Desmodium Tortuosum Research Articles

Performance, Egg Quality, and Composition in Isa Brown Laying Hens Fed with Different Levels of Desmodium tortuosum Leaf Flour.

The objective of this study was to investigate the effects on laying performance, egg quality traits, color, and composition of supplementing a white corn-based diet with Desmodium tortuosum leaf flour. Three hundred 32-week-old hens were distributed to 30 pens of 10 hens each and allocated to six dietary treatments (five replicates per treatment) for 13 weeks. Two control groups of 50 hens received one of either diet Y, based on yellow corn, or diet W, based on white corn. The other groups received a diet based on white corn supplemented with Desmodium tortuosum leaf flour at 2.5%, 5%, 7.5%, or 10% (diet D). Diet D improved laying performance and yolk color at a reduced feed cost per egg but had no effect on cholesterol content. In conclusion, the inclusion of Desmodium tortuosum leaf flour, in a white corn-based diet, is effective in lowering feed cost, increasing egg production, and improving yolk color.

Native forbs interseeded into native grass pastures persist under grazing

AbstractIncorporating native forbs within native warm‐season grass (NWSG) pastures has the potential to benefit cattle, pollinators, and wildlife beyond that of NWSG monocultures. However, when grazing NWSG pastures, rotational stocking is recommended as opposed to continuous stocking. Therefore, to evaluate whether within‐season rest is needed for native pasture sustainability, two NWSG grazing experiments were conducted near Greeneville, TN, 2017–2020, to assess the persistence of native forbs when an 11‐species native forb blend was interseeded into established switchgrass (SG; Panicum virgatum L.) and big bluestem/indiangrass (BBIG; Andropogon gerardii Vitman and Sorghastrum nutans (L.) Nash) pastures. Each experiment was a completely randomized design with four replicates of each within‐season rest grazing treatment (no rest, early rest, middle rest, late rest, and no graze). Within‐season rest was not influential for NWSG tiller density or total forb plant density thus indicating persistence of forbs may not require rotational stocking. Purple prairie clover (Dalea purpurea Vent.) did not establish while Illinois bundleflower (Desmanthus illinoensis (Michx.) MacMill. ex B.L. Rob. & Fernald) was only observed flowering once despite having the greatest seeding rate among forbs. Based on establishment and flowering of the 11 species in the current mixture, interseeding a 6‐species polyculture of black‐eyed Susan (Rudbeckia hirta L.), dixie ticktrefoil (Desmodium tortuosum (Sw.) DC.), eastern purple coneflower (Echinacea purpurea (L.) Moench), lanceleaf coreopsis (Coreopsis lanceolata L.), Maximilian sunflower (Helianthus maximiliani Schrad.), and oxeye sunflower (Heliopsis helianthoides (L.) Sweet) could allow for plant biodiversity while offering floral resources for pollinators during the NWSG grazing season.

Cytotoxicity, Antioxidant Activities, GC-MS and HPLC Fingerprint Analyses of Different Extracts of Desmodium tortuosum (Sw.) DC

The family Fabaceae is the third-largest flowering plant family, and the genus Desmodium has exhibited a wide range of biological activities and a variety of chemical constituents. In the present study, different extracts of Desmodium tortuosum were evaluated for their cytotoxic and antioxidant activities, as well as their total phenolic content (TPC). The antioxidant activities were estimated using the 1,1'-diphenyl-2-picraylhydrazyl free radical (DPPH), while the cytotoxic activity was evaluated via the brine shrimp lethality test (BSLT). The antioxidant activity results revealed that the DPPH radical scavenging activity (SC50) ranged from 1.12 to 61.22 µg/ml with respect to ascorbic acid (SC50 = 7.45 µg/ml). Among all tested fractions, 90% methanol was the most active. On the other hand, the cytotoxic activities were arranged as follows: n-BuOH (LC50 = 310), EtOAc (LC50 = 350), and 70% methanol (LC50 = 380). High-Performance Liquid Chromatography-Fingerprint analyses were used to determine the chemical composition and relative proportions of phenolic compounds. GC-MS analysis indicated the presence of fatty acids and other compounds. The major identified compounds were Benzene (1-butyloctyl) (11.88%) and Himachalene <α-> (11.08%) for the ethyl acetate extract and 10-Undecenoic acid, methyl ester (25.50%) for unsaponifiable matter.

