The western Mediterranean is an area particularly affected by the effects of climate change, which makes it a hotspot, and it is also an area where there is particular competition for land use, where subtropical crops coexist with traditional crops including vines, olives, and almond trees, and where there is growing demand for urban development and tourism (see page 473).
2022
The Seedling Growth Response of Pisum Sativum L. to Different Types of Compost
Bina Jamsher, Muhammad Zafar Iqbal, Muhammad Shafiq, Mohammad Athar
ABSTRACT. The constant increase in the high number of population, anthropogenic and industrial activities are alarming issues and raise food security issues around the world. The treatment of compost acts as an effective and environmentally friendly tool for an increase in vegetable production. This research article records the effects of three soil compost treatments (1) dry leaves (Ficus bengalensis L.), (2) solid waste (mustard oil cake) and (3) chicken manure, alone and in combination, with seedling growth performances of pea in pot culture experiments with five replications. The results showed that soil compost treatments showed a significant (p < 0.05) impact on the physicochemical features of soil and the physiological characteristics of pea (Pisum sativum L.). Soil compost analysis revealed a difference in soil porosity and pH, electrical conductivity, organic matter, total organic carbon, CaCO3, Na+, K+, phosphorous and nitrogen. Plant tissue analysis of pea seedlings also showed different levels of sodium, potassium and phosphorous values. The findings of the present research work concludes that the treatment of F. bengalensis dry leaves (25%) + garden loam (75%) treatment produced maximum growth performance, and the mustard oil cake solid waste (25%) + garden loam (75%) treatment showed the lowest seedling growth performance. The F. bengalensis dry leaves (25%) + garden loam (75%), soil compost application treatment showed the maximum seedling height of pea. The solid waste (SW) mixed with garden loam (GL) (SW 25% + GL 75%) and mustard oil cake solid waste alone treatment showed the lowest seedling growth of pea. The F. bengalensis dry leaves 25% + garden loam 75% compost treatment also influenced on the soil properties.
Keywords: Compost; Ficus benglensis; garden loam; organic matter; pea.
Germination and Early Growth Performance of Prekese, Tetrapleura Tetraptera to Seed Pretreatment Methods and Phosphorus Fertilizer in the Nursery Phase
Adams Latif Mohammed, Frank Addai, Joseph Cobbinah, Elvis Bawa
ABSTRACT. Seeds of Tetrapleura tetraptera trees have poor germination due to their hard and impervious seed coat. This research was conducted to determine the possibilities of reducing seed dormancy using seed pretreatment via the application of sulphuric acid and hot water and then phosphorus for better seedling growth. Seeds pretreated with sulphuric acid had a significantly (P˂0.05) increased germination rate (by 60%) compared to seeds pretreated with hot water (40%). The application of phosphorus fertilizer stimulated the early growth of the species. This research provides information for practical use.
Keywords: germination; hot water; phosphorus fertilizer; sulphuric acid; Tetrapleura tetraptera.
The Phytoremediation Potential of Lavandula angustifolia Mill. Grown in Soils Historically Polluted With Heavy Metals: A Case Study from Baia Mare, Romania
Roxana Vidican, Tania Mihăiescu, Anca Pleșa, Anamaria Mălinaș, Bianca Pop
ABSTRACT. The aim of this research is to evaluate the ability of Lavandula angustifolia Mill. (LA) to accumulate and translocate heavy metals (HMs) from disturbed soils. The study was conducted on a site historically polluted with HMs, located in Baia Mare, Romania. Soil samples and underground (root) and aboveground parts of plants (leaves and stems) were collected from the study site and analysed for HM content (Pb, Cu, Cd, and Zn) by XRF spectroscopy. The potential for phytoremediation of lavender was evaluated according to the bioconcentration (BCF) and the translocation (TF) factors. The results showed that LA efficiently accumulated Cd and Zn. A different partitioning of HM among plant tissues was observed, showing the highest content in the aboveground mass compared to that found in the root (except for Zn). The TF ranged between 0.62 and 3.59, with values higher than unity for Cd and Pb, revealing that this plant is a suitable candidate for phytoextraction of these two trace elements. According to the BCF values, it seems that lavender is able to bioaccumulate high amounts of Cd (6.66), Pb (1.09), and Zn (2.87). Although more research is necessary for conclusive results, our findings confirm the ability of Lavandula angustifolia Mill. to tolerate, accumulate, and translocate high levels of HMs from soil to the aerial parts of the plant.
