Reduction In Dry Matter Research Articles

Pontas hidráulicas, adjuvante e horários de aplicação de fomesafen no controle de picão-preto

A aplicação de defensivos agrícolas é afetada por diversos fatores, dentre eles, destaca-se o momento da aplicação, que pode variar de acordo com o alvo, o produto aplicado e equipamento utilizado. Objetivou-se avaliar pontas hidráulicas, adjuvante e horários de aplicação de fomesafen no controle de picão-preto. Os tratamentos foram arranjados em esquema fatorial 4x2x2, com o primeiro fator constituído de quatro pontas (API-11002; jato leque simples-JLS, AD/D-11002; jato leque duplo-JLD, AVI TWIN-11002; jato leque duplo com indução de ar-JLDIA, e APM-09502; jato leque simples de impacto-JLSIP). O segundo de dois horários de aplicação (3 e 16 horas) e o terceiro de duas misturas em tanque (com e sem adição de adjuvante espalhante adesivo não iônico). Os tratamentos foram avaliados sete, 14 e 21 dias após à aplicação, através do número de plantas vivas, altura das plantas, análise visual e aos 21 dias foi feita matéria seca da parte aérea. A aplicação às 16 horas proporcionou maior controle de todas as características avaliadas, a ponta JLSIP se destacou causando maior redução de matéria seca e de plantas vivas e a adição de adjuvante potencializou o controle da aplicação às 16 horas. O horário de aplicação influencia a ação do herbicida fomesafen, sendo que, sua aplicação às 16 horas proporciona maior controle de B. pilosa em relação à realizada às 3 horas. A ponta JLSIP aumenta a ação de fomesafen e a adição de adjuvante potencializa o efeito desta ponta e da aplicação realizada às 16 horas.

DECOMPOSIÇÃO DE RESÍDUOS DE CULTURAS E MINERALIZAÇÃO DE NUTRIENTES EM SOLO COM DIFERENTES TEXTURAS

RESUMO A sustentabilidade dos sistemas conservacionistas de produção agrícola está intimamente ligada ao retorno dos nutrientes ao solo, por meio da decomposição dos resíduos vegetais. O objetivo deste estudo foi avaliar a decomposição de resíduos culturais e a mineralização de nutrientes em solos com diferentes texturas ao longo de 175 dias de incubação. Os tratamentos consistiram em fatorial 6 x 4 x 5, inicialmente composto por seis tratamentos, sendo quatro resíduos culturais: milho, braquiária, feijão, estilosantes e dois controles, ambos sem resíduo e um com adição de fontes inorgânicas dos nutrientes; quatro diferentes texturas formadas a partir de um mesmo solo e cinco tempos de avaliação após o início da incubação: 0, 25, 75, 125 e 175 dias. Utilizou-se delineamento inteiramente casualizado, com quatro repetições. Ao longo do experimento, avaliaram-se a liberação de C-CO2, taxa de decomposição e cinética de mineralização do N, P, K, Ca, Mg, S, Zn e Cu dos resíduos. A textura do solo não influenciou a liberação de C-CO2, a massa seca remanescente e a mineralização dos nutrientes dos resíduos culturais. Os resíduos de estilosantes e de braquiária apresentaram maior liberação de C-CO2 e redução de massa seca que os demais resíduos. A mineralização do N, P e S ocorreu de forma inversa às relações C/N, C/P e C/S. A decomposição dos resíduos culturais foi regulada pelos teores de N e extrativos solúveis em água; e a mineralização de macronutrientes, pelos seus respectivos conteúdos iniciais nos resíduos.

