Commelina Benghalensis Research Articles

Weed Vegetation Structure in an Area of Organic Acerola Cultivation, Parnaíba, Piauí, Brazil

ABSTRACT: This study aimed to identify and quantify the weed species in an area of organic acerola cultivation in the Distrito de Irrigação dos Tabuleiros Litorâneos do Piauí (DITALPI) in Parnaíba, Piauí, Brazil. Phytosociological sampling was completed in the rainy season, before the farmers adopted management techniques for the plants. Thirty plots of 0.25 m2 were sampled. The plots were located between crop rows, which consisted of herbaceous-subshrub plants. The absolute and relative covers and the absolute and relative frequencies of each species were calculated based on the occurrence and cover of each species. In total, 25 species comprising 13 families were registered, among which the Poaceae family that presented the largest number of species. Commelina benghalensis occurred the most frequently overall. Shannon’s diversity index (H’) and evenness were calculated as 2.30 nats ind-1 and 0.69, respectively. Five species accounted for 79.33% of absolute cover at DITALPI. The species were distributed heterogeneously within the field, and Commelina benghalensis, Urochloa plantaginea, Panicum maximum, Amaranthus spinosus, Cynodonsp., and Cyperus aggregatus were the species most likely to infest the acerola crop. As DITALPI is an area of organic cultivation, understanding these species is essential to help farmers select the best form of control.

Weed Interference in Okra Crop in the Organic System During the Dry Season

ABSTRACT: In organic systems during the dry season, competition of weeds with okra increases the critical period of interference of these species and yield losses. The objective of this research was to determine the critical period of weed interference in organic okra during the dry season in São Luís - MA. The experiment was conducted from October/2014 to January/2015 in randomized blocks, with four replicates. The treatments were the periods of 07, 14, 21, 28, 35, 42 days after the transplanting of the crop with control and coexistence of the infesting community. The species with the highest importance value index were Cynodon dactylon, Eleusine indica, Amaranthus spinosus and Commelina benghalensis. The CPWI was 04 to 53 days after transplanting and yield losses were 69.5%. The organic okra cropping system during the season dry should be free of weeds until the beginning of the harvest to avoid high yield loss.

In vitro antioxidant and anti-cancer activities and phytochemical analysis of Commelina benghalensis L. root extracts

Objective: To explore antioxidant potential, anti-cancer activity, and phytochemicals of Commelina benghalensis L. Methods: The roots of Commelina benghalensis were extracted in different solvents (methanol, ethanol, benzene, chloroform, n-hexane) with a range of polarity. Antioxidant activity was evaluated by reducing power assay, DPPH radical scavenging activity and phosphomolybdenum method, cytotoxicity by MTT assay, apoptotic and cell cycle analysis by flow cytometry, migratory and invasive potential by wound scratch assay and invasion assay, respectively, functional groups analysis by FT-IR spectroscopy and phytochemicals by aluminum chloride colorimetric and Folin- Ciocalteu methods. Results: The extracts showed worthy antioxidant potential. The chloroform extract demonstrated the most significant cytotoxic effect on MDA-MB-231 (breast cancer) cell line, induced apoptosis and reduced migratory and invasive potential of MDA-MB-231 cells. Methanol and ethanol extracts presented good yield of total phenolic and total flavonoid contents. The FTIR spectroscopic studies revealed different characteristic peak values with various functional compounds such as alkenes, alkanes, aliphatic amines, aromatics, alkyl halides, carboxylic acid, alcohols, ester, aldehydes and ketones. Conclusions: The results demonstrate the potential use of Commelina benghalensis as a good antioxidant with significant anti-cancer effect.

