Reduction In Germination Research Articles

Native Endophytic Pseudomonas putida as a Biocontrol Agent against Common Bean Rust Caused by Uromyces appendiculatus.

This study aimed to evaluate the efficacy of endophytic bacterium to control common bean rust disease under greenhouse conditions. Endophytic bacterium Pseudomonas putida ASU15 was isolated from fresh asymptomatic common bean, identified using biochemical and molecular characteristics. In vitro, the inhibitory effect of different concentrations of P. putida (1 × 104, 1 × 105 and 1 × 106), as well as fungicide ortiva (0.01%) on uredospores germination of Uromyces appendiculatus were tested using water agar medium. The concentration showing the highest reduction of uredospores germination was at 1 × 106, while there was complete inhibition of uredospores germination associated with using ortiva. Scanning electron microscope exhibited the ability of P. putida cells to attack the cell wall of the fungal uredospores germ tubes of U. appendiculatus, causing obvious cell wall breakdown. The activities of chitinase, lipase, and protease produced by P. putida ASU15, in vitro, were evaluated spectrophotometrically. Chitinolytic, proteolytic, and lipolytic activities were exhibited, contributing 55.26, 3.87, and 26.12 U/mL, respectively. Under greenhouse conditions, treated plants with P. putida ASU15 (two days before pathogen inoculation or at the same time of pathogen inoculation) or fungicide reduced the disease severity, compared to the control. Applying P. putida ASU15 at the same time of pathogen inoculation showed reduction in disease severity (69.9%), higher than application before pathogen inoculation (54.9%). This study is considered the first report that demonstrates the mycoparasitic strategy of P. putida for controlling U. appendiculatus. In conclusion, our results revealed that P. putida ASU15 affords a significant disease reduction that may be attributed to direct suppression of pathogen spores germination.

Cosmetic Stay-green Trait in Snap Bean and the Event Cascade That Reduces Seed Germination and Emergence

The persistent color (pc) trait in snap bean (Phaseolus vulgaris L.) is a member of the stay-green gene family and falls into the cosmetic subclass. Cosmetic stay-green variants remain green but lose photosynthetic competence during senescence. It is an economically useful trait in snap bean as a result of its effects on pod quality. The trait produces a dark-green, uniform appearance of fresh pods, but has other pleiotropic effects, including a light-green seed color, bleached-white cotyledons on emergence, and foliage and pods that remain green even while senescing. One additional pleiotropic effect is reduced field germination and emergence compared with white- and colored-seeded genotypes. Nevertheless, with the aid of seed-applied fungicides, pc types occupy ≈40% of commercial snap bean acreage in the United States. This research project was aimed at understanding why and how germination and emergence is affected in pc beans. The effect is thought to be related to soil-borne pathogens because fungicide treatment of pc seeds increases germination and emergence rates to levels comparable to treated white- and colored-seeded genotypes. For our experiments, we increased seeds of 45 experimental lines and commercial cultivars (25 of which were pc) under uniform growing conditions. Initial experiments documented that, in the laboratory, all seeds analyzed in a tetrazolium test had high viability. Furthermore, untreated seeds of pc and non-pc types germinated in the laboratory showed no difference in germinability, whereas in the field, germination of pc types was reduced significantly. In addition, pc types showed substantially greater infection rates of seeds and seedlings, with the main pathogen being Fusarium oxysporum Schl. f. sp. phaseoli Kendrick & Snyder. Water uptake by green pc seeds was significantly more rapid than white and colored seeds. Measurements of electrical conductivity revealed that pc types had greater solute leakage than other seed types. When seed anatomic structure was examined, pc types had a significantly thinner testa, especially the osteosclereid layer. The reduction in germination and emergence appears to begin with a thinner, more fragile testa showing increased cracking that may happen during seed harvest and conditioning (but certainly does happen during imbibition), allowing more rapid water uptake during germination that leads to testa rupture. Increased and rapid solute diffusion into the surrounding spermosphere stimulates and attracts pathogens to colonize the seeds before seedlings can become established. Seed handling and conditioning processes before planting could be modified to improve field emergence and stand establishment. Selection for thicker testa may also mitigate some of the damage observed during germination of pc cultivars.

