scholarly journals Timing of Strobilurin Fungicide for Control of Top Dieback in Corn

2017 ◽  
Vol 18 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Eric Adee ◽  
Stewart Duncan
Keyword(s):  
Zea Mays L ◽  
Field Studies ◽  
The Other ◽  
Colletotrichum Graminicola ◽  
Yield Losses ◽  
Fungicide Application ◽  
Dent Corn ◽  
Untreated Check ◽  
Strobilurin Fungicide ◽  
Significant Yield

Significant yield losses can result from top dieback (TDB) in dent corn (Zea mays L.), which is caused by infection by the fungus Colletotrichum graminicola, which also causes anthracnose. Research on the effectiveness of fungicide application is limited because of the unpredictable nature of the disease. Three field studies were established to assess the timing of fungicide application for foliar diseases that developed TDB, one in Illinois (2010) and the other two in Kansas (2015 and 2016). Fungicide applications at tasseling and later were effective in reducing the incidence of TDB by over 20% and increasing yield over 900 kg/ha, or over 7%, while earlier applications (V5 to V8) did not reduce TDB nor increase yield compared with the untreated check.

scholarly journals Epidemics and Yield Losses due to Corynespora cassiicola on Cotton

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2494-2499 ◽  
Author(s):  
Kira L. Bowen ◽  
Austin K. Hagan ◽  
Malcolm Pegues ◽  
Jarrod Jones ◽  
H. Brad Miller
Keyword(s):  
Disease Onset ◽  
Yield Response ◽  
Corynespora Cassiicola ◽  
Yield Losses ◽  
Fungicide Application ◽  
Target Spot ◽  
Significant Yield ◽  
Epidemic Development ◽  
Gompertz Growth Model ◽  
Better Than

Target spot, caused by Corynespora cassiicola, has recently emerged as a problematic foliar disease of cotton. This pathogen causes premature defoliation during boll set and maturation that can subsequently impact yield, and on certain cotton cultivars loss can be substantial. This study sought to better understand target spot epidemics and disease-incited yield losses on cotton. In order to establish a range of disease, varying numbers of fungicide applications were made to each of two cotton cultivars in each of four site-years. Target spot intensity was rated over several dates beginning in late July or early August and continuing into September. Yield of seed plus lint (seed cotton) was recorded at harvest. When analyzed across cultivars, a second or third fungicide application increased yield compared with no treatment. Lack of significant yield response with a single fungicide application may have been due to timing of that application which preceded disease onset. The cultivar PhytoGen 499 WRF had consistently greater defoliation than any of the three Deltapine cultivars grown in each site-year. However, yields of both cultivars responded similarly to the fungicide regimes. Yield loss models based on late August defoliation were only predictive at site-years where conditions favored target spot development, i.e., abundant rain and moderate temperatures. Epidemic development fit the Gompertz growth model better than it did a logistic model. Knowledge of the underlying mathematical character of the epidemiology of target spot will prove useful for development of a predictive model for the disease.

scholarly journals Effect of Foliar Fungicides on Late-season Anthracnose Stem Blight on Soybean

2014 ◽  
Vol 15 (3) ◽  
pp. 118-121 ◽  
Author(s):  
Nathan R. C. Bestor ◽  
Alison E. Robertson ◽  
Daren S. Mueller
Keyword(s):  
Yield Components ◽  
Field Studies ◽  
Specific Yield ◽  
Colletotrichum Truncatum ◽  
Symptom Development ◽  
Yield Losses ◽  
Application Timing ◽  
Late Season ◽  
Fungicide Application ◽  
Stem Blight

Anthracnose stem blight, caused by Colletotrichum truncatum, is responsible for soybean (Glycine max) yield losses in subtropical and tropical growing regions. There are inadequate data regarding the effect of anthracnose stem blight on yield in Iowa, and it is unknown if fungicide application can manage this disease. Field studies were conducted from 2008 to 2010 to determine the effect of fungicide application timing on late-season development of this disease. We also investigated the effect of anthracnose stem blight on yield and specific yield components. Fungicides reduced late-season symptom development when compared to the untreated control; however, there were no differences in yield and yield components. While foliar fungicides can reduce late-season disease development, anthracnose stem blight typically should not affect crop management decisions involving use of foliar fungicides on soybean in Iowa. Accepted 7 July 2014. Publication 14 August 2014.

