Tephrosia Vogelii Research Articles

Bahasa Indonesia

Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae) is one of the papaya insect pests that causes high economic loss. The major constraint in controling this pest with insecticides is the existence of wax layer covering the insect body.The objective of this research was to evaluate the effectiveness of Piper retrofractum (Pr), Anonna squamosa (As), and Tephrosia vogelii (Tv) extracts as well as their mixtures to control P. marginatus imago in the laboratory. Pr, As, and Tv extracts were tested separately and in extract mixtures against female P. marginatus by direct spray on the insect. Each treatment was observed at 24, 48, and 72 hours after treatment (HAT). Our result showed that at the LC95 – 72 HAT, Tv and As extracts were about three times more effective to P. marginatus than Pr extract. The effective concentration that causing around 95% mortality of P. marginatus are 1.250% (Tv), 1.482% (Pr), dan 0.469% (As). Extracts mixtures of Tv + As (2:1, w/w) and As + Ps (2 : 1, w/w) were about 1.67 times more effective than Tv + Pr (2:1, w/w) extracts mixtures. Based on combination index at 72 HST, extract mixtures of Tv + As and Tv + Pr had low sinergistic joint action, meanwhile As + Pr extract mixture had additive joint action. In addition, all the extracts treatments disturbed the formation of the wax coverings the eggs (egg sacs). Pr, As, and Tv extracts as well as their mixtures at certain extract comparison have the alternate potential to control the mealybug P. marginatus.

English

Essential oils are complex mixtures of odours and steam volatile compounds which are deposited by plants in the subcuticular space of glandular hairs, in excretory cavities and canals or exceptionally in heart wood. Essential oils have been found to have no specific biological functions in plants, but constitute many compounds that are insect repellents or act to alter insect feeding behavior, growth and development, ecdysis (moulting) and behavior during mating and oviposition. Others possess antifungal, insecticidal and antiseptic properties. Essential oils of leaves of Tagetes minuta L. (Asteraceae), Fuerstia africana T.C.E. Friers (Labiaae), Tephrosia vogelii Hook. f. (Leguminosae) and Sphaeranthus ukambensis were obtained by steam distillation using the Clevenger apparatus (Guenter, 1949). Compounds in the essential oils were identified by gas chromatography-mass spectrometry (GC-MS). The characteristic volatiles isolated from the four plants were identified as follows: major constituents of the essential oils from F. africana included the following: limonene (39.1%), (Z)-β-ocimene (30.5%), targetone (26.2%), E -targetone (59%), λ-terpinene (26.2 %), peripitenone 23.7%, ocimene allo (22.8%) and Z-targetone (100%). The compounds with the highest relative abundance value in the essential oils included Z-targetone, E-targetone and (Z)-β-Ocimene. Analysis of T. minuta also revealed a number of compounds which included mycene (20.1%), verbinene (8.0%), Z-ocimenone (35.2%), E-caryophylene (25.5%), α-Humelene (11.8%), germacrene D (21.4%) and camphene (2%). The major constituent of T. minuta was Z-ocimene, caryophylene E and mycene. Essential oils from T. vogelii as revealed by the GC-MS analysis were pinene α (32.7%), limonene (35.1%), copaene α (22.9%), β -elemene (36.7%), Z-nerolidol (77.7%), δ-cadinene (67.6%), α humelene (69.6%) and -4-α-ol-(β)copaene (65.7%). The highest proportion of the essential oils constituted Z- nerolidol δ-cadinene, α-humelene and 4-α-ol-β. Copaene. The compounds in essential oils obtained from S. ukambensis were α-copaene (23.8%), β-bourbonene (25.5%), α-gurjunene (14.3%), cymene<2, 5-dimethoxy-para (87.7%), α -humelene (100%), λ- muurolene (17.9%), λ-cadinene (77.3%), caryophylene oxide (54.7%) and δ-cadinene (61.9%). The major compounds contained in essential oils from S. ukambensis were α-humele, λ-cadinene, δ-cadinene and cymene<2, 5-dimethoxy-para. The compounds which were common in the four test plants included: α-pinene, α-humele, ocimene allo and (E) β-ocimene. Each of the test plant secreted essential oils constituting numerous volatiles known to exhibit acaricidal, insecticidal and/or arthropod repellent properties. These plants may be useful sources of compounds for use in the control of arthropods of medical, veterinary and agricultural importance. Key words: Essential oils, GC-MS, Tagetes minuta, F. africana, T. vogelii, S. ukambensis

