CuO and CeO2 Nanostructures Green Synthesized Using Olive Leaf Extract Inhibits the Growth of Highly Virulent Multidrug Resistant Bacteria

One of the major challenges of nano-biotechnology is to engineer potent antimicrobial nanostructures (NS) with high biocompatibility. Keeping this in view, we have performed aqueous olive leaf extract mediated one pot facile synthesis of CuO-NS and CeO2-NS. Prepared NS were homogenous, less than 26 nm in size, and small crystallite units as revealed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Fourier transform infrared spectroscopy (FTIR) of CuO-NS and CeO2-NS showed typical Cu-O prints around 592–660 cm-1 and Ce-O bond vibrations at 453 cm-1. The successful capping of CuO-NS and CeO2-NS by compounds present in the plant extract was further validated by high performance liquid chromatography (HPLC) and thermal gravimetric analysis (TGA). Active phyto-chemicals from the leaf extract simultaneously acted as strong reducing as well as capping agent in the NS synthesis. NS engineered in the present study showed antibacterial potential at extremely low concentration against highly virulent multidrug-resistant (MDR) gram-negative strains (Escherichia coli, Enterobacter cloacae, Acinetobacter baumannii and Pseudomonas aeruginosa), alarmed by World Health Organization (WHO). Furthermore, CuO-NS and CeO2-NS did not show any cytotoxicity on HEK-293 cell lines and Brine shrimp larvae indicating that the NS green synthesized in the present study are biocompatible

ADOPTION OF BT COTTON: THREATS AND CHALLENGES

Adopting new technology always involves advantages and risks; Bt cotton ( Gossypium hirsutum L.) is a new technology well known in developed countries for its many advantages, such as reduced pesticide application, better insect pest control, and higher lint yield. However, its success in developing countries is still a question mark. Global adoption of Bt cotton has risen dramatically from 0.76 million ha when introduced in 1996 to 7.85 million ha in the 2005 cotton-growing season where 54% of the cotton crops in the USA, 76% in China, and 80% in Australia were grown with single or multiple Bt genes. Bollworms are serious cotton pests causing 30-40% yield reduction in Pakistan and 20-66% potential crop losses in India. The major advances shown in this review include: (1) Evolution of Bt cotton may prove to be a green revolution to enhance cotton yield; (2) adoption of Bt cotton by farmers is increasing due to its beneficial environmental effects by reducing pesticide application: however, a high seed price has compelled farmers to use illegal non-approved Bt causing huge damage to crops because of low tolerance to insect pests; and (3) some factors responsible for changes in the efficiency of the Bt gene and Bt cotton yield include internal phenology (genetics), atmospheric changes (CO2 concentration), nutrition, insect pests, boll distribution pattern, disease and nematodes, removal of fruiting branch and/or floral bud, introduction of Bt gene, and terpenoids and tannin production in the plant body

A Review on Overcoming Dual Challenges for Maize Cropping under High Plant Density: Stalk Lodging and Kernel Abortion

Increased optimal plant density is necessary in ensuring future food security by increasing crop productivity. However, maintaining relatively high plant density has to overcome two challenges i.e. kernel abortion and stalk lodging. The response of maize to increased plant density and the effects of increased plant density on maize productivity were discussed in this research. Increased plant density induces increased plant height, causes low photosynthetic capacity, limits the carbohydrate supply and increases kernel abortion. Also, increased plant density incurs a high risk of stalk lodging due to increased ear height and diminished stem diameter associated with reduced vascular bundles that provide, mechanical force. This review proposes a potential capacity of sucrose storage in stalk for tackling kernel abortion and stalk lodging. The mechanisms of boosting stem sugar storage with more efficient unloading, transporting, and storage in internodes are discussed

The impact of seed burial depths and post-emergence herbicides on seedling emergence and biomass production of wild oat (Avena fatua L.): Implications for management.

