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1.
European J Med Plants ; 2022 Apr; 33(4): 25-35
Artigo | IMSEAR | ID: sea-219479

RESUMO

Aims: Ocimum gratissimum is an aromatic and medicinal plant, well known for its medicinal values such as antifungal properties. This study aimed at evaluating the effect of T. diversifolia powder and compost use as biofertilizer on the growth parameters, essential oil (EO), total phenolic and flavonoid content and anticandida activity of O. gratissimum. Study Design: O. gratissimum plants were cultivated for 8 months in an experimental farm designed as a split plot into 4 blocks. Each block was amended (main factor) either with T. diversifolia compost (150 g/plant), powder (40 g/plant) or the synthetic fertilizer NPK (10 g/plant), respectively, followed by sprayed (second factor) with same fertilizer at 20 g/L, 20 g/L and 2 g/L or water every two weeks after transplantation. The control block received no amendment and was sprayed with water or the previous fertilizer. Place and Duration of Study: This work was carried out within August 2019 to October 2020 in Yaoundé-Cameroon. Methodology: Plant growth parameters (fresh and dry leaves weight, florescent weight and plant height) were evaluated at four and eight months after transplantation. The harvested fresh leaves were hydrodistillated for EO and the hot aqueous extract. Both extracts were used for the evaluation of the anticandida activity while the latter was submitted to total flavonoids and phenolic analyses. Results: At 4 and 8 months after transplantation, the synthetic fertilizer and T. diversifolia compost significantly increased plant growth parameters as compared to other treatments. The plants treated with T. diversifolia biofertilizer compost showed the highest total phenolic (53.16 µg GAE/µL), flavonoid (36.32 µg// GAE/µL) content, and EO yield (0.666%). The EO from O. gratissimum treated with T. diversifolia compost showed the best inhibitory activity on C. albicans NR-29451. Conclusion: This study showed that T. diversifolia compost was a promising organic fertilizer in optimizing the growth, secondary metabolites and anticandida activity of O. gratissimum.

2.
Acta sci., Biol. sci ; 42: e47120, fev. 2020. ilus, tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1460916

RESUMO

The establishment of invasive plants negatively affects natural environments. Invasive herbivores that attack weeds can be used as a form of biological control, but natural enemies of herbivores must be associated with this interaction to prevent the invasive phytophagous from become a local pest. We performed a greenhouse experiment to evaluate how the cotton aphid, Aphis gossypii, a ok and invasive herbivore, affects the performance of the weed Tithonia diversifolia, the Mexican sunflower. We also examined the relationship between the aphid and local natural enemies. Seedlings of T. diversifolia were divided in two groups: one infested by the aphid and another not infested. After 22 days, we assessed the relationship between aphid abundance and the presence of natural enemies (Coccinelidae and Aphidius platensis) on infested plants, and compared the vegetative performance of the two seedling groups. Both natural enemies were positively related to high aphid density on infested plants. Plants infested by the aphid presented foliar necrosis and senescence, and a reduction of around 50% in leaf number, foliar area, shoot length and shoot, root and total plant weight compared to non-infested plants. These results indicate potential biological control of Mexican sunflower seedlings by the cotton aphid, and control of this aphid by the studied natural enemies.


Assuntos
Afídeos , Helianthus/microbiologia , Helianthus/parasitologia
3.
Orinoquia ; 23(2): 56-62, jul.-dic. 2019. tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1115040

RESUMO

Resumen El objetivo de este estudio fue evaluar el efecto de la harina de follaje de Tithonia diversifolia como sustitución de fuente tradicional de proteína en dietas para pollos de engorde. Se emplearon 240 pollitos de engorde mixtos de la línea Cobb distribuidos en diseño experimental completamente al azar con arreglo factorial 2 x 4, dos edades de corte 45 y 60 días, con cuatro niveles de inclusión de harina de botón de oro 0, 5, 10 y 15%, tres repeticiones y 10 aves por unidad experimental. No hubo efecto de los niveles de Tithonia sobre el consumo de alimento (P>0,05), los niveles de Tithonia influenciaron (p<0,05) la ganancia de peso y la conversión alimentcia. Los resultados obtenidos evidencian que el uso de harina de follaje de Tithonia se puede constituir como una alternativa en la alimentación del pollo de engorde en inclusiones ≤ 10% en la dieta para los dos estados de desarrollo y permite reemplazar parcialmente una materia prima costosa en etapa de finalización.


