Black Polyethylene Sheet Research Articles

Effectiveness of chemical and physical methods for stump sprout control in Castanea sativa Mill

In Europe, Castanea sativa Mill. is mainly managed as coppice. Health and market problems have raised the interest in the transformation of chestnut coppices into low-density forests for fruit production and silvopastures, or their substitution by naturally occurring broadleaves or timber-oriented plantations. In most cases, a selective or total removal of the existing chestnut stumps is required.We assessed the effectiveness of 7 methods for stump sprout control of Castanea sativa Mill. in Mediterranean conditions (NE Spain). We tested 3 cut-stump herbicide treatments: Roundup Energy Pro® (Glyphosate), Tordon 101® (Picloram + 2,4-D) and Garlon GS® (Fluoxipyr + Triclopyr) and 4 physical methods (stump uprooting or in situ fragmentation by excavator, stump cover with black polyethylene sheet or wood chips).Effectiveness was assessed by means of the number, length and basal width of sprouts in treated stumps one growing season after the treatments application. Phytotoxicity side-effects were assessed by means of foliar symptomatology during the vegetative period following treatments in untreated chestnut stumps neighbouring treated plots and in other broadleaved trees within the treated plots.Stump uprooting and Roundup® Energy Pro cut-stump application provided the highest effectiveness, with near 0 resprouts per treated stump; Garlon GS® and Tordon 101® also showed a high effectiveness (near 10 resprouts per treated stump). Other treatments showed no effectiveness and resprout intensity was not different to control. Herbicide application showed low to moderate phytotoxicity side-effects to neighbouring untreated chestnut stumps, being Roundup® Energy Pro the less phytotoxic. No side-effects were detected in other broadleaved species for any of the herbicides tested.Results suggest that herbicides are an interesting option for chestnut stump removal in poorly accessible or erosion-prone sites, where uprooting with heavy machinery is not feasible. Roundup® Energy Pro and Garlon GS® showed a low phytotoxicity on chestnut and thus can be useful for selective stump removal. The higher phytotoxicity showed by Tordon 101® on chestnut could be a disadvantage for its use if the aim is to reduce the initial density of stumps but maintain some of them in order to transform coppice to an orchard for chestnut production or silvopastures.

EFFECTS OF SOIL SOLARIZATION ON FUNGAL AND BACTERIAL POPULATIONS ASSOCIATED WITH AMARANTHIS VIRIDIS L. (AFRICAN SPINACH) IN LAGOS, NIGERIA

Soil solarization is increasingly used to control soil-borne pathogens because it is environment-friendly. However, performance varied geographically, necessitating experimental trials before its introduction. This study assessed the effects of solarization on soil-borne bacteria and fungi, growth, and proximate composition of Amaranthus viridis (African spinach) in Lagos, Nigeria. Two raised beds were solarized for six weeks with a transparent and black polyethylene sheet, and a non-solarized (control) bed was equally made. The vegetable seeds were planted and their growths were recorded for four weeks. Soil samples at 15-20cm deep and leaves were obtained for microbiological and proximate analysis, respectively. The mean temperature of transparent xxpolyethylene’s soil was 45.33 oC, black polyethylene (35 oC), and non-solarized (33.50 oC). The mean height and width of transparent polyethylene’s A. viridis were 24 and 3cm, black polyethylene (19 and 2.2 cm), and non-solarized (17 and 1.6cm). The transparent polyethylene’s soil had 3100 and 250 cfu/g bacterial and fungal colonies, black polyethylene (3200 and 1900 cfu/g), and non-solarized (37000 and 1900 cfu/g), respectively. The proximate contents of the transparent polyethylene’s A. viridis were (70 moisture, 10 ash, 4.24 protein, 1.45 fat and 9.94 % fibre), black polyethylene (73.35 moisture, 8.36 ash, 3.1% protein, 1.23 fat, and 6.77 % fibre), and non-solarized (76.09 moisture, 5.91 protein, 3.15 ash, 1.31 fat and 6.75 % fibre). Overall, statistical differences (p ≤ 0.05) existed between the solarized and non-solarized and between transparent and black polyethylene (transparent>black>non-solarized). Thus, solarization could be an effective strategy for controlling soil-borne bacteria and fungi of A. viridis in the area studied.