Germination characteristics of maize seeds with high and low- vigour levels in response to on-farm seed priming

On-farm seed priming, which refers to soaking seeds in water, is a pre-sowing seed enhancement technique in agriculture production. This study aimed to investigate the effects of on-farm priming on the germination performance of maize seeds with different vigour levels. Two maize hybrids and four inbred lines were used as experimental materials. Soaking treatment significantly decreased the final germination percentage of low- vigour seeds and had no beneficial effects on high-vigour seeds. With longer soaking times, the reduction in germination increased and there was a positive, negative or neutral effect of water soaking on the germination index. The responses of seeds to on-farm priming varied among the different hybrid / inbred lines used and depending on the length of the treatment. Reducing imbibition damage by PEG soaking had little impact on the poor germination induced by soaking in water. Removal of the seed pericarp alleviated the negative effects of soaking on germination. This study has demonstrated, for the first time, the differential effects of water soaking on maize seeds with different vigour levels. Our results suggested that all influencing factors, such as such as seed initial physiological quality and the technological process, need to be considered to realize the full potential of priming.

Ecofriendly approaches for the management of rose powdery mildew (Podosphaera pannosa var. rosae)

     Rose and miniature rose powdery mildew caused by Podosphaera pannosa is the most important disease in greenhouses and outdoor plantations. The use of fungicides, as a control method, is detrimental to nature and paid public interest. This work was aimed to utilize ecofriendly methods represented with plant extracts and antagonistic fungi. Among 13 plant extracts tested in vitro, garlic (Allium sativum), ginger (Zingiber officinale), and rosemary (Rosmarinus officinalis) were the most effective bioagents that resulted in a significant reduction of conidia germination. This result is supported by the greenhouse assessment of the selected extracts, in which the powdery mildew disease was reduced by up to 88.1%. The use of the commercial product of T. harzianum in the greenhouse was effective as plant extracts.

Lignocellulosic wastes of Carya illinoinensis (Juglandaceae) inhibit germination and seedling develop-ment of Lactuca sativa (Asteraceae)

The study evaluated the effect of Carya illinoinensis plant extracts on lettuce seed germination and development. Experiment was carried out in a completely randomized experimental design with five treatments and replications. Plant extracts were prepared from the dry ground vegetable waste. The concentration was adjusted to 10% m.v-1. The treatments were classified into: heterogeneous pruning residues (HPR), leaves residues (LR), epicarp residues (ER), mesocarp residues (MR), and control treatment (CT, 100% water). The variables evaluated were: first germination count (GP4%), final germination count (GP7%), germination speed index (GSI), germination inhibition (PGI), frequency of abnormal seedlings (FAS), root length (RL), shoot length (SL), and total length of seedling (TLS). Extracts obtained from residues of C. illinoinensis decreased the lettuce seed germination, but their effect depends on the plant tissue (e.g. leaf, epicarp or mesocarp) used at production of plant extracts. Plant extracts from HPR and MR do not result in drastic allelochemical effects. Aqueous extracts from LR and ER reduced significantly the seed germination and the normal development of lettuce seedlings, with an absolute reduction in germination of 90.2% and 79.2%, respectively. Only plant extracts from leaf residues and epicarp residues from C. illinoinensis inhibit the germination and seedling development of L. sativa.

Ultrastructural changes observed in Colletotrichum alienum conidia following treatment with cold plasma or plasma‐activated water

AbstractPrevious studies demonstrated that a reduction in germination of Colletotrichum alienum conidia could be achieved following treatment with cold plasma (CP) or incubation with plasma‐activated water (PAW). In this study, the mode of action of CP and PAW on C. alienum conidia was explored using transmission electron microscopy. Following treatment of the conidia, noticeable ultrastructural changes were observed, including cell wall maceration, disorganization of the cytoplasm and vacuole, and changes to the nuclei and mitochondria. Disorganization of the cytoplasm was exhibited by 85% of conidia after CP or PAW treatment. Also, 85% of conidia were observed with disorganized vacuoles after 6 min of CP treatment and 65% after 3 hr incubation in PAW. Further, 45% or more conidia had modified cell walls after PAW incubation or CP treatment. Deformation of conidia was observed in 23% of conidia after PAW incubation. These ultrastructural changes are a likely reason for the reduced germination of C. alienum conidia following CP or PAW treatment.