Keywords: phytoremediation; lavender; heavy metals; bioconcentration and translocation factors.
Land Use Changes and Effects of Rainfall on Vegetation Cover in Two Mediterranean Basins (Málaga, Spain)
Ana Triano-Cornejo, M. Eugenia Perez-Gonzalez, Tomás M. Fernández-Del Castillo, José D. Ruiz-Sinoga
ABSTRACT. The western Mediterranean is an area particularly affected by the effects of climate change, which makes it a hotspot, and it is also an area where there is particular competition for land use, where subtropical crops coexist with traditional crops including vines, olives, and almond trees, and where there is growing demand for urban development and tourism. It is one of the most sensitive to the effects of climate change because of the markedly contrasting extreme events, including heat waves, torrential rains and drought. In this study we analysed changes in land use, torrential events and the effect of rainfall on vegetation cover and soils in two basins, the main objective being to analyse the evolution of land use and water erosion in recent decades.
The two basins are similar but have different configurations and contrasting uses. One has steep slopes and is characterized by more typical Mediterranean crops, such as vineyards, while the other has been subject to clearing that has modified the steep slopes, and where there has been a change to more competitive crops, including subtropical crops. The results highlight the continuous increase of irrigated crops and urban areas and a gradual disappearance of rainfed crops, the occurrence between torrential events and the correlation between monthly rainfalls and vegetation cover.
Keywords: Mediterranean basins; land use; rainfalls; vegetation cover.
The “Photosynthesis-Growth-Stress Memory” Relationship In Plants Under Conditions of Moisture Fluctuation and Recurrent Drought: Management Options
Anastasia Ştefîrţă, Ion Bulhac, Lilia Brînză, Leonid Voloșciuc, Eduard Coropceanu, Maria Cocu
ABSTRACT. The effect of co-activation of the stress-memory formation potential under repeated drought of Glycine max (Merr.) L. plants was recorded using cytokinin (CK), thiourea (TH) and, especially, complex preparation Polyel. Glycine max plants (Merr.) L. of Moldovitsa, Nadejda and Magia varieties, exposed to two cycles of “drought–rehydration” at the “first trifoliate leaf” and “flowering – pods formation” phases served as test subjects. The tolerance-inducing effect manifests itself by maintaining the content of assimilatory pigments, photosynthesis and growth processes at a significantly higher level. After the restoration of the optimal moisture background, plants pre-treated with CK, TH and the preparation Polyel, which endured moderate stress in the initial stages of ontogenesis, had restored functional processes. The information obtained in this work certainly opens the management perspective of the ability to form stress memory, adaptation and tolerance of plants to the unfavourable fluctuation of humidity and recurrent drought. The management possibilities of plant adaptation and tolerance are discussed.
Keywords: plants; adaptation; resistance; growth; photosynthesis; transpiration; productivity; cytokinin compounds; antioxidant preparation.
