Performance of Frogeye Leaf Spot-Resistant and -Susceptible Near-Isolines of Soybean

Frogeye leaf spot (FLS) caused by Cercospora sojina Hara is a disease of soybean (Glycine max (L.) Merr.) that causes significant seed yield losses in warm, humid environments of southeastern United States. The Rcs3 gene in soybean has been reported to condition resistance to all known races of C. sojina. The objectives of this study were to determine the effectiveness of Rcs3 in limiting seed yield loss due to FLS and to compare the seed yield of the resistant and susceptible near-isolines (NILs) in the absence of significant FLS disease. Four pairs of NILs—Colquitt/Colquitt-Rcs3, Gordon/Gordon-Rcs3, Thomas/Thomas-Rcs3, and Wright/Wright-Rcs 3—were evaluated in 23 field experiments in Alabama, Florida, Georgia, Louisiana, Mississippi, and South Carolina during 1992 to 1994. The amount of damage to susceptible soybean caused by FLS was dependent on the specific environment. All four of the Rcs3 NILs were resistant to the prevalent races of FLS in all environments. In the absence of significant FLS disease, each of the Rcs3 NILs was at least equal to the respective susceptible line in its seed yield. In the presence of FLS infestation, the susceptible lines suffered significant seed yield loss (up to 31%) compared to their Rcs3 NILs. The effect of FLS on seed yield was dependent on cumulative disease severity over the growing season. Thus, the area under disease progress curve was more useful than percent of leaf area infected at the end of the growing season (R7 stage of development) in explaining the seed yield loss due to FLS.

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Resistance to Frogeye Leaf Spot in Selected Soybean Accessions in MG I through MG VI

Plant Health Progress ◽

10.1094/php-2012-0521-02-rs ◽

2012 ◽

Vol 13 (1) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Alemu Mengistu ◽

Jason Bond ◽

Rouf Mian ◽

Randall Nelson ◽

Grover Shannon ◽

...

Keyword(s):

Molecular Markers ◽

Glycine Max ◽

Seed Yield ◽

Leaf Spot ◽

Yield Loss ◽

Field Trials ◽

Maturity Group ◽

Cercospora Sojina ◽

Frogeye Leaf Spot ◽

Glycine Max L

Frogeye leaf spot (FLS) caused by Cercospora sojina Hara is a disease of soybean [Glycine max (L.) Merr.] that causes significant seed yield loss in warm, humid environments worldwide. The Rcs3 gene in soybean has been reported to condition resistance to all known races of C. sojina. The objectives of this study were to: (i) identify maturity group (MG) I to VI accessions resistant to C. sojina race 11 by field screening at two locations; and (ii) determine if the FLS resistance of the symptomless soybean accessions is likely to be conditioned by the Rcs3 allele. A total of 260 accessions including 12 differentials were evaluated for reaction to race 11 in field trials in Missouri and Illinois during 2009, and 20 accessions that did not develop symptoms were retested in 2010 to validate their resistance. The 20 accessions remained resistant and were tested for the potential presence of Rcs3 allele using molecular markers; and none was predicted to carry the Rcs3 allele. These accessions may contain novel loci for FLS resistance and may be used to broaden the base for developing soybean cultivars with frogeye leaf spot resistance. Accepted for publication 16 April 2012. Published 21 May 2012.

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Interactions of shading conditions and irrigation regimes on photosynthetic traits and seed yield of soybean (Glycine max L.)

Legume Research - An International Journal ◽

10.18805/lr-359 ◽

2017 ◽

Author(s):

M. Gholamhoseini ◽

E. Ebrahimian ◽

F. Habibzadeh ◽

R. Ataei ◽

M. S. Dezfulizadeh

Keyword(s):

Seed Yield ◽

Field Experiments ◽

Photosynthetic Electron Transport ◽

Growing Season ◽

Control Treatment ◽

Shade Avoidance ◽

Acceptor Side ◽

Irrigation Regimes ◽

Transport Chain ◽

Glycine Max L

Field experiments were conducted in 2013 and 2014 with eight treatments consisting of combination of four shading periods (shading during vegetative phase (V), reproductive phase (R), whole growing season and a control treatment) and two irrigation regimes (irrigation after depleting 40 and 80 % of available water). Under limited irrigation conditions, the highest PSII quantum yield, the capacity of electrons move beyond QA and electron move from intersystem to PSI acceptor side reduced, with greater decline degree in sunlight treatment. The minimum seed yield was recorded by plants treated with limited irrigation and whole growing season shade. Changes in the state of the photosynthetic electron transport chain and photorespiration rates in response to different shading treatments were primarily related to leaf water loss. In general, the results revealed that shading caused some shade avoidance responses in soybean, which finally reduced seed production.

