Use Of Polyethylene Film Research Articles

Polyethylene Microplastic Particles Alter the Nature, Bacterial Community and Metabolite Profile of Reed Rhizosphere Soils

With the wide use of polyethylene film, the influence of polyethylene microplastic particles produced by its weathering on the rhizosphere soil microenvironment has attracted more and more attention from scientific research circles. In this study, the effects of low (0.2% w/w), medium (1% w/w), and high (2% w/w) doses of polyethylene particles and the combined reed biomass (2% w/w) on soil environmental factors and bacterial communities and metabolites in the reed rhizosphere were evaluated by a 90-day pot microscopic simulation system. The shape and surface microstructure of polyethylene particles in each treatment group changed obviously. A high (2% w/w) dose of microplastics significantly increased the TKN, TOC, and TP in reed root soil. The addition of the biomass significantly improved the activities of urease and sucrase in the soil. The α diversity of bacteria was not significantly affected by the addition of LDPE microplastics and biomass, but the β diversity of the bacterial community and the relative abundance of the Candidatus_Roku Bacteria, Chloroflexi, Unclassified_Blastocatella_Genus were significantly changed by the addition of middle (1% w/w) and high (2% w/w) doses of microplastics. In addition, the spectrum analysis of the soil metabolites showed that the abundance of soil metabolites was changed in each treatment group, and the differential metabolites were significantly up-regulated or down-regulated. Our findings provide a scientific reference to elucidate the impact of LDPE microplastic particles on the inter-rooted soil microenvironment and improve our understanding of the potential risks of microplastics in soil ecosystems.

Improvement of Productivity and Quality of Nepalese Tomato Genotypes Using Black Polyethylene Film as Mulching Material

An experiment was conducted to evaluate the effect of black plastic mulch on yield and other associated characters of promising tomato genotypes developed by the National Horticulture Research Centre, Nepal at the Directorate of Agricultural Research, Tarahara, Nepal, during the winter season of 2019. Nine tomato genotypes (HRDTOM 011, HRD 109, HRDTOM 035, HRDTOM 080, HRDTOM 079, HRDTOM 084, HRDTOM 085, HRDTOM 086, and Pusa Ruby as a check) were evaluated in a randomized complete block design (RCBD) with three replications. Genotypes were transplanted 60 cm apart. Analysis of variance showed significant differences for marketable fruits and yield per plant, average fruit weight, total marketable and unmarketable fruit yield, and total fruit yield. Among the tested genotypes, HARDTOM 011 developed the highest (174) number of marketable fruits per plant with the lowest (12.92 g) individual average fruit weight. In contrast, HRDTOM 080 produced the lowest (36) number of marketable fruits per plant with the highest (49.70 g) individual fruit weight. HRD 109 and Pusa Ruby provided the highest (69.74 t ha-1) and the lowest (38.51 t ha-1) marketable fruit yields, respectively. The highest total fruit yield was also obtained from the HRD 109. Similarly, HRDTOM 085 and HRDTOM 035 had the highest total soluble solids and fruit size, respectively. Firmness of the fruit and pH content did not differ among the genotypes. With the same genotypes and location (Tarahara), a 98% greater yield demonstrated that tomato production may be significantly boosted with the use of polyethylene film as a mulching medium in winter tomato production in Nepal.

GROWTH AND DEVELOPMENT OF TABLE BEET DEPENDING ON DIFFERENT METHODS OF MULCHING IN THE CONDITIONS OF THE RIGHT BANK FOREST STEPPE OF UKRAINE