Management of Nitrogen Stress in Cotton (Gossypium hirsutum L.) Using Greenseeker Technology
Medine Karatas, Emine Karademir
ABSTRACT. This study was performed with GreenSeeker technology in order to determine the possibility of nitrogen stress management in cotton and to determine the differences between the normalized difference vegetative index (NDVI) and nitrogen doses determined with GreenSeeker, to determine the nitrogen deficiency and stress conditions by making use of the value of the NDVI in cotton production and to intervene when necessary and direct the producers in this regard. In the study six nitrogen doses (Control, 60, 120, 180, 240 and 300 kg ha-1) were used. The results showed significant differences between N applications for leaf chlorophyll content (SPAD), NDVI-2 (in the boll formation period), number of bolls (NB), seed cotton (SCY) and fiber yield (FY). On the other hand, there were non-significant differences in terms of (LA) area, NDVI-1 (in the beginning of the flowering), plant height (PH), node number of first fruiting branches (NNFFB), number of monopodial branches (NMB) and number of sympodial branches (NSB), number of nodes (NN), height to node ratio (HNR), seed cotton boll weight (SCBW) and ginning percentage (GP). The highest SCY and FY obtained were from doses of 180 and 120 kg ha-1 N, the highest leaf chlorophyll content and number of bolls obtained were from doses of 120 kg ha-1 N. The highest values of NDVI-2 obtained were from doses of 120, 240 and 300 kg ha-1 N, respectively. There were non-significant differences between N doses for values of the NDVI-1 of flowering, but significant differences observed for values of NDVI-2 of boll formation periods. The findings obtained from this research indicated that leaf chlorophyll and NDVI of the boll formation period can be used for determining differences due to varying N doses in cotton production.
Keywords: cotton; nitrogen doses; NDVI; yield; fiber quality.
Effect of Leucaena leucocephala Leafy Biomass and NPK Fertiliser on The Growth and Yield of Okra, Abelmoschus esculentus (L.) Moench
Adams Latif Mohammed, Kaddiri Nanbaala Kumodu Nasim, Ali Moro
ABSTRACT. Okra, Abelmoschus esculentus (L.) Moench, is a multipurpose vegetable crop grown in tropical and subtropical regions of the world for its immature seed pods and leaves. The crop seldom reaches its yield potential in most of these areas, primarily due to a decline in soil fertility. As a result, a field experiment was carried out at the Faculty of Renewable Natural Resources Demonstration Farm, KNUST-Kumasi to assess the effect of NPK (15:15:15) fertiliser and Leucaena leucocephala leafy biomass application on the growth and yield of okra. The treatment combinations were laid out in a 3 × 3 factorial randomised complete block design with 9 treatments replicated 4 times for a total of 36 experimental units. Leucaena leafy biomass and NPK were evaluated solely and in combinations at a rate of 75 kgN/ha on a weight basis. The treatment combinations were applied as follows: T1 = Control; T2 = 0.14 kg NPK (15:15:15); T3 = 0.07 kg NPK (15:15:15); T4 = 0.5 kg L. leucocephala leafy biomass; T5 = 0.25 kg L. leucocephala leafy biomass; T6 = T2 + T4; T7 = T3 + T5; T8 = T2 + T5; T9 = T3 + T4. The number of days from planting to the first anthesis of okra differed significantly (p ˂ 0.05). T3 showed the least number of days to the first anthesis observation (47 days), while T9 had the highest number of days to the first anthesis (49.3 days). On a weekly basis (starting with 5 weeks after planting, WAP), height was not significantly different among the various treatments. Stem diameter followed a sequence similar to plant height, starting from 5 to 10 WAP, where no significant differences occurred between treatment means. However, mean values revealed that okra plants varied significantly in height; T9 had the tallest plants (27.2 cm), while T2 and T8 had the shortest plants (21.2 and 21.2 cm, respectively). There was a significant difference between the treatment means and stem diameter. In the same advanced line, T9 had the highest stem diameter (9.9 mm), with T5 having the lowest stem diameter (6.9 mm). Fruit yield was also significantly different, with T4 having the most fruit (39,259 fruits per ha) and T8 having the least (19,259 fruits per ha). The fruit dry weight was significantly different, as the highest weight was recorded in T7 (12.5 tonnes/ha) and the lowest was recorded in T9 (5.3 tonnes/ha). The combination treatment T9 [0.07 kg NPK (15:15:15) fertiliser + 0.5 kg L. leucocephala leafy biomass per plot] had a significantly improved height and diameter compared to the other treatments. The highest fruit yield of okra was recorded in T4 (0.5 kg L. leucocephala leafy biomass per plot), and the highest dry weight of okra was registered in T7 (0.07 kg NPK (15:15:15) fertiliser + 0.25 kg L. leucocephala leafy biomass per plot). Therefore, it is recommended that sole L. leucocephala leafy biomass (T4) and its combination with NPK (15:15:15) fertiliser (T9) be adopted by smallholder farmers to cultivate okra in the tropics.