MULTIPLE RESISTANCE OF Sagittaria montevidensis BIOTYPES TO ACETOLACTATE SYNTHASE AND PHOTOSYSTEM II INHIBITING HERBICIDES

ABSTRACT The objective of this research was to evaluate the occurance of multiple resistance of Sagittaria montevidensis (SAGMO) biotypes to acetolactate synthase (ALS) and photosystem II (PSII) inhibiting herbicides through dose-response experiments. The experiment was conducted in a greenhouse from October 2012 to March 2013, in Pelotas, RS. The experimental design was completely randomized, with four replications. Treatments were arranged in a triple factorial design: two biotypes of S. montevidensis(SAGMO 35 - susceptible to herbicides and SAGMO 32 - suspected to be multiple resistance to ALS and PSII inhibiting herbicides), four herbicides (penoxsulam, (imazethapyr+imazapic), bentazon and saflufenacil) and 8 rates of these herbicides (1/32x, 1/16x, 1/8x, 1/4x, 1/2x, 0x, 1x, 2x, 4x, 8x, 16x, 32x and 64x). SAGMO 32 biotype presented high levels of resistance to penoxsulam, (imazethapyr+imazapic) and bentazon. For a 50% reduction in dry matter of the resistant biotype rate of 138 and 2.46 times higher than the label required for the susceptible biotype of the herbicides (imazethapyr+imazapic) and bentazon, respectively, are required. Saflufenacil may be used successfully to controlSagittaria montevidensis resistant in irrigated rice.

Copper translocation and tolerance in seedlings of tree species grown in contaminated soil

ABSTRACTHigh concentrations of copper (Cu) may be toxic to plants, yet some species can be tolerant to soils contaminated by this metal. The study aimed to evaluate Cu translocation and tolerance in seedlings of ‘timbaúva’ (Enterolobium contortisiliquum (Vell.) Morong), ‘pata-de-vaca’ (Bauhinia forficata Link) and ‘amendoim-bravo’ (Pterogyne nitensTul) subjected to Cu-contaminated soil. The study was conducted in a greenhouse for 120 days, using as substrate a clayey Oxisol. The experiment was set in a completely randomized design, using a 3 x 6 factorial scheme, corresponding to three forest species (‘timbaúva’, ‘pata-de-vaca’ and ‘amendoim-bravo’) and six Cu doses in the soil (0, 60, 120, 180, 240 and 300 mg kg-1), with six replicates. The following variables were analysed: total dry matter, Cu content and its accumulation in roots and shoots, tolerance and translocation indices and the coefficient of impact of the contamination on the relative contents of Cu in roots and shoots. ‘Timbaúva’ showed lower reduction in total dry matter with the increase of Cu doses in the soil, proving to be able to decrease Cu translocation to the shoots and tolerate doses of up to 236 mg kg-1 of this metal in the soil. ‘Timbaúva’ seedlings are more tolerant to contamination of Cu in soil, compared with seedlings of ‘amendoim-bravo’ and ‘pata-de-vaca’.

Weed suppression by cover crops: comparative on‐farm experiments under integrated and organic conservation tillage

SummaryCover crops are increasingly being used for weed suppression and to enhance the sustainability of agro‐ecosystems. However, the suitability of cover crops for weed suppression in integrated and organic conservation tillage systems is still poorly investigated. Therefore, a 2‐year field study at eight sites was conducted to test the weed suppressive potential of six legume‐based cover crops, with the aim to reduce herbicide input or mechanical weed management interventions. In all experiments, cover crops were directly sown after cereals before next year's main crop (grain maize or sunflower). The presence of cover crops caused a 96% to 100% reduction of weed dry matter at the four sites managed under integrated production, while effects were lower at the four sited managed under organic production, ranging from 19% to 87%. Cover crops that covered soil quickly and which produced much dry matter had the best weed suppressive potential. However, their weed suppressing effect was difficult to predict, as it depended on the year of the investigation, experimental site, cover crop species, the speed of soil cover in autumn and the density of the resulting mulch layer in spring. The study demonstrated that cover crops are a useful tool to suppress weeds under integrated and organic conservation tillage practices. Our recommendation for supporting weed management in conservation tillage systems is to use locally adapted cover crops that have rapid establishment, good soil coverage and high dry matter production. However, additional weed management measures are required for reliable weed control under on‐farm conditions.

