Sole Culture Research Articles

Pilot-scale outdoor production of Scenedesmus sp. in raceways using flue gases and centrate from anaerobic digestion as the sole culture medium

This work investigated the production of Scenedesmus sp. in semi-continuous mode in three pilot-scale outdoor raceways (7.2 m2) using flue gas for CO2 supply and centrate from the anaerobic digestion of urban wastewater as the sole nutrient source. Experiments were performed at different culture depths, 5, 10 and 15 cm, while evaluating two centrate concentrations (30% and 45%) at dilution rates of 0.2 and 0.3 d−1. Under optimal conditions of 30% centrate, 0.3 d−1 dilution rate and a 15 cm culture depth, a maximum biomass productivity of 22.9 g m−2 d−1 was obtained. The optical properties of the cultures were studied and the results showed a photosynthetic efficiency of up to 2.0% and a quantum yield of 0.3 g biomass E−1. Nitrogen and phosphorus removal rates of 3 g N m−2 d−1 and 0.6 g P m−2 d−1 were recorded, respectively. Lipid productivity of 2.3 g m−2 d−1 was determined possessing a suitable fatty acids profile for biofuel production.

A internacionalização no ifsul e a relevância da língua estrangeira para o desenvolvimento acadêmico e científico da instituição

Preparing students for the ongoing process of internationalization of Education is a complex task, since both technologies and teaching practices change, becoming increasingly global and less specific to a sole culture. An institution that previously delimited and carried out its research in its own must now establish relationships and seek partnerships with institutions of higher education for the preparation, execution and collection of research data. Due to this reality, the objective of this work, is to present a study about the Federal Institute in the South of Rio Grande do Sul - IFSUL, an institution that has made countless efforts and has been in constant movement so that the internationalization process is established in a productive way. The work of IFSUL in projects of the federal government is analyzed, as well as the linguistic and pedagogical training of its teachers regarding the initiatives taken by the Institution in the global scenario. The internationalization process is investigated by the principles presented by Green (2005), and suggestions are made so that the constant work on this topic is more and more satisfactory.

Effects of arbuscular mycorrhizal fungi and Rhizobium on ion content and root characteristics of green bean and maize under intercropping

In order to evaluate arbuscular mycorrhizal fungi and rhizobium bacteria effects on leaf nitrogen (N) and phosphorus (P) concentration and root characteristics of green bean and maize under intercropping, experiment was carried out in the research field of College of Agriculture, Payame Noor University of Azna, Lorestan, Iran. In experiment, sandy loam soil with pH 7.3 and EC 0.49 dS m-1 was used.The treatments comprised three cropping systems (sole cropping of green bean and maize, and intercropping), and four inoculations (control, arbuscular mycorrhizal fungi, rhizobium and mix of arbuscular mycorrhizal fungi and rhizobium). The results showed that inoculation with rhizobium improved length, diameter, volume and area of green bean root.The highest of green bean N, P concentration and root dry mass were observed in sole culture of green bean inoculated with arbuscular mycorrhizal fungi. Moreover, root length, diameter, volume and area of maize increased by arbuscular mycorrhizal fungi, and total concentration of N and P enhanced with use of rhizobium in sole cropping. Although the usage of Rhizobium and AMF can be affected on increasing the root growth and nutrient uptake of crops, application of bacterium and fungi combination at the same time would not be suitable. Overall, intercropping of maize with green bean caused to increase of leaf N and P concentrations and root growth of maize.

Response of Some Soybean Cultivars to Low Light Intensity under Different Intercropping Patterns with Maize