COMPARATIVE EFFICACY OF INSECTICIDAL PLANTS ON THE MANAGEMENT OF GROUNDNUT BRUCHID (CARYEDON SERRATUS)

Laboratory study was conducted to determine the efficacy of four insecticidal plant extracts Azadirachta indica A. Juss., Lantana camara L. (Verbenaceae), Eupatorium odoratum L. (Asteraceae), Tephrosia vogelii Hook against the groundnut bruchid beetle (Caryedon serratus), and a synthetic insecticide (Cypermethrin) (10EC)) under ambient condition of temperature and relative humidity (30°C and 72%). Two hundred grammes of unshelled groundnut was weighed into jute bags and treated with powders of the insecticidal plants. Both treated and untreated bags of groundnut were then infested with newly emerged adult of C. serratus (20 per bag) and covered. The experiment was laid out in a Completely Randomized Design (CRD) with four replications. Parameters assessed included number of egg oviposited, number of eggs hatched (eclosion) and number of adults that emerged from each treatment, total developmental period (egg – adult), sex ratio of the emerged adults and finally percentage germination of the treated seeds. Data collected were analyzed using analysis of variance and means were separated using Duncan multiple range tests at 5% level of significance. The lowest mean number of eggs was laid in A. indica, L. camara and T. vogelli treated seeds compared with the control which recorded the highest number. Similarly, results obtained showed that L. camara, T. vogelii, and A. indica powder significantly reduced damage by C. serratus and increased germination percentage compared with E. odoratum and control. In conclusion, L. camara, T. vogelii, and A. indica have the potentials as alternatives to synthetic insecticides in the management of C. serratus by farmers.

English

The prevalence of anthelmintic resistance and the consumer demand for alternative farming systems that limit the use of chemical anthelmintics has made the search for alternative gastrointestinal nematode parasites control methods crucial. Traditional medicinal/herbal plants can offer an alternative to the reliance on chemical anthelmintic drugs. This study evaluates the efficacy of crude aqueous extracts of Tephrosia vogelii Hook., Tephrosia villosa Pers., and Carica papaya Linn. leaves and Carica papaya Linn. seeds against gastrointestinal nematodes using in vitro egg hatch and larval development inhibition assays. Rectal faecal samples from sheep were subjected to parasitological examination for faecal egg counts (FEC) using the McMaster counting technique. 100 g of dried and poultice aqueous leaf extract of T. vogelii, T. villosa, C. papaya leaves and seeds was blended into liquefaction in 200 ml of distilled water then boiled at 90-100°C for 1 h and cooled. Levamisol and distilled water were used as positive and negative control in the bioassay. Egg hatch assay revealed more than 95.8% reduction in egg hatch at concentration of 500 mg/ml for dried and poultice paste of T. vogelii leaves and C. papaya seeds. Larval development inhibition assay results showed that both dried and poultice paste of T. vogelii leaves and C. papaya seeds extract yielded more than 98% inhibition at a concentration of 500 mg/ml. Based on the LD50 dried extract of C. papaya seeds was most potent extracts for the inhibition of both egg hatching (49.94 mg/ml) and larval development (49.32 mg/ml). Both poultice and dried extract for all the plants showed significant and dose dependent egg and larval development inhibition. These findings indicate that the evaluated plants have potential anthelmintic effect and could provide viable alternatives for the control of gastrointestinal helminthes in ruminants. Key words: Aqueous extracts, Anthelmintic activity, Medicinal plants, Tephrosia vogelii, Tephrosia villosa, Carica papaya.

Potency of Traditional Insecticide Materials against Stored Bean Weevil, Acanthoscelides Obtectus (Coleoptera: Bruchidae) in Tanzania