Ticktrefoil (Desmodium) species as a nutraceutical forage resource for animals

AbstractTicktrefoil (Desmodium) species from the USDA, ARS, Plant Genetic Resources Conservation Unit (PGRCU) germplasm collection in Griffin, GA, were evaluated for their potential livestock nutraceutical (nutritional + pharmaceutical) value in a field small plot study at the Fort Valley State University (FVSU) Agricultural Research Station, Fort Valley, GA. Horse marmalade (Desmodium discolor Vogel), greenleaf ticktrefoil (Desmodium intortum [Mill.] Urb.), panicledleaf ticktrefoil (Desmodium paniculatum [L.] DC.), Hawaii ticktrefoil (Desmodium sandwicense E. May) and twisted ticktrefoil (Desmodium tortuosum [Sw.] DC.) were established in a greenhouse and transplanted to field plots, with plant material from each species harvested, freeze‐dried, ground and analyzed for nutrient content and bioactivity. Crude protein (CP) levels in D. discolor and D. tortuosum averaged 233 g/kg, whereas CP in D. intortum, D. paniculatum and D. sandwicense ranged from 99 to 157 g/kg. The Desmodium species had in vitro true digestibility values of 755 to 878 g/kg. There were no detectable condensed tannins in D. discolor and D. tortuosum, whereas D. intortum, D. paniculatum and D. sandwicense averaged 88, 89 and 73 g/kg total condensed tannin, respectively. There were species differences in flavonoid content (p < .01), with the highest delphinidin and cyanidin concentrations in D. sandwicense and D. paniculatum, respectively. There were no detectable levels of delphinidin or cyanidin for D. discolor or D. tortuosum. Quercitin and kaempferol concentrations were highest in D. intortum and D. paniculatum, respectively, whereas D. discolor and D. tortuosum had the lowest values. The highest protein precipitable phenolics and total phenolic concentrations were for D. paniculatum. Desmodium species have potential as nutraceutical forage for livestock and warrant further investigation.

Chemical Characterization, Antioxidant Capacity and Anti-Oxidative Stress Potential of South American Fabaceae Desmodium tortuosum.

It has been proposed that oxidative stress is a pathogenic mechanism to induce cytotoxicity and to cause cardiovascular and neuronal diseases. At present, natural compounds such as plant extracts have been used to reduce the cytotoxic effects produced by agents that induce oxidative stress. Our study aimed to evaluate the antioxidant and cytoprotective capacity of Desmodium tortuosum (D. tortuosum) extract in the co- and pre-treatment in EA.hy926 and SH-SY5Y cell lines subjected to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability, reactive oxygen species (ROS), nitric oxide (NO), caspase 3/7 activity, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and molecular expression of oxidative stress biomarkers (SOD2, NRF2 and NFκB1) and cell death (APAF1, BAX, Caspase3) were all evaluated. It was observed that the D. tortuosum extract, in a dose-dependent manner, was able to reduce the oxidative and cytotoxicity effects induced by t-BOOH, even normalized to a dose of 200 µg/mL, which would be due to the high content of phenolic compounds mainly phenolic acids, flavonoids, carotenoids and other antioxidant compounds. Finally, these results are indicators that the extract of D. tortuosum could be a natural alternative against the cytotoxic exposure to stressful and cytotoxic chemical agents.

Performance of rabbit does and weaned kits fed a granulated diet supplemented with Desmodium or Panicum fodders.