A two-year study was carried out at Mallawi Agricultural Experiments and Research Station, A.R.C., El-Minia governorate, Egypt, during 2014 and 2015 seasons to determine the compatible soybean cultivar with high maize plant density to achieve farmer's benefit under intercropping conditions. Alternating ridges (70 cm width) between maize and soybean were used as 1:3, 2:4, 2:2, 3:3 and 4:2, respectively, in addition to sole culture of both crops. Local maize cultivar T.W.C. 310 was grown in one plant per hill distanced at 30 cm under intercropping and sole cultures, meanwhile local soybean cultivars (Giza 22, Giza 82 and Giza 111) were drilled in both sides of the ridge (two plants/hill distanced at 15 cm) under intercropping and sole cultures. A split plot distribution in randomized complete block design with three replications was used. The results indicated that maize yield attributes were increased significantly by decreasing maize plant density from 67 to 25% of sole maize under intercropping conditions, meanwhile the converse was true for plant height and grain yield per ha. All the studied maize traits were not affected by soybean cultivars. Also, all the studied maize traits were not affected the interaction between intercropping patterns and soybean cultivars. Soybean yield and its attributes were increased significantly by decreasing maize plant density from 67 to 25% of sole maize under intercropping conditions except plant height. The late-maturing soybean cultivar Giza 22 recorded the highest values of intercepted light intensity within soybean canopy, number of pods per plant, seed index, seed yields per plant and per ha, meanwhile, the highest values of biological yield per ha, plant height and number of branches per plant were recorded for soybean cultivar Giza 111. Soybean cultivar Giza 22 gave the highest seed yield per plant compared to the other cultivars under all the intercropping patterns. Relative yield of soybean showed that the early-maturing soybean cultivar Giza 82 is better adapted to low light intensity than the other cultivars. Land equivalent ratio and area time equivalent ratio values for intercrops were greater than 1.00 indicating less land requirements of intercropping patterns than sole maize. Growing four maize ridges alternating with two ridges of soybean cultivar Giza 82 achieved the highest net return compared to sole maize.

Proteomic analysis through larval development of Solea senegalensis flatfish.

The post-embryonic development of the Senegalese sole, Solea senegalensis, a flatfish of growing interest in fisheries and aquaculture, is associated with drastic morpho-physiological changes during metamorphosis. Although in the last two decades knowledge on sole culture has notably increased, especially in Southern Europe, its progress was restricted due to lack of methods to control reproduction, improve larval quality and increase juvenile disease resistance. A limited knowledge of the physiological, molecular and genetic mechanisms involved is at the base of such limitation. A proteomic study was carried out to explore the molecular events that occur during S. senegalensis ontogenesis. Protein expression changes were monitored in larvae from 5 to 21 dph by combining 2DE and protein identification with de novo MS/MS sequencing. An average of 6177 ± 282 spots was resolved in 2DE gels. Hierarchical cluster analysis of the 705 selected spots grouped them in eight patterns. Thirty-four proteins were identified and assigned biological functions including structure, metabolism highlighting energy metabolism, transport, protein folding, stress response, chromatin organization and regulation of gene expression. These changes provide a sequential description of the molecular events associated with the biochemical and biological transformations that occur during sole larval development.

Advantages of Intercropping Soybean with Maize Under Two Maize Plant Distributions and Three Mineral Nitrogen Fertilizer Rates

The advent of further bioengineering for growing soybean with maize holds only promise for the future of the crop intensification field. The present research studied responses of maize crop and its yield attributes to decrease mineral nitrogen (N) inputs by growing soybean with two maize plant distributions under three cropping systems. Local maize variety T.W.C. 310 was grown under intercropping and sole cultures in one row/ridge in one and two plants/hill spaced at 30 and 60cm, respectively, that received three mineral N fertilizer rates (4, 5 and 6 g N/plant), while local variety of soybean seeds Giza 82 were drilled in two rows/ridge. A split – split – plot design with three replications was used. Light intensity with in maize canopy, ear leaf N and indole acetic acid (IAA) contents were affected by all the studied factors. Mixed pattern increased grain yields per plant and per ha by 1.56 and 3.98 %, respectively, in comparison with sole culture in addition to yielding 1.74 ton/ha of soybean. Increasing number of plants from one to two plants/hill by increasing plant spacing from 30 to 60 cm increased grain yields per plant and per ha. There were no significant differences between the medium and the highest mineral N fertilizer rates for all the studied traits. Soybean improved N use efficiency (NUE) for maize plant of mixed pattern. The mixed pattern had a total yield increase of 29.79 % than sole maize. Growing soybean on both sides of maize ridge that distributed to two plants/hill spaced at 60 cm decreased 47.6 kg N/ha of the recommended mineral N rate of maize plants which formed the best bioengineered treatment under Egyptian conditions.

