Host range, symptoms and effects on pasture production of a Victorian isolate of ryegrass mosaic potyvirus

1992 ◽  
Vol 43 (5) ◽  
pp. 1243 ◽  
Author(s):  
DR Eagling ◽  
O Villalta ◽  
RJ Sward
Keyword(s):  
Host Range ◽  
Field Trial ◽  
Dry Weight ◽  
Pasture Production ◽  
Local Isolate ◽  
Weed Growth ◽  
Field Plots ◽  
Range Study

A local isolate of ryegrass mosaic potyvirus (RMV) was identified from a pasture in Leongatha, south-east Victoria. The virus was mechanically inoculated to ryegrass and oats but could not be detected by ISEM in inoculated and symptomless wheat, cocksfoot or barley. Symptoms associated with infection varied between a white mosaic and a brown necrosis. The presence or absence of RMV did not significantly affect the total herbage yields of field plots. However, infection with RMV resulted in reductions in dry weight of 5-50% in the ryegrass component of total herbage yields; the reduction in ryegrass was compensated by increased weed growth. The extent of the reductions in ryegrass associated with RMV infection varied with both species and cultivar. Both the host range study and the herbage yields from the field trial showed that the Victorian isolate of RMV differed from isolates reported overseas.

scholarly journals Horticultural Characteristics and Susceptibility of Table Beet Cultivars to Cercospora Leaf Spot in New York

2017 ◽  
Vol 27 (4) ◽  
pp. 530-538 ◽  
Author(s):  
Sarah J. Pethybridge ◽  
Niloofar Vaghefi ◽  
Julie R. Kikkert
Keyword(s):  
New York ◽  
Leaf Spot ◽  
Field Trial ◽  
Near Infrared ◽  
Value Added ◽  
Dry Weight ◽  
Disease Assessment ◽  
Canopy Reflectance ◽  
Cercospora Leaf Spot ◽  
Disease Progress

Table beet (Beta vulgaris ssp. vulgaris) production in New York is increasing for direct sale, use in value-added products, or processing. One of the most important diseases affecting table beet is cercospora leaf spot (CLS) caused by the fungus Cercospora beticola. CLS causes lesions on leaves that coalesce and leads to premature defoliation. The presence of CLS may cause buyer rejection at fresh markets. Defoliation from CLS may also result in crop loss because of the inability to harvest with top-pulling machinery. The susceptibility of popular table beet cultivars (Boldor, Detroit, Falcon, Merlin, Rhonda, Ruby Queen, and Touchstone Gold) to CLS was tested using C. beticola isolates representative of the New York population. Two trials were conducted by inoculating 6-week-old plants in the misting chamber. A small-plot replicated field trial was also conducted to examine horticultural characteristics of the cultivars. In the misting chamber trials, disease progress measured by the area under the disease progress stairs (AUDPS) was not significantly different between the red cultivars, Detroit and Ruby Queen, and was significantly higher in ‘Boldor’ than the other yellow cultivar Touchstone Gold. In the field trial, the number of CLS lesions per leaf at the final disease assessment and AUDPS were significantly lower in cultivar Ruby Queen than others and not significantly different between the yellow cultivars. The dry weight of roots was not significantly different among cultivars at first harvest (77 days after planting). At 112 days after planting, the dry weight of roots was significantly higher in cultivar Detroit than Rhonda and Boldor. Leaf blade length and the length:width ratio were cultivar-dependent, which may facilitate selection for specific fresh markets. Significant associations between canopy reflectance in the near infrared (IR) (830 nm), dry weight of foliage, and number of CLS lesions per leaf suggested that this technique may have utility for remote assessment of these variables in table beet research. Implications of these findings for the management of CLS in table beet are discussed.

scholarly journals First Report of Carrot Cyst Nematode Heterodera carotae in Mexico: Morphological, Molecular Characterization, and Host Range Study

2018 ◽  
Vol 50 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Ilia Mariana Escobar-Avila ◽  
Edgar Óliver López-Villegas ◽  
Sergei A. Subbotin ◽  
Alejandro Tovar-Soto
Keyword(s):  
Host Range ◽  
Molecular Characterization ◽  
Cyst Nematode ◽  
First Report ◽  
Range Study

scholarly journals The Enhancement of Soybean Growth and Yield in a Field Trial through Introduction of Mixtures of Bradyrhizobium japonicum, Bacillus sp. and Pseudomonas chlororaphis