Pig manure treatment with housefly (Musca domestica) rearing – an environmental life cycle assessment

The largest portion of a product’s environmental impacts and costs of manufacturing and use results from decisions taken in the conceptual design phase long before its market entry. To foster sustainable production patterns, applying life cycle assessment in the early product development stage is gaining importance. Following recent scientific studies on using dipteran fly species for waste management, this paper presents an assessment of two insect-based manure treatment systems. Considering the necessity of manure treatment in regions with concentrated animal operations, reducing excess manure volumes with the means of insects presents a potentially convenient method to combine waste reduction and nutrient recovery. An analytical comparison of rearing houseflies on fresh and pre-treated pig manure is reported with reference to agricultural land occupation, water and fossil depletion potential. Based on ex-ante modelled industrial scale rearing systems, the driving factors of performance and environmentally sensitive aspects of the rearing process have been assessed. Expressed per kg manure dry matter reduction, the estimated agricultural land occupation varied between 1.4 and 2.7 m2yr, fossil depletion potential ranged from 1.9 to 3.4 kgoil eq and the obtained water depletion potential was calculated from 36.4 to 65.6 m3. System improvement potential was identified for heating related energy usage and water consumption. The geographical context and the utility of the co-products, i.e. residue substrates and insect products, were determined as influential variables to the application potential of this novel manure treatment concept. The results of this study, applied at the earliest stages of the design of the process, assist evaluation of the feasibility of such a system and provide guidance for future research and development activities.

Effects of Potassium Sulfate on Adaptability of Sugarcane Cultivars to Salt Stress under Hydroponic Conditions

The effect of potassium sulfate (K2SO4) on adaptability of sugarcane to sodium chloride (NaCl) stress was investigated under hydroponic conditions. Two sugarcane cultivars, differing in salinity tolerance, were grown in half strength Johnson's solution at 80 mM NaCl with 0, 2.5 and 5.0 mM potassium (K) as K2SO4. Salinity disturbed above and below-ground dry matter production in both sugarcane cultivars. However, salt sensitive cultivar showed more reduction in shoot dry matter and higher root:shoot ratio compare to the salt tolerant cultivar under. Application of K significantly (p < 0.05) improved dry matter production in both sugarcane cultivars. The concentration of Na was markedly increased with increasing salinity; however, the application of K reduced its uptake, accumulation and distribution in plant tissues. Salinity induced reduction in K concentration, K-uptake, K utilization efficiency (KUE) and K:Na ratio in both sugarcane cultivars was significantly improved with the addition of K to the saline growth medium.

A study of the discrete and interactive effects of different polysaccharides on the digestibility of diets fed to barramundi (Lates calcarifer)

This study examined the single, paired and combined inclusion effect of a range of different polysaccharide types on the dry matter, protein and energy digestibility of diets fed to barramundi (Lates calcarifer). The different polysaccharides included pregelled starch, cellulose, lignin and pectin. There were significant differences among the digestibility parameters of the diets with the different inclusion levels of each of the different polysaccharide types. Using a manova analysis, effects were noted for polysaccharide type, inclusion level and interaction terms on the digestibilities of dry matter, protein and energy. Cellulose addition resulted in a reduction in both dry matter and energy that was largely commensurate with its inclusion level, but its effect on protein digestibility was marginal. Starch had the least effect on any of the digestibility parameters of all the polysaccharide types examined. Pectin had the largest effect on dry matter, while lignin had the greatest impact on diet protein and energy digestion. In the diets with paired combinations of polysaccharides, lignin and pectin were responsible for negatively synergistic interactions in all digestibility parameters. These results show that different polysaccharide classes can have distinctly different effects on diet digestibility parameters.

Association mapping and genomic prediction for resistance to sudden death syndrome in early maturing soybean germplasm.