The bean weevil, Acanthoscelides obtectus is a major insect pest of stored common bean, Phaseolus vulgaris an important source of plant protein in many parts of the world, Tanzania inclusive. In rural Tanzania, most smallholder farmers apply traditional insecticide materials in the protection of bean from insect pests. The laboratory study investigates the potency of the selected traditional insecticide materials employed by small scale farmers to reduce stored bean losses caused by A. obtectus . The materials were identified and collected from Kimuli and Mabira villages in Kagera region and from Dar es Salaam. The effect of the materials to A. obtectus at different doses and durations was determined by both the number of surviving insects in treated set-ups reflecting the insect mortality and by the insects' reproductive performance at first filial generation (F1). The findings revealed effectiveness of the materials against A. obtectus to vary in the order: Azadirachta indica > Tephrosia vogelii > Nicotiana tabacum > Vegetation ash > Ocimum gratissimum > Crassocephalum crepidioides . Kruskal-Wallis test indicated significant differences in the number of A. obtectus survivors among the treatments at different doses during the study periods and also in the number of insects’ progeny (F1) produced at the end of their life cycle. It was concluded that the materials exhibit potency against A. obtectus at varying levels. Keywords : Traditional insecticide materials, Acanthoscelides obtectus , potency, Phaseolus vulgaris , mortality

English

This investigation lies within the framework of studying the phytochemistry of two medicinal plants Tithonia diversifolia and Tephrosia vogelii and assessing their potentials in controlling the helminthiasis in goats. The crude extracts were obtained from the leaves by Soxhlet methodology and phytochemical screening, fecal eggs reduction and the anthelmintic activities were tested in various laboratories in Butare. The results from this investigation showed that both T. diversifolia and T. vogelii have lots of active principles grouped in alkaloids, tannins, flavonoids, terpenoids,and sterols and exhibit anthelmintic activities in goats. The percentages of reduction of fecal eggs are 98, 97, 96 and 95% with methanol crude extract of T. vogelii, infusion of T. vogelii, methanol crude extract of T. diversifolia and infusion of T. diversifolia, respectively. This investigation showed the efficacy of both T. vogelii and T. diversifolia against gastrointestinal nematodes in goats and therefore their potentials in assuring more the animal health care in Rwanda by for treating the parasitic nematodes in goats by plant-based drugs instead of crude extracts. Key words: Anthelmintic activity, feacal egg, gastro-intestinal nematodes, goats, phytochemical screening traditional medicine, Tithonia diversifolia, Tephrosia vogelii, medicinal plant, Rwanda.

Fatty Acid Composition of Lebrunia bushiae Staner and Tephrosia vogelii Hook.f. Seed Oils

Aim: The nutritive and medicinal values of vegetable oils rely on the nature of their fatty acids (FAs). This study aimed to determine the nature and content of FAs in Lebrunia bushiae Staner and Tephrosia vogelii seed oils which are used by the local population of South Kivu province in DRC mainly for medical purposes. Materials and Methods: The seeds were harvested from Bunyakiri, zone close to the National Parc Kahuzi-Biega, in South-Kivu province/DRC. The oils were manually expressed, and the FAs composition characterized by gas chromatography (GCMS). Results: Ten major FAs were detected in Lebrunia bushiae seed oil comprising of 4 saturated and 6 unsaturated of which oleic acid (18:0;43.0%), linoleic acid (18:1;11.74%) and erucic acid (22.1;14.07%) predominate. In the Tephrosia vogelii oil, 5 saturated and 5 unsaturated FAs were detected comprising in majority of linoleic acid (40.34%), oleic acid (19.97%), alpha linolenic acid (7.62%), palmitic acid (13.98%) and stearic acid (5.78%).

Sub-acute Toxicity of Aqueous Extracts of Tephrosia vogelii, Vernonia amygdalina and Senna occidentalis in Rats

There is an intense search for new plant-derived medicines to match the ever increasing prevalence of drug resistance. Toxicity profiles of three commonly used plants against helminthosis in Uganda will support their optimum use. Objective: To evaluate the sub-acute toxicity of aqueous leaf extracts of Tephrosia vogelii (TV), Vernonia amygdalina (VA) and Senna occidentalis (SO). Methods: One hundred Wistar white albino rats in 10 groups were dosed orally daily with 200, 400 and 600 mg/kg of TV, VA and SO for 28 days or Goodwin’s physiological solution. Daily changes in behaviour, feed/water intake and weight (weekly) were monitored. On day 29, blood for haematology, serum for biochemical analysis and organs (lungs, liver, kidney, heart and small intestines) for histopathology were collected. Results: Continued exposure of rats to 600 mg/kg doses of SO and VA extracts led to elevation of ALT, AST and ALP and cholesterol in the treatment groups. SO and VA at 600 mg/kg elevated urea and uric acid; depressed bilirubin while VA and TV 600 mg/kg caused the reverse. Histopathology findings (villi sloughing, pneumonitis, liver and kidney degeneration) further supported these results. Conclusion: The very low toxicity of the aqueous leaf extracts of TV, VA and SO at high doses makes them safe at currently non-standardised doses used for animal treatment.