Angiospermic flora of Gafargaon upazila of Mymensingh district focusing on medicinally important species

Gafargaon upazila has been floristically explored to identify and assess the angiospermic flora that resulted in occurrence of 203 taxa under 174 genera and 75 families. Magnoliopsida is represented by 167 taxa under 140 genera and 62 families, while Liliopsida is constituted by 36 taxa belonging to 34 genera and 13 families. Vegetation analysis shows that herbs are represented by 106 taxa, shrubs 35, trees 54, and climbers by 8 species. In Magnoliopsida, Solanaceae is the largest family possessing 10 species, whereas in Liliopsida, Poaceae is the largest family with 12 species. The study has identified 45 medicinal plants which are used for treatment of over 40 diseases including diabetes, ulcer, diarrhoea, dysentery, fever, cold and cough, menstrual problems, blood pressure and urinary disorders by the local people. Some noticeable medicinal plants used in primary healthcare are Abroma augusta (L.) L.f., Coccinia grandis (L.) Voigt., Commelina benghalensis L., Cynodon dactylon (L.) Pers., Holarrhena antidysenterica Flem., Glycosmis pentaphylla (Retz.) A. DC., Mikania cordata (Burm. f.) Robinson, Ocimum tenuiflorum L. and Rauvolfia serpentina (L.) Benth. A few number of species are also employed in cultural festivals in the study area. Cardamine flexuosa With., Oxystelma secamone (L.) Karst., Phaulopsis imbricata (Forssk.) Sweet, Piper sylvaticum Roxb., Stephania japonica (Thunb.) Miers and Trema orientalis L. have been found to be rare in the investigated area. In order to preserve botanical resources of Gafargaon upazila, particularly the rare, threatened and medicinal plants, conservation measures need to be undertaken through both in-situ and ex-situ methods for their sustainable use.

Weed hosts of Meloidogyne spp. and the effect of aqueous weed extracts on egg hatching

SummaryWeeds have a great economic impact on agricultural production because they compete with crops for resources and are alternative hosts for pests, microbial pathogens and plant‐parasitic nematodes. This study aimed to investigate the susceptibility of weeds to the root‐knot nematodes Meloidogyne javanica and Meloidogyne incognita and assess the effect of aqueous weed extracts on M. javanica egg hatching. Four experiments were conducted, two for each nematode species. Weeds were inoculated with 2000 nematode eggs and grown for 60 days under greenhouse conditions. Soyabean cv. Monsoy 7110 was used as control. The weeds Ipomoea grandifolia, Solanum americanum, Digitaria horizontalis, Amaranthus deflexus, Sorghum halepense and Commelina benghalensis were susceptible to M. javanica and M. incognita in at least one experiment (reproduction factor, RF >1). Crotalaria juncea and Eleusine indica were susceptible to M. incognita in one experiment, and Digitaria insularis, Sida rhombifolia, Bidens pilosa, Urochloa decumbens, Crotalaria breviflora, Cenchrus echinatus, Crotalaria ochroleuca and Crotalaria spectabilis were immune or resistant (RF <1 or RF = 0). Alternanthera tenella, C. juncea, S. rhombifolia, C. ochroleuca, C. spectabilis, C. breviflora, B. pilosa, E. indica, U. decumbens and C. echinatus were resistant or immune to M. javanica (RF <1 or RF = 0). Compared with the control (water), all weed extracts reduced M. javanica egg hatch. Our results highlight the importance of weed control in agricultural systems, as nematodes can survive and multiply in weed roots during the off‐season. Weed leaves and shoots, however, may be an interesting source of compounds with nematicidal activity.

Accumulation of macronutrients in cowpea and weeds in competition and under soil water deficit

The ability of a plant species to succeed in colonization of agroecosystem depends on its efficiency in the use of growth resources even in deficient conditions. The present study aimed to evaluate the effects of competition and water deficit in the soil on the accumulation of macronutrients of Vigna unguiculata L. Walp., Commelina benghalensis L. and Waltheria indica L. The study was conducted in a greenhouse, in randomized block design, with four replications. The treatments were arranged in a 5 × 2 factorial, with the first factor corresponding to types of interaction among species (V. unguiculata + C. benghalensis; V. unguiculata + W. indica; V. unguiculata in monoculture, C. benghalensis in monoculture and W. indica in monoculture), and the second of water regimes (irrigated and water deficit). The water deficit differently affects macronutrient content on the species, with decreased of K, Ca and Mg in cowpea, and N, P, K and Ca in W. indica. For C. benghalensis, the water deficit does not reduce the macronutrient contents on the plant. The competition between plants intensifies the effects of water deficit only on C. benghalensis, with a decreased on the content of all macronutrients studied. Under irrigated conditions, competition between plants was more damaging the weeds compared to cowpea. The C. benghalensis specie, free from interference, has a high potential for nutrient extraction under irrigated and water deficit regimes.

