scholarly journals Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 960-966 ◽  
Author(s):  
Wade H. Elmer ◽  
Joseph J. Pignatello

Pyrolyzed biomass waste, commonly called biochar, has attracted interest as a soil amendment. A commercial prototype biochar produced by fast pyrolysis of hardwood dust was examined in soils to determine if it could reduce the damaging effect of allelopathy on arbuscular mycorrhizal (AM) root colonization and on Fusarium crown and root rot of asparagus. In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to asparagus field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium oxysporum f. sp. asparagi and F. proliferatum compared with a control. Concomitant with these effects was a 100% increase in root colonization by AM fungi at the 3.0% rate. Addition of aromatic acids (cinnamic, coumaric, and ferulic) that are known allelopathic agents affecting asparagus reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate. When dried, ground, asparagus root and crown tissues infested with Fusarium spp. were added to soilless potting mix at 0, 1, or 5 g/liter of potting mix and then planted with asparagus, there was a decrease in asparagus root weight and increase in disease at 1 g/liter of potting mix but results were inconsistent at the higher residue rate. However, when biochar was added at 35 g/liter of potting mix (roughly 10%, vol/vol), these adverse effects on root weight and disease were equal to the nontreated controls. A small demonstration was conducted in field microplots. Those plots amended with biochar (3.5% [wt/wt] soil) produced asparagus plants with more AM colonization in the first year of growth but, in the subsequent year, biochar-treated plants were reduced in size, possibly due to greater than average precipitation and the ability of biochar to retain moisture that, in turn, may have created conditions conducive to root rot. These studies provide evidence that biochar may be useful in overcoming the deleterious effects of allelopathic residues in replant soils on asparagus.

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 493-498 ◽  
Author(s):  
T. C. Reid ◽  
M. K. Hausbeck ◽  
K. Kizilkaya

Growth chamber, greenhouse, and field experiments were conducted with fungicides and biological control agents, including nonpathogenic isolates of Fusarium oxysporum, to test their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies with asparagus seedlings in soil, Trichoderma harzianum strain T-22, benomyl, and fludioxonil treatments increased root weight and decreased root disease compared with the infested control when a low level of F. oxysporum f. sp. asparagi and F. proliferatum was used. The fungicide fludioxonil limited plant death caused by Fusarium spp. at high inoculum levels, whereas T. harzianum strain T-22 was not effective. Nonpathogenic isolates of F. oxysporum were effective in limiting Fusarium disease on asparagus seedlings in culture tubes, although isolates differed in their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies, no significant differences in plant death were found between asparagus plants growing in media infested with F. oxysporum f. sp. asparagi and F. proliferatum and left untreated, and those treated with nonpathogenic F. oxysporum. The efficacy of fungicides and biological control products to control Fusarium crown and root rot under commercial field conditions could not be evaluated due to low disease pressure.


2017 ◽  
Vol 6 (06) ◽  
pp. 5415
Author(s):  
Mane S. R. ◽  
Kumbhar V. R. ◽  
Birajdar G. M. ◽  
Naryankar R. S. ◽  
Gavali M. T. ◽  
...  

Clitoria ternatea L. is an excellent herbal medicinal plant. Arbusular Mycorrhizal fungal (AMF) colonization and biomass of three different tested conditions of Clitoria ternatea plant was investigated. Inoculums of indigenous AMF and Trichoderma harzianum was tested greenhouse experiment and compared with natural condition after 60th days of treatment. Percentage of Arbuscular mycorrhizal (AM) infection, number of resting spores and AM fungi species varies in different land. Among three different conditions, natural conditions showed maximum root colonization (75.89%) than treated one but minimum spore density (358.8/100gsoil). Highest spore density (481.6/100g soil) was found in T. harzianum treated condition followed by indigenous AMF treatment Acaulospora Glomus and Sclerocystis these three genera were found frequently. AMF inoculums and T.harzianum treatments conditions were observed promising biomass data of 60th days after treatment (DAT).When AMF are more colonized to plants then enhanced the biomass productivity.