Study on Okra (Abelmoschus esculentus L.) Response to Salt Stress Environment under Kabul Climatic Conditions, Afghanistan

Abstract − The research was conducted to examine the effects of saline-irrigation water on growth and fresh pod weight of okra (Abelmoschus esculentus L.) under climatic conditions of Kabul province, Af-ghanistan. This study consisted of four treatments having different salinity levels of irrigation water, (T1:0.0mM, T2:5mM, T3:10mM, and T4:20mM), which were applied throughout the growing season of okra in plastic pots with a randomized complete block design. Results showed that saline irrigation water caused a significant reduction in germination of seeds (in T1:98% germination, T4: 53% germination), leaf length (in T1:9.17 cm, T4:6.8cm leaf length), shoot height (in T1:15.43cm, T4: 13.87cm Shoot height) and root length (in T1:15.37cm, T4:8.7cm root length). Okra plants grown under salt stress conditions showed a significantly decline in yield as compared to control treatment. While 6904kg/ha yield was obtained in control treatment (T1), 6696kg/ha, 4772kg/ha, 3100kg/ha yield were obtained in T2, T3 and T4 applications, respectively. Water use efficiency was maximum in the control treatment and minimum in treatment level 20mM. A maximum value of 13.08kg/ha/mm was computed for control treatment and minimum value of 5.87kg/ha/mm for treatment level 20mM, the water use efficiency value for treatment level 5mM and 10mM were 12.68kg/ha/mm and 9.04kg/ha/mm respectively. As a result, okra growth parameters were decreased significantly with the increasing concentration of ECiw (electrical conductivity of irrigation water). Salinity adversely affected morphological and physiological characteristics of okra.

LEAD TOLERANT DYNAMICS OF KENAF (HIBISCUS CANNABINUS L,) AND MESTA (HIBISCUS SABDARIFFA L.) AT GERMINATION STAGE

Efforts were given to evaluate the lead (Pb) tolerant dynamics of kenaf (Hibiscus cannabinus L,) and mesta (Hibiscus sabdariffa L.) varieties at germination stage against high levels of Pb toxicity. Six levels of Pb viz. 0, 200, 400, 600, 800, 1000 mg Pb L–1 were applied to the germination medium of kenaf (var. HC–95, HC–3, HC–2)and mesta varieties (var. Samu–93 and VM–1). Results showed significant reduction of germination, root and shoot growth, fresh and dry biomass production due to elevated levels of Pb. With respect to germination, kenaf HC–95 and HC–2 were more dynamic to tolerate Pb than kenaf HC–3, mesta Samu–93 and VM–1. Seed germination of mesta Samu–93 and VM–1 were affected at elevated concentrations of Pb and degenerated just after sprouting. At higher levels of Pb, the kenaf and mesta seedlings showed some deformities like twisting, curling, discoloring and growth stunting. Pb contents were increased in seedlings with the increasing of Pb treatment. Highest Pb was accumulated by kenaf HC–2 (19492±239 mg kg–1) at highest treatment. Maximum amount of Pb (4.45±0.40 mg petridish–1) was uptaken by kenaf HC–95 followed by kenaf HC–3. It is concluded that the degree of Pb tolerant dynamics was kenaf HC–95>kenaf HC–3>kenaf HC–2>mesta Samu–93 >mesta VM–1. The research findings will be helpful for selecting kenaf and mesta varieties for grown in Pb contaminated soil and phytoremediation of Pb contaminated site.

Water restriction in seeds of Cereus jamacaru DC.

Mandacaru (Cereus jamacaru DC.) is a cactus widely found in the Caatinga, with its seeds usually subjected to adverse conditions. Therefore, the objective of this study was to evaluate the effect of water restriction on germination and vigor of mandacaru seeds by using different salts and osmotic potentials. To that end, we used saline solutions of NaCl, KCl, CaCl2 and MgCl2 prepared at the osmotic potentials of 0.0; -0.2; -0.4; -0.6; -0.8; -1.0 and -1.2 MPa. Four replicates of 50 seeds per treatment were used, distributed in “gerbox” boxes between blotter paper and under temperature of 25 °C. Counts of the number of germinated seeds were performed daily for 21 days after root protrusion. The variables analyzed were the following: water content (%), germination (%), mean germination time and normal seedlings (%). A completely randomized following the factorial scheme 4 × 7 (salts × osmotic potentials) was employed. Results obtained suggest that mandacaru seeds show the ability to germinate in saline soils, a characteristic found in arid and semi-arid areas. Decreased osmotic potential promoted reductions in germination (%) and vigor of Cereus jamacaru DC seeds. The MgCl2 salt was the one that most negatively affected the germination and initial seedling development.