Host weed species range of Meloidogyne ethiopica whitehead (Tylenchida: Meloidogynidae) found in Brazil

Meloidogyne ethiopica is considered to be one of the most economically important emerging nematode species, reported to cause crop losses to several hosts worldwide. The significance of this species is due to its high virulence and degree of polyphagia, in addition to persisting on weed hosts within agricultural fields. This study evaluated the host status of 36 different weed species, confirming the polyphagia habit of M. ethiopica and indicating which plant species may be alternative hosts for this plant nematode. Weed species were inoculated with 5000 eggs and second-stage juveniles (J2) of M. ethiopica, with gall index (GI), nematode/g root (Nem/g), and reproduction factor (RF) value determined following 60 days post inoculation. The data obtained indicate that many weed species may be excellent hosts for M. ethiopica. Plants deemed susceptible (RF ≥ 1.0) were: Acanthospermum australe, Amaranthus deflexus, A. hybridus, A. spinosus, A. viridis, Bidens pilosa, B. subalternans, Cardiospermum halicacabum, Commelina benghalensis, Cynodon dactylon, Euphorbia heterophylla, Galinsoga parviflora, Ipomoea grandifolia, I. nil, I. purpurea, Leonurus sibiricus, Nicandra physaloides, Oxalis corniculata, Portulaca oleracea, Raphanus raphanistrum, Sida rhombifolia, Solanum americanum, S. pseudocapsicum, S. sisymbriifolium, Sonchus oleraceus and Talinum paniculatum, representing 72.2% of the species assessed. The species Conyza bonariensis, Cyperus rotundus, Digitaria horizontalis, D. insularis, Echinochloa colonum, Eleusine indica, Lolium multiflorum, Polygonum hydropiperoides, Rhynchelytrum repens and Senecio brasiliensis were resistant to M. ethiopica (RF < 1.0). Based on the new host records presented, it is vital that control of weed species within agricultural fields are considered as part of effective management of M. ethiopica.

Floristic diversity of receiving environments polluted by effluent from agri-food industries

Till date, there are few studies on the flora found in receiving environments polluted by effluent from agri-food industries. Floristic inventories of ten receiving environments in Cameroon. were carried out using the line transect method from upstream to downstream discharge areas in the Littoral and Center regions during the dry and rainy season. The abundance/dominance (AD) of each floristic survey was assessed using Braun–Blanquet scale. Species richness of the different receiving environments is marked by higher and lower Shannon Weaver (H′) diversity index values, respectively in the rainy season and dry season from upstream to downstream. Regularity values (R) show that the maximum number of species is involved in the covering of the surface. In terms of floristic composition, the Simpson's diversity index (D) shows similarities between the different receiving environments. The Sorensen index (Q) shows similar number of common species between upstream and downstream zones of the same site. Nitrophilous species are abundant. Some could be organic pollution indicators, namely: Pennisetum purpureum, Cynodon dactylon, Commelina benghalensis, Lemna minor, Acroceras zizanoides, Echinochloa pyramidalis and Panicum maximum. The Poaceae family dominates the ten receiving environments.