Phytotoxic effect of herbicides on gladiolus and their effectiveness against weed flora associated with the crop

The present investigation was conducted during 2018-19 at Centre for Quality Planting Material, RDS Seed Farm CCSHAU, Hisar, Haryana. The experiment comprised of 16 treatments i.e. nine herbicidal treatments [viz. oxyfluorfen @ 500 g ha-1, pendimethalin @ 1000 g ha-1, butachlor @ 1000 g ha-1, carfentrazone @ 30 g ha-1 and metsulfuron-methyl @ 5 g ha-1 in combinations of pre and pre/post-emergence application at 50 DOP (days of planting) after the HW (hand weeding) or without HW], five mulch treatments (viz. mulching of black polyethylene sheet of 100 µ alone, and the paddy straw mulching @ 10 tonnes ha-1 in combinations with HW at 75 DOP or pre-emergence application of pendimethalin @ 1000, 1250 & 1500 g ha-1), and one treatment of hand weeding/hoeing (at 25, 50 & 75 DOP), and weedy check (control), laid out in simple randomized block design with three replications. Polypogon monspeliensis, Phalaris minor, Cyperus rotundus and Cynodon dactylon among monocots and Chenopodium murale, Convolvulus arvensis, Fumaria parviflora and Coronopus didymus in dicots were found dominant weeds in experimental field. Among the application of herbicides or mulch materials either alone or in combinations, black polyethylene mulch (T13) was found highly effective in controlling weeds followed by pendimethalin 1000 g fb HW + pendimethalin 1000 g (T12), straw mulch fb HW at 75 DOP (T14) and pendimethalin 1500 g/ha + straw mulch (T6). Amongst the herbicidal treatments, pendimethalin 1000 g fb HW + pendimethalin 1000 g (T12) was found comparatively more efficient in controlling weeds without any phytotoxic effect on crop. Interestingly, the applications of oxyfluorfen as a pre-emergence and metsulfuron-methyl as a post-emergence in different herbicidal combinations caused phytotoxicity in crop plants up to the level of growth check or one leaf burning, and the phytotoxic effect of metsulfuron-methyl was more than the oxyfluorfen. At 30 DOP the maximum level of phytotoxicity (1.70) was recorded with the pre-emergence application of oxyflurofen 500 g fb HW + oxyflurofen 500 g (T3), while at 60 DOP it was observed non-significant with most of the herbicidal applications, whereas at 90 DOP and 120 DOP, it was recorded highest (i.e. 2.73 and 2.97, respectively) with the application of oxyfluorfen 500 g fb metsulfuron-methyl 5 g (T2) and it was followed by post-emergence application of metsulfuron-methyl 5 g in combinations with pre-emergence application of other herbicides (T8 & T11). Overall, the application of mulch materials (either alone as a black polyethylene sheet of 100µ or paddy straw @ 10 tonnes ha-1 in the combination with HW or pendimethalin 1500 g ha-1) was found very effective with the aspect of weed control in gladiolus.

Effect of shade level and mulch type on growth, yield and essential oil composition of damask rose (Rosa damascena Mill.) under mid hill conditions of Western Himalayas.

A field experiment was conducted at the experimental farm of CSIR-Institute of Himalayan Bioresource Technology, Palampur, India for two consecutive years (2015–16 and 2016–17). The aim of the study was to test the hypothesis whether different shade level and mulch type would influence the growth, flower yield and essential oil profile of R. damascena. Yield attributes viz., numbers of flowers plant-1, fresh flower weight plant-1, flower yield, and essential oil yield were significantly higher under open sunny conditions as compared to 25% and 50% shade levels. However, plants grown under 50% shade level recorded significantly higher plant height (cm), plant spread (cm) and the lowest numbers of branches as compared to control. Among mulches, black polyethylene mulch recorded significantly higher growth, and yield attributes of damask rose as compared to other mulches. Black polyethylene mulch recorded 74.5 and 39.2% higher fresh flower yield as compared to without mulch, during 2015–16 and 2016–17, respectively. Correlation studies showed a positively significant correlation between quality and quantity traits. A total of twenty-six essential oil compounds were identified which accounted for a total of 88.8 to 95.3%. Plants grown under open sunny conditions along with the applications of black polyethylene mulch produced a higher concentration of citronellol and trans-geraniol. Damask rose planted in open sunny conditions and mulched with black polyethylene sheet recorded significantly higher flower yield.