2017 ◽  
Vol 9 (2) ◽  
pp. 274-279 ◽  
Author(s):  
Renata M. ILIČIĆ ◽  
Radmila N. PIVIĆ ◽  
Zoran S. DINIĆ ◽  
Dragana S. LATKOVIĆ ◽  
Slobodan A. VLAJIĆ ◽  
...  
Keyword(s):  
Carbon Content ◽  
Bradyrhizobium Japonicum ◽  
Field Trial ◽  
Agricultural Practices ◽  
Dry Weight ◽  
Growth And Yield ◽  
Pseudomonas Chlororaphis ◽  
Bacillus Sp ◽  
Commercial Fertilizer ◽  
Positive Effects

The effects of plant growth promoting (PGP) bacteria on soybean growth and yield were tested in field conditions using four treatments: (A) Bradyrhizobium japonicum strain 526, combined with cell-free supernatants (CFS) of Bacillus sp. strain Q10 and Pseudomonas chlororaphis strain Q16; (B) B. japonicum 526 + Bacillus sp. Q10; (C) B. japonicum 526 + P. chlororaphis Q16 and (D) commercial fertilizer containing B. japonicum, which served as a control. The average values of dry weight per nodule and shoot dry weight had the maximum values in the B treatment. In dry shoots collected at the flowering stage, nitrogen and carbon content was similar across all treatments, while that of sulphur decreased in treatment A. Relative to the control (D), all treatments showed positive effects on pods number and grain mass per plant, with the best results yielded by treatment A. Nitrogen and sulphur content in grain were significantly higher in treatment C, whereas maximum carbon content was measured in treatment B. In the control, it was obtained the yield of 4,000 kgha-1, which was in accordance with data reported by the seed producer for the same growing conditions (the maximum value). The yields of 4,229, as well as 4,286 and 4,400 kg ha-1 were measured for variants C, B and A, respectively, which were statistically significant higher (5.73 to 10%) than the commercial fertilizer (D). The improvement in soybean growth and yield in the field trial achieved by addition of PGP strains Bacillus sp. Q10 and P. chlororaphis Q16 to B. japonicum 526 can result in more productive agricultural practices.

scholarly journals Pectin-Rich Amendment Enhances Soybean Growth Promotion and Nodulation Mediated by Bacillus Velezensis Strains

Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 120 ◽  
Author(s):  
Mohammad K. Hassan ◽  
John A. McInroy ◽  
Jarrod Jones ◽  
Deepak Shantharaj ◽  
Mark R. Liles ◽  
...  
Keyword(s):  
Plant Growth ◽  
Bradyrhizobium Japonicum ◽  
Field Trial ◽  
Growth Promotion ◽  
Orange Peel ◽  
Dry Weight ◽  
Shoot Length ◽  
Soybean Seeds ◽  
Bacillus Velezensis ◽  
Greenhouse Tests

Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel (OP) amendments to Bacillus velezensis (Bv) PGPR strains could increase soybean growth and nodulation by Bradyrhizobium japonicum in greenhouse and field experiments to reduce variability. The treatments included untreated soybean seeds planted in field soil that contained Bv PGPR strains and non-inoculated controls with and without 0.1% (w/v) pectin or (1 or 10 mg/200 μL) orange peel (OP) amendment. In greenhouse and field tests, 35 and 55 days after planting (DAP), the plants were removed from pots, washed, and analyzed for treatment effects. In greenhouse trials, the rhizobial inoculant was not added with Bv strains and pectin or OP amendment, but in the field trial, a commercial B. japonicum inoculant was used with Bv strains and pectin amendment. In the greenhouse tests, soybean seeds inoculated with Bv AP193 and pectin had significantly increased soybean shoot length, dry weight, and nodulation by indigenous Bradyrhizobium compared to AP193 without pectin. In the field trial, pectin with Bv AP193 significantly increased the shoot length, dry weight, and nodulation of a commercial Bradyrhizobium japonicum compared to Bv AP193 without pectin. In greenhouse tests, OP amendment with AP193 at 10 mg significantly increased the dry weight of shoots and roots compared to AP193 without OP amendment. The results demonstrate that pectin-rich amendments can enhance Bv-mediated soybean growth promotion and nodulation by indigenous and inoculated B. japonicum.