Rabbit production is increasing in developing countries and can play a crucial role in the fight against poverty. The current work assessed the effect on rabbit does' reproduction and young kits' growth when either Panicum maximum, common name Guinea grass, or Desmodium tortuosum, common name Beggarweed is included in their diet. Diets ReC and GrC (standard granulated diets) served as control diets, formulated for doe Reproduction and kit Growth respectively. The trial diets were diets RePan/GrPan (diet ReC/GrC supplemented with dry P. maximum) and diets ReDes/GrDes (diet ReC/GrC supplemented with dry D. tortuosum). Thirty-six primiparous local breed five-month old rabbit does were randomly allocated to each one of the three dietary treatments. After a 15-day dietary adaptation period, does were each bred to one of 12, related, breeding males. Does were then assigned to individual maternity cages maintaining the same dietary treatment for the ensuing 65 days of the trial (30 days of gestation + 35 days of suckling). Thus, there were a total of 12 replicates per treatment: diet ReC, diet RePan or diet ReDes. At weaning, 72 kits, from the three adult feed treatment groups, were, while maintaining the integrity of the feed group of their individual mothers, divided into 12 blocks with 6 weaned kits per block, with each block allocated one of the three diets. Thus, for each of the three diets there were four separate blocks, i.e., four replicates, each with six group-housed weaned kits that received a growth diet which contained the same supplement or not as their mother diet to which they had access prior to weaning; the control diet GrC (Composition slightly different from Diet ReC composition) and trial diets GrPan and GrDes over a 3-day transition phase were adapted to the weaned kits physiological state and fed for a total of 56 days. The results indicated that the use of D. tortuosum significantly improved (P < 0.05) litter size, milk quantity, and kit survival rate from birth to weaning as compared with both control and RePan diets. The study showed that after weaning, compared with control and GrPan diets, the use of D. tortuosum increased (P < 0.05) the growth performance of weaned kits, improved meat nutritional quality by reducing (P < 0.05) cholesterol concentration and increasing (P < 0.05) the n-3 fatty acid proportion, and also reduced the individual kit feed cost to slaughter weight.

Phytochemical trials and evaluation of the antioxidant activity of plants used in the treatment of type 2 diabetes in the Central African Republic- Case of Khaya anthotheca, Desmodium tortuosum and Millettia laurentii

Excess free radicals equivalent to oxidative stress is an important cause of many diseases that pose a serious public health problem. Type 2 diabetes is one of these diseases. In the Central African Republic, it is estimated that more than 60,000 diabetics and 75% of diabetic deaths are caused by cardiovascular complications [1]. The traditional African pharmacopoeia offers an alternative to synthetic antidiabetics. The objective of this study is the phytochemical sorting and evaluation of the antioxidant activity of three samples of plants of the Central African pharmacopoeia known for their antidiabetic activity. The extracts of the three plants are obtained after maceration in ethanol or methanol for 48 hours at room temperature (25 °C.) followed by double filtration on cotton, then on 3 mm wattman paper and evaporation of the filtrates at rotary evaporator. The powder thus obtained allowed us to carry out phytochemical and antioxidant tests. After the phytochemical sorting, the antiradical activity by the DPPH and the inhibition of the lipid peroxidation by the ferric thiocyanate method were evaluated Phytochemical sorting revealed that these plants contain sterols, polyterpenes, polyphenols, flavonoids and saponins. Those exhibiting the antioxidant and antiradical important activity are Khaya anthotheca and Desmodium tortuosum with respectively 10.4 ± 0.3; 9.5 ± 0.7, rich in polyphenols and flavonoids, whereas for Millettia laurentii 13.6 ± 0.5 contains more sterols and polyterpenes with ethanol as solvent but thin-layer chromatography for methanol extracts indicates that the latter also contains a fairly high content of polyphenols.

