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Full-Text Articles in Life Sciences
Impact Of New Technologies On Weed Control In Louisiana Rice Production, David C. Walker
Impact Of New Technologies On Weed Control In Louisiana Rice Production, David C. Walker
LSU Doctoral Dissertations
Field studies were conducted in 2018-2021 at the LSU Agricultural Center’s H.R. Caffey Rice Research Station (RRS) near Crowley, LA, and the Dean Lee Research and Extension Center (DLREC) near Alexandria, LA to evaluate off-target florpyrauxifen movement on soybean. Soybean was treated with florpyrauxifen at the V4-V5 or R1-R2 growth stages. Soybean injury was evaluated at 1, 7, 14, and 28 days after treatment (DAT) and soybean plant height (cm) was recorded at 7, 14, and 28 DAT. At soybean maturity, yield and individual yield components were subjected to regression analysis to describe the relationship between florpyrauxifen rate and soybean …
Cover Cropping In Soybean-Corn Rotation System: Economic, Agronomic, And Soil Fertility Impact, Jose Rodolfo Mite
Cover Cropping In Soybean-Corn Rotation System: Economic, Agronomic, And Soil Fertility Impact, Jose Rodolfo Mite
LSU Doctoral Dissertations
Planting winter-annual cover crops prevent soil erosion, reduces water runoff, and improves soil structure and soil quality. This research was conducted from 2017 to 2019 to evaluate the nutrient turnover of different species of cover crops in soils under different row crop production systems in Northeast and Central Louisiana. In Northeast Louisiana (Site 1, 2, and 3), treatments (cover crops and no cover crop) were arranged in a strip trial with three replications. At the Ben Hur Research Station, the treatments included three planting dates (September, October, and November) with [7 kg ha-1 of phosphorus (P) and potassium (K)] …
Evaluation Of Soil Type And Seeding Rate On Winter Cover Crop Species In A Soybean Production System, Donna S. Morgan
Evaluation Of Soil Type And Seeding Rate On Winter Cover Crop Species In A Soybean Production System, Donna S. Morgan
LSU Doctoral Dissertations
The integration of winter annual cover crops into a cropping system can potentially improve soil health and crop production, however, the impact of variables such as seeding rates, across two very different soil types, has not been well documented. A two-year study was conducted at the Dean Lee Research Station and Extension Center in Alexandria, Louisiana to evaluate the effects of cover crop seeding rate and soil type on cover crop biomass, weed suppression, soil fertility, and soybean (Glycine max L) growth and yield. Analysis of potential economic impacts was also performed to estimate financial net returns for three …
Soybean Response To Dicamba: Associated Injury Criteria And Development Of A Model To Predict Yield Loss, Matthew Ryan Foster
Soybean Response To Dicamba: Associated Injury Criteria And Development Of A Model To Predict Yield Loss, Matthew Ryan Foster
LSU Doctoral Dissertations
In research conducted using indeterminate soybean [Glycine max (L.) Merr.], fourteen injury criteria observed following dicamba at 0.6 to 280 g ae ha-1 (1/1000 to ½ of 560 g ha-1 use rate) were rated using a scale of 0= no injury, 1= slight, 2= slight to moderate, 3= moderate, 4= moderate to severe, and 5= severe. Greatest crop injury 15 d after treatment (DAT) was observed following dicamba applied at 0.6 to 4.4 g ha-1 at V3/V4 for upper canopy pale leaf margins (3.8 to 4.2) and at R1/R2 for terminal leaf cupping (4.1 to 5.0) …
Incorporation Of Biorationals And Trap Crop For Stink Bug Management In Soybeans, Kukuh Hernowo
Incorporation Of Biorationals And Trap Crop For Stink Bug Management In Soybeans, Kukuh Hernowo
LSU Doctoral Dissertations
Stink bugs are one of the most important seed sucking pests impacting soybean production in Louisiana. Exploration of chemicals that exhibit attraction or repellent activities toward this major pest would be beneficial to develop a push-pull strategy against this pest complex. Spinosad and neem are two commercially available natural insecticides that were claimed to have attractant and repellent activities against stink bugs. To test the potential of these chemicals, a series of experiments was conducted to investigate the olfactory, tactile, feeding, and oviposition preference of stink bugs toward different commercial spinosad products and neem. Additionally, two years of field experiments …
Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward
Documentation Of Siderophore Activity, Metal Binding, And Its Effect On Symptomatology Of Cercospora Leaf Blight Caused In Soybean By Cercosporin From Cercospora Cf. Flagellaris, Brian Michael Ward
LSU Doctoral Dissertations
Cercospora leaf blight of soybean (Glycine max) is a serious problem in the mid-south of the United States and is present in most soybean-growing regions of the world. The causal organisms, Cercospora kikuchii, C. cf. flagellaris and C. cf. sigesbeckiae, utilize the photo-activated toxin cercosporin as the primary pathogenicity factor. The disease has historically been understood to progress from a purpling or bronzing of the leaves to a blight in which tissue dies. Previous literature showed possible binding of cercosporin to metals and previous work in our group showed possible use of minor element nutrition in the plant to reduce …
The Roles Of Avr4 In Fungal Virulence,Cercosporin Biosynthesis And Its Potential Use In Host Induced Gene Silencing For Controlling Cercospora Leaf Blight Disease Of Soybeans, Josielle Santos Rezende