Effect of Vineyard Row Orientation on Growth and Phenology of Glyphosate-Resistant and Glyphosate-Susceptible Horseweed (Conyza canadensis)

Weed Science ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Marisa Alcorta ◽  
Matthew W. Fidelibus ◽  
Kerri L. Steenwerth ◽  
Anil Shrestha
Keyword(s):  
Leaf Area ◽  
Growth And Development ◽  
Dry Weight ◽  
Conyza Canadensis ◽  
Light Penetration ◽  
Low Light ◽  
Weed Growth ◽  
Light Levels ◽  
East West ◽  
Number Of Seeds

Horseweed has become increasingly common and difficult to control in San Joaquin Valley vineyards, due in part, to the evolution of glyphosate resistance. The development of weed-suppressive vineyard designs in which the trellis design, spacing, and row orientation combine to cast dense shade on the weed canopy zone (WCZ) may reduce weed growth. The relevance of such a system to horseweed, which can grow to be as tall, or taller, than a typical grapevine trellis, is uncertain. Also unknown is whether a glyphosate-resistant (GR) biotype and glyphosate-susceptible (GS) biotype would perform similarly under such conditions. Therefore, we compared the growth and development of two potted horseweed biotypes (GR and GS) in vinerows oriented east–west (EW) and north–south (NS). Rows oriented EW allowed less light penetration to the WCZ than NS rows throughout the study, and horseweed biotypes responded to low light levels by producing leaves with larger specific leaf area and leaf area ratios than those in the NS rows. Also, the leaf, stem, and root dry weight of the horseweed plants in the EW rows was reduced by 30% compared to the horseweed plants in NS rows. Leaf number was also reduced in the horseweed plants in the EW rows, but only for the GS biotype. Row orientation did not affect phenological development or the number of seeds produced by the GR or GS biotypes, but the GR biotype budded, flowered, and set seed approximately 1 wk earlier than the GS biotype. Thus, shade associated with the EW vinerows reduced horseweed growth, but not fecundity, and the GR biotype reached reproductive maturity earlier than the GS biotype.

Host range of Phytophthora sp. causing leaf fall disease of nutmeg(Myristica fragrans Houtt.)

2016 ◽  
Vol 50 (6) ◽  
Author(s):  
Sumbula V. ◽  
Sally K. Mathew ◽  
Mini Raj N.
Keyword(s):  
Host Range ◽  
Black Pepper ◽  
Hypersensitive Reaction ◽  
Leaf Fall ◽  
Monsoon Period ◽  
Phytophthora Spp ◽  
South West Monsoon ◽  
Myristica Fragrans Houtt ◽  
West Monsoon ◽  
Range Study

Leaf fall disease caused by Phytophthora sp. has become a serious problem in major nutmeg growing areas of Kerala during South - West monsoon period. Host range study was carried out to find out the infectivity of Phytophthora isolates of nutmeg on other known hosts of Phytophthora spp. including arecanut, coconut, cocoa, rubber, black pepper, cardamom, camboge, vanilla, rose, coreopsis, eucalyptus, colocasia and citrus. Phytophthora isolates of nutmeg showed characteristic symptoms on rubber, vanilla, rose, coreopsis, eucalyptus and citrus, whereas, cocoa, black pepper and colocasia developed hypersensitive reaction and the pathogen failed to cause infection on arecanut, coconut, cardamom and camboge.

Tillage effect on root rot severity, growth and yield of beans

1995 ◽  
Vol 75 (1) ◽  
pp. 183-186 ◽  
Author(s):  
C. S. Tan ◽  
J. C. Tu
Keyword(s):  
Root Rot ◽  
Soil Compaction ◽  
Growth Yield ◽  
Dry Weight ◽  
Growth And Yield ◽  
Soil Tillage ◽  
Susceptible Cultivar ◽  
Deep Tillage ◽  
Rhizoctonia Root Rot ◽  
Field Plots

The effect of soil tillage on plant growth, yield and root rot severity of beans was investigated in field plots with and without root rot infestation in 1992 and 1993. There was a significant reduction in root rot severity, and an increase in plant dry weight and yield in the root-rot-infested soils with deep tillage in both years. Deep tillage also significantly increased plant dry weight and yield in the non-root-rot soils in a dry year. The resistant cultivar (A300) had significantly less root rot damage than the susceptible cultivar (Harowood) in both root rot and non-root rot infested soils. Significant differences in plant dry weight and yield in relation to cultivars were not detected. Therefore, deep tillage can reduce soil compaction and increase yield of beans and reduce root rot severity. Key words:Phaseolus vulgaris L., deep tillage, fusarium root rot, rhizoctonia root rot, yield

Effect of Herbicides on Field Violet (Viola arvensis) in Direct-Seeded Spring Wheat