Effect of Tephrosia vogelii Hook.f. Leave Extracts on the Isolated Heart of Toad : Hypothesis of the Mechanism of Action.

The ichtyotoxic plants contain substances, which could present a danger to the consumers of caught fish with it. The isolated heart of toad was used in this experimentation according to the modified method of Langendorff. It was a question of having collected the filtrate obtained from the grinding of leaves dried by Tephrosia vogelii in Lock-Ringer, in perfuse the isolated heart of toad with solutions of increasing concentrations by this filtrate. Then to measure the various peaks describing the variations of the contractions and the frequencies of the heart by means of a recorder on paper. Reference solutions were also used except the foliar extracts of T. Vogelii. T.vogelii (10 -3 to 10 -2 mg/ml) reduce the amplitude of contraction (negative inotropic) and frequency (negative chronotropic) of the isolated heart of toad; of which both are in a dosedependent manner (increased and cumulative). The threshold of the effect on contraction and frequency were 3x10 -3 mg/ml and 2x10 -3 mg/ml respectively with maximal effect being 10 -2 mg/ml for contraction and frequency. The rotenone (10 -6 M) just like T.vogelii (5.5x10 -3 mg/ml) decreases the contraction and frequency whilst ATP (10 -6 M) increases the two parameters. In presence of the rotenone or T.vogelii, the positive inotropic effect induced by ATP is reduced and a negative chronotropic effect is observed. We established that there is an antagonism between the action of the rotenone and the ATP; and that would be via the calcium. The effect of T.vogelii on the isolated heart of toad would have been cause by the rotenone.

Toxicity and repellent effects of leaf extracts of four Kenyan plants against nymphs and adults of Rhipicephalus appendiculatus (Neuman 1901)

Ticks are important arthropod vectors of diseases of man and farm animals in Africa and in spite of the efforts to control them using synthetic acaricides, they continue to be amongst the leading vectors of disease-causing agents. Unfortunately, over-reliance on synthetic acaricides for tick control has led to problems including acaricide resistance, environmental pollution, and acaricide residues in products destined for human consumption. These problems highlight the need for alternative tick control methods that are environment friendly and yet effective. In the current study, the repellency and toxic effects of essential oils extracted from four Kenyan plants namely;Tagetes minuta L.(Asteraceae), Fuerstia. africana T.C.E. Friers (Lamiaceae), Tephrosia vogelii Hook. f. (Leguminosae) and Sphaeranthus ukambensis against the ixodid tick Rhipicephalus appendiculatu were determined. Essential oils were extracted by steam distillation from fresh plants using Clevenger apparatus. Host seeking nymphs (2-3 weeks old)and adult ticks were used and fumigant toxicity bioassay was done using four concentrations (0.1µ/ml, 0.01 µ/ml, 0.001 µ/ml, and 0.0001µ/ml) of the essential oils, each in four replicates and with ten ticks per replicate. In the control experiment, ticks were exposed to n- hexane. Mortality was recorded every 48 hours for 2 weeks. In repellency bioassay, a Y tube olfactometer and same concentrations as above were used. Treated paper discs were placed in one arm and control (discs treated with hexane) in the other. Ticks were introduced at the main arm and allowed to make choices on the direction of movement. Ticks on the two arms were counted after 30 minutes. The essential oils showed dose dependant mortality and repellency values. The highest repellency value for R. appendiculatus adults was observed with T. vogelii (93.8% at 0.01µ/ml) while for the nymphs, both S. ukambensis and T. vogelii recorded the highest repellency values of 100% and 95% respectively both at 0.1µ/ml concentration. Essential oils from Fuerstia. africana recorded the highest mortality values for nymph (97.8% at 0.1µ/ml) and adult (53.2 % 0.1µ/ml) Rhipicephalus appendiculatus . The present study has demonstrated that Tephrosia vogelii, Tagetes minuta and Sphaeranthus ukambensis have repellent and toxic effects on Rhipicephalus appendiculatus and therefore can