Sudden death syndrome (SDS), caused by Fusarium virguliforme, has spread to northern soybean growing regions in the US causing significant yield losses. The objectives of this study were to identify loci underlying variation in plant responses to SDS through association mapping (AM) and to assess prediction accuracy of genomic selection (GS) in a panel of early maturing soybean germplasm. A set of 282 soybean breeding lines was selected from the University of Minnesota soybean breeding program and then genotyped using a genome-wide panel of 1536 single-nucleotide polymorphism markers. Four resistance traits, root lesion severity (RLS), foliar symptom severity (FSS), root retention (RR), and dry matter reduction (DMR), were evaluated using soil inoculation in the greenhouse. AM identified significant peaks in genomic regions of known SDS resistance quantitative trait loci cqSDS001, cqRfs4, and SDS11-2. Additionally, two novel loci, one on chromosome 3 and another on chromosome 18, were tentatively identified. A ninefold cross-validation scheme was used to assess the prediction accuracy of GS for SDS resistance. The prediction accuracy of single-trait GS (ST-GS) was 0.64 for RLS, but less than 0.30 for RR, DMR, and FSS. Compared to ST-GS, none of multi-trait GS (MT-GS) models significantly improved the prediction accuracy due to weak correlations between the four traits. This study suggests both AM and GS hold promise for implementation in genetic improvement of SDS resistance in existing soybean breeding programs.Electronic supplementary materialThe online version of this article (doi:10.1007/s11032-015-0324-3) contains supplementary material, which is available to authorized users.

Dynamics of reserves of soybean seeds during the development of seedlings of different commercial cultivars

Physiological quality and vigor of the seeds comprise properties that determine a high level of activity and performance during germination and seedling emergence, having a direct relation with the establishment of the stand of a crop. In this context, the assessment of seedling development, including the analysis of the seed reserves mobilization are a reliable method to investigate the physiological potential of seed lots. In this preliminary study, the aim was to investigate the dynamics of seed reserves mobilization of a sample of soybean commercial cultivars. By means of the seedling length bioassay and weight of dry matter of seeds, cotyledons, hypocotyls and radicles, information on the reserves mobilization during the germination process was obtained. Data were subjected to analysis of variance and Scott and Knott test, and afterwards, phenotypic correlations between traits were obtained. The results have shown that the dry matter of seeds, reserves reduction of seeds and dry matter of seedlings are positively correlated, and thus, seeds containing more reserves may be more effective during the early development of seedlings. In contrast, reserve reduction of seeds and conversion efficiency of the seeds reserves in the dry matter of seedlings are negatively correlated.

Critical period of crop sensitivity to water deficit stress in elephant foot yam (Amorphophallus paeoniifolius)

The effect of Water Deficit Stress (WDS) at different growth period on growth and productivity of Amorphophallus and the critical period of crop sensitivity to WDS was investigated during 2011-12 and 2012-13 with the variety Gajendra. Cut pieces of corm weighing 500 g were planted in RBD with four replications in the experimental plot of CTCRI. The treatments were, viz. T1 - Control (without water deficit stress), T2 - WDS during four and five months after planting, T3 - WDS during five and six months after planting and T4 - WDS during six and seven months after planting. Control plots were irrigated when the soil moisture was depleted to 50% of field capacity, whereas WDS was imposed by withholding water. The significant reduction in leaf area in WD stressed plants resulted in significant reduction in corm dry matter as well as corm yield per plant. Compared to control plants, the reduction in corm yield was 41.19% more due to WDS during 4-5 Months After Planting (MAP) (78.52%) than during 6-7 MAP (37.33%). The observed results indicate that WDS during 4 and 5 or 5 and 6 months crop growth period significantly affected growth and productivity of Amorphophallus. Apart from the initial establishment period and growth period between 4 and 6 months are critical and therefore crop must be irrigated adequately during these periods for achieving more corm yield.

Herbicidal Combinat ion for Effect ive Management of Complex Weed Flora in Transplanted Rice (Oryza sat ivaL.)