Keywords: effect; organic fertiliser; inorganic fertiliser; okra production.
The Production of Low-Alcohol Wines by Sequential Semi-Anaerobic Must Fermentation
Vasile Răzvan Filimon, Roxana Mihaela Filimon, Ancuța Nechita, Florin Dumitru Bora, Liliana Rotaru, Valeriu V. Cotea
ABSTRACT. Nowadays, consumers go towards products that provide food security and nutritional richness, consumption of highly alcoholic beverages not complying with these health-related requirements. This study aimed to obtain low-alcohol wines by performing sequential alcoholic fermentation of grape must (Muscat Ottonel). Thus, 11 commercial yeast strains (10 Saccharomyces cerevisiae and 1 Torulaspora delbrueckii) were preliminarily tested in anaerobic and semi-anaerobic conditions. Based on laboratory tests, grape must fermentation was sequentially initiated in semi-anaerobic conditions (loose cotton plugs; intermittent homogenization), with the T. delbrueckii strain (106 CFU/mL) and the addition of preliminarily selected S. cerevisiae strains (104 CFU/mL), to the consumption of 50% of the sugars in the must, to complete the fermentation. By applying this technology, dry wines were obtained with an alcohol content lower by up to 1.10% vol., but with a lower concentration of volatile terpenes, due to additional must oxidation. Also, semi-anaerobiosis enhanced glycerol synthesis by yeasts (< 35%), with a positive impact on the sensory characteristics of the wine. Keywords: alcoholic fermentation; glycerol; low-alcohol wine; non-Saccharomyces yeast; Torulaspora delbrueckii.
* Abstract published in Conference Programme dedicated to LIFE SCIENCES TODAY FOR TOMORROW
The Influence of Tillage Systems on Soil Compaction in the Corn Crop
Gabriel-Dumitru Mihu, Denis Țopa, Anca Elena Calistru, Gerard Jităreanu
ABSTRACT. During the last decades, no-tillage has started to be used on more and more areas, being a conservative tillage system practiced in many farms in the country. The aim of this study was to quantify the effects of the no-tillage system on the physical properties of the soil compared to the conventional system, in a plateau area with cambic chernozem soil under the current climatic conditions in the north-east of Romania, in order to implement it in agricultural practice of the studied area. The soil samples were taken in natural and undisturbed conditions for bulk density and moisture content, soil penetration resistance was determined using the Eijkelkamp penetrologger. The status of soil compaction, the various porosity categories, and the soil moisture content were all determined based on field and laboratory analysis. Measurements performed at a depth of 0-40 cm showed a lower bulk density in the conventional system, and in terms of variation in values from sowing to harvesting, there was a maximum increase of 18% in the 10-20 cm soil layer, an intermediate of 10% in the topsoil and 20-30 cm layers, and a minimum of 1% in the 30-40 cm layer. Total porosity, which reflects soil pore volume, is inversely correlated with bulk density, which means that under conventional tillage practices, soil macropore volume (>0.05 cm) was higher (47.79-60.82% v/v) than under no-tillage practices (45.90-50.79% v/v) for 0-40 cm depth at the sowing time. The results confirm that the no-tillage system conserves more water in the soil under current climatic conditions.