Effect of drip irrigation and mulching on yield, water-use efficiency and economics of tomato

This study investigated the combined effects of drip irrigation and mulches on yield, water-use efficiency and economic return of tomato. The treatments of the study comprised different combinations of three drip irrigation levels (100, 75 and 50% of crop water requirement, ETc) and two mulches (black polyethylene sheet and paddy straw). The yield and yield-contributing characters in the mulched treatments for all levels of irrigation were significantly higher compared to those in the unmulched treatments. The yield of tomato increased with the increasing amount of irrigation water in unmulched treatment. The trend was reversed when drip irrigation was coupled with mulches. The highest yield for each mulch (81.12 t/ha for polyethylene and 79.49 t/ha for straw) was obtained when 50% of water requirement was applied. With 100% water application, polyethylene-mulched treatment produced lower yield than the straw-mulched treatment. The highest water use efficiency of 592 kg/ha/mm was obtained with 50% water application under polyethylene mulch. The highest net return (US$ 7098/ha), incremental net return (US$ 1556/ha), and incremental benefit-cost ratio (7.03) were found for 50% water application with straw mulch. The study thus reveals that drip irrigation with mulch has an explicit role in increasing the land and water productivity of tomato.

English

Quality changes of kola nut (Cola acuminata) as affected by processing methods and short-term storage environments were investigated. The experiment was conducted at the Teaching and Research Laboratory of the Department of Crop Science, University of Nigeria Nsukka, Nigeria. The treatments comprised of: three different colour plastic buckets – red, green, white and three inner linings - Newbouldia laevis leaves, Spondias mombin leaves and Black polyethylene sheets giving a 3 × 3 × 3 treatment combinations. The N. laevis, S. mombin and Black polyethylene sheets were laid inside the buckets as beddings for the kola nuts. About 0.45 kg of kola nuts (coated and uncoated) numbering 20 nuts were put in each storage container. Sensory quality of the nuts after storage was determined with quantitative descriptive analysis in expert panel, using six quality attributes. Physical parameters measured were; weight loss, pest incidence and sprouting incidence. Weight loss was significantly lower in white plastic storage container for coated kola nut while green plastic container reduced weight loss for uncoated. Black polyethylene sheet as inner-ling of the storage container significantly (P≤ 0.05) reduced weight loss and pest incidence in coated kola nut compared to uncoated. N. laevis and S. mombin significantly reduced weight loss in kola nuts. It is evident in this study that coated kola nut genotype were kept better than the uncoated kola nut. Key words: Processing methods, kola nut, storage treatments, quality characteristics

Effect of coloured polyethylene mulch and harvesting stage on growth and yield of industrial sugarcane in Nigeria

Plastic mulch increases soil temperatures and accelerates plant growth and development. Field trials were conducted in 2010 and 2011 at the National Cereals Research Institute, Badeggi to assess the effect of mulching and harvesting time on the agronomic performance of a sugarcane variety named NCS 008. The treatments consisted of three-coloured polyethylene mulches (black, red, and green) with one treatment without mulch as a control and two harvesting stages (10 and 12 months after planting). The experiment was laid out as a randomized complete block design in a factorial arrangement and replicated three times per treatment. Sugarcane setts planted on plots mulched with black polyethylene sheet established significantly (P<0.05) faster than those planted on plots mulched with red and green coloured polyethylene sheet as well as those planted on plots without mulch. Plants in the control plots had the least performance for all parameters measured during the experiment. Coloured polyethylene significantly (P < 0.05) increased the stalk length, stalk girth, number of tillers, chewable stalk and yield of NCS 008 for the main, as well as, the ratoon crops. Harvesting stage significantly influenced the stalk length, stalk girth and yield. Plots harvested 12 months after planting performed better than plots harvested 10 months after planting. Keyword : Polyethylene colour (black, red and green), plastic mulch, harvesting stage, NCS 008 African Journal of Biotechnology Vol. 12(10), pp. 1078-1083

Bio-economic assessment of chemical and non-chemical weed management strategies in dry seeded fine rice ( Oryza sativa L.)