2007 ◽  
Vol 64 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Milene Moreira ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
Sandra Maria Gomes-da-Costa ◽  
Elke Jurandy Bran Nogueira Cardoso

Araucaria angustifolia (Bert.) O. Ktze. is an endangered Brazilian coniferous tree that has been almost exterminated in the native areas because of uncontrolled wood exploitation. This tree has been shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) and, therefore, AMF may be essential for forest sustainability and biological diversity. Root colonization, density and diversity of AMF spores were assessed in two Araucaria forest stands at the State Park of Alto Ribeira (PETAR), at two sampling dates: May and October. A comparison was made between a mature native stand composed of Araucaria trees mixed into a variety of tropical trees and shrubs, without any sign of anthropogenic interference (FN) and an Araucaria stand planted in 1987 (R), which has been used as a pasture. Assessments included percent root colonization, AMF spore numbers and species richness, Simpson's dominance index (Is), and Shannon's diversity index (H). Mycorrhizal root colonization did not differ between ecosystems in May. In October, however, the native stand (FN) presented a higher colonization than the planted forest (R), and the root colonization was more intense than in May. When considering both sampling periods and forests, 27 species of AM fungi, with higher numbers of spores in FN than in R were found. Canonical discriminant analysis (CDA) indicated Shannon's diversity index as the ecological attribute that contributed the most to distinguish between forest ecosystems, with higher value of H in FN in relation to R. CDA showed to be a useful tool for the study of ecological attributes.


2010 ◽  
Vol 61 (5) ◽  
pp. 399 ◽  
Author(s):  
K. J. Owen ◽  
T. G. Clewett ◽  
J. P. Thompson

Root-lesion nematode (Pratylenchus thornei) significantly reduces wheat yields in the northern Australian grain region. Canola is thought to have a ‘biofumigation’ potential to control nematodes; therefore, a field experiment was designed to compare canola with other winter crops or clean-fallow for reducing P. thornei population densities and improving growth of P. thornei-intolerant wheat (cv. Batavia) in the following year. Immediately after harvest of the first-year crops, populations of P. thornei were lowest following various canola cultivars or clean-fallow (1957–5200 P. thornei/kg dry soil) and were highest following susceptible wheat cultivars (31 033–41 294/kg dry soil). Unexpectedly, at planting of the second-year wheat crop, nematode populations were at more uniform lower levels (<5000/kg dry soil), irrespective of the previous season’s treatment, and remained that way during the growing season, which was quite dry. Growth and grain yield of the second-year wheat crop were poorest on plots previously planted with canola or left fallow due to poor colonisation with arbuscular mycorrhizal (AM) fungi, with the exception of canola cv. Karoo, which had high AM fungal colonisation and low wheat yields. There were significant regressions between growth and yield parameters of the second-year wheat and levels of AMF following the pre-crop treatments. Thus, canola appears to be a good crop for reducing P. thornei populations, but AM fungal-dependence of subsequent crops should be considered, particularly in the northern Australian grain region.


Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Nasser Aliasgharzad ◽  
Saheb Bolandnazar ◽  
Mohammad Neyshabouri ◽  
Nader Chaparzadeh

AbstractDrought is a world-spread problem seriously influencing crop production. Arbuscular mycorrhizal (AM) association and soil microorganisms can help plant growth under water stress condition by improvement of its nutrient and water uptake. In this experiment, onion plants (Allium cepa L. cv. Red Azar Shahr) were inoculated with three AM fungi species (Glomus versiforme, G. intraradices, G. etunicatum) or left un-inoculated as non-mycorrhizal plants, in a sterile or non-sterile sandy loam soil. Plants were irrigated at 7, 9 or 11-day intervals to keep the soil moisture content to field capacity at the irrigation time. Mycorrhizal root colonization decreased (p < 0.05) with an increase in irrigation interval, and the highest root colonization was achieved at 7-day irrigated onions in symbiosis with G. versiforme. Phosphorus content in plant tissue was significantly increased in mycorrhizal than non-mycorrhizal onions. Plants inoculated with G. versiforme at 9-day interval treatment had the highest leaf P content, while the lowest P was observed in non-mycorrhizal plants at all irrigation intervals. Onions inoculated by G. versiforme or G. etunicatum at 9-day irrigation interval had the highest K content. Results revealed that the inoculation of onion plant with G. versiforme or G. etunicatum and increasing irrigation interval up to 9 days, could improve P and K uptake.