Keywords: no-tillage; conventional tillage; soil physical properties.
* Abstract published in Conference Programme dedicated to LIFE SCIENCES TODAY FOR TOMORROW
Comparative Analysis of The Influence of Different Biostimulators on the Germination and Sprouting Behaviour of Four Wheat Varieties
Alina Elena Marta, Cristina Slabu, Mihaela Covașă, Iuliana Motrescu, Carmenica Doina Jităreanu
ABSTRACT. Wheat is an important cereal around the world and is a nutrient source in people’s diets. In this work, we focused on the potential of some biostimulators on four wheat varieties – Dropia, Glosa, Gruia, and Pegasus, with a focus on the effects during the first developing stages from germination to the appearance of the second leaf. Our results indicated that germination and some biochemical traits can be strongly influenced by biostimulants, with the effects also depending on the genetic background of the variety. Some treatments proved beneficial for germination, and also growth as found by the biometric measurements, while others inhibited both traits. Some of the biostimulants increased the concentration of the photosynthetic compounds, thus being recommended for use during all stages of wheat development. Dropia, Glosa, and Gruia reacted positively in most tests, their germination and plant and root development were stimulated by Super fifty, Atonik, Asfac, and Cropmax. Thus, we recommend the use of these biostimulants in the first development stages. The concentrations of photosynthetic pigments increased after treatment with Asfac, Atonik, and Cropmax. The treatment showing the most inhibitory effects was Lebosol.
Keywords: wheat; biostimulator; wheat sprouts.
Cover story
Agriculture, especially livestock farming, is a major driver of climate change through its contribution to the total emissions of greenhouse gases (GHGs).
The dairy sector has been identified as an important source of GHG emissions, mainly via carbon dioxide, methane and nitrous oxide. In a dairy farm located in Romania, total carbon dioxide equivalent (CO2e) emissions were assessed using the Cool Farm Tool calculator (CFT). Results showed annual GHG emissions of 553,170 kg CO2e, almost half of which were released through enteric fermentation. Lactating cows were the major contributor to total GHG emissions, while heifers released the lowest emissions.
The two scenarios simulated in this study showed that both the changes made in dairy diet composition and livestock manure management could result in lower GHG emissions. These results confirm the importance and utility of the CFT for the quantification of GHG emissions in dairy farms and its important role as a decision support tool to guide the adoption of good agricultural practices (see page 323).
Spatial and Diametric Evolution of a Rare Species, Prunus Avium, in Different Biotopes in Northwest Tunisia
Jdaidi Nouri, Selmi Houcine, Aloui Foued, Chaabane Abbes
ABSTRACT. This paper aimed to investigate and analyse the diametric and spatial distribution of Prunus avium populations in Tunisia. This study may help us document better information about the ecological processes and its functioning. Dendrometric and ecological data were collected on four square plots of an area of 1 ha each within two forests, Tabarka and Ain Draham, in northwest Tunisia. The results presented in this work show that P. avium individuals present a diametrical structure in the form of an “inverted J” translated by the dominance of the seedlings compared to the other classes. The analysis of the spatial distribution shows that wild cherry is identified by its aggregates and variable size (approximately 5 m and 20 m). It is coherent with the mode of vegetative propagation by suckering and the dispersal of fruits by birds.
This investigation opens insight into other species to ensure good sustainable management of natural resources.
Keywords: Tunisia; Prunus avium; spatial structure; diametric structure.