Wheat (Triticum aestivum L) is among the most important cereal crops widely cultivated in the world. Wild oat (Avena fatua L.) competes with wheat for moisture, sunlight, space and nutrition. The successful management of weeds requires sound knowledge of their biology and response to different herbicides. This study inferred the impact of different constant temperature regimes and seed burial depths on seedling emergence and biomass production of wild oat. Moreover, the impact of different post-emergence herbicides applied at different growth stages on biomass production of wild oat was tested. The influence of different wild oat-wheat density (WWD) combinations on biomass production of wheat and wild oat was also inferred. Different constant temperature regimes significantly altered seed germination and biomass production of wild oat. The highest seed germination percentage and biomass production were noted under 15°C and 20°C, whereas the lowest values were recorded under 30°C. Similarly, days to start emergence, seedling emergence percentage and biomass production of wild oat was significantly affected by different seed burial depths. The lowest and the highest values of these parameters were observed under 4 and 10 cm depth, respectively. Different post-emergence herbicides and wild oat growth stages significantly altered biomass production. The highest reduction in fresh and dry biomass was recorded with herbicides' application at 2-4 leaf stage compared with anthesis stage. Clodinofop resulted in higher reduction of fresh biomass, whereas higher reduction in dry biomass was noted with Sulfosulfuron. Seed germination of both species was not affected by different WWD combinations, except for the treatment where no seed was sown of both species. These results indicate that deep burial of seeds could prevent seedling emergence, whereas post-emergence herbicides must be applied at 2-4 leaf stage of wild oat for its effective management

The influence of environmental factors on seed germination of Xanthium strumarium L.: Implications for management.

Xanthium strumarium L. (Common cocklebur) is a noxious weed prevailing in different ecosystems around the world. It incurs significant yield and economic losses in different cropping systems globally. Successful management of any weed species depends on sound knowledge of seed germination biology. However, detailed knowledge on seed germination biology of the species is missing. Therefore, we investigated the impact of different environmental factors on seed germination and seed burial depths on seedling emergence of two X. strumarium populations. The impact of different sorghum mulch doses (0-10 t ha-1) on seedling emergence of the tested populations was also explored. Seed germination was evaluated under different photoperiods (0, 12 and 24), constant temperatures (0-50°C with 5°C stepwise rise), and different levels of pH (3-12), salinity (0-600 mM) and osmotic potential (0 to -1.6 MPa). Seedling emergence was observed for seeds buried at different depths (0-15 cm). Seeds of both populations proved non-photoblastic; however, higher germination was recorded under 12-hour photoperiod. The seeds germinated under a wide range of constant temperatures (10-45°C), pH (4-10), osmotic potentials (0 to -0.8 MPa) and salinity levels (0-400 mM NaCl). However, the highest germination was observed under 30-31°C temperature and neutral pH (7.51-7.52). Seeds were able to withstand 400 mM salinity and -1.00 MPa osmotic potential. Seedling emergence was initially improved with increasing burial depth and then a sharp decline was noted for the seeds buried >3 cm depth. Most of the seeds of both populations did not emerge from >8 cm depth. Different sorghum mulch doses linearly suppressed seedling emergence of tested populations, and 5.83-5.89 t ha-1 mulch application suppressed 50% of seedling emergence. Seedling emergence was completely retarded with 8 t ha-1 sorghum mulch. The tested populations germinated under diverse environmental circumstances indicating that the species can become troublesome in marginal habitats and cropped lands. Deep burial of seeds and application of sorghum mulches suppressed seedling emergence. Thus, deep burial followed by shallow tillage and application of sorghum mulches could be used as a successful strategy to manage the species in agricultural fields. Nonetheless, management strategies must be developed to control the species in other habitats

Chitosan nanoparticles loaded with mesosulfuron methyl and mesosulfuron methyl + florasulam + MCPA isooctyl to manage weeds of wheat (Triticum aestivum L.)