Effects of Bunium persicum essential oil on the reduction of spore germination, growth, and expression of FUM1 and FUM14 genes in Fusarium verticillioides isolates.

Background and Purpose: Black Cumin of Kerman (Bunium persicum) is an Iranian plant that is commonly used as an antispasmodic, carminative, and antimicrobial substance. The present study aimed to assess different components of the essence of B. persicum and its effect on antifungal activity, spore germination inhibition, and expressions of FUM1 and FUM14 genes in Fusarium verticillioides strains.Materials and Methods: The essence was extracted by hydrodistillation and analyzed through gas chromatography-mass spectroscopy. A broth microdilution method was used for the determination of the minimum inhibitory concentration (MIC). In addition, the expression of FUM1 and FUM14 genes of toxigenic F. verticillioides was assessed by using the real-time polymerase chain reaction (RT-PCR) technique.Results: Based on the findings, most of the essence consisted of γ-terpinene (15.56%), propanal, and 2-methyl-3-phenyl (14.18%). The oil showed a good antifungal activity (mean MIC value: 2556.8 μg/ml) as well as the inhibition of spore germination and mycelial growth (P<0.05). The RT-PCR demonstrated that the expression levels of FUM1 and FUM14 of B. persicum-treated F. verticillioides were 0.43 and 0.53 folds lower than the control samples, respectively.Conclusion: These findings revealed that the essential oil of B. persicum has different components responsible for the inhibition of mycelial growth and spore germination of F. verticillioides as well as reduction of expressions of FUM1 and FUM14 genes involving fumonisin production.

Effects of Seed Coating Agents on Some Agronomic Properties and Rhizobacterial Population of Vigna unguiculata

The agricultural activities had tremendously benefitted from the application of pesticides. However, various objectionable practices among farmers had exposed the soils, plant and its community of organisms to different level of toxicity. Therefore, this study evaluated the effects of seed coating agents on germination rate, shoot length, leave numbers and population of rhizobial and phosphate solubilizing bacteria (PSB) of beans plant (Vigna unguiculata). The mesocosm experiment was carried out in a greenhouse using a randomized block design with five replicates over the period of 5 weeks. The seed coating agents used were Imidadoprid-Thiram powder formulations and black powdery waste from dry-cell batteries. The seed coating agents were applied at the recommended rate value of 1.25 g/kg and at the rate that double the concentration of recommended field rate (2.50 g/kg). The application of Imidadoprid-Thiram at recommended rate and spent battery waste at the same rate did not have any significant effect (p &gt; 0.05) on the germination of V. unguiculata as compared to the control. However, significant reductions (p &lt; 0.05) in germination were observed in the seed coated with both coating agents at the rate above the recommendation value. Likewise, no significant effect (p &gt; 0.05) of seed coating agents was observed on the average number of leaves of growing V. unguiculata seedling but significant reductions (p &lt; 0.05) were observed in the shoot length of all the treated seedling as compared with control. Both Imidadoprid-Thiram and spent battery wastes were observed to have a significant negative (p &lt; 0.05) effect on the average numbers of both rhizobia and PSB counts in the rhizosphere region of V. unguiculata, with effects more pronounced in higher doses.