Agricultural Trends in Romania in the Context of the Current Trends of the World Economy
Nicoleta Mateoc-Sîrb, Cristina-Viorica Bacău, Anișoara Duma Copcea, Teodor Mateoc-Sîrb, Camelia Mănescu, Simona Niță, Oana Sicoe-Murg, Gabriel Suster
ABSTRACT. The role of agriculture is an extremely important one because it provides the necessary production of foods for the population and, at the same time, represents a source of raw materials for different processing industries. For a growing population, agriculture has been the main source of agri-food products that must ensure the food security of the population. Compared to other states of Europe, Romania is one of the European countries with the most favourable soil and climate conditions for agriculture. The last world crises, from the crisis in 2008 to the pandemic crisis in 2020-2021, and especially to the current conflict between Russia and the Ukraine, have brought up the issue of food self-sufficiency. During the current period, it is important to know what production can be obtained in Romanian agriculture and if it can provide the food necessary for the population. An analysis regarding the dynamics of the cultivated areas and production of the main crops in Romania has been carried out, for each of its 8 development regions. The data, collected from different sources, were analysed using different methods. The research results highlight, for example, that Romania can easily achieve the self-sufficiency stage for most agricultural products of plant origin. In conclusion, natural resources, as well as the existence of a certain material base in Romanian agriculture, can ensure the increase of agricultural production, the satisfaction of the food needs of the population, as well as a certain availability for export.
Keywords: agricultural holdings; cultivated areas; realized production; food self -sufficiency.
* Abstract published in Conference Programme dedicated to LIFE SCIENCES TODAY FOR TOMORROW
The Influence of Genotype, Soil Tillage and Fertilisation on Carbon Sequestration in Maize
Elena Petcu, Cătălin Lazăr, Elena Partal, Laura Conţescu, Daniela Horhocea
ABSTRACT. The increase in the concentration of greenhouse gases in the Earth’s atmosphere, especially that of CO2, is a major concern because it is the main source leading to global warming, and its impact on climate change is still widely studied. The intensity and frequency of drought and flooding increase due to the change in climate, which has a negative impact on crop productivity and food security. The aim of this paper was to demonstrate the role of corn in carbon sequestration based on plant biomass and soil organic carbon accumulation. We presented the main factors that contribute to carbon sequestration and concrete examples regarding the capacity of corn hybrids created at National Agricultural Research and Development Institute (NARDI) Fundulea, as well as aspects regarding the importance of soil tillage and fertilisation. In contrast to genotypes in which this ratio was lower, maize genotypes that demonstrated a rise in the root:stem ratio under drought stress conditions produced more biomass, suggesting that the roots of these genotypes can grow at water potentials where stem growth is inhibited, which are attributes that also prove their good potential for carbon sequestration under climate change conditions. The organic carbon content in the superficial soil layer decreased with the intensification of the degree of soil mobilisation (9.95% when working the soil with the chisel, 17.91% for ploughing), but fertilisation had a beneficial effect. The biomass was higher than that of the unfertilised soil. This means that a higher carbon input has a positive influence on the carbon stock in the soil.
Keywords: maize; carbon sequestration; hybrids; soil tillage; fertilisation.
* Abstract published in Conference Programme dedicated to LIFE SCIENCES TODAY FOR TOMORROW
Assessment of Greenhouse Gas Emissions From Dairy Farming Using the Cool Farm Tool
Roxana Vidican, Anamaria Mălinaș, Cristina Moldovan, Anca Pleșa, Mirela Ranta
ABSTRACT. Climate change is one of the greatest challenges mankind has ever faced and could lead to potentially devastating global problems, with a need for urgent mitigation and adaptation. Agriculture, especially livestock farming, is a major driver of climate change through its contribution to the total emissions of greenhouse gases (GHGs). The dairy sector has been identified as an important source of GHG emissions, mainly via carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). In this study, total CO2 equivalent (CO2e) emissions were assessed from a dairy farm (65 dairy cows) located in Romania using the Cool Farm Tool calculator (CFT). We specifically aimed to calculate: (1) the total CO2 equivalent (CO2e) and CO2e per kg FPCM (fat- and protein-corrected milk); (2) methane emissions from enteric fermentation; (3) GHGs resulting from feeding practices; (4) GHGs from manure management; and (5) a simulation of two different scenarios and their impact on GHG emissions. Our results showed annual GHG emissions of 553,170 kg CO2e, almost half of which were released through enteric fermentation. Lactating cows were the major contributor to total GHG emissions, while heifers released the lowest emissions. The two scenarios simulated in this study showed that both the changes made in dairy diet composition and livestock manure management could result in lower GHG emissions. These results confirm the importance and utility of the CFT for the quantification of GHG emissions in dairy farms and its important role as a decision support tool to guide the adoption of good agricultural practices.