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Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia

Plant Disease ◽

10.1094/pdis-06-10-0454 ◽

2011 ◽

Vol 95 (3) ◽

pp. 263-268 ◽

Cited By ~ 4

Author(s):

S. K. Gremillion ◽

A. K. Culbreath ◽

D. W. Gorbet ◽

B. G. Mullinix ◽

R. N. Pittman ◽

...

Keyword(s):

United States ◽

Disease Resistance ◽

Leaf Spot ◽

Field Experiments ◽

Disease Incidence ◽

The United States ◽

Yield Potential ◽

Cercospora Arachidicola ◽

Breeding Lines ◽

Progress Curve

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

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Peanut (Arachis hypogaea L.) Response to Lactofen at Various Postemergence Timings1

Peanut Science ◽

10.3146/ps10-7.1 ◽

2012 ◽

Vol 39 (1) ◽

pp. 9-14 ◽

Cited By ~ 7

Author(s):

P. A. Dotray ◽

W. J. Grichar ◽

T. A. Baughman ◽

E. P. Prostko ◽

T. L. Grey ◽

...

Keyword(s):

Arachis Hypogaea ◽

Field Experiments ◽

Yield Loss ◽

Growing Season ◽

High Plains ◽

Application Timing ◽

Texas High Plains ◽

Arachis Hypogaea L ◽

Seed Fill ◽

Preharvest Interval

Abstract Field experiments were conducted at nine locations in Texas and Georgia in 2005 and 2006 to evaluate peanut tolerance to lactofen. Lactofen at 220 g ai/ha plus crop oil concentrate was applied to peanut at 6 leaf (lf), 6 lf followed by (fb) 15 days after the initial treatment (DAIT), 15 DAIT alone, 6 lf fb 30 DAIT, 30 DAIT alone, 6 lf fb 45 DAIT, 45 DAIT alone, 6 lf fb 60 DAIT, and 60 DAIT alone in weed-free plots. Lactofen caused visible leaf bronzing at all locations. Yield loss was observed when applications were made 45 DAIT, a timing that would correspond to plants in the R5 (beginning seed) to R6 (full seed) stage of growth. At all locations except the Texas High Plains, this application timing was within the 90 d preharvest interval. Growers who apply lactofen early in the peanut growing season to small weeds should have confidence that yields will not be negatively impacted despite dramatic above-ground injury symptoms; however, applications made later in the season, during seed fill, may adversely affect yield.

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Improved Management Efficacy of Late Leaf Spot on Peanut Through Combined Application of Prothioconazole with Fluxapyroxad and Pyraclostrobin

Agronomy ◽

10.3390/agronomy10020298 ◽

2020 ◽

Vol 10 (2) ◽

pp. 298 ◽

Cited By ~ 3

Author(s):

Daniel J. Anco ◽

Justin B. Hiers ◽

James S. Thomas

Keyword(s):

South Carolina ◽

Leaf Spot ◽

Yield Loss ◽

Integrated Management ◽

Commercial Production ◽

Yield Potential ◽

Independent Action ◽

Late Leaf Spot ◽

Critical Part ◽

Combined Application

Late leaf spot, caused by Nothopassalora personata, is the most economically important fungal disease affecting peanut foliage in South Carolina and can result in combined management and yield loss costs of greater than 490 dollars/ha. Application of protectant fungicides is a critical part of effective integrated management under commercial production, and their strategic alternation and combination in management programs can provide enhanced control. Trials were conducted in Blackville, SC, from 2017 to 2019 to investigate whether combinations of prothioconazole with fluxapyroxad plus pyraclostrobin could provide more efficacious management of late leaf spot compared to either product alone. Two applications of 0.11 kg/ha prothioconazole with 0.05 kg/ha fluxapyroxad plus 0.1 kg/ha pyraclostrobin resulted in significantly (p < 0.05) less (24% to 42%) peanut canopy defoliation compared to the same number of applications of either product applied individually, with the combined application reflecting significant (p < 0.0202) synergism compared to component products as assessed through independent action methodology. An increased rate of fluxapyroxad plus pyraclostrobin application (0.1 and 0.2 kg/ha, respectively), with 0.16 kg/ha prothioconazole did not improve management relative to their combination at the examined lower rate (p = 0.89). Peanut yield was not adversely affected following combined applications. Cost-effectiveness of this combination depends on the actual disease intensity and yield potential of a given crop.