Potencies of Justicia adhatoda L. for its possible phytotoxic activity

The phytotoxic effects of Justicia adhatoda L. were investigated on cauliflower, broccoli, tomato, foxtail millet and barnyard grass. The experiments were carried out under laboratory and in pot experiments. Six different aqueous methanol extract concentrations (control, 0.001, 0.003, 0.01, 0.03 and 0.1 g DW equivalent mL-1 extract) were tested in the laboratory and six aqueous extract concentrations (control, 1.0, 2.0, 3.0, 4.0 and 5.0 g DW mL-1 extract equivalent) were evaluated in the pot experiment. Results showed a reduction in germination and growth (shoot length, root length and biomass weight) at higher extract concentration compared to control. The leaf extracts from J. adhatoda showed that the foxtail millet and barnyard grass are germinating below 50 % both in the laboratory condition and in the pot experiment at their maximum concentration. When maximum extracts have been applied, we have found less than 0.5 cm of shoot and root of foxtail millet and barnyard grass. Maximum dry weight reduction was observed in foxtail millet and barnyard grass at the same concentration. The findings show that J. adhatoda may have phytotoxic potential and thus contains phytotoxins. Therefore, J. adhatoda can be used in sustainable crop production as a mulch or soil additive to suppress weeds.

A Performance Comparison of Anaerobic and an Integrated Anaerobic-Aerobic Biological Reactor System for the Effective Treatment of Textile Wastewater

The accumulation of recalcitrant azo dyes from untreated textile effluents has adversely impacted the ecosystem. The immense stability in their nature is conferred by the presence of azo bonds (N=N) in their structure. The reduction of this azo bond occurs exclusively under anaerobic conditions giving rise to colorless aromatic amines, which are carcinogenic. In the present study, a synthetic textile effluent containing mixed azo dyes such as Reactive Red, Reactive Black, and Reactive Brown, was treated using activated sludge under anaerobic conditions in a lab-scale anaerobic sequential batch reactor (An-SBR). At a concentration of 100 mg/L of mixed azo dyes, the An-SBR gave a maximum of 88% decolorization detected through UV-visible spectroscopy. Physicochemical analyses revealed 73% removal of BOD, 90% TDS removal, 69% COD removal, 4.05% TKN removal, 66% chloride removal, and 73% hardness removal. When the concentration of dyes was increased to 500 mg/L, the treatment showed a decrease in decolorization efficiency. This was then compared to a sequential anaerobic-aerobic treatment process performed in An-SBR and a laboratory-scale aerobic moving bed biofilm reactor (MBBR). The study revealed that the sequential process held more potential for commercial application than exclusively an anaerobic process. The metabolites formed during the treatment phase were extracted and analyzed by FT-IR and HPLC and identified through GC-MS analyses and were compared to those found in the untreated effluent. A phytotoxicity test was conducted on the remainder (secondary) sludge using Vigna unguiculata, and it was found to show a 50% reduction in germination and retardation in root and shoot length.

A Natural Antifungal from Cassava Starch Fermentation Wastewater

Sour cassava starch production process, during the fermentation step, an acidic wastewater is generated, in this study named wastewater of cassava starch fermentation (WCSF). It has been studied the effect of WCSFs (from three industrial source: WCSF 1, 2 and 3) and patterns of organic acids (lactic, acetic, propionic and butyric acids, which were the main organic acids present in the WCSFs) singly or together on the development and growing of Botrytis cinerea, Monilinia fructicola and Colletotrichum gloeosporiodes. WCSFs showed antimicrobial effect on the three fungi studied. WCSF2 inhibited the germination of conidia from the three fungi, while WCSFs 1 and 3 inhibited conidia germination of B. cinerea and C. gloeosporiodes. The acetic, propionic, butyric and the mix acids were also effective in the reduction of conidial germination. In the analysis of mycelia growth, it has been observed that the growing was statically smaller, in relation to negative control, for all fungi in the treatments with the WCSFs and with the pattern solution of butyric acid. Which suggest that the WCSFs compounds and butyric acid are effective inhibitor for fungi and justify future studies using this wastewater.

Response of groundnut (Arachis hypogaea L.) genotypes to accelerated ageing treatment