Keywords: dairy; greenhouse gases; emissions; climate change; enteric emissions; Cool Farm Tool.
* Abstract published in Conference Programme dedicated to LIFE SCIENCES TODAY FOR TOMORROW
Observations of Sexual Behaviors in Goats (Capra Hircus) Raised on Non-Professional Farms
Corneliu Gașpar, Luminița-Iuliana Ailincăi, Adina-Ximena Dodan
ABSTRACT. This study focuses on monitoring the sexual behaviours of male and female goats (Capra hircus) at each stage of mounting and observing sexual reflexes and related peculiarities. The ethological behaviours of females and males were observed twice per day, between 6:00 and 8:00 a.m. and between 19:00 and 21:00 p.m, and the anatomical parts of females in estrus were inspected and scanned. Each mount was recorded using a video camera. A digital timer was also used to record the stages of sexual act (prelude and copulation). The sexual behaviours of a common breed of goats reared in non-professional holdings was studied in August, September and October 2020 and 2021. Sexual behaviour was observed in a total of 24 goats, 5 males, aged 3–8 years, and 19 females, aged 1–10 years, raised in a rural area (Priponesti) in Galati County. The data gathered provide details of the sexual behavior of this species, supplementing the information currently available. The most numerous mounts were carried out by the 4-year-old buck (M1 male) with 7 out of 20, representing 35% of the total mounts observed. The mount was characterized by very high duration of courtship (average 98%) compared to the true mounting (average 2%) (p < 0.05). The postlude behavioural manifestations observed were bucks continuing to inspect the anogenital area of the female, wagging their tongues while the goats expressed a characteristic bleat. Keywords: sexual behavior; goats; true mounting; courtship; non-professional farms.
Increased Tolerance to Chlorhexidine Following Prolonged Exposure in Staphylococcus Species Isolated from the Skin and Mucosae of Dogs
Ozana-Maria Hrițcu, Gheorghe Solcan, Iuliana E. Măciucă, Dorina Timofte, Vanessa Schmidt
ABSTRACT. This study aimed to investigate if canine staphylococci isolates could develop tolerance to chlorhexidine digluconate after long-term exposure. Staphylococci (Staphylococcus pseudintermedius and coagulase-negative staphylococci, methicillin-susceptible and methicillin-resistant), with and without genotypic chlorhexidine resistance, were investigated for phenotypic chlorhexidine tolerance by determining the MBC (minimal bactericidal concentration) at various time points. The testing was performed as follows: determination of MBC for 30 minutes and 24 hours (MBC 24h-1); exposure of isolates for seven days to concentrations of chlorhexidine equal to 1/2 MBC 24h-1; determination of MBC for 24 h after the first week (MBC 24h-2); exposure of isolates for seven days to concentrations of chlorhexidine equal to 1/2 MBC 24h-2 and rest in Mueller–Hinton broth for seven days; determination of MBC for 24 h after the second week (MBC 24h-3). The MBC for 30 minutes ranged between 16–32 µg/ml compared to the MBC 24h-1 which was between 1–8 µg/ml. The MBCs for 24 h dropped from 8 µg/ml to 0.5 µg/ml for isolate 1, from 2 µg/ml to1 µg/ml for isolate 6 and from 2 µg/ml to 0.5 µg/ml for isolate 8 after being exposed for seven days to concentrations of chlorhexidine equal to 1/2 MBC 24h-1. For one CoNS (coagulase-negative staphylococci), the MBC 24h-2 increased four times from 1 µg/ml (MBC 24h-1) to 4 µg/ml and dropped again to 1 µg/ml after the second week. These results suggest that continuous exposure to chlorhexidine could lead to the selection of chlorhexidine-tolerant staphylococci that could withstand concentrations used during routine decolonisation procedures.