Harvest pruning of young Sultana vines under various training systems

1978 ◽  
Vol 18 (95) ◽  
pp. 847 ◽  
Author(s):  
P May ◽  
PR Clingeleffer ◽  
CJ Brien ◽  
PB Scholefield
Keyword(s):  
The Other ◽  
Bud Burst ◽  
Harvest Time ◽  
Yield Losses ◽  
Training Systems ◽  
Four Seasons ◽  
Significant Yield ◽  
Second Year ◽  
Split System

Trellis drying of Sultana grapes necessitates the severing of the fruit bearing canes from the vine at harvest time (Harvest pruning, HP). Two experiments have shown that HP of young vines, from the beginning of cropping onwards, caused no greater yield losses than those reported for mature vines, viz 10 per cent. In one experiment, HP gave significant yield reductions over six seasons, amounting to about 7 per cent, apparently due to fewer berries per bunch. Vines harvest pruned only every second year suffered losses mainly in the season following HP. In the other experiment, HP did not cause any loss of yield over four seasons. With or without HP, vines on a 0.9 m and 1.2 m wide T-trellis yielded about 20 per cent more than vines on a 0.3 m trellis, apparently because of better bud burst. Providing vines with two trunks, each producing the crop or replacement shoots only in alternate seasons, did not prevent HP losses. Such vines yielded similarly to one-trunk vines while vines with one trunk and planted in pairs yielded less. A 'split system' of training was used where each vine had all fruiting canes placed on one trellis wire whilst spurs producing all replacement shoots were trained on the other wire, the arrangement alternating down the row from vine to vine. HP of such vines was more than twice as fast as that of conventionally trained vines; other management advantages are discussed.

scholarly journals Yield Losses Due to Crown Rust in Winter Oats in Alabama

2016 ◽  
Vol 17 (2) ◽  
pp. 95-100 ◽  
Author(s):  
K. L. Bowen ◽  
A. K. Hagan ◽  
M. Pegues ◽  
J. Jones
Keyword(s):  
Flag Leaf ◽  
Relative Yield ◽  
Field Studies ◽  
Crown Rust ◽  
Common Disease ◽  
Yield Losses ◽  
Application Timing ◽  
Fungicide Application ◽  
Head Extension ◽  
Better Than

Crown rust is a common disease on winter oats in Alabama. While considered the most destructive disease of oats, little has been done in recent years, with current cultivars, to demonstrate yield losses due to crown rust. Field studies were conducted to determine the effect of fungicides and application timing on crown rust severity and yield. All fungicides reduced crown rust and improved yield. Two fungicide applications were better than a single fungicide application for reducing crown rust. Relative to yield, a single fungicide application during flag leaf development (FS 8-9) was better than a single application during head extension (FS 10.3). When compared with the non-treated control, significant yield gains were obtained with Tilt and Headline in all four years and Stratego YLD in three of four years. Fungicide programs resulted in a broad range of crown rust severities; disease levels were highly related to decreases in yield in each of four years. In two study years, ‘Coker 227’ was more damaged by crown rust, with about 10% yield loss for each unit disease, than was ‘Horizon 270,’ with 2.5 to 4.5% loss. However, in 2013, virulence patterns of the crown rust pathogen shifted and disease on Horizon 270 was greater than that on Coker 227; relative yield losses were also much lower in 2013. Accepted for publication 15 April 2016. Published 4 May 2016.

ATRAZINE PERSISTENCE AND RESIDUE EFFECTS ON ROTATION CROPS

1985 ◽  
Vol 65 (2) ◽  
pp. 363-368 ◽  
Author(s):  
J. A. IVANY ◽  
J. M. SADLER ◽  
E. R. KIMBALL ◽  
K. B. McRAE
Keyword(s):  
Prince Edward Island ◽  
Trifolium Pratense ◽  
Sandy Loam ◽  
Red Clover ◽  
Field Studies ◽  
Phleum Pratense ◽  
Winter Rye ◽  
Yield Losses ◽  
Hordeum Vulgare L ◽  
Significant Yield

Field studies on Prince Edward Island (P.E.I.) loam to fine sandy loam soils from 1977 to 1980 determined the rate of breakdown of atrazine and soil residue effects on crops grown in rotation with silage corn (Zea mays L.). The rate of breakdown was rapid during the first 30 days after application with an estimated half-life of 23 days when averaged over rates and years. Timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) were most sensitive to atrazine residues; yields of red clover were reduced significantly from the 1.13-kg/ha rate and of timothy after the 2.25-kg/ha rate. Yields of winter rye (Secale cereale L.) broadcast seeded in standing corn in August and barley (Hordeum vulgare L.) seeded the next spring were not affected, or reduced only slightly, by atrazine residues from initial applications of 1.13 kg/ha but showed significant yield losses at the 2.25- and 4.50-kg/ha rates. Alfalfa (Medicago sativa L.) seeded the next spring after atrazine use was tolerant of residues showing significant yield losses only at the 4.50-kg/ha rate. In this study, atrazine applied at 1.13 kg/ha in silage corn was sufficiently broken down to permit production of all crops studied except red clover.Key words: Atrazine, residue, clover (red), timothy, alfalfa, rye (winter), barley

scholarly journals Characterization of Maize Genotypes (Zea mays L.) for Resistance to Striga asiatica and S. hermonthica and Compatibility with Fusarium oxysporum f. sp. strigae (FOS) in Tanzania