Abstract The objective of this study was to evaluate the effect of flour from foliage of Tithonia diversifolia as substitution of traditional source of protein in diets for broilers. We used 240 mixed fattening chicks of the Cobb distributed in a completely randomized experimental design with a 2 x 4 factorial arrangement, two cutting ages of 45 and 60 days, with four inclusion levels of 0, 5, 10 and 15% gold button flour, three repetitions and 10 birds per unit experimental. There was no effect of Tithonia levels on feed intake (P> 0,05), Tithonia levels influenced (p <0,05) weight gain and feed conversion. The results obtained in final weight show that the use of gold button foliage flour can be constituted as an alternative in the feeding of the broiler in inclusions ≤ 10% in the diet for the two stages of development and allows partially replacing a expensive raw material in the final stage.


Resumo O objetivo desta pesquisa foi avaliar o efeito do farelo de folhagem Tithoni diversifolia em substituicao da fonte tradicional de proteína na dieta para frangos de corte. Foram utilizados 240 pintos de corte da linha Cobb distribuídos em delineamento experimental inteiramente ao acaso em arranjo fatorial 2 x 4, duas idades de corte 45 e 60 dias, com quatro níveis de inclusão de 0, 5, 10 e 15% de farelo de tithonia, três repetições e 10 aves por unidade experimental. Não houve efeito dos níveis de Tithonia sobre o consumo de alimento (P>0,05), os níveis de Tithonia influenciaram (P<0,05) o ganho de peso e a conversão alimentar. Os resultados obtidos sugerem que o uso de farelo de folhagem de Tithonia Os resultados obtidos no peso final evidenciam que o uso de farinha folhagem pode-se constituir como uma alternativa na alimentação de frango em inclusões ≤ 10% na dieta para as duas fases de desenvolvimento e permite substituir parcialmente matéria-prima cara na fase final.

4.
Asian Pacific Journal of Tropical Biomedicine ; (12): 245-253, 2018.
Artigo em Chinês | WPRIM | ID: wpr-700122

RESUMO

Objective: To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting, and investigate its safety against animal cells. Methods: The saline extract was prepared, with NaCl (0.15 M), by constant stirring of the dried and pulverized leaves, followed by volume reduction by lyophilization. The extract was phytochemical characterized using ultra-performance liquid chromatography, and total phenol and flavonoid analysis also was performed.The antioxidant capacity was determined through DPPH? radical, the antimicrobial property was evaluated against standard bacteria and fungi, and the viability assays were performed against mice splenocytes. Results: Fifteen compoundswereidentifiedbelongingtotwomainclassesterpenoidsandphenolics.Theextract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid. Moreover, extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule [(3.042±0.019) mg AAE/g and (4.12±0.10) mg AAE/g to saline extract and butylated hydroxytoluene, respectively].The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes, in concentrations lower than 50 μg/mL, promoting higher proliferation in these cells. Conclusions: Saline extract from Tithonia diversifolia leaves presents potential antioxidant, antifungal properties and induces immunostimulation in mice splenocytes.

5.
Asian Pacific Journal of Tropical Biomedicine ; (12): 245-253, 2018.
Artigo em Chinês | WPRIM | ID: wpr-950434

RESUMO

Objective: To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting, and investigate its safety against animal cells. Methods: The saline extract was prepared, with NaCl (0.15 M), by constant stirring of the dried and pulverized leaves, followed by volume reduction by lyophilization. The extract was phytochemical characterized using ultra-performance liquid chromatography, and total phenol and flavonoid analysis also was performed. The antioxidant capacity was determined through DPPH· radical, the antimicrobial property was evaluated against standard bacteria and fungi, and the viability assays were performed against mice splenocytes. Results: Fifteen compounds were identified belonging to two main classes terpenoids and phenolics. The extract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid. Moreover, extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule [(3.042±0.019) mg AAE/g and (4.12±0.10) mg AAE/g to saline extract and butylated hydroxytoluene, respectively]. The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes, in concentrations lower than 50 μg/mL, promoting higher proliferation in these cells. Conclusions: Saline extract from Tithonia diversifolia leaves presents potential antioxidant, antifungal properties and induces immunostimulation in mice splenocytes.