Nanoherbicides are articulated by empowering the potential of nanotechnology for the efficacious delivery of chemical or biological herbicides with the aid of nanomaterial‐based herbicide combinations. Therefore, the goal of this work was to investigate the chitosan nanoparticles loaded with mesosulfuron methyl and mesosulfuron methyl + florasulam + (2-methyl-4-chlorophenoxyacetic acid) MCPA isooctyl herbicides as a possible environmentally benign substitute to manage weeds in wheat. Due to intriguing characteristics including biocompatibility, low allergenicity, biodegradability, and nontoxicity, chitosan biopolymers as sustainable chitin derivatives have received intense scrutiny in the biomedical business. The manufactured nanoparticles were characterized by using ultraviolet absorbance, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The average particle size as revealed by SEM was 40–70 nm in a cluster form with the porous structure. The maximum absorption peaks of both nanoparticles of mesosulfuron methyl and mesosulfuron methyl + florasulam + MCPA isooctyl were 330 and 360 nm. The FT-IR analysis showed an intensive peak at 2θ value of 30.55° for mesosulfuron methyl and 32.79° for mesosulfuron methyl + florasula + MCPA isooctyl, which correspond to the 78 and 198 planes of the anatase phase, respectively. The nanoparticles were sprayed at the third to fourth leaf stages of the targeted weeds. Seven different doses were applied. A total of 100% mortality and visual injury were caused by the chitosan-based nanoparticles of both herbicides at the recommended dose of standard herbicide. The 5-fold lower dose showed the minimum chlorophyll content (5.75%), plant height (2.35 cm), fresh biomass (1.08 g), and dry biomass (0.33 g) of a weed mixture. For the same traits, the herbicide nanoparticles at 10-fold lower dose of commercial herbicides exhibited a similar effect as the recommended dose. Nanoherbicides could recuperate the conventional herbicide effectiveness by enhancing the stability and reducing the toxicity

Optimizing planting geometry for barley-Egyptian clover intercropping system in semi-arid sub-tropical climate.

Intercropping legumes with cereals has been a common cropping system in short-season rainfed environments due to its increased productivity and sustainability. Intercropping barley (Hordeum vulgare L.) with Egyptian clover (Trifolium alexandrinum L.) could increase the grain yield of barley and improve resource use efficiency of the intercropping system. However, non-optimum planting geometry has been a hurdle in the adaptation of barley-based cropping systems. This study was aimed at optimizing the planting geometry, and assess the productivity and profitability of barley-Egyptian clover intercropping system. Ten different planting geometries, differing in number of rows of barley, width and number of irrigation furrows and planting method were tested. Intercropping barley with Egyptian clover improved 56-68% grain yield of barley compared with mono-cropped barley. Barley remained dominant crop in terms of aggressiveness, relative crowding coefficient and competitive ratio. The amount of water used was linearly increased with increasing size of barley strip from 3 to 8 rows. The highest water use efficiency (4.83 kg/cf3) was recorded for 8-row barley strip system with 120 cm irrigation furrows compared to rest of the planting geometries. In conclusion, 8-rows of barley planted on beds with Egyptian clover in 120 cm irrigation furrows had the highest net income and cost benefit ratio. Therefore, it is recommended that this planting geometry can be used for better economic returns of barley-Egyptian clover intercropping system. However, barley strips with >8 rows were not included in this study, which is limitation of the current study. Therefore, future studies with >8 barley rows in strip should be conducted to infer the economic feasibility and profitability of wider barley strips

Facile biosynthesis of Ag-NPs using Otostegia limbata plant extract: Physical characterization and auspicious biological activities

Silver nanoparticles (Ag-NPs) synthesized through reduction by Otostegia limbata green extract are, hereby, reported for the first time. It is very interesting to observe that in this case, O. limbata plant extract acts as a strong chelating agent in Ag-NPs formation through AgNO3. Scanning electron microscope (SEM) studies expose that Ag-NPs formation is highly homogenous and spherical with mean particle size of 32±0.8 nm. A typical Ag absorption peak has been observed at 419 nm by ultra violet (UV)-visible spectroscopy which have endorsed the successful formation of single phase Ag-NPs. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) examination further validates the crystalline pure phase structure of Ag-NPs. Promising results have been recorded against protein kinase inhibition assay and antibacterial assay having prominent pathogenic strains. Our present study explores that biosynthesized eco-friendly Ag-NPs have great potential, in the future, for anticancer drug development with wide range pharmaceutical applications