EVALUATION OF THE WOUND HEALING ACTIVITY OF COMMELINA BENGHALENSIS LEAVES EXTRACT IN EXPERIMENTAL RATS

Wound is still a worldwide health problem. Both conventional and synthetic drugs used in the treatment of wound are inadequate and sometimes they cause fatal side effects. In the absence of a reliable drug in modern medicine, there are a number of medicinal preparations in Ayurveda recommended for the treatment of wound. In view of severe undesirable side effects caused by synthetic agents, there is a growing need to follow systematic research methodology to evaluate the scientific basis for the traditional herbal medicines that are claimed to possess therapeutic effects. The benefits of herbal wound healing agents attract the researchers to evaluate their use in modern medicine and to minimize the undesirable or unpleasant effect of synthetic medicines. As we know, herbal medicines are natural in origin, safe to consume in the modern day many herbal plants like aloe, neem, turmeric, brahmi, senna, ashwagandha, asafetida, ginger, fennel, sankhpusphi, are extensively used in modern medicine and showed their potential benefits. Commelina benghalensis is a herbaceous plant growing throughout India. In our study we found that the methenolic extract of Commelina benghalensis shows significant increase in breaking strength of the skin and histopathological studies also shows increase in the number of macrophages . Various concentrations of mehenolic extract of Commelina benghalensis are used i.e 5% methenolic extract of Commelina benghalensis and 10% methenolic extract of Commelina benghalensis and both the concentration are shown to increase the breaking strength although 10 % methenolic extract shows more collegen fibres in histological section. Hence the present study is designed to evaluate wound healing of potential of Commelina benghalensis leaves in rats

Ethnobotanical study on Wetland macrophytes of medicinal importance in the Western Highlands of Cameroon

The objective of the study was to make a survey of wetland medicinal plants in the Western Highlands of Cameroon. Eighteen (18) wetlands in four divisions namely Penka-Michel (Menoua division), Batcham (Bamboutos division), Bassap- Bafang (Haut-Nkam division) and Foumban (Noun division) were visited between the months of May and August 2015. Semi-structured interviews were conducted among 38 traditional practitioners and herbalists. Eighteen transects of 1 m × 10 m (10 m²) were established to study the phytosociology of wetland medicinal macrophytes with other associated plants. In each transect, 10 quadrats of 1 m x 1 m were traced in which all plant species including medicinal plants were inventored and counted. A total of 82 wetland macrophytes of medicinal importance grouped into 64 genera and 40 families were documented to treat over 74 different ailments. The most frequent family was the Asteraceae with the highest number of genera (7) followed by Fabaceae and Poaceae with 4 genera each. The most cited plant species were Emilia coccinea (Sims) G. Don, Commelina benghalensis L. and Coccinia barteri (Hook.f.) Keay. Emilia coccinea (Sims) G. Don alone is used for treating 14 ailments while Commelina benghalensis L. and Coccinia barteri (Hook.f.) Keay were used to treat 5 and 4 ailments respectively. The most regularly used plant part was the leaves (55.75 %) followed by whole or entire plant (24.54 %) for treating several diseases such as palpitation, skin diseases, digestive problems, dysentary, influenza, infertility, boil, sore throat, sexual impotence and kidney problems among others. The wetlands in the Western Highlands of Cameroon are rich in medicinal macrophyte species which are used as food or food products for traditional health care.Keywords: Ethnobotany, wetlands, medicinal macrophytes, Infertility, Western Highlands of Cameroon

"Green Synthesis and Characterization of Silver Nano- conjugates using Some Common Medicinal Weeds Leaf Aqueous Extracts"

Nanotechnology is one of the most rapidly progressing fields of technology, and it has opened up many new frontiers of research for modern society. It deals with the nanoparticles having a size of 1-100 nm in one dimension. These nano-conjugates can be prepared easily by different chemical, physical, and biological approaches. However, the green synthesis approach is the most favoured one because this method is more natural, less hazardous, and eco-friendly. Our present study gives an overview of some common medicinal weeds Heliotropium indicum (Family: Boraginaceae), Tridax procumbens (Family: Asteraceae), Cleome rutidosperma (Family: Cleomaceae), Commelina benghalensis (Family: Commelinaceae), and Euphorbia hirta (Family: Euphorbiaceae) leaf aqueous extract mediated green synthesis of silver nano-conjugates. After synthesis, silver nanoparticles were examined by using advanced characterization techniques, including UV-Vis Spectrophotometer, DLS, and FT-IR. The UV-Vis absorption spectroscopy results highlighted a single peak within the range of 402-429 nm for all the five nano-conjugates. The DLS data highlighted that the particle size of the nano-conjugates ranges between 18.17 nm-105.7 nm. Whereas the similarities between the FT-IR data of the sample and nanoparticle confirm the conjugation of different bioactive compounds of the aqueous leaf extracts with the metal nanoparticles.