Goal. Study the influence of soil mulching methods on the growth, development of table beet plants, root crop yield and their quality indicators in the conditions of the Right-Bank Forest-Steppe of Ukraine. Methods. Analysis, synthesis, generalization, laboratory and field experiment. Results. The use of mulching crops with organic and inorganic materials has a positive effect on reducing the duration of the growing season of table beets. The emergence of seedlings in the control variant was observed on the 17th day after sowing, and in the variants where mulching was used - on the 15th day. The formation of the first pair of real leaves during mulching of the soil with a transparent and black polyethylene film was ahead of the control by 3 days, and by humus, sawdust and agrofiber by 4 days. The use of inorganic materials promotes faster onset of technical ripeness, namely 3-6 days earlier, and mulching with organic materials - 6-7 days, respectively. The use of different methods of mulching crops contributes to the growth of the leaf surface of table beets by 4.3-5.8 thousand m2 / ha, or 15.5-20.9%, respectively. The period "beginning of root formation-technical ripeness" was characterized by the largest accumulation of biomass in table beet plants compared to the previous period. Based on this, the productivity of photosynthesis increased - 2.7-3.0 g / m2 × day, depending on different methods of mulching. The use of polyethylene film provided an increase in photosynthesis net productivity by 8% in the case of agrofiber by 12%. The most favorable conditions for the formation of the maximum indicator of photosynthesis net productivity have developed in the case of arable materials use (sawdust, humus). In the period "beginning of root formation-technical ripeness" the productivity of photosynthesis in this case was 2.9-3.0 g / m2 × day, which is 16-20% higher than the control. Conclusions. The results of research show that the use of different methods of mulching seedlings with polyethylene film, agrofiber and local organic materials, contributes to the intensification of physiological and biochemical processes occurring in the plant of table beet. Further study and improvement should focus on in-depth study of innovative mulching methods using modern high-yielding varieties and hybrids of table beets.

Optimization of water use in Coffea arabica L. grown under different agronomic practices

Lower water availability due to climate change has dramatically affected coffee yields and quality. Characteristics related to plants and soil can be explored to obtain more productive and sustainable coffee production under adverse crop conditions. To this end, the objective of this study was to evaluate the potential for using different agronomic practices to optimize water use in coffee plants and to mitigate the effects of lower water availability to the crop. In the plots, three soil management systems (polyethylene film, brachiaria and bare soil) were used. In the subplots, two types of fertilizers were used (conventional and controlled-release fertilizer). Five soil conditioners (coffee husk, gypsum, water-retaining polymer, organic compost, and the control) were distributed throughout the sub-subplots. The plant growth, soil moisture, leaf physiology and anatomy, and soil chemical properties of coffee plants were analysed. The management of the soil cover using polyethylene film or brachiaria stood out as agronomic practices that can be combined with coffee husk applications to enable the better use of water by coffee plants and to favour soil conditioning. Controlled-release fertilizer and gypsum allowed for improvements in the anatomical and physiological characteristics of the plants. The use of organic compost favoured greater water availability; however, it caused losses in terms of coffee growth and physiological parameters due to nutritional imbalance. Therefore, based on results, the use of polyethylene film, brachiaria, controlled-release fertilizer, coffee husks, and gypsum are potential agronomic practices for optimizing water use and mitigating the effects of water deficit in coffee plants

Behavioral Characteristics of Cement Concrete Pavements in South Kazakhstan: Climatic Changes and Optimal Construction Method

The present paper describes experiments and research outcomes concerning the construction of cement concrete pavements in South Kazakhstan, taking into account significant climate changes. The study has identified potential problems in the construction of cement concrete pavements in the region, where there was no experience of their construction until the mid-2000s. In order to develop an optimal solution, the technical factors that characterize the process of arranging these coatings using sliding molds are analyzed and quantitatively normalized. These factors include the optimal amount of mortar for curing concrete, the optimal joint cutting time, the interval and effective width of expansion joints to prevent the formation of cracks in concrete at an early age. The effectiveness of the use of polyethylene film to prevent the formation of contraction cracks and maintain the required mode of hardening of the cement concrete pavement is shown. The main cause of damage to the expansion joints along the length of the day coverage of coatings in the conditions of South Kazakhstan has been established. Recommendations have been developed for the installation of cement-concrete pavement and expansion joints during the construction of roads in this region. The accumulated data on climatic factors and methods of work with the use of polyethylene film have made it possible to create an optimal method for the construction of cement concrete pavements, which will improve the quality of roads in South Kazakhstan.