Light intensity and sowing depth on the emergence and development of weeds

Background: Weeds are one of the ecological factors that affect the agricultural economy permanently. Thus, understanding the weed emergence and development is essential in decision making for management strategies. Objective: This study aimed to evaluate the effect of different sowing depths and light intensities on the emergence and development of the weed species Euphorbia heterophylla and Desmodium tortuosum under field conditions. Methods: Each species consisted of an experiment carried out in a completely randomized design with four replications. Treatments [...]

Desmodium tortuosum, Euphorbia heterophylla and Moringa oleifera Effect on Local Rabbit Does Milk Production and Pups’ Performances

Desmodium tortuosum and Euphorbia heterophylla are fields&amp;rsquo; weeds. Moringa oleifera plant is adapted to several agroecological zones and has many food and medicinal virtues. This work assessed these three plants potential to induce milk production. Thus, 96 primiparous local breed rabbit does, 10 months old, with an average 2983.6&amp;plusmn;212.4 g weight were used. They were grouped into 4 blocks containing 24 animals each. Then, one diet among 4 diets was randomly assigned to each group. Panicum maximum as fodder was mixed with a commercial pellet rabbit feed, the control (Pan). Then, this control diet was supplemented with Desmodium tortuosum (Des), Euphorbia heterophylla (Eup) and Moringa oleifera (Mor) in pellet partial substitution. The parameters monitored were the litter size, the pups&amp;rsquo; average daily weight gain, the does&amp;rsquo; weights before and during gestation, and after farrowing. Likewise, the milk production at peak lactation was evaluated. As a result, compare to Pan, Des, and Eup diets improved the total rabbit pups&amp;rsquo; number from 96 to 112, and it represented a 16.67% gain. But Mor diet reduced Pan diet performance to 76 newborn rabbits, it was a 20.83% loss. Moreover, Des, Eup, and Mor diets induced an improvement in the milk quantity at peak lactation. In this order, these improvements were +15.51, +27.74, and +19.98%, respectively, compared to Pan diet which produced 109.6 g. In conclusion, Desmodium tortuosum and Euphorbia heterophylla could be used as green forages to improve milk production in local rabbit does breeding.

Early-Season Effects of Wildfire on Soil Nutrients and Weed Diversity in Two Plantations

Abstract This study assessed early-season effects of spontaneous wildfires on soil fertility and weed diversity in two managed plantations – cashew and teak – in Ilorin, Nigeria. Soil pH and nutrients in the topsoils and subsoils of burned and unburned plantations plots after a spontaneous wildfire were analysed. Species diversity and similarity were determined based on the composition and abundances of weed flora two months post-fire. The fire effects on soil nutrients and weed composition in the plantations were evaluated using the canonical correspondence analysis. Burns incidence significantly improved the organic carbon, organic matter, and Ca contents while reducing total N and Mg in both plantations. Twenty-eight weed species were distributed in 9 angiosperm families. Fire differently affected weed composition, abundance and diversity in the plantations. Burning improved soil organic carbon and organic matter contents and restricted Tephrosia bracteolata, Desmodium tortuosum, Daniellia oliveri, Senna obtusifolia and Zornia latifolia to the burned cashew plantation. The occurrence of Euphorbia heterophylla, Eriosema psoraleoides and Crotalaria retusa in the burned teak plantation was associated with a direct fire effect on soil Na and Ca contents. Burning influenced soil nutrients in the studied plantations, but weed diversity increased in the teak plantation and was reduced in the cashew plantation.

Homocitrate Synthase Genes of Two Wide-Host-Range Bradyrhizobium Strains are Differently Required for Symbiosis Depending on Host Plants.