The Roles Of Avr4 In Fungal Virulence,Cercosporin Biosynthesis And Its Potential Use In Host Induced Gene Silencing For Controlling Cercospora Leaf Blight Disease Of Soybeans, Josielle Santos Rezende
LSU Doctoral Dissertations
The AVR4 effector, secreted by Cladosporium fulvum, has been demonstrated to be involved in pathogen virulence. Recent studies further demonstrated that Avr4 is highly conserved among several Cercospora species, indicating a potential important role of this gene in fungal virulence. Therefore, investigation to determine whether this fungal effector gene is present in Cercospora cf. flagellaris (previously known as C. kikuchii), the causal agent of soybean cercospora leaf blight (CLB) disease, and whether it plays any role in CLB disease development, is of great interest. In the present study, the Avr4 gene from C. cf. flagellaris was cloned and mutants lacking …
Sensitivity And Resistance Of Cercospora Kikuchii, Causal Agent Of Cercospora Leaf Blight And Purple Seed Stain Of Soybean, To Selected Fungicides, Paul Patrick Price, Iii
Sensitivity And Resistance Of Cercospora Kikuchii, Causal Agent Of Cercospora Leaf Blight And Purple Seed Stain Of Soybean, To Selected Fungicides, Paul Patrick Price, Iii
LSU Doctoral Dissertations
ABSTRACT Isolates of Cercospora kikuchii, the causal agent of Cercospora leaf blight (CLB) and purple seed stain (PSS), were used to determine baseline sensitivities to selected quinone outside inhibitor (QoI) and demethylation inhibitor (DMI) fungicides by conducting radial growth assays on fungicide-amended media. The effective concentration to inhibit 50% radial growth (EC50) for each isolate was calculated by linear interpolation of the dose-response relationship. All baseline distributions were non-normal with outliers towards the less sensitive ends of the spectra, and median EC50 values for azoxystrobin, pyraclostrobin, trifloxystrobin, flutriafol, propiconazole, and tetraconazole were 0.081, 0.013, 0.012, 0.273, 0.143, 1.47 µg/ml, respectively. …
Simplicillium Lanosoniveum, A Mycoparasite Of Phakopsora Pachyrhizi And Its Use As A Biological Control Agent, Nicole A. Ward
Simplicillium Lanosoniveum, A Mycoparasite Of Phakopsora Pachyrhizi And Its Use As A Biological Control Agent, Nicole A. Ward
LSU Doctoral Dissertations
In 2007, a filamentous fungus was recovered from sori of soybean rust (SBR), caused by Phakopsora pachyrhizi, collected from Louisiana and Florida. This fungus was identified as Simplicillium lanosoniveum on the basis of ITS sequence data and morphological traits. Simplicillium lanosoniveum was found coiling within sori and around urediniospores and showed a trophic attraction to rust sori, extending from sorus to sorus. In co-inoculated soybean leaves, the fungus did not grow or establish on leaf surfaces until sori erupted. Similarly, S. lanosoniveum colonized within 3 days and sporulated within 4 days on leaves showing disease symptoms. In field studies, when …
Isoflavone Distribution In Soy Seed And Antioxidant Activity Of Defatted Soy Flour Extract, Xiaohua Yue
Isoflavone Distribution In Soy Seed And Antioxidant Activity Of Defatted Soy Flour Extract, Xiaohua Yue
LSU Doctoral Dissertations
Soy isoflavones distribution in soy cotelydon, coat and germ were determined. The ƒÀ-Glucoside form of isoflavones was the major class of isoflavones in all three soy parts. Soy germ was the richest source of the isoflavones among the three soybean parts. Distribution of the isoflavones in soy cotyledon was different from that in soy coat or germ. As defatted soy flour is a main byproduct in the soy oil refining process, utilizing the low value byproduct as a valuable food antioxidant was investigated in this study. The level of isoflavones in the defatted soy flour extract was 55 mg/g, which …
The Influence Of Morningglory (Ipomoea Lacunosa), Hemp Sesbania (Sesbania Exaltata), And Johnsongrass (Sorghum Halepense) On Reproduction Of Rotylenchulus Reniformis On Cotton Gossypium Hirsutum L. And Soybean Glycine Max. (L.) Merrill, Michael John Pontif
LSU Doctoral Dissertations
Microplot studies were conducted to evaluate the effects of cotton (LA. 887), soybean (Pioneer 96B21), and three endemic weed species, pitted morningglory (Ipomoea lacunosa), hemp sesbania (Sesbania exaltata), and johnsongrass (Sorghum halepense), on reproduction of the reniform nematode, (Rotylenchulus reniformis). Over two microplot trials the co-culture of cotton with any of the three weeds suppressed numbers of reniform nematode juveniles in soil. When grown singly, reniform nematode reproductive values after 60 days on cotton averaged 69.0, while those for morningglory, hemp sesbania, and johnsongrass averaged 42.0, 23.5, and 18.0, respectively. Reproductive values for cotton co-cultured with morningglory averaged 38.7. Those …
Cercospora Leaf Blight Of Soybean: Pathogen Vegetative Compatibility Groups, Population Structure, And Host Resistance, Guohong Cai
LSU Doctoral Dissertations
Nitrogen nonutilizing mutants were used to assess vegetative compatibility of 58 isolates of Cercospora kikuchii, 55 of which were isolated from soybean plants in Louisiana. Only 16 of 56 self-compatible isolates were assigned to six multi-member vegetative compatibility groups (VCGs), 01-06, with two or three isolates in each VCG. The other 40 isolates were not vegetatively compatible with any isolates other than themselves. All six multi-member VCGs contained isolates from different soybean cultivars, and three included isolates from different locations. Only one VCG included isolates both from soybean leaves and from seeds, while two and three multi-member VCGs included isolates …