Mobile pneumatic transporter for snow and garbage removal from roofs and house areas

Snow removal from roofs and near-house territories is relevant for the Perm Territory in the winter. The article discusses a mobile pneumatic transporter for garbage and snow removal consisting of a fan, a loading bin, an ejector chamber, and a vibrator. The main novelty of the plant is the use of polyethylene film for transport ducts. Air ducts were made by soldering with a hot iron. In the suture allowances, sutures were made to hang air ducts on a cable when removing snow from the roof. The calculation of the ejection funnel for the fan FS-2101/SP 220D is given in the work. As the funnel body, a plumbing two-rib tee with a diameter of 150 mm was used, in which a confuser of Æ100 mm was made. Since there is no data in the literature on the coefficient of friction of polyethylene, measurements of the total pressure losses in the system from the funnel to the final point of unloading, the dependence of the air flow rate and the suction rate from the loading hopper were made on the forty-meter air duct. After the calculations, a mixing chamber with a diameter of 125 mm was added to the tee. The pneumatic transporter demonstrated the ability to move snow to a distance of 40 meters at a speed of 10 m/s. Snow capacity is 9 cubic meters per hour. When removing snow from the roof along the air duct suspended with a slope of 1: 4, the snow can slide without the fan turned on. The pneumatic transporter can be used as a loader to a height of at least 4 m. The advantage of our pneumatic transporter over snowplows is the electric fan drive. This allows you to store the installation in the utility rooms of a residential building, without violating fire safety. The film ducts are compactly folded into a storage roll.

Reaction of Sweet Maize to the Use of Polyethylene Film and Polypropylene Non-Woven Fabric in the Initial Growth Phase

Sweet maize (Zea mays L. var. saccharata Bailey) is a valuable vegetable adapted to growing in temperate climate conditions. Temperature, especially in the beginning of the growing period, has a crucial effect on vegetation and yield. The best maize initial growth requires soil temperature above 10 °C. Maize covered by polyethylene film and polypropylene non-woven fabric leads to an increase in temperatures which accelerates crop growth. Three years (2012–2014) of field experiments were carried out at the Research and Didactic Station in Psary, belonging to the Department of Horticulture of Wroclaw University of Environmental and Life Sciences. A three-factorial experiment was established using the randomized subblock method in three repetitions in the years 2012–2014. Cobs were harvested in the milk-dough phase of grain maturity. Hybrid Rustler F1 produced, on average, 35.4% more marketable yield than Signet F1. On average, 10.2% more cobs and 22.7% more cobs (with Hybrid Rustler F1 and Signet F1, respectively) were harvested in cases when the sowing was performed in the third decade of April. The use of covers contributed to a significant increase in the yield compared to the yield of uncovered plants. Transparent foil also contributed to a significant increase in the number of cobs harvested in the marketable yield.

Biodegradable mulching film with an optimum degradation rate improves soil environment and enhances maize growth