The use of indigenous ecological resources for pest control in Africa

Reducing the losses from crop pests will help to increase food availability and boost economic growth in sub- Saharan Africa (SSA). However, the existing crop protection paradigm that relies on synthetic agrochemical pesticides has had only a marginal impact on the productivity of many poor smallholder farmers who constitute a major segment of agri- culture in SSA. This is primarily because many of them are not able to afford or access these imported chemicals. A solution to this crop protection problem may be to harness biologicalresourcesthatarelocallyavailable,suchasendemic insect natural enemies and indigenous pesticidal plant mate- rials. Two specific examples of this already under develop- ment in Africa are the use of the pesticidal plant, Tephrosia vogelii, and the harvesting of the endemic insect baculovirus, Spodoptera exempta nucleopolyhedrovirus (SpexNPV). Both of these can be produced locally and have shown promise in trials as inexpensive and effective tools for pest control in Africa and their use is currently being scaled up and evaluated by African networks of researchers. A focus on these systems illustrates the potential for using locally-available natural re- sources for improved crop protection in Africa. The consider- ation of these pesticidal plants and insect natural enemies in the wider context of natural capital that provide valuable ecosystem services (including pest control), will facilitate greater recognition of their true economic and societal worth. While both of these model systems show promise, there are also very significant challenges to be overcome in developing production, supply and marketing systems that are economi- cally viableand sustainable.Theregulatoryenvironment must also evolve to accommodate and facilitate the registration of new products and the establishment of appropriate supply chains that share the benefits of these resources equitably with the local communities from which they are harvested.

Antifungal and antioxidant activity of crude extracts of three medicinal plants from Cameroon pharmacopea

Three medicinal plant (Milletia laurentii, Tephrosia vogelii, Croton macrostachyus) extracts traditionally used in Cameroon to manage infectious diseases, were chosen and screened for their phytochemicals composition, antioxidant properties and antifungal activity againstTrichophyton rubrum, Trichophyton soudanense and Trichophyton violaceum. Plant powders were extracted by maceration in methanol and water. Afforded extracts were studied for their: phytochemical composition using indicators, antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods and antifungal activity using the agar dilution methods. Extraction yield were better with methanol than water for all the medicinal plants. Amongst the 11 phytochemical compounds (alkaloids, phenols, flavonoids, triterpenoids, saponines, anthraquinones, tannins, anthocyanins, coumarins, essential oils, steroids, glycosides, lipids) tested, 9 were differently present in relative high amount in extracts, while glycosides and steroids were absent in all plant extracts. Aqueous extracts of T. vogelli showed the best antioxidant activity while methanolic extract of C. macrostachyus showed the lowest with IC50 values of 0.30 and 0.11 mg/ml, respectively.M. laurentii showed IC50 of 0.19 and 0.21 mg/ml for aqueous and methanolic extracts, respectively. All the extracts tested showed significant activity against the threeTricophyton species tested, with minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) varying from 17.50 to 27.50 and 20 to 30 mg/ml, respectively. These findings support the continued sustainable screen of medicinal plants as source of bioactive principles. Key words: Medicinal plant, phytochemical screening, antifungal, antioxidant.

KEEFEKTIFAN TIGA JENIS INSEKTISIDA NABATI TERHADAP KUTU PUTIH PEPAYA PARACOCCUS MARGINATUS DAN KEAMANANNYA TERHADAP LARVA KUMBANG PREDATOR CURINUS COERULEUS

Effectiveness of three botanical insecticides against the papaya mealybug Paracoccus marginatus and their safety to the predatory Curinus coeruleus larvae. Preparations of Tephrosia vogelii (Tv) leaf extract (0.5% and 1% w/v), Annona squamosa (As) seed extract (0.5% and 1%), and Cinnamomum multiforum (Cm) leaf essential oil (1% and 2%), and their mixtures (Mix-1: Tv 0.25% + As 0.25% + Cm 0.5%; Mix-2: Tv 0.5% + As 0.5% + Cm 1%) were tested for their effectiveness on third-instar nymphs of Paracoccus marginatus by spraying the test materials on undetached papaya leaves and by direct spraying on the test insects using Potter spray tower. Tv extract was also applied on the test insects placed on undetached papaya leaves. The safety test was done by direct spraying of the test materials on the predatory Curinus coeruleus larvae using Potter spray tower. Tv and As extracts at a concentration of 1% each are potential to be used for the control of P. marginatus. Spraying of T. vogelii extract on the test P. marginatus nymphs placed on papaya leaves was more effective than spraying of the test materials on papaya leaves or direct spraying on the test insects only. The treatment with Cm essential oil required twice the concentration of Tv and As extracts to obtain the same level of effectiveness. The treatment with Mix-2 caused lower P. marginatus mortality than the sum of mortality caused by its components applied separately. Nonetheless, the three botanical insecticides and their mixtures were safe to C. coeruleus larvae. On the other hand, although the synthetic insecticide imidacloprid (neonicotinoid), included in the study for comparison, was effective against P. marginatus, it was also toxic to the predatory C. coeruleus larvae so its use should be avoided or limited.