ASSOCIATION OF INDAZIFLAM AND OXYFLUORFEN IN COFFEE PRE- TRANSPLANTATION

Weed management in the pre-transplantation of coffee plants is an essential condition for the future success of the crop. Currently, the producer has few options to perform chemical management at this stage. Therefore, one of the solutions that is being used is the tank mixing of products proven efficient with new products on the market, such as indaziflam. The objective of this study is to know the selectivity of indaziflam, associated or not with oxyfluorfen, in coffee pre-planting and its effectiveness in weed control. Thus, the following treatments were tested in the field: indaziflam (25 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.), indaziflam (50 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.), oxyfluorfen (960 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.), indaziflam (25 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.) + oxyfluorfen (960 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.), indaziflam (50 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.) + oxyfluorfen (960 g ha&lt;sup&gt;-1&lt;/sup&gt; a.i.), plus a weeded and a non-weeded control. All treatments caused low intoxication in the seedlings, but without impairing the development and orphological variables of the plants. The treatments were efficient in controlling the species &lt;em&gt;Bidens pilosa L&lt;/em&gt;., &lt;em&gt;Commelina benghalensis&lt;/em&gt; L., &lt;em&gt;Urochloa decumbens&lt;/em&gt;, &lt;em&gt;Emilia fosbergii&lt;/em&gt; and &lt;em&gt;Melampodium perfoliatum&lt;/em&gt; until 68 days after application. At 104 days, it was observed that there was a reduction in the efficiency of the products. It is concluded that the associated use of indaziflam and oxyfluorfen does not cause intoxications capable of interfering with the development of coffee plants. The association of these herbicides or their isolated applications is efficient in the control of weeds in the pre-transplantation of coffee plants, and the choice of the best management strategy is dependent on the weed community present in each area.

On the Ecology of Weeds in the Orchards habitat During Summer Season in Nile Delta, Egypt

The present study aims to investigate the ecology of weed communities associated with some orchards habitat using the variations in environmental factors to determine the distribution and abundance of the recognized weed communities in the study areas. The sampled stands were distributed in four Governorates. Field visits were started from January 2014 to September 2015, 45 stands were selected for sampling the vegetation types during summer season. The application of TWINSPAN classification based on the importance values of 49 plant species recorded in selected 45 sampled stands representing the summer orchards sites in the study areas led to the recognition of four vegetation groups (Euphorbia heterophylla, Commelina benghalensis, Cynanchum acutum and Xanthium strumarium were the dominate plants). In summer season, the application of DCA technique proved that, the plant communities recognized by TWINSPAN classification were markedly distinguishable and having clear pattern of segregation on the ordination plane. The application of CCA technique was used to determine the most effective soil variables controlling the abundance and distribution of weed communities associated during summer season.

Bioproductivity and grain quality of two cowpea varieties in relation to frequency of hand weeding

The concern for human health and safety coupled with the increase in herbicides resistant weeds necessitated the need to investigate the effect of frequency of hand weeding on weed suppression, productivity and grains quality in two varieties of cowpea (Tvx 3236 and Ife brown). Plot layout was a split-plot arrangement in complete randomized block design with three replications. The cowpea lines were subjected to five treatments of frequency of hand weeding. Data on weed and crop were subjected to Analysis of Variance. Means were separated using Duncan Multiple Range Test at 0.05 level of significance. Weed species that were found to be preponderant include Brachiaria deflexa, Euphorbia heterophylla and Commelina benghalensis. The three hand weeding at 3, 6 and 9 weeks after planting (WAP) showed the highest weed control efficiency of 90.48 % followed by those of two hand weeding at 3 and 6 WAP (86.98%) and one hand weeding at 3 WAP (74.68%). The weed free check was the most effective in controlling weeds (93.80%). Growth and productivity of the two cowpea lines were enhanced with increase in frequency of hand weeding when compared with the weedy check. Weeds reduced crop yield by 56.17%. The results of grain quality such as crude protein, lipid content, ash and crude fibre were also enhanced with increase in frequency of hand weeding. Generally, growth and yield were higher in Ife brown than Tvx3236. The research was limited to one cropping season and there is need for reproducibility for consistent of results. The study concluded that weeding twice and three times were found to be feasible since these frequencies of weeding times promoted effective weed reduction, higher growth, and yield and grain quality of the two cowpea varieties studied.Keywords: growth and yield, proximate composition, three hand weeding, cowpea productivity