Biodegradable film is considered as a promising alternative to polyethylene film in rainfed farming of arid and semi-arid regions, since the widespread use of polyethylene film has led to many negative effects, such as environmental pollution and land degeneration. In order to identify an optimal biodegradable film for summer maize, field experiments were conducted to investigate the effects of biodegradable films with different degradation rates on soil water storage (SWS), soil temperature, soil organic carbon (SOC), the growth stages, grain yield, water use efficiency (WUE), and economic return over three growing seasons from 2014 to 2016. Three biodegradable films one with a fast degradation rate (B1), one with a moderate degradation rate (B2), and one with a slow degradation rate (B3), were compared with a polyethylene film (P) and a flat planting system without film mulching was used as the control (CK). The degradation progress of the three types of biodegradable film (B1, B2, and B3) was on time or delayed by about 10 days during normal years (2014 and 2015 seasons) and advanced by 10–20 days during the extreme year (2016 season, plants affected by both lodging and high temperature). Soil temperature and SWS increased significantly under B1 (3.6 °C higher at 5 cm and 2.4 °C higher at 25 cm) and B2 (3.7 °C higher at 5 cm and 2.3 °C higher at 25 cm), compared with CK before the biodegradable film degraded. However, there was no difference in soil temperature and SWS after the biodegradable films B1 and B2 had degraded. The B3 and P treatments led to similar soil temperatures and SWS values throughout the maize seasons. After 3 years of experiments, the SOC levels ranked from high to low were 2.85%, 5.30%, 11.72%, and 15.07% higher in CK than that in B1, B2, B3, and P, respectively. The season length was the longest in B2 (117, 117 and 112 d) for all three seasons. Average grain yield, WUE, and net revenue in B2 were 18.40%, 25.10% and 32.97%, 11.90%, 6.62% and 20.46%, 11.43%, 6.82% and 15.71%, and 32.50%, 45.64% and 41.05% higher than in B1, B3, P, and CK, respectively. The results suggested that biodegradable film with a moderate degradation rate could improve the soil environment, promote maize growth, increase net revenue and reduce loss of SOC relative to B1, B3 (no significant difference with B1 in SOC level) and P. Therefore, B2 was the best biodegradable film for summer maize production in regions with sub-humid drought-prone climates.

Effects of Bio-degradable Mulches on the Yield of Maize and the Density of Soil Microbe

The use of polyethylene film has a problem such as increasing rural environmental contamination, collection costs and farmers’ workload. The objective of this study was to evaluate bio-degradable films in terms of yield of maize and soil environment. Treatments were bio-degradable film A (BDF A), bio-degradable film B (BDF B), high density polyethylene (HDPE), and non-mulched (NM) soil. Daily mean values of soil temperature (10 cm depth) under BDF A, BDF B, and HDPE were higher than in NM soil by 2.2, 2.8, 3.1℃ respectively. In the mulching cultivation of maize, bio-degradable film began to degrade from 50~60days after the planting. The degradation was much progressed in the harvest time and almost decomposed in the following spring. The weight of ear of maize was not shown significantly by mulching treatments. There were little changes of soil chemical properties for the bio-degradable film mulching. After using bio-degradable films, the contents of biomass-C and dehydrogenase activity increased from 92 to 137~147 mg kg -1 , and from 87 to 123~168 mg kg -1 respectively.

Use of polyethylene films photografted with 2‐(dimethylamino)ethyl methacrylate as a potential adsorbent for removal of chromium (VI) from aqueous medium

ABSTRACTA new polymeric adsorbent material based on polyethylene (PE) was prepared by photografting of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) as a positively chargeable monomer to a PE film. The effects of the experimental parameters, such as the pH value, temperature, and grafted amount on adsorption of chromium(VI) (Cr(VI)) ions were investigated for the DMAEMA‐grafted PE (PE‐g‐PDAMEMA) films. The maximum adsorption capacity was obtained at the initial pH value of 3.0 for a PE‐g‐PDMAEMA film with 1.8 mmol/g and the maximum adsorption capacity obtained was higher than or compatible to those of many of the other polymeric adsorbents prepared for Cr(VI) ions. The adsorption kinetics obeyed the mechanism of the pseudo‐second order kinetic model and adsorption of Cr(VI) ions on PE‐g‐PDMAEMA films was well expressed by the Langmuir isotherm model. A high Langmuir adsorption constant suggests that the adsorption of Cr(VI) ions occurs between protonated dimethylamino groups and ions mainly through the electrostatic interaction. Cr(VI) ions adsorbed were successfully desorbed from a PE‐g‐PDMAEMA film in solutions of NaCl, NH4Cl, NH4Cl containing NaOH, and NaOH and a PE‐g‐PDMAEMA film was regenerated and repeatedly used for adsorption of Cr(VI) ions without appreciable loss in the adsorption capacity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43360.