2005 ◽  
Vol 19 (2) ◽  
pp. 359-371 ◽  
Author(s):  
Rory F. Degenhardt ◽  
Dean Spaner ◽  
K. Neil Harker ◽  
William R. Mcgregor ◽  
Linda M. Hall
Keyword(s):  
Spring Wheat ◽  
Crop Production ◽  
Field Experiments ◽  
Plant Density ◽  
Dry Weight ◽  
Effective Control ◽  
Weed Species ◽  
Weed Growth ◽  
Direct Seeded ◽  
Cereal Fields

The agrestal field violet, a pervasive weed in Europe, has been identified in reduced-tillage cereal fields in Alberta. The efficacy of herbicides in direct-seeded spring wheat was assessed on natural field violet infestations in Alberta in 2002 and 2003. Only fluroxypyr + 2,4-D, applied postemergence, provided control of field violet in 2002 when rainfall was limiting. Over both years, this herbicide combination reduced biomass by 59 to 69% and plant density by 83 to 91%, relative to nontreated plots. The herbicides metsulfuron, sulfosulfuron, and thifensulfuron + tribenuron only suppressed weed growth under drought conditions in 2002 but controlled the weed in 2003 when rainfall was greater, reducing plant density by 82 to 92% and rendering remaining plants sterile. Suppression was also observed with MCPA + mecoprop + dicamba in 2002 and 2003 and with metribuzin only in 2003. Effective control of field violet was conferred by a pre–crop emergence application of glyphosate at 445 g ae/ha in 2003, the only year that this treatment was evaluated. Activity of herbicides on three- to four-leaf seedlings was also evaluated in a greenhouse dose– response assay. All herbicides had greater efficacy in the greenhouse, and those that provided control in situ reduced field violet dry weight by 85% at less than the recommended rate used in field experiments. Management of field violet is possible with herbicides registered for use on spring wheat in Alberta. However, the weed does not appear to cause significant crop production losses; hence, herbicide selection should be based on knowledge of all weed species present within the field.

scholarly journals Efficacy of Non-Chemical Weed Control during Plug Establishment of a Wildflower Meadow

2007 ◽  
Vol 25 (2) ◽  
pp. 83-88
Author(s):  
Jonathon I. Watkinson ◽  
Wallace G. Pill
Keyword(s):  
Weed Control ◽  
Panicum Virgatum ◽  
Wood Chip ◽  
Cost Effective ◽  
Dry Weight ◽  
Growing Season ◽  
Schizachyrium Scoparium ◽  
Shoot Biomass ◽  
Experimental Conditions ◽  
Weed Growth

Abstract The efficacy of non-chemical weed control during plug establishment of a wildflower meadow on glyphosate-killed turf grass was studied. Each field sub-block (not-tilled or twice-tilled to 15 cm (6 in) depth) on killed grass received the following sub-plot soil cover treatments: no cover, woven polypropylene weed fabric, double shredded hardwood/softwood mulch at 7.5 cm (3 in) depth, or fabric covered by mulch. Each 3 × 3 m (10 × 10 ft) subplot was planted in late spring with 100 plugs on 30 cm (1 ft) centers at the following frequency: Baptisia australis (10), Coreopsis lanceolata (20), Solidago speciosa (10), Panicum virgatum (20), and Schizachyrium scoparium (40). Tillage of the killed grass not only failed to benefit wildflower establishment, but increased weed shoot biomass during the second growing season. Greater wildflower shoot dry weights at 120 days after transplanting with mulch (with or without underlying fabric) than with fabric alone or no cover was associated with greater soil moisture, reduced soil temperature range, and reduced weed cover and shoot biomass. Weed fabric compared to no cover failed to affect wildflower shoot dry weights during either growing season but decreased weed growth during the second growing season. Fabric under mulch compared to mulch alone generally failed to affect wildflower growth and had no effect on weed growth during either growing season. During the second growing season, weed shoot dry weights remained low in mulched plots and remained high in non-mulched plots. Regardless of cover, wildflower shoots underwent considerable dry weight gain, while weed shoot dry weights generally remained constant or declined during the second growing season compared to the first. We conclude that, at least under our experimental conditions, applying a 7.5 cm (3 in) layer of wood chip mulch directly over glyphosate-killed turf was the most efficaceous and cost effective method of establishing a wildflower meadow using wildflower plugs. Neither placing weed fabric under the mulch nor twice-tilling the killed turf before mulch application benefitted wildflower shoot growth.

Sign in / Sign up

Export Citation Format

Share Document