Influence of tank hydrodynamics on vertical oxygen stratification in flatfish tanks

In sole (Solea spp.) culture, like in other flatfish culture, it is likely that a vertical gradient of dissolved oxygen (DO) occurs with the lower concentrations being at the tank bottom. This lower concentration at the tank bottom is a consequence of fish oxygen consumption and of the presence of the boundary layer. This fact generates lower DO concentrations in the near-bottom zone where soles are lying most of the time. The aim of this work was to study the hydrodynamic conditions that determine the oxygen gradient that occurs in the layer of water adjacent to flatfish.Three flow rates were tested in a circular tank and in a rectangular or raceway tank. For each flow rate, water velocities, boundary layer thickness and Reynolds number were calculated. Results showed that the vertical gradient of dissolved oxygen diminishes when water velocity and Reynolds numbers (Re) increase. At the fish density used in this work (11.6kgm−2), when Re decreased under 6000, a large increase in the DO gradient was observed. Guidelines are presented to determine in which situations, as defined by hydraulic parameters, Re>6000 is achieved and DO stratification avoided.The present work shows that in raceways, the flow rate required to avoid DO stratification is higher than that typically needed to maintain water quality (oxygen, ammonia-nitrogen, carbon dioxide and suspended solids). In circular tanks, it can be easier to achieve velocities that are high enough to avoid stratification with low water inlet flow rates, by adjusting the area of the water entry orifices.

Effect of intercrops on plant growth, lac encrustation and lac yield inFlemingia semialataroxb

A field experiment was conducted for three years (2003-04 to 2005-06) to assess performance of vegetable intercrops on shoot length, lac encrustation (broodlac) length and sticklac yield of Flemingia semialata. Integration of vegetable crops with F. semialata showed significant increase in shoot length for lac insect settlement, lac encrustation length and sticklac yield over sole lac culture at both the planting patterns and vegetable crops schedules. During 2003-04 and 2005-06, the highest increase in sticklac was obtained at paired row planting with vegetable crops Schedule I by 36.38 and 140.85%, respectively, whereas in 2004-05 it was at single row with Schedule II by 62.48% as compared to sole lac culture with same plantation pattern.

Interferências no consórcio de milho com Urochloa spp.

Objetivou-se com este trabalho estudar a inter-relação entre a cultura de milho e cultivares de Urochloa spp. em consórcio, assim como a interferência de plantas daninhas nesses sistemas. O ensaio foi aleatorizado em três blocos em esquema de parcelas subdivididas, sendo as parcelas constituídas por sete sistemas de produção (Urochloa brizantha cv. 'Marandu' e cv. 'Piatã' e U. decumbens cv. 'Basilisk' em cultivo solteiro e em consórcio com o milho e cultivo solteiro de milho) e as subparcelas pelo controle de plantas daninhas (com e sem capina manual). Verificou-se que o estabelecimento dos consórcios de milho com as cultivares de Urochloa spp. não afeta os componentes de rendimento de produção, altura e produtividade do milho, assim como não reduz a comunidade de plantas daninhas, mas interfere na densidade populacional e massa de matéria seca por planta e por área das cultivares de Urochloa spp. Houve níveis de interferência semelhantes das plantas daninhas entre os sistemas de produção sem capina, devido à similaridade entre suas comunidades de plantas daninhas, com predomínio de espécies consideradas altamente competitivas, como Panicum maximum, e à predominância de espécies como Richardia brasiliensis e Ageratum conyzoides, associadas ao controle com capina.

Competition in the Parasitization of Callosobruchus maculatus between Dinarmus basalis and Choetospila elegans on Vigna unguiculata (Walp.) Seeds

<p>Laboratory study was carried out to investigate the efficacy of hymenopteran parasitoids, (<em>Dinarmus basalis</em> and <em>Choetospila elegans)</em> parasitization of <em>Callosobruchus maculatus</em> on cowpea (<em>Vigna unguiculata</em>) seeds in the Department of Crop Science, University of Calabar, Nigeria. Treatments were the inoculation of <em>D. basalis</em> (sole), <em>C. elegans</em> (sole), a mixture of <em>D. basalis</em> and <em>C. elegans</em> into infested cowpea seeds and the control which received no parasitoids. The introduction of parasitoids was repeated at 3 d interval, and all treatments were replicated 3 times. Result indicated that early introduction of the parasitoids caused significantly (P ? 0.05) higher mortality of <em>C.maculatus</em> than late introduction. Mix culture of both parasitoids was significantly more efficacious than sole culture. The emergence of each parasitoid and the mortality of <em>C. maculatus</em> in sole culture showed a highly significant (P ? 0.01) positive relationship (r = 0.487) between <em>C. maculatus</em> and <em>D. basalis</em> but non-significant (P ? 0.05) though positive association (r = 0.289) with <em>C. elegans</em>. A multiple regression analysis between <em>C. maculatus </em>mortality and the emergence of the two parasitoids in mix culture also indicated a highly positive significant (P ? 0.01) relationship (R = 0.751, R<sup>2</sup> = 0.564). Pearson Correlation analysis also showed a significant (P ? 0.05) positive association (r = 0.464, and 0.401) between <em>C. maculatus</em> mortality and emergence of <em>C. elegans</em> and <em>D. basalis</em> in mix culture, respectively. However, a non significant (P ? 0.05) negative relationship (r = -0.336) was observed between the two parasitoids in their emergence in mix culture, but <em>D. basalis</em> contributed more to the mortality of <em>C. maculatus</em> than <em>C. elegans</em>. Data from this study showed that <em>D. basalis</em> and <em>C. elegans</em> have potentials to be deployed as biological control entities in the management of <em>C. maculatus</em> as a part of the integrated pest management strategies of storage pests in the tropics.</p>