Effect of Light Environment on Growth and Phenylpropanoids of Yarrow (Achillea collina cv. SPAK) Grown in the Alps

A 2-year field study on the effect of different light environments, obtained by using cladding materials (polyethylene films and shade net) able to cut off specific regions of the photosynthetically active radiation and ultraviolet wavebands, on the growth and phenylpropanoids content of Achillea collina grown in the Alps was conducted. Overall the plant growth was strongly enhanced in the second growing season irrespective of radiation treatment. The light environment did not affect total biomass accumulation, but only carbon allocation to leaves or inflorescences. Indeed the phenylpropanoid levels in inflorescences appeared to be more sensitive to the light environment than leaves as the latter showed high constitutive amounts of these compounds. However, the use of polyethylene films improved to some extent the content of caffeic acid derivatives in leaves. Our results showed that yarrow production, in the alpine situation considered, is influenced by the growing season and the light environment, providing a basis to optimize its quality, depending on the concentration of bioactive compounds, by means of proper agronomic practices.

STATUS OF HIGH TUNNELS IN THE US

Use of high tunnels in the United States has a much shorter history compared to Europe and Asia. High tunnels were of little consequence in the US until the early sixties when Dr. Emery Emmert, University of Kentucky, built a wooden frame with a single layer of plastic polyethylene film instead of glass. Prior to his use of polyethylene film, he designed crude wooden structures over which he placed wooden frames covered with stretched cellophane supported by wires. In these structures, he grew commercial crops of lettuce, tomato, cucumber and bedding plants for several years. The first plastic greenhouse (crude high tunnel) was constructed at the Kentucky Agricultural Experiment Station in 1953 and remained in use until 1959. Its primary appeal was its comparatively low construction cost. In 1983, Dr. Bernie Kratky, University of Hawaii, reported the construction and utilization of a simple and inexpensive greenhouse or “rainshelter” similar to the modern day high tunnel. The rainshelters were constructed of PVC pipe with a single layer of 6 mil greenhouse grade polyethylene on top and screening on the sides and ends.

Plastic mulching in agriculture—Friend or foe of N2O emissions?

Polyethylene (PE) mulching is a very common method in agriculture worldwide because the use of PE films can improve product quality and yield by mitigating extreme weather changes, optimizing growth conditions and extending the growing season. Other than the problem with disposal of the plastics hardly any other of its effects on the environment are known. To determine whether covering fields with PE films affects N2O emission, we conducted two experiments: first, comparing N2O emissions of furrows and PE-mulched ridges of a radish field which had received different amounts of N fertilizer and second, assessing whether PE mulching increases N2O emissions from PE-mulched ridges in comparison to non-PE-mulched ridges and furrows of a non-fertilized field. To achieve those aims we took comparative closed chamber measurements in conjunction with a photoacoustic infrared trace gas analyzer during the growing seasons of 2010 and 2011 at a radish and soy bean field site in South Korea. For the radish field site we found significant differences between the N2O emitted by furrows and PE-mulched ridges and found extraordinarily low N2O fluxes from those spots of the ridges which were totally PE-mulch-covered between plant hole openings. At the soy bean field we observed that plant holes of PE-mulched ridges showed only 68% of the emission measured of soils around soy bean plants of non-PE-mulched ridges, implying that PE mulching may decrease N2O emissions. Since our result is contrary to very recent findings we consider the extremely low soil moisture at our sites as explanation for the differences. Because knowledge on how PE mulches affect production and emissions of greenhouse gases is very limited, our study contributes greatly to understanding N2O emission behavior of PE-mulched, poor sandy soils in a temperate monsoon climate.