Reduction in germination of crop seeds due to depletion of food reserves and decline in synthetic activity due to ageing has become a serious concern to groundnut growers who need adequate, high quality seeds to sustain groundnut production. Therefore, to stimulate farmers’ interest in groundnut production, an experiment was conducted to evaluate some groundnut varieties for their tolerance to seed ageing stress, with a view to recommending varieties that can be considered for production in tropical countries. Seeds of nine elite groundnut genotypes, sourced from The International Crops Research Institute of Semi-Arid Tropics (ICRISAT), Kano and three other genotypes sourced from local seed dealer in Ibadan, Nigeria were subjected to seed quality assessments in the seed testing laboratory of Institute of Agricultural Research and Training, Ibadan. The seed lots were subjected to accelerated ageing procedures of 42 °C temperature and 100% relative humidity for 24 hours. Twenty-five seeds of each genotype were drawn from each genotype in three replicates at 3, 6, 12 and 24 hours of ageing. The drawn samples were reassessed to determine their tolerance ability to ageing stress. Percentage germination was transformed using arc-sine before the data on preliminary seed germination and seedling vigour data and seed ageing data were subjected to analysis of variance (ANOVA) using SAS™ Means were separated using Duncan Multiple Range Test (DMRT) at 5% level of significance while k-means non-hierarchical clustering analysis was used to group the genotypes based on their response to the ageing. Result showed that seeds of the groundnut genotypes differ in their response to ageing stress factors. Seeds of ‘Samnut-24’, ‘Samnut-25’ and ‘Ex-Dakar’ (R) were found to be more tolerant to ageing stress while ‘Samnut 22’ and ‘Boro White’ were susceptible to ageing stress. Optimum ageing for 24 hours is recommended for testing seeds of groundnut varieties for storage tolerance

Effect of intermittent drying on the energy consumption and physiological quality of soybean seeds

Energy efficiency can be considered as one of the main components of sustainability. This study aimed to explore an alternative to reduce the energy consumption of drying process, besides to preserve the nutritional reserve of soybean seeds by applying intermittent drying. We dried soybean seeds in a fixed bed dryer and compared the conventional and intermittent operation results. Physiological quality of dried seeds was assessed in terms of germination, vigor, and fissure, in addition, the energy consumption of the operation was calculated. Results indicate a 46% reduction in energy consumption for intermittent operation in comparison to conventional drying for air temperature of 50°C and 42% for air temperature of 70°C. High temperature (70°C) caused a reduction in germination and vigor of seeds, accelerating deterioration, and compromising soybean quality. Practical applications Drying is essential to prolong the life of soybeans, reducing the typical postharvest moisture content. However, one of the main disadvantages of this technique is the high-energy consumption and the loss in the nutritional and physical-chemical quality of the final product compared to other methods of drying, especially at high drying temperatures. The global energy crisis and consumption of quality dry foods further challenge the development of innovative food drying techniques to deal with these difficulties. Intermittent drying is considered as one of the promising alternatives to improve energy efficiency and product quality without increasing the cost of the dryer. The results of this study show that the use of intermittent drying is an alternative that significantly contributes to reduce the energy demand of the process and contributes to the quality of dry soybeans in the field.

Influence of the mass of Luetzelburgia auriculata (Allemão) Ducke seeds on tolerance to saline stress

Luetzelburgia auriculata is used in the reforestation of degraded areas in Brazil due to its adaptation to the conditions of the country’s semiarid region. However, saline stress is one of the main abiotic factors with a negative impact on plant development. The aim of the present study was to evaluate the influence of the mass of Luetzelburguia auriculata seeds on tolerance to saline stress. The experiment was conducted with a completely randomized design in a 2 x 5 factorial scheme with two classes of seeds [light (&lt; 0.35 g) and heavy (≥ 0.35 g)], from ten morphologically similar mother plants that showed natural variation in seed mass, and five salinity levels, distributed in four replicates of 25 seeds. We evaluated the following variables: germination rate; germination speed index; mean germination time; initial seedling growth; and fresh and dry mass of the shoots, cotyledons and roots. The data were submitted to analysis of variance. Means for seed classes were compared using the F-test and regression analysis was performed for NaCl levels. The increase in saline stress led to reductions in germination, root length, fresh and dry mass of the shoots, and the GSI, as well as a delay in MGT. Seedlings from heavy seeds (≥ 0.35 g) exhibited greater tolerance to salt stress than those from light seeds (&lt; 0.35 g), due to lower occlusion caused by NaCl levels. Thus, heavy seeds of L. auriculata are more tolerant to salt stress and should be prioritized, especially in the presence of high salinity levels

Seed germination and performance of sunflower seedlings submitted to produced water

