Growth, yield and nitrogen uptake in rice crop grown under elevated carbon dioxide and different doses of nitrogen fertilizer

Climate change associated with rising atmospheric carbon dioxide (CO2) concentration may have impact on crop production and soil health. Increase in atmospheric CO2 concentration may enhance crop growth with higher demand for nutrients by the crop. An experiment was conducted during July-October, 2013 using Free Air Carbon Dioxide Enrichment facility at the Indian Agricultural Research Institute, New Delhi to study the impact of elevated CO2 and nitrogen (N) dose on growth, yield and nitrogen uptake in rice crop. Four doses of N, i.e., control, 0.6 g N pot-1 (75% recommended dose of N), 0.8 g N pot-1 (100% recommended dose of N) and 1.0 g N pot-1 (125% recommended dose of N) were applied in both ambient (395 ppm) and elevated CO2 (550±20 ppm) conditions. Grain and biomass yield of rice was significantly higher under elevated CO2 condition. Plant growth and yield parameters also increased with increased N doses in both elevated and ambient CO2 conditions. Nitrogen concentration of grain and straw decreased under high CO2 level but N uptake increased under elevated CO2 condition. Agronomic efficiency of N was higher under elevated CO2 while recovery efficiency of N remained unaffected. The study showed that although yield of rice increases under elevated CO2 condition, to maintain plant nitrogen concentration, application of additional dose of N is required.

Impact of gamma irradiation on growth, yield and physiological attributes of maize

Feeding the increasing global population with adequate supply of cereals for food, particularly with limited agricultural area, is a challenging task. In this context, emphasis on enhancing food producing processes gains attention. Gamma irradiation, up to certain doses, is known to improve crop yield without using chemical fertilizers. Among the cereals, maize is an important crop, which accounts for 9% of total food grain production. Here, we presumed that gamma ray pretreatment to maize seeds would be beneficial and boost the maize productivity and yield. In this study, we conducted field experiments to assess the gamma irradiation induced effect on seedling emergence, plant growth, yield and yield attributes of maize (HQPM-1). Grains of maize were exposed to gamma radiation doses ranging from 0.0025, 0.005, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4 0.50, 1.0 and 2.0 kGy with the help of 60Co γ-radiation source facility available in the Centre. The germination of irradiated seeds was assessed in an incubator chamber and the irradiated seeds were sown in the field during kharif (July-October) 2013 and 2014 seasons at the IARI, New Delhi, research farm. The germination was >90% up to 0.1 kGy dose, beyond which, germination of seeds in the incubator as well as in field condition declined significantly. Few seedlings still came out from relatively higher doses of gamma irradiation (>0.5 kGy). However, these seedlings could not survive more than seven days. Results of present study indicated that plant growth parameters, such as plant height, photosynthetic rate, chlorophyll content, leaf area index at ‘tasseling’ as well as at ‘silking’ stage affected positively at lower doses (<0.2 kGy). The biological yield, grain weight (g) (cob-1), grains (cob-1) and 100 grain weights responded positively to the lower doses (≈ 0.1 kGy) of gamma irradiation. Our results indicated improvement in biological yield by 35.2% at 0.1 kGy as compared to the control (00 kGy). However, maximum reduction (33%) was recorded at 0.5 kGy. Similarly, grain yield (ton ha-1) was improved by 8.3% at 0.1 kGy as compared to the control, but reduced the most by 56.9% at 0.5 kGy compared to the respective control.

The efficacy of polyherbal formulation of Moringa oleifera, Viola odorata, Allium sativum against microbes- synergistic effect.

The purpose of our present study is to test antimicrobial and antifungal activity of polyherbal formulations. The testing of the antimicrobial activity on polyhernal formulation was done against gram positive (Staphylococcus aureus, Bacillus subtilis) and gram negative (Salmonella typhi, Escherichia coli,) bacteria. The testing of antifungal activity was done against Aspergillus niger and Candida albicans with different combinations of polyherbal formulation. The microorganism to be tested was grown in relevant nutritional media. The solvent used for the extraction of Moringa oleifera, Viola odorata, Allium sativum was methanol. These methanolic extracts of chosen plants were further used in specific proportions for the preparation of polyherbal formulation (PF-1, PF-2, and PF-3). The resultant compositions were further used to check the efficacy against selected experimental microorganisms. PF-3 showed the significant high zone of inhibition against all the experimental microorganisms as compared to the other two combinations PF-1 and PF-2. Thus, the result has revealed that the antimicrobial activity is due to the synergistic effect of secondary metabolites present in these selected plants.

Novel Mucoadhesive Polymers –A Review.

The current article focuses on polymers used in mucosal delivery of therapeutic agents. The mucoadhesive drug delivery system is a popular novel drug delivery method because mucous membranes are relatively permeable, allowing for the rapid uptake of a drug into the systemic circulation and avoiding the first pass metabolism. Mucoadhesive polymers have been utilized in many different dosage forms in efforts to achieve systemic delivery of drugs through the different mucosa. These dosage forms include tablets, patches, tapes, films, semisolids and powders. The objective of this review is to study about novel mucoadhesive polymers and to design improved drug delivery systems.