Purple Nutsedge (Cyperus rotundus) Management in an Organic Production System

Research was initiated in March 2005 to test various integrated purple nutsedge management strategies over two growing seasons in an organic production system in which bell pepper was grown as a fall crop. Main plots consisted of integrated purple nutsedge management strategies from mid-March through July 2005 and 2006. The main-plot factors were (1) green polyethylene film, (2) clear polyethylene film, (3) turnip followed by (fb) green polyethylene film, (4) turnip fb clear polyethylene film, (5) tillage every 3 wk, and (6) fallow. Subplots consisted of hand-weeding, mulching with wheat straw, and no weeding following bell pepper transplanting in early August. Purple nutsedge tuber density was determined in March, August, and November each year. Viable tubers were categorized into three sizes: small (0.1 to 0.25 g), medium (0.26 to 0.50 g), and large (> 0.50 g). The initial tuber density averaged 500 small, 300 medium, and 110 large tubers m−2in mid-March 2005 (910 total tubers m−2). Total tuber density increased to > 5,400 tubers m−2in fallow, nonweeded plots by November 2006. Yearly tuber density remained relatively constant over the 2 yr when the fallow period was fb hand-weeding in the bell pepper crop. Density of large and medium tubers in the season-long management systems remained stable, whereas small tubers were prone to depletion over time. Frequent tillage or use of a polyethylene film with or without turnip resulted in a lower density of large tubers in November 2006 relative to fallow treatments, regardless of management intensity in bell pepper. The density of large tubers after 2 yr was similar among treatments involving frequent tillage or use of a polyethylene film with or without turnip, regardless of subplot treatment; this was also observed for medium tubers, but not for small tubers. All hand-weeded plots had comparable densities of small tubers, ranging from 25 to 194 viable tubers m−2. Intensive management involving frequent tillage or use of a translucent polyethylene film with or without turnip fb hand-weeding was not effective in eradicating purple nutsedge over two growing seasons. Purple nutsedge management costs calculated for each main-plot treatment revealed that use of a translucent polyethylene film alone was at least 4.5-fold more costly than frequent tillage. This research demonstrates that season-long management is essential to prevent purple nutsedge proliferation over time.

Effect of different biodegradable and polyethylene mulches on soil properties and production in a tomato crop

The use of plastic materials for mulching is a very common practice for vegetable crops. Black polyethylene is the most widely used due to its excellent properties and low cost. However, the massive use of these materials supposes an environmental risk. In the last few years, the use of starch-based biodegradable films has been introduced as an alternative to conventional mulches. These materials can be incorporated into the soil at the end of the crop season and undergo biodegradation by soil microorganisms. A 2-year study was conducted to determine the response of a tomato crop to seven mulch materials (polyethylene and biodegradable) in open fields in Central Spain. Biodegradable films underwent early decomposition, but in general remained functional during use and did not affect yield and the fruit quality attributes (total soluble solids, firmness, dry weight, juice content and shape). The temperatures reached under polyethylene films were always higher than under biodegradable films, which could be a disadvantage in certain circumstances, especially in hot climates, although may be advantageous in cool conditions. The use of polyethylene films resulted in the lowest values of soil microbial biomass C and soil organic matter mineralization, probably due to the increase of temperature registered under mulches. The analysis of the marketable yield components indicates that the variability in yield mainly depended on the number of fruits, with mean fruit weight being practically constant in the different treatments and seasons, which suggests the strong varietal character of this parameter.