Keywords: Staphylococcus; chlorhexidine; tolerance; MBC.
Impact of Seasonal Changes in Freshwater Phytoplankton and Zooplankton Biodiversity at Valankulam Lake, Coimbatore District, Tamil Nadu, India
Bala Mohan, Sheela Priyadarshinee, Ramaswamy Kalpana, Periyakali Saravana Bhavan, Narasimman Manickam, Perumal Santhanam, Duraiswamy Prabha
ABSTRACT. The plankton communities are important source of food for the aquatic organisms, and if any undesirable changes in aquatic environment may affect plankton diversity and density. Therefore, assessment of planktonic communities in the freshwater ecosystems is essential because they serve as bio-indicators of water quality parameters. Hence, the present research was focused to evaluate the freshwater phytoplankton and zooplankton diversity and their abundance in Valankulam Lake (Lat. 10.59° N and Long. 76.57° E), at Coimbatore city, Tamil Nadu, India. Results from the study revealed that a total of 77 species of phytoplankton and zooplankton were recorded, under 37 families and 46 genera. In addition to that, a total of 43 phytoplankton species were recorded under 25 families and 30 genera, (which includes; 15 species of Cyanophyceae, 17 species of Chlorophyceae, 08 species of Bacillariophyceae, 03 species of Euglenophyceae). and a total of 34 species of zooplankton were recorded under 12 families and 17 genera, (which includes 13 species of Rotifera, 09 species of Cladocera, 08 species of Copepoda and 04 species of Ostracoda). The maximum plankton diversity was observed during the monsoon season and the minimum in the summer season. Results from study revealed the ecological status of the lake is categorized as moderately polluted due to the presence of municipal waste and industrial discharges into the lake water. Therefore, the assessment of planktonic communities in water bodies will be useful to monitor and maintain the water quality parameters and wealth of aquatic biota in the aquatic ecosystem.
Keywords: plankton; species composition; community structure; water quality.
The Influence Of Differentiated Fertilisation On The Sugar Level In The Must, For The Aligote and Feteasca Alba Varieties, Under the Conditions of the Iasi Vineyard
Nicoleta Luminita Paraschiv, Mariana Volf, Elena Liliana Chelariu
ABSTRACT. Wine soils from the country’s main vineyards contain 0.05-0.25 g total N per 100 g soil, 0.9-20 mg P_2 O_5/100 g soil and 6.5-36 mg K_2 O/100 g soil. The amount of fertiliser that the plant will use – the degree of use – depends on the age of the stumps, the type of rootstock and the planned production. Acting as a factor for the intensification of production, mineral fertilisers, used as a complement to organic fertilisation, contribute not only to maintaining and increasing soil fertility but also to the quantitative and qualitative growth of production. Since the natural reserves of nutrients are limited, the application of natural and mineral fertilisers, scientifically based and differentiated according to the concrete pedoclimatic conditions, is of particular importance from an ecological and economic point of view. The research undertaken highlighted that the use of chemical fertilisers, in different dosages and ratios, favourably influenced the accumulation of sugar in the must for both varieties, with values that were between 178 g/L sugars for the Aligote variety and 170.7 g/L for Feteasca alba. The P-K relationship positively influenced the accumulation of sugars for both varieties, 177.4 g/L sugars for the Aligote variety and 171.3 g/L for Feteasca alba.
Keywords: chemical fertilisers; must; vines.
© by the authors; licensee Journal of Applied Life Sciences and Environment, Iasi, Romania. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)