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1004
Author(s):  
John Lobulu ◽  
Hussein Shimelis ◽  
Mark D. Laing ◽  
Arnold Angelo Mushongi ◽  
Admire Isaac Tichafa Shayanowako
Keyword(s):  
Grain Yield ◽  
Fusarium Oxysporum ◽  
Biocontrol Agent ◽  
Zea Mays L ◽  
Control Treatment ◽  
Yield Reduction ◽  
Maize Genotypes ◽  
Significant Yield ◽  
The Mean

Striga species cause significant yield loss in maize varying from 20 to 100%. The aim of the present study was to screen and identify maize genotypes with partial resistance to S. hermonthica (Sh) and S. asiatica (Sa) and compatible with Fusarium oxysporum f. sp. strigae (FOS), a biocontrol agent. Fifty-six maize genotypes were evaluated for resistance to Sh and Sa, and FOS compatibility. Results showed that FOS treatment significantly (p < 0.001) enhanced Striga management compared to the untreated control under both Sh and Sa infestations. The mean grain yield was reduced by 19.13% in FOS-untreated genotypes compared with a loss of 13.94% in the same genotypes treated with FOS under Sh infestation. Likewise, under Sa infestation, FOS-treated genotypes had a mean grain yield reduction of 18% while untreated genotypes had a mean loss of 21.4% compared to the control treatment. Overall, based on Striga emergence count, Striga host damage rating, grain yield and FOS compatibility, under Sh and Sa infestations, 23 maize genotypes carrying farmer preferred traits were identified. The genotypes are useful genetic materials in the development of Striga-resistant cultivars in Tanzania and related agro-ecologies.

scholarly journals Comparative Genomics Used to Predict Virulence Factors and Metabolic Genes among Monilinia Species

2021 ◽  
Vol 7 (6) ◽  
pp. 464
Author(s):  
Marina Marcet-Houben ◽  
Maria Villarino ◽  
Laura Vilanova ◽  
Antonieta De Cal ◽  
Jan A. L. van Kan ◽  
...  
Keyword(s):  
Brown Rot ◽  
Weather Conditions ◽  
Genomic Variation ◽  
Disease Development ◽  
Stone Fruits ◽  
Yield Losses ◽  
Future Studies ◽  
Metabolic Genes ◽  
Pome Fruits ◽  
Significant Yield

Brown rot, caused by Monilinia spp., is among the most important diseases in stone fruits, and some pome fruits (mainly apples). This disease is responsible for significant yield losses, particularly in stone fruits, when weather conditions favorable for disease development appear. To achieve future sustainable strategies to control brown rot on fruit, one potential approach will be to characterize genomic variation among Monilinia spp. to define, among others, the capacity to infect fruit in this genus. In the present work, we performed genomic and phylogenomic comparisons of five Monilinia species and inferred differences in numbers of secreted proteins, including CAZy proteins and other proteins important for virulence. Duplications specific to Monilinia were sparse and, overall, more genes have been lost than gained. Among Monilinia spp., low variability in the CAZome was observed. Interestingly, we identified several secondary metabolism clusters based on similarity to known clusters, and among them was a cluster with homology to pyriculol that could be responsible for the synthesis of chloromonilicin. Furthermore, we compared sequences of all strains available from NCBI of these species to assess their MAT loci and heterokaryon compatibility systems. Our comparative analyses provide the basis for future studies into understanding how these genomic differences underlie common or differential abilities to interact with the host plant.

scholarly journals Quantification of Avoidable Yield Losses in Oilseed Brassica Caused by Insect Pests

2011 ◽  
Vol 51 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Jagdev Kular ◽  
Sarwan Kumar
Keyword(s):  
Seed Yield ◽  
Yield Loss ◽  
Insect Pests ◽  
Block Design ◽  
Maximum Yield ◽  
The Other ◽  
Yield Losses ◽  
Eruca Sativa ◽  
Mustard Aphid ◽  
Randomized Block Design