Dry seeding of rice offers potential to be opted as a resource conservation technology but its sustainability is endangered by heavy weed infestation. Experiments were conducted during summer season of 2009 to look for effective and economically viable weed control method(s) in dry seeded rice. Four mulching materials of natural origin as sorghum, sunflower and wheat residues each soil incorporated at 8 t ha -1 and black polyethylene sheet strips as artificial origins were used. A weedy check and manual weeding were included for comparison. Label doses of post emergence herbicides, bis-pyribac sodium and penoxsulam, at 30 and 15 g a.i. ha -1 were also used. Manual weeding accounted for maximum (99%) inhibition in weed density and dry weight. Bispyribac sodium suppressed weed count and dry weight by ≈ 80%. Among non-chemical weed management strategies, sorghum residues scored over 50% reduction in weed density and dry weight. Plastic sheet strips were least effective against weeds. Manual weeding scored highest paddy yield of 4.17 t ha -1 . Bispyribac sodium with 3.51 t ha -1 paddy yield appeared superior to penoxsulam. Sorghum, sunflower and wheat residues resulted in

Effect of Mulching, Manures and chemical fertilizers on anatomical characters of (Solanum tuberosum L.) potato plants

Anatomy studies were carried out in the experimental field, College of Agriculture, University of Baghdad to have better understanding of the influence of mulching with black polyethylene sheets, organic manure and chemical fertilizer on the anatomy changes in potato shoot and leaves tissues. Results showed that leaves area, leaves area index and chlorophyll percentage were significantly increased by using mulching and chemical fertilizer by (7463.70 cm2, 3.97, 45.33 SPAD units) respectively. Also this treatment significantly increased total stomata number and in both lower and upper sides of the leaf by (957,721,176) stomata /mm2 respectively. But by using mulching treatment with organic manure significantly increased vessels and sieve tubes diameter by (12.5, 2.75) micron for respectively. However the control treatment significantly increased leaves thickness spongy mesophyll by (45) micron, while the palisade parenchyma thickness was significantly increased to 26.25 micron in mulching and chemical fertilizers treatment. In conclusion, the interaction between mulching with black polyethylene sheets and fertilizing with organic and chemical manure , caused same anatomy characteristic changes which increased the potatoes plant yield and the ability to drought tolerance.

Effect of Mulching, Manures and chemical fertilizers on anatomical characters of (Solanum tuberosum L.) potato plants

Anatomy studies were carried out in the experimental field, College of Agriculture, University of Baghdad to have better understanding of the influence of mulching with black polyethylene sheets, organic manure and chemical fertilizer on the anatomy changes in potato shoot and leaves tissues. Results showed that leaves area, leaves area index and chlorophyll percentage were significantly increased by using mulching and chemical fertilizer by (7463.70 cm2, 3.97, 45.33 SPAD units) respectively. Also this treatment significantly increased total stomata number and in both lower and upper sides of the leaf by (957,721,176) stomata /mm2 respectively. But by using mulching treatment with organic manure significantly increased vessels and sieve tubes diameter by (12.5, 2.75) micron for respectively. However the control treatment significantly increased leaves thickness spongy mesophyll by (45) micron, while the palisade parenchyma thickness was significantly increased to 26.25 micron in mulching and chemical fertilizers treatment. In conclusion, the interaction between mulching with black polyethylene sheets and fertilizing with organic and chemical manure , caused same anatomy characteristic changes which increased the potatoes plant yield and the ability to drought tolerance.

Efficiency of seed extraction methods in the control of loss and low seed quality in egusi melon (Colocynthis citrullus L.)