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Influence of Broadleaf Weeds on Chlorothalonil Deposition, Foliar Disease Incidence, and Peanut (Arachis hypogaea) Yield

Weed Technology ◽

10.1017/s0890037x00041336 ◽

1997 ◽

Vol 11 (1) ◽

pp. 51-58 ◽

Cited By ~ 14

Author(s):

Stanley S. Royal ◽

Barry J. Brecke ◽

Frederick M. Shokes ◽

Daniel L. Colvin

Keyword(s):

Arachis Hypogaea ◽

Leaf Spot ◽

Field Experiments ◽

Yield Loss ◽

Disease Incidence ◽

Weed Biomass ◽

Late Leaf Spot ◽

Foliar Disease ◽

Weed Density ◽

Weed Plants

Field experiments were conducted at Jay and Marianna, FL in 1988 and 1989 to determine the effects of sicklepod, Florida beggarweed, and common cocklebur density on chlorothalonil deposition to peanut foliage, peanut foliar disease incidence, and peanut yield. At a density of four weed plants per 8 m of row, Florida beggarweed and sicklepod reduced chlorothalonil deposition on peanut foliage by 20%, while common cocklebur reduced fungicide deposition by 34%. At the same density, incidence of the foliar diseases early leaf spot and late leaf spot increased 10% with Florida beggarweed, 14% with sicklepod, and 20% with common cocklebur compared with weed-free peanut. The predicted peanut yield loss from a weed density of four plants per 8 m was 16 to 19% for Florida beggarweed, 23 to 25% for sicklepod, and 31 to 39% for common cocklebur. Weed biomass increased with increasing weed density.

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CANOLA YIELD AND PROFITABILITY AS INFLUENCED BY VOLUNTEER WHEAT INFESTATIONS

Canadian Journal of Plant Science ◽

10.4141/cjps89-145 ◽

1989 ◽

Vol 69 (4) ◽

pp. 1235-1244 ◽

Cited By ~ 11

Author(s):

J. T. O’DONOVAN ◽

K. J. KIRKLAND ◽

A. K. SHARMA

Keyword(s):

Triticum Aestivum ◽

Multiple Regression ◽

Seed Yield ◽

Field Experiments ◽

Yield Loss ◽

Brassica Campestris ◽

Triticum Aestivum L ◽

Economic Threshold ◽

Rectangular Hyperbola

The effects of different densities of volunteer wheat (Triticum aestivum L. ’Neepawa’) on the yield of canola (Brassica campestris L. ’Tobin’ and B. napus L. ’Westar’), and the seed yield of the volunteer wheat were determined in field experiments conducted at Vegreville, Alberta and Scott, Saskatchewan. Hyperbolic models provided a good fit to the data in most instances and indicated that volunteer wheat can severely reduce canola yield. A model pooled over locations and years indicated that volunteer wheat populations as low as one plant m−2 reduced canola yield by approximately 1%. Yield loss predictions from the models were used to determine the economics of volunteer wheat control with herbicides. In some cases, revenue losses due to reduced canola yield could be alleviated when the value of the volunteer wheat was considered.Key words: Volunteer wheat, canola, rectangular hyperbola, multiple regression, economic threshold, volunteer cereals

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Field Pea and Lentil Tolerance to Interrow Cultivation

Weed Technology ◽

10.1017/wet.2017.90 ◽

2017 ◽

Vol 32 (2) ◽

pp. 205-210 ◽

Cited By ~ 1

Author(s):

Katherine A. Stanley ◽

Steven J. Shirtliffe ◽

Dilshan Benaragama ◽

Lena D. Syrovy ◽

Hema S. N. Duddu

Keyword(s):

Weed Control ◽

Field Experiments ◽

Yield Loss ◽

Growing Season ◽

Field Pea ◽

Crop Damage ◽

Growth Stages ◽

Row Crops ◽

Narrow Row ◽

Mechanical Weed Control

AbstractInterrow cultivation is a selective, in-crop mechanical weed control tool that has the potential to control weeds later in the growing season with less crop damage compared with other in-crop mechanical weed control tools. To our knowledge, no previous research has been conducted on the tolerance of narrow-row crops to interrow cultivation. The objective of this experiment was to determine the tolerance of field pea and lentil to interrow cultivation. Replicated field experiments were conducted in Saskatchewan, Canada, in 2014 and 2015. Weekly cultivation treatments began at the 4-node stage of each crop, continuing for 6 wk. Field pea and lentil yield linearly declined with later crop stages of cultivation. Cultivating multiple times throughout the growing season reduced yield by 15% to 30% in both crops. Minimal yield loss occurred when interrow cultivation was conducted once at early growth stages of field pea and lentil; however, yield loss increased with delayed and more frequent cultivation events.