6.
Braz. arch. biol. technol ; 59: e16150775, 2016. tab, graf
Artigo em Inglês | LILACS | ID: biblio-951313

RESUMO

ABSTRACT Essential oils are pharmacologically active and unexplored compounds. The inhibitory properties of essential oils from Baccharis dracunculifolia, Conyza bonariensis, Tithonia diversifolia and Ambrosia polystachya were evaluated in the coagulation and fibrinogenolysis induced by snake venoms. The essential oil from Conyza bonariensis extended the clotting time of Lachesis muta from 52.2 to 115.2 seconds and that of Bothrops moojeni from 108.3 to 2340.0 seconds, when pre-incubated with the venoms. The longest clotting times for Bothrops atrox venom were observed after incubation with the essential oils from Conyza bonariensis and Tithonia diversifolia: the times increased from 100.8 to 264.0 and 227.7 seconds, respectively. The prior incubation of the essential oils with plasma and subsequent addition of Lachesis muta venom resulted in a pro-clotting effect. The oils from Ambrosia polystachya and Baccharis dracunculifolia caused 100% of inhibition on the fibrinogenolysis induced by Bothrops moojeni and Lachesis muta venoms (the oils were previously incubated with the venom). The results indicate that the essential oils show promise as adjuvants for the treatment of snakebites.

7.
Asian Pacific Journal of Tropical Biomedicine ; (12): 950-956, 2016.
Artigo em Chinês | WPRIM | ID: wpr-502756

RESUMO

Objective: To determine the cytotoxicity, reduction in nitric oxide production and anti-oxidative activity of the aqueous leaf extract from Tithonia diversifolia (T. diversifolia) in an in vitro model. Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells (PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide (LPS)-induced nitric oxide pro-duction in RAW264.7 cells was measured using the Griess reagent. The chemical anti-oxidant was evaluated by ABTS-and DPPH-radical scavenging assays. Results: The half-maximal cytotoxic concentration values were 145.87 mg/mL and 73.67 mg/mL for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC50 on PBMCs proliferation was 4.42 mg/mL. The non-cytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC50 value of 11.63 mg/mL. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was (32.62 ± 1.87) and (20.99 ± 2.79) mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPH-radical assay. However, the extract did not confer death protection in a hydrogen peroxide-induced RAW264.7 co-culturing model. Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-M-induced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7 macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.

8.
Asian Pacific Journal of Tropical Biomedicine ; (12): 950-956, 2016.
Artigo em Chinês | WPRIM | ID: wpr-950684

RESUMO

Objective To determine the cytotoxicity, reduction in nitric oxide production and anti-oxidative activity of the aqueous leaf extract from Tithonia diversifolia (T. diversifolia) in an in vitro model. Methods Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells (PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays. Results The half-maximal cytotoxic concentration values were 145.87 μg/mL and 73.67 μg/mL for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC

9.
Rev. bras. entomol ; 58(1): 32-46, Jan.-Mar. 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-707148

RESUMO

Lagochile emarginata (Gyllenhal): morphology of immature and imago, and biological records (Coleoptera, Scarabaeidae, Rutelinae). The last larval instar and pupa of Lagochile emarginata are described. Pupa of the genus Lagochile Hoffmannsegg, 1817 is described for the first time. Redescription of the imago, clarifications on the morphology of immature Scarabaeoidea and biological notes are presented.

10.
Asian Pacific Journal of Tropical Biomedicine ; (12): 740-742, 2014.
Artigo em Chinês | WPRIM | ID: wpr-951845

RESUMO

Objective: To evaluate the antioxidant activity of extracts of dried flowers of Tithonia diversifolia (Hemsl) A. Gray (T. diversifolia) dry flower-a shrubby plant belonging to the Asteraceae family and very common in Brazil, providing data to help prevent premature aging skin. Methods: The tests of phytochemical screening included total phenols, tannins, flavonoids, alkaloids and saponins. The active antioxidant was determined by 2,2-diphenyl-1-picryl-hydrazyl method. Results: The phytochemical screening of T. diversifolia dry flowers revealed the presence o phenolic compounds (tannins, flavonoids and total phenols), while alkaloids and saponins were not detected. The IC50 values showed a strong antioxidant activity of the plant extracts. Conclusions: Therefore, this study suggests the possibility of using dry flowers extracts of T diversifolia for the prevention of cell aging, as was shown to have significant antioxidant activity.

11.
Asian Pacific Journal of Tropical Biomedicine ; (12): 740-742, 2014.
Artigo em Chinês | WPRIM | ID: wpr-672445

RESUMO

Objective:To evaluate the antioxidant activity of extracts of dried flowers of Tithonia diversifolia (Hemsl) A. Gray (T. diversifolia) dry flower-a shrubby plant belonging to the Asteraceae family and very common in Brazil, providing data to help prevent premature aging skin. Methods: The tests of phytochemical screening included total phenols, tannins, flavonoids, alkaloids and saponins. The active antioxidant was determined by 2,2-diphenyl-1-picryl-hydrazyl method. Results: The phytochemical screening of T. diversifolia dry flowers revealed the presence of phenolic compounds (tannins, flavonoids and total phenols), while alkaloids and saponins were not detected. The IC50 values showed a strong antioxidant activity of the plant extracts. Conclusions: Therefore, this study suggests the possibility of using dry flowers extracts of T. diversifolia for the prevention of cell aging, as was shown to have significant antioxidant activity.