Evaluation of the nematicidal potential of some botanicals against root-knot nematode, Meloidogyne incognita infected carrot: In vitro and greenhouse study

In this study effort was made to manage the root-knot nematode, Meloidogyne incognita by the utilization of selected plants such as Coccinia grandis, Commelina benghalensis, Leucas cephalotes, Phyllanthus amarus and Trianthema portulacastrum. During the in vitro experiment, the second juveniles (J2s) of M. incognita directly treated with aqueous extracts of the plant leaves at 1000, 2000, 3000, 4000 and 5000 ppm concentrations. As a result, the 5000 ppm concentration was found most toxic against the survival of second stage juveniles of M. incognita compared to other concentrations. Maximum mortality of 91% was observed in 5000 ppm extract of P. amarus after 72 h of exposure with LC50 value 2084.49 ppm while minimum mortality of 6.2% was found in 1000 ppm extract of T. portulacastrum after 24 h with LC50 value 9484.18 ppm. The percent mortality of juveniles calculated the LC50 values of all the treatments after 24, 48 and 72 h. Similarly, the in vitro tests showed a gradual decrease in the rate of egg hatching of M. incognita with the increasing concentrations of aqueous leaves extracts of plants, i.e., 1000 ppm to 5000 ppm and exposure period. Maximum inhibition in egg hatching was found at 5000 ppm (86.5%) after seven days in the extract of P. amarus while least was observed in T. portulacastrum at 1000 ppm (10.6%). The findings indicate that the plant extracts were found lethal to J2s and also inhibit egg hatching. In pots under greenhouse conditions, the plants treated with both the doses (50 and 100 g/pot) of fresh chopped leaves of the selected botanicals significantly experienced the reduced infestations in relation to root gall index, egg masses/root system and nematode population/250 g soil. The P. amarus treated at 100 gm / pot showed highest nematicidal efficacy with the maximum reductions in all the pathological parameters as compared to the untreated uninoculated control simultaneously resulted in maximum increase of growth and physiological parameters of carrot such as shoot and root lengths, shoot and root fresh weights, shoot and root dry weights, chlorophyll and carotenoid contents and nitrate reductase activity (NRA). The information derived from this study suggests that the leaves of P. amarus plant can be used for the management of M. incognita and could be a possible replacement for synthetic nematicides.

Role of Prevalent Weeds and Cultivated Crops in the Epidemiology of Maize Lethal Necrosis Disease in Major Maize Growing Agroecological Zones of Uganda

In Uganda, the severe Maize lethal necrosis (MLN) disease, which threatens subsistence maize production is caused by co-infection of maize plants with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV). However, there is no information about natural hosts of MLN causing viruses and their role in epidemiology of MLN in Uganda. The aim of this study was to determine existence of natural alternative weed and cultivated crop hosts of MLN causing viruses. Three seasonal surveys between 2014 and 2015 were carried out in five major maize growing agroecological zones of Uganda. Weeds and cultivated crops growing in proximity to maize were observed for virus symptoms and tested for MLN causing viruses using Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay and Reverse Transcriptase Polymerase Chain Reaction. Data was collected on frequency of occurrence of weeds and cultivated crop species and MLN virus disease incidence. Digitaria abyssinica, Bidens pilosa and Commelina benghalensis were the most common weed species while Phaseolus vulgaris, Manihot esculenta, Arachis hypogaea), Musa sp, Glycine max and Ipomoea batatas were most common cultivated crops. Pennisetum purpureum, Digitaria abyssinica, Cyperus rotundus, Amaranthus spinosus, Commelina benghalensis and Eleusine indica weeds species are natural hosts of Maize chlorotic mottle virus. Among the cultivated crops, Phaseolus vulgaris, Manihot esculenta and Sesamum indicum are natural hosts of MCMV. Only Sorghum (Sorghum bicolor) and sweet potato (Ipomoea batatas) tested positive for SCMV. MCMV incidence in weeds ranged from 2% to 63%% and 2% to 29% in cultivated crops. MLN causing viruses were prevalent in weeds and cultivated crops located in known hotspots for MLN in Uganda. The study has revealed that alternative hosts of MLN-causing viruses are present in major maize growing agroecological zones of Uganda and act as sources of inoculum to sustain MLN epidemics.