The nifV gene encodes homocitrate synthase, the enzyme that catalyzes the formation of homocitrate, which is essential for arranging the FeMo-cofactor in the catalytic center of nitrogenase. Some host plants, such as Lotus japonicus, supply homocitrate to their symbionts, in this case, Mesorhizobium loti, which lacks nifV. In contrast, Bradyrhizobium ORS285, a symbiont of Aeschynomene cross-inoculation (CI) groups 2 and 3, requires nifV for symbiosis with Aeschynomene species that belong to CI group 3, and some species belonging to CI group 2. However, it currently remains unclear whether rhizobial nifV is required for symbiosis with Aeschynomene species belonging to CI group 1 or with other legumes. We generated nifV-disruption (ΔnifV) mutants of two wide-host-range rhizobia, Bradyrhizobium SUTN9-2 and DOA9, to investigate whether they require nifV for symbiosis. Both ΔnifV mutant strains showed significantly less nitrogenase activity in a free-living state than the respective wild-type strains. The symbiotic phenotypes of SUTN9-2, DOA9, and their ΔnifV mutants were examined with four legumes, Aeschynomene americana, Stylosanthes hamata, Indigofera tinctoria, and Desmodium tortuosum. nifV was required for the efficient symbiosis of SUTN9-2 with A. americana (CI group 1), but not for that of DOA9. SUTN9-2 established symbiosis with all three other legumes; nifV was required for symbiosis with I. tinctoria and D. tortuosum. These results suggest that, in addition to Aeschynomene CI groups 2 and 3, CI group 1 and several other legumes require the rhizobial nifV for symbiosis.

Fluctuación poblacional de trips (Frankliniella cf. gardeniae) en cultivos de mango en Tolima, Colombia

El mango es una de las frutas tropicales con mayor producción a nivel mundial; en Colombia es un cultivo con gran potencial de exportación. Sin embargo, insectos plaga como los trips, pueden incidir en su calidad y producción. En esta investigación se evaluó la relación de la fluctuación poblacional de trips (Frankliniella cf. gardeniae) con las condiciones climáticas, la fenología del mango (var. Yulima y Tommy) y los hospederos alternos en el Guamo y San Luis (Tolima). Semanalmente se muestrearon trips en inflorescencias, hojas jóvenes de mango y en arvenses asociadas, se registraron los estados fenológicos del cultivo, las condiciones climáticas (temperatura, humedad relativa y precipitación) y se determinó la probabilidad de presencia de trips en inflorescencias de mango. En total se recolectaron 8.609 individuos de trips entre adultos y ninfas. La fluctuación poblacional de F. cf. gardeniae presentó relación positiva con la floración (r = 0,79 var. Yulima y Tommy) y la temperatura (r = 0,43 var. Yulima; r = 0,48 var. Tommy). Se registraron los géneros fitófagos Frankliniella y Haplothrips, en las arvenses Desmodium tortuosum y Melochia parvifolia. Las flores y frutos hasta tamaño de 8 mm fueron las más susceptibles al ataque del insecto. Finalmente, la mayor probabilidad de presencia de trips en inflorescencias de mango presentó dos períodos marcados, de 7 a 63 y de 161 a 203 días después de floración. F.cf. gardeniae en mango se comportó como una plaga ocasional, presente cuando la fuente de alimento estuvo disponible y las condiciones climáticas fueron adecuadas.

Type 3 Secretion System (T3SS) of Bradyrhizobium sp. DOA9 and Its Roles in Legume Symbiosis and Rice Endophytic Association.

The Bradyrhizobium sp. DOA9 strain isolated from a paddy field has the ability to nodulate a wide spectrum of legumes. Unlike other bradyrhizobia, this strain has a symbiotic plasmid harboring nod, nif, and type 3 secretion system (T3SS) genes. This T3SS cluster contains all the genes necessary for the formation of the secretory apparatus and the transcriptional activator (TtsI), which is preceded by a nod-box motif. An in silico search predicted 14 effectors putatively translocated by this T3SS machinery. In this study, we explored the role of the T3SS in the symbiotic performance of DOA9 by evaluating the ability of a T3SS mutant (ΩrhcN) to nodulate legumes belonging to Dalbergioid, Millettioid, and Genistoid tribes. Among the nine species tested, four (Arachis hypogea, Vigna radiata, Crotalaria juncea, and Macroptilium atropurpureum) responded positively to the rhcN mutation (ranging from suppression of plant defense reactions, an increase in the number of nodules and a dramatic improvement in nodule development and infection), one (Stylosanthes hamata) responded negatively (fewer nodules and less nitrogen fixation) and four species (Aeschynomene americana, Aeschynomene afraspera, Indigofera tinctoria, and Desmodium tortuosum) displayed no phenotype. We also tested the role of the T3SS in the ability of the DOA9 strain to endophytically colonize rice roots, but detected no effect of the T3SS mutation, in contrast to what was previously reported in the Bradyrhizobium SUTN9-2 strain. Taken together, these data indicate that DOA9 contains a functional T3SS that interferes with the ability of the strain to interact symbiotically with legumes but not with rice.