This study determines the effect of methods of seed extraction on seed loss and viability on Egusi melon (Colocynthis citrullus L). Three methods of fruit breaking; vertical cut with knife, horizontal cut with knife and hitting with wooden club were tested to determine their effect on seed damage. Three covering materials; grass straw, black polyethylene sheet and no cover were also tested to determine their effect on the number of days to fruit fermentation and seed germination. The result showed that percentage seed loss resulting from vertical cutting with knife was 16% and was significantly higher than 3.4% seed loss arising from horizontal cut with knife and 0% from hitting with wooden club. It was also discovered that fruits covered with grass straw took 8.67 days to complete fruit fermentation while under black polyethylene cover it occurred at 12 days. Fruits that were left uncovered fermented at 9.33 days. Seed germination was also significantly affected by covering materials. Seed germination of 85.3, 80.0 and 30.0 were recorded on seeds obtained from fruits that were fermented with no cover, grass straw and black polyethylene cover respectively. Key words: Seed extraction, germination, seed loss.

Covering Tree Line with Black Poly Ethylene Sheets for Composting Fresh Animal Manures Reduces Weeds and Improves Tree Growth in Newly Established Orchards

Three field experiments were carried out over two growing seasons to evaluate the response of weeds and the volume of fruit trees; peach, pear and olive to composting of manures at 10 kg·m-2. Planting holes were prepared early January. Animal manures from different sources; broiler, cow, layer and sheep were mixed in the top 20-cm of the soil surface over a 40-cm band X 2.5m row per treatment in the planting row then either non covered or covered with black polyethylene (BPE) sheets for six weeks or for the period from January to October. Trees were then planted late February. The same treatments were repeated in November of the next year. Weeds were significantly reduced and fruit trees were significantly larger in the treatments with manures in the BPE-covered treatments as compared to the non-covered treatment. Perennials; Cynodon dactylon (L.) Pers. and Cardaria draba L. in addition to Convolvulus arvensis L. and Sorghum halepense (L.) Pers. tolerated the composting process. Most annual weeds did not appear in composted manure subplots. Main annual weeds included; Amaranthus blitoides S. Wats. A. garacilis Desf. Sinapis arvensis L. Chenpodium album L. in addition to some weeds species belonging to Leguminosae and Caryphyllaceae.

The effects of the degree of soil cover with an impervious sheet on the establishment of tree seedlings in an arid environment

Low precipitation and high evaporation rates hinder the establishment of tree seedlings in arid environments. The objective of this study was to assess the effect of covering different fractions (0, 30, 70 and 100%) of the wetted area surrounding seedlings of Acacia saligna (Labill.) H.L. Wendl. with a black polyethylene sheet on the seedlings development and water use. The cover treatments were applied to plots with and without Acacia seedlings. Within the mulched areas at all depths, soil temperatures close to the edges were lower than at the corresponding depth close to the center, but still higher than in the non-mulched plots. In plots with Acacia seedlings, the total soil water losses were similar among treatments. However, the cumulative evaporative losses near the soil surface were lower with larger mulched areas. During early growth stages, roots grew deeper in the 30% mulch treatment and more laterally in the other mulched treatments. The non-mulched treatment produced the smallest root system. Larger canopies developed in the mulched treatments and the gross water use efficiency increased with the increasing fraction of the mulched area. Optimum utilization of stored soil water and seedling development were attained with the 70% mulch treatment.