SYNERGISTIC ACTION OF MIXED EXTRACTS OF BRUCEA JAVANICA (SIMAROUBACEAE), PIPER ADUNCUM (PIPERACEAE), AND TEPHROSIA VOGELII (LEGUMINOSAE) AGAINST CABBAGE HEAD CATERPILLAR, CROCIDOLOMIA PAVONANA

ABSTRACT Extracts seeds, fruits, and leaves of Brucea javanica, Piper aduncum, and Tephrosia vogelii were tested separately and also in mixture (3:2.5:1) in the laboratory for their insecticidal activity against the cabbage head caterpillar, Crocidolomia pavonana. B. javanica, P. aduncum, and T. vogelii plant materials were extracted with ethyl acetate-methanol (9:1), ethyl acetate, and ethyl acetate respectively by using maceration method. Insecticidal bioassays were done by a leaf-residue feeding method. Second-instar larvae C. pavonana were fed extracttreated broccoli leaves for 48 hrs and then were presented untreated leaves until the surviving larvae reached the fourth-instar stage. Larval mortality was assessed at 5 days after treatment, and the data analyzed by the probit method. The results showed that larval mortality started at first day treatment and increased at second day’s treatment. After changing with untreated leaves the mortality decreased significantly. Based on LC50 and LC95 values, T. vogelii leaf extract was more toxic (LC50= 0.06%, LC95= 0.12%)than P. aduncum fruit extract (LC50= 0.24%, LC95=0.32%) and B. javanica seed extract (LC50=0.17%, LC95=0.41%). Based on value of LC50 (0.03%) and LC95 (0.05%), the toxicity of a mixture of B. javanica, P. aduncum, and T. vogelii extract (3:2.5:1) against C. pavonana larvae was very toxic. Based on the combination index according to the independent joint action model, the extract mixture had a strongly synergistic joint action against C. pavonana larvae, at level LC50 and LC95, with a combination index of 0.225 and 0.190. The mixture extract worked better than each single extract against C. pavonana.

Managing Tephrosia mulch and fertilizer to enhance coffee productivity on smallholder farms in the Eastern African Highlands

In Maraba, Southwest Rwanda, coffee productivity is constrained by poor soil fertility and lack of organic mulch. We investigated the potential to produce mulch by growing Tephrosia vogelii either intercropped with smallholder coffee or in arable fields outside the coffee, and the effect of the mulch on coffee yields over two years. Two accessions of T. vogelii (ex. Gisagara, Rwanda and ex. Kisumu, Kenya) were grown for six months both within and outside smallholder coffee fields in the first year. Experimental blocks were replicated across eight smallholder farms, only a single replicate per farm due to the small farm sizes. The accession from Rwanda (T. vogelii ex. Gisagara) grew more vigorously in all experiments. Soils within the coffee fields were more fertile those outside the coffee fields, presumably due to farmers’ long-term management with mulch. Tephrosia grew less well in the fields outside coffee, producing only 0.6–0.7Mgha−1 of biomass and adding (in kgha−1) 19 N, 1 P and 6 K in the mulch. By contrast, Tephrosia intercropped with coffee, produced 1.4–1.9Mgha−1 of biomass and added (in kgha−1) 42–57 N, 3 P and 13–16 K in the mulch. Coffee yields were increased significantly by 400–500kgha−1 only in the treatments where Tephrosia was intercropped with coffee. Soil analysis and a missing-nutrient pot experiment showed that the poor growth of Tephrosia in the fields outside coffee was due to soil acidity (aluminium toxicity) combined with deficiencies of P, K and Ca.In the second year, the treatments in fields outside coffee were discontinued, and in the coffee intercrops, two Tephrosia accessions were grown in treatments with and without NPK fertilizer. Tephrosia grew well and produced between 2.5 and 3.8Mgha−1 biomass for the two accessions when interplanted within coffee fields, adding 103–150kgNha−1, 5–9kgPha−1 and 24–38kgKha−1. Tephrosia mulch increased yields of coffee by 400kgha−1. Combined use of NPK+Tephrosia mulch increased Tephrosia biomass production and in turn yielded an additional 300–700kgha−1 of coffee. Over the two years, this was equivalent to a 23–36% increase in coffee yield using Tephrosia intercropping alone and a further 25–42% increase in coffee yield when NPK fertilizer was also added. Agronomic efficiency (AE) of nutrients added were 30% greater when the Tephrosia mulch was grown in situ and the two cultivars of Tephrosia did not differ in AE. The AE of Tephrosia mulch was 87% that of NPK fertilizer, reflecting the rapid mineralization of Tephrosia mulch. There was a synergistic effect of Tephrosia mulch on the efficiency with which NPK fertilizer was used by coffee. The increase in coffee yields was positively related to the amount of nutrients added in the Tephrosia biomass. Tephrosia intercropping required 30 man-daysha−1 less than current farmer management due to reduced labour required for weeding, and benefit–cost ratios ranged between 3.4 and 5.5. The Tephrosia-coffee intercropping system offers great potential for agroecological intensification for smallholder farmers in the East African highlands.