12.
Artigo em Inglês | IMSEAR | ID: sea-157220

RESUMO

Proximate composition and phytochemical constituents of stems of A. africana and T. diversifolia (Asteraceae) were investigated. The stems of these species contain anti-oxidant, anticancer, anti-tumor, anti-viral, anti-inflammatory and anti-allergic properties which cures malaria, skin diseases, athlete’s foot, asthma, gonorrhoea and to stop bleeding. The stems of these two species revealed the presence of flavonoids, tannins, saponins and cardiac glycosides. The proximate analysis of the stems of A. africana and T. diversifolia showed the moisture content of 15.7% and 20.6%, total ash of 6.10% and 6.55%, acid insoluble ash of 0.55% and 0.33%, sulphated ash of 18.8% and 14.0%, protein content of 7.87% and 9.62%, fat of 3.68% and 4.21%, fibre of 12.30% and 15.82%, carbohydrate of 75.97% and 70.35%, volatile ether soluble of 7.33% and 1.66%, water soluble of 3.33% and 0.33% and diluted alcohol soluble of 5.33% and 5.66%. The results of this study suggest the popular use of A. africana and T. diversifolia in herbal medicine.

13.
Braz. j. pharm. sci ; 48(1): 109-116, Jan.-Mar. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-622895

RESUMO

Tithonia diversifolia (Hemsl.) A. Gray is an Asteraceae shrub, popularly known as Mexican sunflower and cultivated for ornamental and therapeutic uses in different countries. In folk medicine, it is of value for treating diabetes, malaria and infectious diseases. These indications have been corroborated by various pharmacological assays. Given the lack of data on anatomical aspects of T. diversifolia, this work aimed to investigate the leaf and stem microscopic characters of this medicinal plant and potential vegetal drug. Samples of mature leaves and young stems were sectioned and stained. Histochemical tests and scanning electron microscopy were also performed. The leaf has anomocytic stomata on both sides, dorsiventral mesophyll and several collateral vascular bundles arranged as a ring in the midrib. The stem shows angular-tangential collenchyma, an evident endodermis and sclerenchymatic caps adjoining the phloem. The main characters for anatomical identification are the different types of trichome (non-glandular, capitate and non-capitate glandular), the midrib features and the localization of the secretory ducts near the vascular system.


Tithonia diversifolia (Hemsl.) A. Gray é um arbusto da família Asteraceae, popularmente conhecido como girassol-mexicano e cultivado como ornamental e medicinal em vários países. Tradicionalmente, é usado no tratamento de diabetes, malária e doenças infecciosas. Essas indicações têm sido corroboradas por diversos ensaios farmacológicos. Em razão das escassas informações sobre aspectos anatômicos de T. diversifolia, este trabalho objetivou investigar os caracteres microscópicos foliares e caulinares dessa planta medicinal e potencial droga vegetal. Amostras de folhas adultas e caules jovens foram fixadas, seccionadas e coradas. Testes histoquímicos e microscopia eletrônica de varredura foram também realizados. A folha apresenta estômatos anomocíticos em ambas as superfícies, mesofilo dorsiventral e vários feixes vasculares colaterais dispostos em círculo na nervura central. O caule exibe colênquima angular-tangencial, endoderme nítida e calotas esclerenquimáticas apostas ao floema. Os principais caracteres para a identificação anatômica são os diferentes tipos de tricoma (tector, glandular capitado e não capitado), os aspectos da nervura central e a localização dos dutos secretores nas proximidades do sistema vascular.


Assuntos
Folhas de Planta/classificação , Asteraceae/classificação , Microscopia/métodos , Plantas Medicinais/classificação , Tricomas
14.
Rev. bras. plantas med ; 13(3): 328-336, 2011. ilus, tab
Artigo em Português | LILACS | ID: lil-601040

RESUMO

O potencial alelopático de quatro diferentes extratos de plantas medicinais (Eclipta alba, Gomphrena globosa, Tabernaemontana catharinensis e Tithonia diversifolia) foi avaliado na germinação de Bidens pilosa e Lactuca sativa. Dentre os resultados obtidos no teste de germinação, notou-se um maior poder inibitório do extrato de G. globosa sobre sementes e plântulas de Bidens pilosa e Lactuca sativa independente da concentração utilizada e aumento da atividade inibitória de extratos T. catharinensis e de T. diversifolia com aumento da concentração destes. Quanto ao Índice de Velocidade de Germinação, os dados demonstraram redução do índice devido a elevada mortalidade das plântulas submetidas aos extratos de G. globosa e de T. catharinensis e a germinação tardia das sementes submetidas ao extrato de T. diversifolia. Quanto ao vigor das sementes, as menores porcentagens de sobrevivência ocorreram extratos à 2,5 por cento para B. pilosa e 10 por cento para L. sativa.