Long term continuous use of similar herbicide is major culprit for weed shift and herbicide resistance. Therefore, a field experiment was conducted at Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar during kharif 2012 to evaluate the performance of new broad spectrum herbicide molecules. Pre-emergence application of Pretilachlor 750 g ha−1 with no irrigation during initial one week along with post-emergence application of Bispyribac-Na 20 g ha−1 provided broad spectrum control of complex weed flora at 30 and 60 days after transplanting (DAT) resulted in significantly lower weed density and dry matter than rest of the weed control treatments. This treatment thus, provided higher weed control efficiency (98.7%) and yield (5729 kg ha−1), than test treatment i.e. pre-emergence application of Pretilachlor alone. However, one conoweeding (15 DAT)+one hand weeding (45 DAT) recorded higher weed density and dry matter at both the stages. Alone post-emergence application of Bispyribac-Na and twice hand weedings produced at par yield with Pretilachlor 750 g ha−1 with no irrigation during initial one week along with application of Bispyribac-Na 20 g ha−1. Among different doses of Penoxsulam, the increase in dose of Penoxsulam caused significant reduction in weed density and dry matter thus registered higher grain yield. Post-emergence application of Penoxsulam at 22.5 and 25 g ha−1 produced comparable yield with Bispyribac-Na. Conoweeding + one hand weeding was found least effective compared to rest of the treatments.

Evaluation of Broadleaf Weeds Control with Selectivity of Post-Emergence Herbicides in Sugar Beet (&lt;i&gt;Beta vulgaris&lt;/i&gt; L.)

The reduction of herbicide applications is a main research priority in recent years. In order to study the effect of individual post-emergence application of sugar beet broad-leaf herbicides at four to six true-leaf stage of weeds, experiments were conducted during 2013. Treatments included untreated control and several rates of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid on Portulaca oleracea, Solanum nigrum, Amaranthus retroflexus and Chenopodium album. A completely randomized layout with three replications was used for each herbicide. Three weeks after spraying (WAS), plants were harvested and measured their dry weight. These herbicides were more effective to control Portulaca oleracea than other weeds, thereupon minimum dose required for a satisfactory efficacy of 90% reduction of Portulaca oleracea aboveground dry matter (ED90) were 299.22, 1138.31 and 129.44 g a.i ha-1 of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid, respectively. Solanum nigrum was more affected by clopyralid application (132.40 g a.i ha-1), and did not make significant difference in Portulaca oleracea. Chloridazon had lower effect for control of Chenopodium album due to existence of powdery covering on abaxial side of the leaves. Biomass ED50 or ED90, based on log-logistic dose–response curves, for Chenopodium album was considerably higher than other species. These results showed that tank mixtures with other herbicides may be required for satisfactory weed control and reduction in applied herbicides doses.

Evaluation of Broadleaf Weeds Control with Selectivity of Post-Emergence Herbicides in Sugar Beet (&lt;i&gt;Beta vulgaris&lt;/i&gt; L.)

The reduction of herbicide applications is a main research priority in recent years. In order to study the effect of individual post-emergence application of sugar beet broad-leaf herbicides at four to six true-leaf stage of weeds, experiments were conducted during 2013. Treatments included untreated control and several rates of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid on Portulaca oleracea, Solanum nigrum, Amaranthus retroflexus and Chenopodium album. A completely randomized layout with three replications was used for each herbicide. Three weeks after spraying (WAS), plants were harvested and measured their dry weight. These herbicides were more effective to control Portulaca oleracea than other weeds, thereupon minimum dose required for a satisfactory efficacy of 90% reduction of Portulaca oleracea aboveground dry matter (ED90) were 299.22, 1138.31 and 129.44 g a.i ha-1 of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid, respectively. Solanum nigrum was more affected by clopyralid application (132.40 g a.i ha-1), and did not make significant difference in Portulaca oleracea. Chloridazon had lower effect for control of Chenopodium album due to existence of powdery covering on abaxial side of the leaves. Biomass ED50 or ED90, based on log-logistic dose–response curves, for Chenopodium album was considerably higher than other species. These results showed that tank mixtures with other herbicides may be required for satisfactory weed control and reduction in applied herbicides doses.