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Dual-purpose canola—a new opportunity in mixed farming systems

Australian Journal of Agricultural Research ◽

10.1071/ar07285 ◽

2008 ◽

Vol 59 (4) ◽

pp. 291 ◽

Cited By ~ 61

Author(s):

J. A. Kirkegaard ◽

S. J. Sprague ◽

H. Dove ◽

W. M. Kelman ◽

S. J. Marcroft ◽

...

Keyword(s):

Seed Yield ◽

Compensatory Growth ◽

Field Experiments ◽

Yield Loss ◽

Growth Yield ◽

Farming Systems ◽

Gross Margin ◽

Dual Purpose ◽

Trade Offs ◽

Spring Canola

The term dual-purpose canola describes the use of a canola crop for forage before seed production. It could potentially provide a profitable and flexible break-crop option for mixed farms, but there have been no studies to test the concept in Australia. We investigated the feasibility of using canola in this way in field experiments near Canberra, Australia, from 2004 to 2006, using European winter and mid–late maturing Australian spring canola varieties. Winter varieties sown from early March to mid-April produced 2.5–5.0 t/ha of biomass providing 0.3–3.5 t/ha of high-quality forage grazed by sheep in winter. The spring varieties produced similar amounts of vegetative biomass from April sowing but were unsuited to the earlier March sowing as they flowered in early winter and did not recover from grazing. The canola forage was readily eaten by sheep; alkane-based estimates of diet composition indicated that >85% of the organic matter intake consisted of canola. Canola forage was also highly digestible (86–88%) and Merino hoggets grew at 210 g/day from a dry matter intake of 1530 g DM/day. The canola generally recovered well when grazed in winter before bud elongation. Delays in flowering associated with heavy grazing ranged from 0 to 4 days when grazed before buds were visible, to 28 days if the crop had commenced flowering. Significant delays in flowering (>14 days) associated with winter grazing did not reduce seed yield or oil content when favourable spring conditions allowed compensatory growth. Yield loss was observed when winter and spring conditions were unfavourable for compensatory growth, or if grazing continued too late into spring (late September) irrespective of seasonal conditions. The yield loss was more than offset by the value of the grazed forage and the mean gross margin for dual-purpose canola over the four experiments was $240 to $500 higher than for grain-only canola depending on the value assumed for the forage. The study indicates there is considerable scope to capture value from grazing early-sown canola crops during winter without significant, uneconomic trade-offs with seed yield. Further investigations in other medium to high rainfall environments in southern Australia are warranted.

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Impact of Foliar Fungicides on Frogeye Leaf Spot Severity, Radiation Use Efficiency and Yield of Soybean in Iowa

Agronomy ◽

10.3390/agronomy11091785 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1785

Author(s):

Xavier A. Phillips ◽

Yuba R. Kandel ◽

Daren S. Mueller

Keyword(s):

Leaf Spot ◽

Health Indicators ◽

Radiation Use Efficiency ◽

Growing Seasons ◽

Frogeye Leaf Spot ◽

Aerial Vehicle ◽

Glycine Max L ◽

Use Efficiency ◽

The Impact ◽

Radiation Use

Frogeye leaf spot, caused by Cercospora sojina K. Hara, is a major soybean (Glycine max L. Merr.) disease that has become more prevalent in the upper Midwest and can be managed with foliar fungicides. Incorporating disease severity into a parameter directly related to yield may better relay the impact of disease on yield and yield components than severity alone. Experiments during the 2018 and 2019 growing seasons in fields located in north central and southwestern Iowa were completed to (i) determine how foliar fungicides affected frogeye leaf spot, remotely sensed plant health indicators, and soybean yield, and (ii) compare the relationship and impact of foliar fungicides and frogeye leaf spot on radiation-use efficiency (RUE) estimated using unmanned aerial vehicle reflectance data. Fungicides affected frogeye severity and yield in one of the three locations; in Lewis 2018, the flutriafol + fluoxastrobin treatment reduced frogeye leaf spot severity by over 50% and increased yield by 19% compared to non-treated controls. Applications of foliar fungicides increased canopy coverage compared to non-treated controls (p = 0.012), but NDVI, SPAD values, and RUE values did not differ between fungicide treatments at all three locations. Estimated soybean RUE values (1.05 to 1.66 g Mj−1) were within the range of known values. Overall, this study indicates that RUE can be a valuable resource to estimate the impact of the disease on yield, however, additional research will be needed to use RUE within certain pathosystems.

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