2015 ◽  
Vol 13 (4) ◽  
pp. e1009
Author(s):  
Ana I. Borrego-Benjumea ◽  
José M. Melero-Vara ◽  
María J. Basallote-Ureba

<p><em></em><em>Fusarium oxysporum</em> (<em>Fo</em>), <em>F. proliferatum</em> (<em>Fp</em>) and <em>F. solani</em> (<em>Fs</em>) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of <em>Fusarium</em> spp. was determined on substrate artificially infested with <em>Fo</em>5<em>, Fp</em>3<em> </em>or <em>Fs</em>2 isolates,<em> </em>amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of <em>Fo</em>5 and <em>Fs</em>2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of <em>Fp</em>3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of <em>Fusarium</em>. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but <em>Fp</em>3 caused lower severity than <em>Fo</em>5 and <em>Fs</em>2. Severity reduction was particularly high at 30ºC (by 15 days incubation for <em>Fs</em>2 and by 30-45 days for <em>Fo</em>5), after PPM treatment, as well as PM-2% for <em>Fo</em>5<em> </em>and <em>Fs</em>2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in <em>Fo</em>5 and <em>Fs2</em>, with some rates of the three OAs tested, depending on incubation period and temperature.<br /><strong></strong></p>


1990 ◽  
Vol 115 (4) ◽  
pp. 550-554 ◽  
Author(s):  
Tracy L. Wacker ◽  
Gene R. Safir ◽  
Christine T. Stephens

Asparagus (Asparagus officinalis L.) seedlings inoculated with the sicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thaxt. sensu Gerd.) Gerd. & Trappe (GF) d Fusarium oxysporum (Schlect.) Snyd. & Hans. (FO) were grown under field and greenhouse conditions. In the fi, shoot volumes of GF-inoculated plants were greater than nonGF plants from the 3rd through the 13th month of growth. By the 14th month, GF-inoculated plants grown in high-P soils had significantly lower disease ratings than nonGF plants grown in low-P soils, and rhizosphere populations of FO were lowest in high-P soils, regardless of VAM status. In greenhouse studies, FO inoculation of VAM-infected asparagus plants reduced GF root colonization levels under well-watered (0 MPa), but not under water stress, conditions (- 1.5 MPa). Well-watered plants inoculated with both FO and GF were less diseased and sustained lower rhizosphere populations of FO than plants inoculated with FO alone. The differences in FO populations and disease ratings in these studies were apparently unrelated to final plant tissue P levels.


Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1318-1324 ◽  
Author(s):  
Wade H. Elmer

Replanted asparagus fields commonly fail to produce a profitable stand due to alleopathic residues left behind from the previous asparagus crop, elevated densities of pathogenic Fusarium spp., and low densities of vesicular arbuscular mycorrhizae (VAM). Formononetin, a plant isoflavone that stimulates VAM spores to germinate, and sodium chloride (NaCl), a disease-suppressing amendment, were evaluated alone and in combination for their effect on reestablishing asparagus at two locations in abandoned asparagus fields. Greenhouse studies also were conducted with naturally and artificially infested soils. Formononetin was applied as a crown soak or soil drench, and NaCl was applied as a granular treatment. Feeder roots from soil cores sampled from field plots and from greenhouse transplants were assayed for colonization by VAM and for lesions caused by Fusarium oxysporum and F. proliferatum. Formononetin increased the number of VAM vesicles in roots from the field and greenhouse studies and reduced the percent root lesions caused by Fusarium spp. when compared with the nontreated controls. NaCl was more effective than formononetin in reducing the percentage of root lesions in both field and greenhouse experiment when compared with untreated plants but had no effect on VAM colonization. However, there was evidence that NaCl negated the effect of formononentin on VAM colonization. The NaCl treatment increased the May 2001 spear number by 15% and marketable spear weight by 23%. At one site, treatment with formononetin increased mean number of stalks per plant by 29% in 2000 and 14% in 2001. Both formononetin and NaCl improve growth and reduce disease of asparagus in replanted asparagus and may be useful in reestablishing asparagus in abandoned asparagus field.


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