Automatic segmentation and measurement methods of living stomata of plants based on the CV model

BackgroundThe stomata of plants mainly regulate gas exchange and water dispersion between the interior and external environments of plants and play a major role in the plants’ health. The existing methods of stomata segmentation and measurement are mostly for specialized plants. The purpose of this research is to develop a generic method for the fully automated segmentation and measurement of the living stomata of different plants. The proposed method utilizes level set theory and image processing technology and can outperform the existing stomata segmentation and measurement methods based on threshold and skeleton in terms of its versatility.ResultsThe single stomata images of different plants were the input of the method and a level set based on the Chan-Vese model was used for stomatal segmentation. This allowed the morphological features of the stomata to be measured. Contrary to existing methods, the proposed segmentation method does not need any prior information about the stomata and is independent of the plant types. The segmentation results of 692 living stomata of black poplars show that the average measurement accuracies of the major and minor axes, area, eccentricity and opening degree are 95.68%, 95.53%, 93.04%, 99.46% and 94.32%, respectively. A segmentation test on dayflower (Commelina benghalensis) stomata data available in the literature was completed. The results show that the proposed method can effectively segment the stomata images (181 stomata) of dayflowers using bright-field microscopy. The fitted slope of the manually and automatically measured aperture is 0.993, and the R2 value is 0.9828, which slightly outperforms the segmentation results that are given in the literature.ConclusionsThe proposed automated segmentation and measurement method for living stomata is superior to the existing methods based on the threshold and skeletonization in terms of versatility. The method does not need any prior information about the stomata. It is an unconstrained segmentation method, which can accurately segment and measure the stomata for different types of plants (woody or herbs). The method can automatically discriminate whether the pore region is independent or not and perform pore region extraction. In addition, the segmentation accuracy of the method is positively correlated with the stomata’s opening degree.

A beetle biocontrol agent of rice-field weeds recognizes its host plants by surface wax long-chain alkanes and free fatty acids

The importance of long-chain alkanes and free fatty acids present in leaf surface waxes of two Commelinaceae rice-field weeds, Commelina benghalensis L. and Murdannia nudiflora (L.) Brenan, was evaluated as short-range attractant and oviposition stimulant in the Lema praeusta (Fab.) (Coleoptera: Chrysomelidae). Surface waxes were extracted by dipping leaves in n-hexane for 1 min at 27 ± 1 °C. Thin-layer chromatography, gas chromatography–mass spectrometry, and gas chromatography–flame ionization detection analyses of n-hexane extracts revealed 20 n-alkanes from C14 to C36 and 13 free fatty acids from C12:0 to C22:0. Pentacosane and palmitoleic acid were predominant among n-alkanes and free fatty acids, respectively. Females showed attraction to one leaf equivalent surface wax of both weeds against the control solvent (petroleum ether) in Y-tube olfactometer bioassays. However, the insect could not discriminate between one leaf equivalent surface waxes of two weeds, suggesting that both weeds were equally attractive to females. Among all identified alkanes and fatty acids, females showed attraction towards individual docosane, tricosane, pentacosane and heptacosane, and tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis and M. nudiflora, respectively. A synthetic blend of either docosane, tricosane, pentacosane, and heptacosane, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis, or tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of M. nudiflora, served as short-range attractant and oviposition stimulant in L. praeusta.

Total phenolic content and antioxidant activity of methanolic extract of selected wild leafy vegetables grown in Bangladesh: A cheapest source of antioxidants.