Simultaneous Laccase Production and Color Removal by Culturing Fungus Pycnoporus sp. SYBC-L3 in a Textile Wastewater Effluent Supplemented with a Lignocellulosic Waste Phragmites australis

We conducted experiments to culture Pycnoporus sp. SYBC-L3 in a medium comprising an industrial waste (dye-containing textile effluent) and a lignocellulosic waste (Phragmites australis) that achieved laccase production while having the color removed from the wastewater. Our experimental results showed that the fungus grew well in liquid submerged cultivation with the diluted textile effluent as the sole culture medium, but relatively low extracellular laccase activity (1.8 U/mL) was produced. Addition of the lignocellulosic biomass enhanced laccase production and color removal. The highest laccase activity was found to be 6.5 U/mL in the presence of Phragmites australis stem. Under this condition, 70 % color removal occurred in the culture medium. This study provided an alternative novel scheme to remove color in textile wastewater while having an economic value added by producing laccase.

Reduction of Nitrogen and Phosphorus Content in Piggery Water with Algal Culture

Animal waste causes environmental problems like eutrophication of ground and water. The objective of this study was to fix the total nitrogen (TN) and total phosphorus (TP) in swine waste into biomass by investigating the performance of sole and mixed algae species culture with fast growth algae Scenedesmus obliquus and wild algae Chlorella sp. Wastewater concentrations varied from 25 to 100% and initial pH varied from 6 to 9 were conducted. The results indicated that the initial wastewater concentration and pH are crucial to biomass growth and the removing rate of TN and TP. It was found out that the maximum biomass growth rate of 73 mg/l/d was achieved with mixed species culture in 75% piggery wastewater (with TN and TP of 54 and 12 mg/l) with pH 7, meanwhile, the removing rate of TN and TP reached 87.3% and 64.3% with 10 days culture, respectively.

EVALUATION OF SEED YIELD AND COMPETITION INDICES FOR INTERCROPPED BARLEY (HORDEUM VULGARE) AND ANNUAL MEDIC (MEDICAGO SCUTELLATA)

Annual medic is an annual crop which performs well in various forage cropping systems. However availability of medic seeds is a major challenge for livestock producers in Iran. This study was conducted to determine if intercropping annual medic with barley can produce supplement medic seeds while barley grain yield as the main crop is not compromised. Two experiments were carried out at the experimental farm of University of Tehran. In experiment I (2007), a randomized complete block design with eight cropping ratios comprising of 1B:1M (one row of barley: one row of annual medic), 2B:2M, 4B:4M, 6B:6M, 6B:2M, 4B:2M, 2B:4M, and 2B:6M along with sole culture of barley and annual medic was studied. In experiment II (2009 and 2010), four new treatments were added to the intercropping ratios used in experiment I and also weeds were controlled. The overall results as indicated by competition indices including LER, RCC, and MAI revealed that regardless of ratios, the grain yield of barley when intercropped with medic was lowered. The total seed yield of both crops however, was improved in some of the intercropping ratios when compared to the monoculture of either crop. In 2007 where weeds were not controlled, the LER of the cropping ratio of 2H:2M was 1.32 which is an indication of 32 percent yield advantage over the sole cropping of the two crops. When weeds were controlled (2009 and 2010) the intercropping ratio of 6B:2M was the highest and had a LER of 1.29. The yield advantage of intercropping of medic and barley over their monoculture was also confirmed by RCC and MAI indices. The results of this study indicated that although intercropping of annual medic with barley, using 6B:2M replacement series yielded 259 kg ha -1 less grain compared to barley sole cropping but it produced a 365 kg ha -1 annual medic seed which has significantly higher market value than barley.