Bioactivity of selected plant powders against Prostephanus truncatus (Coleoptera: Bostrichidae) in stored maize grains

Crude powders of Azadirachta indica, Lantana camara, and Tephrosia vogelii, each at six concentrations (0.0, 2.0, 4.0, 6.0, 8.0, and 10% w/w), and Actellic Super&lt;sup&gt;TM&lt;/sup&gt; 2% dust were evaluated for repellence anti-feeding and toxicity to adult Prostephanus truncatus. Treatments were laid out in a completely randomised design with four replicates. Results showed that powders were strongly repellent (PR values 73.0&amp;ndash;90.0%) and caused 46.2&amp;ndash;52.2 and 69.7&amp;ndash;85.6% reductions in grain damage and F&lt;sub&gt;1&lt;/sub&gt; progeny, respectively. Results showed that powders were weakly toxic to P. truncatus causing 40% kill 21 days after treatment compared to 100% kill by Actellic Super&lt;sup&gt;TM&lt;/sup&gt;2% dust 5 DAT. The findings are discussed in the context of their relevance for integrated pest management options in smallholder agriculture.

Soil Incorporated Plant Residues and Nemacur affected Weed Population and Soil Nitrogen Dynamics in Asclepia Field

Abstract : Field trials were conducted for two seasons in 2006 and 2007 to test the effect of Tagetes patula , Lantana camara , Tephrosia vogelii , Azadirachta indica and Nemacur on the growth of asclepiad, soil pH, and soil nitrogen as well as weed population dynamics . The experiment was replicated three times under complete randomized block design. Chopped plant materials were applied singly or in combination with nemacur. T. patula was applied at 300 g/m 2 , A. indica at 150 g/m 2 , L. camara at 10% w/w, and T. vogelii at 10% w/w. Organic plant materials were applied at half rate in combination with nemacur at 20 g/m 2 . Nemacur treatment alone was applied at a full rate of 40 g/m 2 . Tagetes patula with nemacur reduced weed biomass by between 33.6% and 36.6% while L. camara alone decreased the population density of Oxalis cornulata weed by between 14% and 17% compared to the untreated control. The improvement of nutrient status of the soil and the control of weeds could have led to an improvement of yield characteristic of asclepias. A combination of L. camara with nemacur may be used instead of synthetic nematicides alone to control weeds and improve soil nutrient levels.

