Lakewood) treated with simulated acidic rain solutions of pH 4.2, 3.5, or 3.0 (SO42−:Cl−:NO3−, 2.2:1.4:1.0). The soils were sandy, highly acidic, and deficient in mineral nutrients. Treatment with rain solution was started 53 days before planting the pine seeds and continued during germination. Seedling emergence and seedling mortality were affected significantly by solution pH, soils, and species. Seedling emergence of all pine species on Atsion and Lakewood soils decreased with increasing solution acidity. On Downer soil seedling emergence was unaffected by solution acidity probably because the buffering action of the soil decreased the acidity of the rain solution. Seedling mortality of all species increased with increasing treatment acidity on all soils and was significantly higher on Atsion (100% at pH 3.0) than on the other soils. Although solution acidity significantly increased the concentration of Al in the soil solution, there was no evidence of Al toxicity. Two isolated fungal species, a Trichoderma and a Penicillium, significantly reduced seedling emergence and increased seedling mortality of P. rigida in sterile, acid-washed quartz sand; however, neither seedling emergence nor seedling mortality was affected significantly by solution acidity.

Antifungal effect of an ectotrophic mycorrhizal fungus, Lactarius sp., associated with basswood seedlings

1970 ◽  
Vol 16 (8) ◽  
pp. 798-800 ◽  
Author(s):  
J. Y. Park
Keyword(s):  
Mycorrhizal Fungus ◽  
Agar Plate ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Antifungal Compound ◽  
Damping Off ◽  
Antifungal Effect ◽  
Pine Seedlings ◽  
Strong Inhibitory Effect ◽  
Greenhouse Tests

An ectotrophic mycorrhizal fungus associated with basswood, Lactarius sp., produces a potent antifungal compound. The compound's strength was assessed by determining the percentage spore germination of Penicillium implication in Lactarius sp. culture filtrates. Antifungal properties were evaluated by pairing Lactarius sp. with 23 known pathogenic fungi on Hagem agar plate cultures. Greenhouse tests revealed a strong inhibitory effect of Lactarius sp. against fungi that frequently cause damping-off of pine seedlings.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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