Increase in night temperature in rice enhances respiration rate without significant impact on biomass accumulation

Night temperature (NT) increases faster than day temperature with global warming and this may have strong implications for crop yield. One of the assumptions is the increase in night respiration and thus the increase in carbon losses over time. Some rice cultivars (indica, aus and japonica types) were grown in the field in the Philippines and in heated greenhouses in Montpellier, France, to quantify the response of respiration to increased NT and its implication at crop level. Increased NT by 3.8 and 5.4°C over the whole crop cycle in two greenhouse experiments and by 1.9°C in the field from 33 days after transplanting up to maturity using a free-air-controlled enhancement increased night respiration rate significantly. Overall, the cost in CH2O of night respiration over crop duration was 17 to 20% (field) and 8 to 18% (greenhouse) of the potential shoot dry matter (including that lost by respiration). Additional respiratory burden due to increased NT was only 1 to 7% of the potential shoot dry matter at maturity, and was not associated with significant loss in additional dry matter. The absence of any dry matter reduction with increased NT within indica cultivars questions the assumptions of recent papers.

Effect of Different Fungicides Application on Wheat Yield and Soil Native Status of Arbuscular Mycorrhizal Fungi

A field experiment was conducted to investigate the effect of fungicides on soil native status of Arbuscular mycorrhizal fungi (AMF) and yield of wheat grown in randomized complete block design with three replications during Rabi 2011-12. Three different fungicides commonly practiced by the farmers i-e Chloroflorochlorine, Acrobat and Redimoldgold were applied to crop. The recommended level of Chloroflorochlorine was 1 kg/ha, while that of Acrobat and Redimoldgold were 620 g/ha, respectively. Data revealed that wheat yield, plants nutrients uptakes and soil spores density of AMF and their roots infection intensity decreased with fungicides application as compared with the treatment applied with no fungicides. Highest reduction in grain yield shoot dry matter and plant height were noted with application of Acrobat 50% more than recommended level. Grain and shoot dry matter yields of 3621 and 9212 kg/ha, respectively, produced in this treatment, which 17% less than the treatment of no fungicides application. The application of acrobat 50% more than recommended level also showed decreases maximum in soil total N and AB- DTPA extractable P and Cu, which was significantly (p<0.05), lower by 8 and 40%, respectively over the treatment of no fungicides application. Redimoldgold applied as 50% more than recommended level decreased more AB-DTPA extractable Zn and Mn contents lowered as 48 and 200%, respectively over the treatment of no fungicides application. The highest decreases in plant N and P uptake were observed by the application of Acrobat applied as 50% more than recommended level, lowered as 23 and 30%, respectively over the treatment of no fungicides application. Maximum decrease in spores density and their roots infection intensity were recorded by the application of Acrobat 50% more than recommended level, which were 67 and 50%, respectively, lower than the treatment of no fungicides application. Results suggest that application of fungicides reduces the efficiency of AMF native status in soil and cause reduction in wheat yield and plants nutrients uptake.

Deficit Irrigation of Durum Wheat (Triticum durum Desf): Effects on Total Dry Matter Production, Light Interception and Radiation Use Efficiency Under Different Nitrogen Rates

&lt;p&gt;On-farm trial was conducted from 2005 to 2008 to test the hypothesis that reduction of total dry matter (TDM) in crops can occur after a decreased radiation use efficiency (RUE) due to shortage of nitrogen and irrigation, we applied three irrigations treatments (D1, D2 and D3) and four nitrogen rates (N1, N2, N3 and N4). Photosynthetic active radiation absorbed or cumulative light interception (PARabs) and RUE of Durum wheat were measured. Results showed that D1N1 treatment recorded the highest LAI, PARabs, TDM and RUE. The maximum LAI was obtained 140 DAS (days after sowing) under treatment D1N2 (6.42) and the lowest LAI at the same phase belonged to treatment D2N4 (3.86). At the harvest, the maximum of TDM was 1487 g m&lt;sup&gt;-2&lt;/sup&gt; recorded under treatment D1N1. The minimum value obtained was 930 g m&lt;sup&gt;-2&lt;/sup&gt; under treatment D3N4. Also, PARabs was improved under D1N1 and D1N2 treatments. With reduced N application rates and irrigation doses, PARabs was decreased and the lowest values were observed under D3N4 condition. The RUE, varied from 1.55 g MJ&lt;sup&gt;-1&lt;/sup&gt; (D1N1) to 1.24 g MJ&lt;sup&gt;-1&lt;/sup&gt; (D3N4), was affected and decreased under deficit irrigation and low nitrogen conditions. In conclusion, the results of this study seem to show that D1N1 and D1N2 treatments can be beneficial for Durum wheat under field conditions in semi arid zone of Tunisia, for the purpose of improving RUE and maximizing grain yield.&lt;/p&gt;