Nowadays, more attention has been paid on wild plants as new source of natural antioxidants. Therefore, methanolic extracts of 10 traditionally consumed wild leafy vegetables of Bangladesh were analyzed for their total phenolic content (TPC) and free radical scavenging activity. Folin-Ciocalteu method followed by spectrophotometric measurement was used to quantify the TPC of the selected wild leafy vegetables. Free radical scavenging activity was examined utilizing 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay. Different concentrations of the plant extract were applied to ascertain the dose response relationship in inhibiting DPPH free radical. The results revealed that the TPC ranged from 102.20 to 710.42 mg GAE/100g dry weight (DW). The highest TPC was observed in Bauhinia acuminata (Shetokanchan) while Leucas aspera (Shetodhron) exhibited the lowest TPC among the undertaken vegetables. The studied samples proportionately inhibited DPPH with increasing concentrations. At high concentration (500 µg.mL-1), the percentage inhibition of DPPH radical by plant extract ranged from 68.1 ±2.65 % to 93.1 ±1.23 %. The highest DPPH radical inhibition was observed in Bauhinia acuminata (Shetokanchan) (93.10 ±1.23 %), followed by Commelina benghalensis (Bat baittashak) (91.97 ±1.31 %), Hydrocotyle sibthorpiodes L. (Sakumubakla) (91.83 ±2.13 %). The lowest DPPH radical inhibition among the studied samples was observed in Leucas aspera (Shetodhron) (68.1 ±2.65 %). IC50 values measured by DPPH assay in this study ranged from 11.64 to 313.79 µg.mL-1. The study findings indicated that the samples under study possesses strong activity against DPPH, and thus could be used as natural antioxidants in the food and/or pharmaceutical industry.

Tillage, crop establishment, residue management and herbicide applications for effective weed control in direct seeded rice of eastern Indo–Gangetic Plains of South Asia

Weeds are the major production constraint in direct seeded rice (DSR) due to the concurrent emergence of competitive weeds and absence of water at initial growth stages to smother weed growth, leading to decreased crop yield. DSR has emerged as an alternative to the conventional water, labour and energy–intensive puddled transplanted rice (PTPR) in the eastern Indo–Gangetic Plains (IGP) of India. Hence, three field experiments were conducted (2008–2010) to evaluate integrated weed management options that included transplanted rice under puddled and unpuddled conditions, zero till DSR with or without residue retention and cover crops, zero till transplanted rice (ZTTPR) (experiment I); different combination of herbicides with or without cover crops (experiment II and III). Results revealed that during 1st year of study, zero–till direct seeded rice (ZTDSR) with (ZTDSR + R) or without (ZTDSR–R) residue retention and ZTDSR after the cover crops of sesbania [Sesbania aculeata (Willd.) Pers.] (ZTDSR + SB) or cowpea [Vigna unguiculata (L.) Walp.] (ZTDSR + CP) had greater weed density and dry matter accumulation than puddled transplanted rice (PTPR). However, in the 2nd and 3rd years, similar or lower weed density and dry matter accumulation was recorded in zero–tilled (ZT) plots. In 3rd year, plots under ZTDSR–R, ZTDSR + R, ZTDSR + SB, and ZTDSR + CP accumulated 14.3, 33.3, 23.1, and 60%, respectively, less weed dry matter over PTPR. Plots under ZTDSR produced almost similar or more grain yield to PTPR in all the three years of experimentation. On the basis of 3 years’ average data, the highest grain yield was recorded in plots under ZTDSR + R or –R followed by ZTTPR and ZTDSR + CP. While in experiment II, mungbean [Vigna radiata (L.) R. Wilczek] as cover crop fb bispyribac–Na at 25 g ha−1 resulted in the highest grain yield in 2008; but in 2009, weed free plots were superior–most. With regard to herbicides, pre–emergence application of pendimethalin EC at 1000 g ha−1; effectively controlled aerobic grassy weeds such as Eragrostis tenella var. japonica (Thunb.) Roem. & Schult. but was ineffective against Echinochloa colona (L.) Link. Similarly, bispyribac–Na at 25 g ha−1 was most effective for control of E. colona and Commelina benghalensis L., but incompetent against E. tenella. Overall, from the weed management viewpoint, this study recommends combination of pendimethalin at 1000 g ha−1fb bispyribac–Na at 25 g ha−1 for effective control of diverse weed flora encountered in DSR.