Quantification of Avoidable Yield Losses in OilseedBrassicaCaused by Insect PestsA six year field study was conducted from 2001-2002 to 2006-2007 at Punjab Agricultural University, Ludhiana, India to study the losses in seed yield of differentBrassicaspecies (B. juncea, B. napus, B. carinata, B. rapaandEruca sativa) by the infestation of insect pests. The experiment was conducted in two different sets viz. protected/sprayed and unprotected, in a randomized block design, with three replications. Data on the infestation of insect pests, and seed yield were recorded at weekly intervals and at harvest, respectively. The loss in seed yield, due to mustard aphid and cabbage caterpillar, varied from 6.5 to 26.4 per cent.E. sativasuffered the least loss in seed yield and harboured the minimum population of mustard aphid (2.1 aphids/plant) and cabbage caterpillar (2.4 larvae/plant). On the other hand,B. carinatawas highly susceptible to the cabbage caterpillar (26.2 larvae/plant) and suffered the maximum yield loss (26.4%).

scholarly journals Inheritance of Antibiosis Resistance to the Dectes Stem Borer, Dectes texanus, in Soybean PI165673

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 738
Author(s):  
Lina M. Aguirre-Rojas ◽  
Lawrent L. Buschman ◽  
Brian McCornack ◽  
William T. Schapaugh ◽  
Erin D. Scully ◽  
...  
Keyword(s):  
North America ◽  
Larval Stage ◽  
Stem Borer ◽  
Plant Introduction ◽  
Lower Number ◽  
Soybean Plant ◽  
Yield Losses ◽  
First Instar ◽  
Significant Yield ◽  
Antibiosis Resistance

Dectes texanus larvae girdles the stems of soybean and cultivated sunflowers causing significant yield losses in North America. The soybean Plant Introduction (PI) 165673 exhibits antibiosis resistance to the larval stage. The objectives of this study were: (1) to determine the inheritance of D. texanus resistance in PI165673; (2) evaluate PI165673 antibiosis resistance before 21 d post infestation; (3) evaluate girdling damage in PI16563 at the end of the season. K07-1544/PI165673 F2 and F2:3 populations were tested for resistance to D. texanus in 2011 and 2012, and PI165673 antibiosis resistance and girdling damage were evaluated in 2014. Segregation for resistance to D. texanus and heritability estimates in the F2 and F2:3 populations indicated that resistance was controlled by two genes with dominant and recessive epistasis. Antibiosis evaluations indicated: (1) PI165673 contained lower number of larvae and eggs relative to the number of oviposition punctures at 15 d post infestation; (2) the proportion of first-instar larvae was higher in PI165673 at 15 d post infestation; (3) larvae reach the sixth-instar stage in PI165673. None of the PI165673 plants were girdled at the end of the season. Identification of additional sources of D. texanus resistance is required to impair larval development in the stem.

Fungicide efficacy on tar spot and yield of corn in the Midwestern United States

2022 ◽  
Author(s):  
Darcy E. P. Telenko ◽  
Martin I. Chilvers ◽  
Adam Byrne ◽  
Jill Check ◽  
Camila Rocco Da Silva ◽  
...  
Keyword(s):  
United States ◽  
Growth Stage ◽  
Field Trials ◽  
Corn Belt ◽  
Yield Losses ◽  
Single Application ◽  
Midwestern United States ◽  
Tar Spot ◽  
Significant Yield ◽  
Foliar Fungicide

Tar spot of corn caused by Phyllachora maydis has recently led to significant yield losses in the eastern corn belt of the Midwestern United States. Foliar fungicides containing quinone outside inhibitors(QoI), demethylation inhibitors(DMI), and succinate dehydrogenase inhibitors(SDHI) are commonly used to manage foliar diseases in corn. To mitigate the losses from tar spot thirteen foliar fungicides containing single or multiple modes of action (MOA/FRAC groups) were applied at their recommended rates in a single application at the standard tassel/silk growth stage timing to evaluate their efficacy against tar spot in a total of eight field trials in Illinois, Indiana, Michigan, and Wisconsin during 2019 and 2020. The single MOA fungicides included either a QoI or DMI. The dual MOA fungicides included a DMI with either a QoI or SDHI, and fungicides containing three MOAs included a QoI, DMI, and SDHI. Tar spot severity estimated as the percentage of leaf area covered by P. maydis stroma of the non-treated control at dent growth stage ranged from 1.6 to 23.3% on the ear leaf. Averaged across eight field trials all foliar fungicide treatments reduced tar spot severity, but only prothioconazole+trifloxystrobin, mefentrifluconazole+pyraclostrobin+fluxapyroxad, and mefentrifluconazole+pyraclostrobin significantly increased yield over the non-treated control. When comparing fungicide treatments by the number of MOAs foliar fungicide products that had two or three MOAs decreased tar spot severity over not treating and products with one MOA. The fungicide group that contained all three MOAs significantly increased yield over not treating with a fungicide or using a single MOA.

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