Ethnobotanical survey of biopesticides and other medicinal plants traditionally used in Meru central district of Kenya

Ethnopharmacological relevanceThe purpose of this study was to carry out a survey and document plants used in Meru-central district by traditional healers with emphasis on those used as biopesticides. Materials and methodsThe study was carried out at Igane and Gatuune sub-locations, Abothuguchi East division of Meru-Central district, Kenya. The data collection involving 23 traditional healers was done using semi-structured questionnaire, focused group discussion and transect walks. Plants samples were collected and botanically identified at the herbarium of the Department of Land Resource Management and Agriculture Technology in the University of Nairobi. ResultsThe results of the ethnobotanical survey revealed that herbalists belonged to both gender with the majority being male (82.6%) and female (17.4%). Their ages ranged from 28 to 82 years. Seventy (70) plant species, belonging to 35 families, were identified as being used as biopesticides and also as medicinal. The families encountered were Asteraceae (10%), Euphorbiaceae (8.6%), Lamiaceae (8.6%), Fabaceae(8.6%), Caesalpiniaceae (5.7%), Rubiaceae (5.7%), Liliaceae (4.3%), Apocynaceae (2.9%), Flacourtiaceae (2.9%), Verbenaceae (2.9%) and the rest of the 24 families had 1.4% each. These medicinal plants were used to treat and manage a wide range of diseases and conditions including parasitic, microbial, helminthosis, protozoa, cuts and wounds, fractures, dental, arthritis, allergic, snake bites, reproductive as well as metabolic. Among the plants used, shrubs were the commonest at 42.8%; trees were 32.9%, while herbs and liana were at 22.9% and 1.4%, respectively. Majority of the respondents used leaves, roots and bark to make their herbal preparations with only a few using seeds, flowers, whole plant, flower sap and pods. The plants that were cited by the respondents to be used as biopesticides were Prectranthus barbatus Andr. (47.8%), Tephrosia vogelii Hookf. (39.1%), Ocimum gratissimum L (34.7%), Vernonia lasiopus O.Hoffm. (8.7%), Cascabella thevetia( L.)Lippold (4.3%) and Oncoba routledgei Sprague (4.3%). ConclusionMeru central district is rich in biodiversity of biopesticides and other medicinal plants and there is need for further pharmacological studies to validate their use as potential drugs for pests and disease control.

Highly Variable Insect Control Efficacy of Tephrosia vogelii Chemotypes

Tephrosia vogelii has been used for generations as a pest control material in Africa. Recently, two chemotypes have been reported based on the occurrence (chemotype 1) or absence (chemotype 2) of rotenoids. This could have an impact on the efficacy and reliability of this material for pest control. We report that chemotype 2 has no pesticidal activity against Callosobruchus maculatus Fabricius (family Chrysomelidae) and that this is associated with the absence of rotenoids. We present a first report of the comparative biological activity of deguelin, tephrosin, α-toxicarol, and sarcolobine and show that not all rotenoids are equally effective. Tephrosin was less toxic than deguelin which was less active than rotenone, while obovatin 5-methyl ether, the major flavonoid in chemotype 2 was inactive. We also report that in chemotype 1 the occurrence of rotenoids shows substantial seasonal variation.

Rotenoid content and in vitro acaricidal activity of Tephrosia vogelii leaf extract on the tick Rhipicephalus appendiculatus

This study aimed to determine the rotenoid content of leaf extracts of the white (TVW) and purple (TVP) varieties of Tephrosia vogelii, both collected in North-Kivu Province, Democratic Republic of Congo and to evaluate their in vitro acaricidal efficacy on the tick Rhipicephalus appendiculatus. The high performance liquid chromatography analysis of rotenoid compounds from those extracts revealed that the contents of rotenone and deguelin were respectively higher in the leaves of TVW (0.044% and 1.13%) than in TVP (0.014% and 0.66%). Batches of 20 live adult ticks were immersed for 15min in six different doses of each plant extract (0.625; 1.25; 2.5; 5; 10 and 20mg/mL of distilled water) and in the solution of Milbitraz® (12.5%m/v emulsifiable concentrate of amitraz) as a positive control. Additionally 9.5% ethanol and distilled water control groups were included. Tick mortalities were recorded every 24h for 5 days. The results indicated that there was no significant difference (P>0.05) between the acaricidal effect of Milbitraz® and the plant material used at a dose of at least 2.5 or 5mg/mL for TVW and TVP respectively. However, the dose response relationship determined at the fifth day after treatment showed a similar acaricidal effect for the two plant varieties with similar lethal dose 50 (LD50) of 0.83 and 0.81mg/mL for TVW and TVP respectively. It is concluded that T. vogelii leaves may be used for the control of R. appendiculatus in areas where synthetic acaricides are either not available or affordable. However, T. vogelii extract should be sprayed in order to limit the potential risks of ecotoxicity linked to rotenoid compounds.