Morphology of Some Species in the Subfamily Papilionoideae

Morphological study of ten species in the subfamily Papilionoideae was carried out with the view to documenting diagnostic characters that would distinguish or group the species. The species studied belong to four tribes, namely: tribe Desmodieae – Desmodium tortuosum (Sw.) DC., Desmodium scorpiurus (Sw.) Desv., Desmodium adscendens (Sw.) DC., tribe Phaseoleae – Cajanus cajan (L.) Millsp., Calopogonium mucunoides Desv., Centrosema molle (Mart.) ex. Benth., Mucuna pruriens (Linn.) Walp., Vigna unguiculata (Linn.) Walp., tribe Crotalarieae – Crotalaria retusa Linn., tribe Robinieae – Gliricidia sepium (Jacq.) Walp. Qualitative and quantitative traits which had not been documented in previous works, especially in Nigeria, were studied. These include plant life span; leaf/leaflet apex, base, margin and pubescence; stem type, colour, shape and pubescence; sepal colour and pubescence; nature of margin of petal standard and presence or absence of pedicel; fruit colour, pubescence, tip and shape; seed colour, shape, surface and presence or absence of prominent hilum on the seed; number of seeds per fruit; pedicel length; length and width of petal standard, keel and wing. Characters of taxonomic value documented in this study were leaf type, leaf shape, leaf base, petiole type, stem type, seed shape, petal standard length, petal keel length and petal wing width. Data were subjected to one - way analysis of variance using Duncan’s multiple range test. It was noted that the important characters that can be used in establishing taxonomic relationship in the sub-family Papilionoideae were leaf type, leaf shape, leaf base, petiole type, stem shape, petal colour, petal margin and seed shape.

Short-term effects of early-season fire on herbaceous composition, dry matter production and soil fertility in Guinea savanna, Nigeria

The ecological impact of fire regimes on plant diversity and soil fertility has become a subject of intense discussion, especially in savannas where recurring incidences are common. This study assessed the short-term effects of early-season fire on herbaceous composition, dry matter yield and soil fertility in the Guinea savanna belt of Nigeria. Data on ground cover, dry matter yield (DMY) in plants and concentrations of C, N, P, K, Ca and Mg in soil were collected from 10 delineated subplots in the burned and unburned zones of four sites after annual wildfire had occurred. Ground cover was significantly higher in the burned zones, increasing progressively from January to April (dry season). Eleven herbaceous species in addition to 2 tree seedlings occurred and represented families of Asteraceae, Cyperaceae, Fabaceae and Poaceae. Digitaria nuda, Brachiaria lata, Daniellia oliveri and Aeschynomene indica were limited to the burnt zones while Cyperus tuberosus, Mariscus alternifolius and Rottboellia cochinchinensis were restricted to the unburned zones. DMY ranged from 0.32 g m-2 (Desmodium tortuosum) to 52.96 g m-2 (Megathyrsus maximus). Average biomass in the burned and unburned sites was 35.86 g m-2 and 28.42 g m-2, respectively. Soil C, N and P concentrations decreased (positive deterioration index - DI), while those of K, Ca and Mg improved (negative DI) in the burned sites. Burning altered the growth (ground cover) and composition of plant species in the short term, and could significantly influence soil nutrient dynamics in the long term, especially with recurring fire events.

CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of &lt;em&gt;Macroptilium heterophyllum&lt;/em&gt;, &lt;em&gt;Stylosanthes humilis&lt;/em&gt;, &lt;em&gt;Rhynchosia&lt;/em&gt;&lt;strong&gt; &lt;/strong&gt;&lt;em&gt;mínima&lt;/em&gt;, &lt;em&gt;Desmodium tortuosum &lt;/em&gt;Sw. Dc, &lt;em&gt;Merremia aegyptia,&lt;/em&gt; &lt;em&gt;Mimosa tenuiflora&lt;/em&gt; Wild, &lt;em&gt;Bauhinia cheilantha&lt;/em&gt; and as well &lt;em&gt;Macroptilium lathyroides&lt;/em&gt;, &lt;em&gt;Caesalpinia pyramidalis &lt;/em&gt;and &lt;em&gt;Mimosa tenuiflora&lt;/em&gt; hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM), crude protein (CP) mineral matter (MM) ether extract (EE) neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (LIG), insoluble neutral detergent nitrogen, (INDN) insoluble acid detergent nitrogen, (ADIN), total phenol (TF) and total tannin (TT) were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

Preliminary Studies on Two Viruses Infecting Two Wild Plants: Talinum triangulare (Jacq) Willd and Desmodium tortuosum (SW) DC in Samaru, Zaria, Kaduna State

In other to find an alternative hosts of virus diseases of cowpea in Zaria area, two virus disease symptoms were observed on two wild plants growing near each other at the edge of an experimental field, Department of Biological Sciences, Ahmadu Bello University, Zaria. The virus isolate in Talinum triangulare was found not to be sap transmissible in all the buffers used at different molarities and pH values; although the virus was found to be seed transmissible in T. triangulare, and also transmissible through grafting to healthy looking seedlings of Vigna unguiculata var. IAR-01-1006. Also symptoms were not observed in whiteflies (Bemisia tabaci) inoculated seedlings of the test plants. The virus isolate in Desmodium tortuosum, however, was found to be sap transmissible to healthy looking seedlings of D. Tortuosum and a number of other plant diseases, especially members of Fabaceae family. Chlorotic local lesions were observed in Chenopodium amaranticolor. 0.1 M phosphate buffer, pH 7.4 was found to be suitable for isolation and purification of the virus in D. tortuosum. The present study has also shed some light on the possible propagation host (V. unguiculata var. IAR-01-1006) for T. triangulare virus isolate, a propagation and assay hosts (V. unguiculata var. IAR-01-1009 and C. amaranticolor) for D. tortuosum virus isolate. The results obtained suggested that the symptoms observed in the two wild plants were induced by two different virus isolates. It is, therefore, suggested that further studies like molecular and immunological techniques need to be carried out in order to explore more of the properties of these viruses, with the view to develop control measures; since the viruses have shown to be a potential threat to some of the most important Leguminosae crops in the area studied.

First Report of Soybean Rust (Phakopsora pachyrhizi) on Florida Beggarweed (Desmodium tortuosum) in Alabama.

Soybean rust (SBR), caused by the fungus Phakopsora pachyrhizi, was detected on Florida Beggarweed (Desmodium tortuosum) for the first time in Alabama in November, 2009. The pathogen was not observed in 2010 or 2011, probably because of the exceptionally dry, hot weather in the region. The pathogen was observed on multiple mature leaves of plants, evenly distributed through a field at the Wiregrass Research and Extension Center in Headland, Alabama, located in the southeast region of the state. Florida Beggarweed can serve as an overwintering host for SBR. Symptoms on leaves were consistent with SBR symptoms previously described on soybeans (1). Sori in multiple pustules were observed on the undersurface of the leaves. Urediniospores and paraphyses were observed microscopically and identified as P. pachyrhizi. Symptomatic leaves from 20 plants were analyzed using an Envirologix monoclonal antibody strip test kit at the Auburn University Plant Diagnostic Laboratory. A subsample of 20 plants were positive for the pathogen. Representative symptomatic leaves were sent to the USDA Molecular Diagnostic Laboratory in Beltsville, Maryland, for confirmation. DNA was extracted from sori aseptically removed from leaves using a Qiagen DNeasy Plant Mini Kit, and amplified with primers Ppa1 and NL4. The resulting partial ITS2 and 28S ribosomal RNA sequences were 100% identical to GenBank entry DQ354537. Voucher specimens were deposited in the USDA Agricultural Research Service, National Fungus Collection (BPI). To our knowledge, this is the first report of the disease on Florida Beggarweed in Alabama.