Desempenho da cultura da rúcula cultivada em época de verão em túneis baixos de polietileno perfurado

O túnel baixo é um tipo de ambiente protegido utilizado, principalmente, em cultivo de espécies de pequeno porte, como alface, morango, pimentão, rúcula e pepino. Por serem estruturas de menor porte, apresentam menor custo de instalação em relação ao túnel alto. A presença de material plástico em sua cobertura proporciona um ganho térmico durante o dia, facilitando o crescimento das plantas, protegendo as culturas do impacto da chuva, dos ventos frios e das temperaturas mínimas. Esta pesquisa teve o objetivo de avaliar o efeito de filme de polietileno com diferentes intensidades de perfurações (0; 5; 10; 15 e 20%), no microclima em túneis baixos e no desenvolvimento da cultura da rúcula (Eruca vesicaria sativa (Mill) Thell) em época de verão. Os resultados mostraram que houve diferença de produtividade entre os túneis com diferentes níveis de perfuração e houve diferenças significativas quanto às características físicas da planta em alguns tratamentos comparativos à testemunha. Quanto aos aspectos relacionados com o microclima, verificou-se, por meio de análise estatística, que a temperatura do ar observada nos horários mais críticos do dia (11 às 15 h) apresentou diferenças significativas entre o ambiente coberto com túnel sem perfuração e o solo descoberto; com relação à umidade absoluta do ar, quanto maior o nível de perfuração do plástico de cobertura do túnel, menor a umidade absoluta observada.

Use of fabric and compost mulches for vegetable production in a low tillage, permanent bed system: Effects on crop yield and labor

AbstractWe tested the usefulness of mulching with polypropylene landscape fabric and compost as alternatives to bare soil for growing red cabbage and watermelon. Polypropylene landscape fabric has features similar to the polyethylene film that is popular for commercial vegetable production, but its durability permits multi-year use, which would reduce excessive waste produced from the typical single-season use of polyethylene film. On the other hand, compost used as mulch enhances soil development while providing weed suppression and water retention, among other benefits. Yields of red cabbage and watermelon were measured for 3 years in plots receiving either 10 cm compost, landscape fabric, or no mulch. Labor associated with crop production and weed suppression was measured as time spent on each task. Cabbage yields over 3 years followed the treatment order of compost > no mulch > fabric, while for melon yields it was compost > fabric > no mulch. Total labor required over 3 years for both crops, according to treatments, was fabric > compost > no mulch. However, labor for the fabric-treated plots dropped sharply after the first year, because fabric was left in place after initial placement. Labor for unmulched cabbage plots increased over time due to weeding and transplanting; labor for unmulched and compost-mulched melon plots increased for the same reasons. Compost provided the highest crop yields with a moderate labor investment. Surface-applied compost substantially increased underlying soil nutrient levels. The study indicates that polypropylene landscape fabric may be a potential alternative to the more traditional polyethylene film for permanent beds in vegetable production.

Reduction of congener specific PCBs in water and peanut oil by polyethylene packaging film

The use of polyethylene film to reduce the concentration of selected polychlorinated biphenyl (PCB) congeners (one each from tri to deca chlorinated) from aqueous and oil systems, was investigated. The trend in removal of PCBs from the aqueous system showed an inverted mirror pattern of its uptake by the polyethylene film. There appeared to be little loss of PCBs from the oil during the duration of the study. The rate loss from each system was compared as a function of PCB congener types. The results show that the lower chlorinated congeners were removed at a faster rate from the water than their higher counterparts. In the oil, the congeners with higher chlorination generally were removed at a faster rate than those with lower chlorination. The mass balance ratio confirmed that the PCBs removed from the dissolved solutions were sorbed by the contacting polyethylene film.

Detection of viral antigens by solid phase radioimmunoassay on polyethylene film

Polyethylene film, without any pretreatment, may serve as a solid phase (SP) for RIA. Viral antigens (HBsAg, and influenza virus) are detected by SP-RIA on the film with a sensitivity of about 2–3 ng/ml or 40–60 pg/assay. The use of polyethylene film allows one to record RIA autographically. The use of micro amounts of reagents and specimens tested is an added advantage. No special equipment is necessary, the method is inexpensive, easy to perform and may be used for mass screening.