Effect of Manures and Mulching on yield of potato (Solanum tuberosum L.) Desiree

This studies was conducted in the experimental field, Department of Horticulture, College of Agriculture, University of Baghdad, Abu-Ghraib,during at the fall and spring seasons 2006-2007. by using Desiree cultivar potato. The aim of this study was to investigate the effect of sources of organic manure and mulching with black polyethylene sheets in the growth, yield and yield component of potato plans. Split- plot design were adapted, the first factor inculded either without black polyethylene sheet (M0) or using it (M1). The second factor was included the using of 6 types of organic manure; the first without organic manure (control T0). The second chemical fertilizer (T1), The third sheep manure (T2), The forth local peatmoss(T3),The fifth dry Pow humus(T4) and the sixth liquid Humic acid. L.S.D were used to compare the means at a 5% level of significances. The results showed that Mulching with black polyethylene (M1) significantly increased the yield/ plant and total yield for both seasons to reached 615.11and 710.56 gm and 29.40 and 35.82 ton hec for both seasons respectively . as compared with the control (M0) to reached 525.56 and 663.89 gm and 23.05 and 33.25 ton hec. And showed of Treating potato plants with chemical fertilizer (T1) and sheep manure (T2) significantly increased the total yield in fall season to reached 33.91and 30.79 ton hec respectively while in spring season was 42.70 and 41.42 ton hec as compared with the control (T0) to reached 19.45 and 29.72 ton hec to both control seasons respectively.And results showed of Mulching with black polyethylene and chemical fertilizer (MITI) and mulching with black polyethylene with sheep manure (M1T2) significantly increased the total yield in fall season to reached 38.30 and 34.62 ton hec and in spring season 44.27 and 43.14 ton hec while to decreased 17.05 and 28.30 ton hec. in control treatment (M0T0) without Mulching and manuring for both seasons.

Effect of Manures and Mulching on quality characters of potatoes (Solanum tuberosum L.) Desiree CV.

This studies was conducted in the experimental field, Department of Horticulture, College of Agriculture, University of Baghdad, Abu- Ghraib, during at fall and spring seasons 2006-2007 by using Desiree cultivar class (A) in the fall season and class (Eilte) in spring season. The aim of this study was to investigate the effect of sources of organic manure and mulching with black polyethylene sheets on quality characters of potatoes. Split- plot design were adapted in this experiment the first factor inculded either without black polyethylene sheet (M0) or using it (M1). The second factor was included using of 6 types of organic manure; the first without organic manure (control T0). The second chemical fertilizer (T1), The third sheep manure (T2), The forth local peatmoss (T3), The fifth dry Pow humus (T4) and the sixth liquid Humic acid. L.S.D were used to compare the means at a 5% level of significances. The results showed that Mulching potato plants with black polyethylene (M1) increased significantly the percentage of dry matter, starch and protien in potato tubers for both seasons and the percentage to reach (14.31, 8.76, 0.94%) respectively for fall season, as compared with the control (M0) to reach (13.85, 8.35, 0.77%). While in spring season the percentage was (16.83, 11.00, 1.22%). Respectively as compared with the control the percentage to reach (15.53, 9.81, 1.01%) respectively. And Mulching with black polyethylene and chemical fertilizer (M1T1) and mulching with black polyethylene with sheep manure (M1T2) significantly increased the dry matter and starch in potato tubers in fall season the percentage in dry matter to reach (15.14 and 14.88%) respectively and the percentag in starch to reach (9.50 and 9.26%) respectively as compared with the control (M0T0) without Mulching and manuring to reach (12.26 and 6.91%) respectively, while in spring season the percentage of dry matter was (17.93 and 17.58%) and for starch was (11.98 and 11.67%) respectively. as compared with the control (M0T0) to reach (13.92 and 8.15 %) resrectively.

Subsurface Dykes - Case Study for its Suitability in Kerala

The average annual rainfall of 3000 mm in Kerala is 3 to 5 times more than many other states. But. in Kerala, rainwater is not much retained on the land due to the steep/undulating topography and low water holding capacity and shallow depth of topsoil. Most of the water stored in the soil during rainy season escape to the lower reaches and then to the rivers/sea. The subsurface dykes constructed at AMPRS, Odakkali using black polyethylene sheet and at Thrangalikadavu. across Bharatapuzha. using Sand-Cement-Bentonite grout was effective in increasing the sub-soil water reserve. The study revealed that water level during summer season at the dyke upstream rose by about 60 to 80cm. The wells constructed near the dyke. both for drinking water supply and lift irrigation yielded more water for longer duration

Comparison of quality and yield of copra processed in CRI improved kiln drying and sun drying

CRI improved copra kiln was constructed according to the CRI specifications and evaluated to test the performances. The moisture content of drying coconut was reduced from 52% to 8% in 62 h. Thermal efficiency of kiln drying was 16%. The copra was graded as 82% milling ordinary grade 1 (MO GI) and the rest of 18% was MO GIII (burnt copra). White copra was not processed in the kiln drying. Coconut cups were spread on black polyethylene sheet and dried under direct sun. The average initial moisture content of coconut was reduced from 50% to 10% in 6 days of drying. Thermal efficiency of sun drying was 23%. The copra was graded as 25% white copra, 55% MO GII and the rest of 20% was MO GIII (mouldy cups) copra. The net loss per batch of the kiln drying was grater than that of the sun drying.