Glyphosate Efficacy, Absorption, and Translocation in Selected Four Weed Species Common to Florida Citrus

Glyphosate is the most widely used herbicide for postemergence weed control in Florida citrus (Citrus spp.). Variation in susceptibility of certain weed species to glyphosate has been observed in last few years. Therefore, understanding the mechanism underlying such phenomenon is required. Experiments were conducted to evaluate differences in tolerance of four weed species to glyphosate by quantifying glyphosate efficacy, the amount of epicuticular wax, absorption, and translocation of carbon-14-labeled glyphosate (14C glyphosate). The results of glyphosate efficacy study suggested that application of glyphosate at 3 oz/acre resulted in 99%, 90%, and 84% control of florida beggarweed (Desmodium tortuosum), spanishneedles (Bidens bipinnata), and johnsongrass (Sorghum halepense), respectively. Increasing application rate and addition of nonionic surfactant (NIS) usually did not improve glyphosate efficacy. Ivyleaf morningglory (Ipomoea hederacea) was the most tolerant and resulted in 0% and 25% control when glyphosate applied at 3 and 24 oz/acre, respectively. Biomass reduction in all weed species reflected a similar trend to percent control in response to all glyphosate treatments. Glyphosate absorption and translocation in the weed species were differed with the quantity of wax extracted. Ivyleaf morningglory had the lowest leaf wax content (10.8 μg·cm−2) and showed less absorption (62% to 79%) and translocation (15% to 39%) of 14C-glyphosate compared with other weed species. The absorption of 14C-glyphosate was in the range of 87%, 71% to 83%, and 72% to 83%; and translocation was 34% to 50%, 32% to 52%, and 53% to 58% in florida beggarweed, spanishneedles, and johnsongrass, respectively. Increasing glyphosate application rate from 6 to 12 oz/acre and addition of NIS usually increased 14C-glyphosate translocation.

Comparing the Risks and Benefits of Early Applications of Chlorimuron for Weed Control in Peanut

Abstract Chlorimuron is applied from 60 days after peanut (Arachis hypogaea L.) emergence (DAE) until 45 days prior to harvest to control Florida beggarweed [Desmodium tortuosum (Sw.) DC]. Research trials were conducted in Georgia from 2006 to 2008 to determine whether the benefits of controlling smaller weeds earlier in the season compensate for the potential risk of significant peanut injury from chlorimuron. Chlorimuron at 9 g ai/ha was applied at 21, 35, 49, 63, 77, and 91 DAE. Additionally, flumioxazin (105 g ai/ha) preemergence was included as a treated control, along with a nontreated control. Main plots were split into subplots; weed-free and weeds present. Flumioxazin controlled Florida beggarweed 82%. Chlorimuron controlled Florida beggarweed 38 to 67%, with applications 21 and 35 DAE more efficacious than later applications. With weeds present, peanut treated with chlorimuron at any application timing yielded less than peanut treated with flumioxazin. Weed-free peanut treated with chlorimuron at any application timing yielded less than peanut treated with flumioxazin. These data indicate that chlorimuron applied earlier than 60 DAE provided better Florida beggarweed control with greater peanut yield than when applied at the recommended time intervals. However, Florida beggarweed control and peanut yield from any of the chlorimuron treatments were consistently less than flumioxazin.