The Influence of Municipal Treated Wastewater on Morpho-Physiological Characteristics of Eucalyptus Plants

The effects of municipal-treated wastewater on growth and gas exchange characteristics were studied in eucalyptus plants cultivated in a greenhouse under continuous sub irrigation with 70 % Long Ashton solution as a control, 100 % treated wastewater, and treated wastewater diluted 50 % with tap water. Irrigation with wastewater resulted in a reduction of total dry matter per plant and the shoot-to-root ratio and increased specific leaf mass, irrespective of the dilution. The gas exchange characteristics were adversely affected by the irrigation with wastewater, with photosynthetic rates been negatively affected. Total chlorophyll and carotenoids content were reduced in plants grown under treated wastewater. The results demonstrated that when the eucalyptus plants were grown under treated wastewater as the only source of mineral nutrients they were able to produce nearly 50 % of the dry matter produced by the plants grown under appropriate mineral nutrient supply, irrespective of the dilution. Therefore, the contribution of mineral nutrients and organic matter from the treated wastewater used as agricultural irrigation will be significant in lower the fertilizer rates without reducing dry matter production per plant.

Winery waste recycling through anaerobic co-digestion with waste activated sludge

In this study biogas and high quality digestate were recovered from winery waste (wine lees) through anaerobic co-digestion with waste activated sludge both in mesophilic and thermophilic conditions. The two conditions studied showed similar yields (0.40m3/kgCODfed) but different biological process stability: in fact the mesophilic process was clearly more stable than the thermophilic one in terms of bioprocess parameters.The resulting digestates showed good characteristics for both the tested conditions: heavy metals, dioxins (PCDD/F), and dioxin like bi-phenyls (PCBs) were concentred in the effluent if compared with the influent because of the important reduction of the solid dry matter, but remained at levels acceptable for agricultural reuse. Pathogens in digestate decreased. Best reductions were observed in thermophilic condition, while at 37°C the concentration of Escherichia coli was at concentrations level as high as 1000UFC/g. Dewatering properties of digestates were evaluated by means of the capillary suction time (CST) and specific resistance to filtration (SRF) tests and it was found that a good dewatering level was achievable only when high doses of polymer (more than 25g per kg dry solids) were added to sludge.

Crescimento inicial de mandioca submetida à aplicação de herbicidas em pós-emergência

Objetivou-se com esse trabalho avaliar o crescimento inicial de plantas de mandioca após aplicação de herbicidas em pós-emergência da cultura. O experimento foi realizado em ambiente protegido, no delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos pela aplicação, aos 25 dias após a emergência a cultura, dos herbicidas bentazon, clomazone, fomesafen, fluazifop-p-buthyl, glyphosate, nicosulfuron, chlorimuron-ehtyl, a mistura fluazifop-p-buthyl + fomesafen e sulfentrazone, além de uma testemunha sem aplicação. A intoxicação visual das plantas de mandioca foi avaliada aos 7, 14, 21 e 28 dias após a aplicação dos herbicidas. Aos 35 dias após a aplicação determinou-se a estatura, diâmetro do caule e a matéria seca das plantas. O sulfentrazone e o glyphosate causaram a morte da mandioca. Todos herbicidas causaram redução da matéria seca do caule, com exceção do fluazifop-p-buthyl. O chlorimuron-ethyl e o nicosulfuron foram os herbicidas que causaram maior redução do acúmulo de matéria seca e da área foliar da cultura. O diâmetro do caule foi reduzido pelos herbicidas bentazon, nicosulfuron e chlorimuron-ethyl. Conclui-se que o crescimento da mandioca foi alterado pela aplicação dos herbicidas, com exceção do fluazifop-p-buthyl.