Cobertura do substrato com filme plástico e o cultivo hidropônico da roseira: produtividade, consumo de água, temperatura e salinização

Roseiras das cultivares Anna e Sari foram conduzidas em cultivo hidropônico em bancadas com e sem cobertura do substrato. O material usado para a cobertura foi o polietileno (PEBD) de coloração preta e com espessura de 0,18 mm. Como substrato de cultivo, foi usada a mistura de areia:turfa = 4:1 v/v. Os transplantes foram feitos em novembro de 1995, dispostos em fila única com 7,5 plantas/m2. Para o controle da fertirrigação, foi usado o método que se baseia no uso de um lisímetro, colocado em cada bancada, o qual permite obter o percentual de drenado prefixado e também controlar o limite máximo de salinidade do percolado, a partir do qual é adicionada água para lavar o excesso de sais do substrato. O percentual teórico de drenagem foi fixado em 10% do volume irrigado, a salinidade máxima em 4000 mmS/cm e as fertirrigações em duas por semana. Como resultado do uso da cobertura do substrato, foi verificada redução do consumo hídrico de 35% e 16%, correspondente as cultivares Anna e Sari e também menor salinização dos substratos. O uso da cobertura do substrato permitiu uma melhoria de qualidade de flores e também ganho em produtividade, com menor consumo hídrico, resultando em maior eficiência de uso da água. A umidade no ambiente das raízes manteve-se mais estável principalmente na superfície do substrato, comprovando o uso da cobertura como uma técnica, a mais, para o controle da umidade e da salinidade do substrato, com redução da quantidade de drenagem, de água e de fertilizantes administrados, com redução dos custos de produção e benefícios para o ambiente.

Development of Eco‐friendly and Non‐hazardous Weed Control Technology for Lowland Rice by Smothering through LDPE Film

AbstractIntensive use of chemical herbicides and pesticides has raised serious concern about their effect on non‐target organisms, plants, human bodies and the environment. Hence there is a continuous search for benign, harmless, non‐hazardous and eco‐friendly technology to control the growth of weeds which compete with crops for water, nutrients, light and space; thus reducing crop yield significantly. An attempt was made to control the weeds through smothering. This controls the weeds by cutting off light from the photosynthetic portion of weed plants by using black polyethylene sheets (LPDE film) which inhibit the top growth. Experiments to control the weeds in a lowland rice field through smothering were conducted in the high rainfall coastal region of eastern India wth eight treatments including smothering and conventional methods like hand/mechanical weeding and herbicides, etc. The treatment of smothering for one week + puddling + transplanting proved to be better than other conventional methods and may replace herbicide and hand/mechanical weeding totally with a better rice yield.

Sunning as a technique for disinfesting stored beans

The effectiveness of sunning (solar heating) as a small farm technique for controlling the bean bruchids Zabrotes subfasciatus (Boheman) and Acanthoscelides obtectus (Say) was investigated. Bean seeds infested with mixed-stage larvae were placed on clear or black polyethylene sheets or inside polyethylene pouches with clear upper and black lower surfaces and exposed to the sun for five hours each day for 0, 3 and 5 successive days. No live insects emerged from seeds heated in the pouches while the few that emerged from seeds on the black sheets resulted in damage to less than 1% of the seeds. Of the three polyethylene systems used, the clear sheet was the least useful, while the pouches even for only 3 days, were the most effective in eliminating infestations. These studies demonstrated that effective bruchid control can be achieved with daily 5-h exposure periods of seeds for a successive 5-day duration. However, the success of the method of control may be influenced by the time of the year and prevailing environmental conditions.