ABSTRACT The use of produced water becomes an option in the irrigation of non-food crops with potential for biofuel production. However, its effects on different stages of plant development and mainly on seed germination should be known. The study was conducted to evaluate the performance of sunflower seedlings subjected to different types of produced water. An experimental design in a factorial scheme was adopted to evaluate 3 cultivars (Catissol 01, Embrapa 122 and IAC Iaramã) and 6 types of water (distilled water - control, public-supply water, water resulting from the water and oil separation process - WOS, filtration in sand filter - SAF, filtration in sand + charcoal filter - SCF, and filtration in sand + osmosis filter - SOF). In addition, the substrate was moistened with polyethylene glycol (PEG) solutions, simulating the osmotic potentials of the evaluated waters, and a sensitivity test was conducted with lettuce seeds under conditions similar to those adopted for sunflower. The cv. Catissol showed higher percentages of germination and vigor of seedlings, regardless of the water used. There was a trend of reduction in germination and vigor of seedlings with the use of produced water treated with the WOS, SAF and SCF systems. All water potentials simulated by PEG solutions reduced the germination and vigor of lettuce seeds, and the effect was more pronounced for the WOS system. SOF was the only one capable of making the produced water non-toxic to sunflower seeds and lettuce seedlings.

Inactivation of Clostridioides Difficile Spores in Carpeting and Upholstery to Reduce Disease Recurrence in Households and Nursing Care Facilities

Objective: Clostridioides difficile (formerly Clostridium difficile) is among the most reported hospital and community-acquired gastrointestinal infections. Spores produced by this bacterium cause the initial disease and recurrent C. difficile infections (rCDI) and survive for long periods in the environment. Killing of C. difficile spores in carpeting and upholstery is very challenging without destruction or alteration of the fiber matrix material. In this study, we evaluated a fiber-safe standardized method for inhibiting germination of C. difficile spores recovered from in carpeting and upholstery material and thereby reduce the risk of disease incidence in households and nursing care facilities. Methods and Results : In this study, we found that the most effective procedure for the recovery of C. difficile spores from short-fiber textile surfaces used an ammonium phosphate-gelatin buffer, stainless steel beads to extract the spores from the carpet samples, and the addition of a heat activation step prior to plating. Virasept®, a known sporicide containing hydrogen peroxide and peroxyacetic acid, was evaluated for marked reduction of viable C. difficile spore number in carpet and fabric models. After a 30 min contact time, application of the sporicide at ~ 75 ml m2 of carpet (or 51.2 ml m2 upholstery fabric) resulted in a 3-log reduction in germination of five different C. difficile spore types (a ~99.9% decrease), representing five different Nap biotypes. Despite effective inhibition of C. difficile spore germination, Virasept treatment did not visibly damage or discolor carpet or fabric fibers. Conclusions: Results of this study show the potential effectiveness of a robust regimen for the practical treatment of carpeting and upholstery fabric in nursing care facilities, and residential homes to prevent community- and environmentally-acquired reinfection and recurrence of CDI in susceptible individuals.

Effect of 2,4-D sub-dose on the initial development of common bean crop

The adoption of cultures tolerant to synthetic auxins can increase the occurrence of drift of these herbicides, interfering in the development of naturally sensitive cultures, such as beans. The aim of this study was to evaluate the germination and initial development of bean seedlings, using sub-doses of the herbicide 2,4-D. The design of experiment I was completely randomized, with eight treatments and four replications, except for germination, with eight replications. The seeds were sowed in 100 mL of water with concentrations of 0.0; 1.12; 2.14; 4.18; 8.37; 16.75; 33.50 and 67.00 g a.e. L-1 of 2,4-D. Germination, length, seedling fresh and dry mass and electrical conductivity were evaluated. The design of experiment II was completely randomized with five treatments and four replications. The beans were sowed in sand and then sprayed at concentrations of 0.0; 8.37; 16.75; 33.50 and 67.00 g e.a. L-1 of 2,4-D. Seed emergence, injury, fresh and dry shoot mass were evaluated. According to the regression analysis, there was a reduction in germination, regardless of the concentration used, as well as the seedling length. Seeds sown in this solution presented impaired root system and development, tending to mortality. Electrical conductivity increased as herbicide concentrations increased, indicating lower physiological potential of seeds. In experiment II, increasing 2,4-D concentrations reduced emergence and increased injury to bean plants. It is concluded that the sub-doses of the 2,4-D herbicide negatively affect the germination and initial development of bean seedlings.