The allelopathic potential of four different extracts of medicinal plants (Eclipta alba, Gomphrena globosa, Tabernaemontana catharinensis and Tithonia diversifolia) was evaluated on the germination of Bidens pilosa and Lactuca sativa. The results obtained in the germination test indicated a greater inhibitory activity of G. globosa extract on Bidens pilosa and Lactuca sativa seeds and seedlings, regardlessof the used concentration, and an increase in the inhibitory activity of T. catharinensis and T. diversifolia extracts with an increase in their concentrations. As to Germination Speed Index, the data demonstrated a reduction due to the high mortality of seedlings subjected to G. globosa and T. catharinensis extracts and a late germination of seeds subjected to T. diversifolia extracts. As to the vigor of seeds, the smallest survival percentages occur at 2.5 percent for B. pilosa and at 10 percent for L.sativa.


Assuntos
Bidens , Feromônios/química , Feromônios/uso terapêutico , Germinação , Técnicas In Vitro , Lactuca , Extratos Vegetais , Plantas Medicinais , Sementes , Amaranthaceae , Asteraceae , Eclipta , Estruturas Vegetais , Preparações de Plantas/uso terapêutico , Tabernaemontana
15.
Academic Journal of Second Military Medical University ; (12): 189-192, 2010.
Artigo em Chinês | WPRIM | ID: wpr-840382

RESUMO

Objective: To isolate and identify the chemical constituents of the EtOAc fraction of Tithonia diversifolia. Methods: The dried aerial parts of Tithonia diversifolia were extracted with 80% EtOH,and the chemical constituents of the ethyl acetate portion from the extract were isolated by column chromatography with silica gel, Sephadex LH-20 and MCI. The isolated compounds were identified by NMR and MS analysis. Results: Ten compounds were isolated from EtOAc extract, and identified as, vanillin (1), ergosterol (2), ergosterol peroxide (3), 3-methoxy-4-hydroxy-trans-cinnamaldehyde (4), 3-hydroxybenzaldehyde (5), 7-methylesculetin (6) , 5-hydyoxymethyl furfural (7), nepetin (8) , docosanoic acid 2, 3-dihydroxypropyl ester(9) and 13-hydroxyeupatorochromene(10). Conclusion: Vanillin, ergosterol, ergosterol peroxide, 3-methoxy-4-hydroxy- trans-cinnamaldehyde, p-hydroxybenzaldehyde, 7-methylesculetin, 5-hydyoxymethyl furfural, docosanoic acid 2, 3-dihydroxypropyl ester, and 13- hydroxyeupatorochromene have been isolated from Tithonia diversifolia for the first time.

16.
Rev. biol. trop ; 54(2): 395-402, jun. 2006. mapas, graf, tab
Artigo em Inglês | LILACS | ID: lil-492058

RESUMO

We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage.


Se estudió la germinación y crecimiento de las plántulas del girasol mexicano Tithonia diversifolia. Se usaron métodos de periodo de latencia y germinación, y el efecto de varias concentraciones de tres herbicidas sobre las plántulas jóvenes. Las pruebas iniciales de germinación con semillas frescas y almacenadas revelaron un bajo porcentaje de germinación (30%). Las semillas de malezas permanecieron latentes. Al someter las semillas a tratamientos de calor húmedo de 80 y 100oC y luz se terminó con el periodo de latencia en las semillas frescas y en las almacenadas. La luz aumentó el porcentaje de germinación a cerca del 70%. Hubo un incremento gradual en el porcentaje de germinación en el periodo de almacenamiento en las semillas salidas de la latencia. Los promedios de cociente de área foliar, tasa neta de asimilación y tasa de crecimiento relativo son comparativamente altos en las plántulas jóvenes. Las concentraciones de 0.5-2.0% de Gramoxone, Primextra y Galex son tóxicas para las plántulas de un mes de edad.


Assuntos
Animais , Germinação/fisiologia , Helianthus/fisiologia , Herbicidas/farmacologia , Plântula/crescimento & desenvolvimento , Sementes/fisiologia , Controle de Insetos , Estações do Ano , Fatores de Tempo , Germinação/efeitos dos fármacos , Isópteros/fisiologia , Luz , México , Nigéria , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos
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