Evaluation of Sorghum-Cowpea Intercrop Productivity in Savanna Agro-ecology using Competition Indices

The competitive behaviour of sorghum-cowpea intercrops at different planting patterns were studied at the Abubakar Tafawa Balewa University Teaching and Research farm, Bauchi in the northern Guinea savanna of Nigeria during the 2005 and 2006 growing seasons. The treatments comprised of three row arrangements of sorghum/cowpea mixtures; one row of sorghum for one row of cowpea (1S:1C), two rows of sorghum for one row of cowpea (2S:1C) and one row of sorghum for two rows of cowpea (1S:2C), respectively. Sole crops of sorghum and cowpea were included as check to compare yields of intercropped mixtures. Results indicated that grain and straw yields of both sorghum and cowpea were higher in sole cropping than in the intercropping mixtures. However, the 2S:1C planting arrangement exhibited higher LER, competitive indices values, SPI and MAI (N7857.11) compared to the other planting arrangements and the sole crops. From this study, it is inferred that intercropping of sorghum with cowpea at 2S:1C planting pattern will give higher income, better land use efficiency and thus enhancing sustainability of crop production than sole culture of each crop species.

Effects of Intercropping (Canola-Faba Bean) on Density and Diversity of Weeds

In order to evaluate the biological effect and interference of crop and weed in canola-faba bean intercropping in comparison with mono culture, an experiment was conducted in randomize completely blocks design with three replication at Ramin Agriculture and Natural Resources, University. In this experiment treatments were different compositions of canola (Brassica napus L. var. haylo) and faba bean (local cultivar). Plant densities (0, 20 and 40 plants per m2) for canola and four levels include (0, 20, 40 and 60 plants per m2) for faba bean in accordance with additive form mixed culture system respectively. Weed dry weight was affected by culture system and different levels of plant densities in mixed culture and there were significant difference 1%. Lowest weed dry weight was obtained in 20-60 and 40-60 plants m-2 canola-bean intercropping. In the intercropping parts only two species was observed while in the sole culture more than three species were exist. Results showed that with increasing in bean diversity, weed dry weight declines. According to our results, it is possible to control weed effectively by using intercropping system, but more studied is required. Diversity of weeds had been clearly affected. Results showed that only Beta and Malva species were existed in intercropping comparing to sole cultures that Brassica, Beta, Rumex and Malva were existed.

INFLUENCE OF NITROGEN FERTILIZER ON YIELD AND ITS COMPONENTS OF BARLEY AND LUPIN OR CHICKPEA IN SOLELY OR INTERCROPPING PLANTING UNDER THE CONDITIONS OF NEWLY RECLAIMED SOIL.

A field trial conducted on barley, lupin and chickpea crops waspracticed in sand loamy newly reclaimed soil at the experimental farmof the Faculty of Agriculture, Fayoum University, during 2006/07 and2007/08 seasons. This work was designed to study the effect of nitrogenfertilizer rates (15, 30 and 45 kg N/fed.) on the three crops grown as soleand intercropping (barley/chickpea and barley/lupin). A split split-plotarrangement in randomized complete block design with threereplications was used. The obtained results showed that, compared withthe barley/chickpea pattern, monocrop chickpea had significantlyimproved yielding and quality traits. Whereas, intercropping had higherseed index. Fertilization with 45% N (N3) led to increases in vegetativeand reproductive and consequently seed yield/fed. However, similarmeans of height to first branch and seed index were obtained fromapplication of 30 kg N/fed. (N2) which produced the highest harvestindex. Compared with monocrop culture, barley/lupin intercroppingresulted in significant increases of lupin height traits in addition itssuperiority for number of branches and seed index but with inferior seedweight/plant. The heaviest weight of seeds/plant and yield/fed. wereobtained from soled lupin. Nitrogen application results revealed theadequacy of N3 for lupin where it produced acceptable seed yield/fed.due to its superior number of pods and harvest index. Except seed andharvest indices all barley traits were significantly affected byintercropping in favour to soled culture. Intercropping barley producedmore than half yield/fed. Compared with solid culture. Nitrogenfertilization indicated the suitability of N2 (30 kg N/fed.) for producingimproved yield insignificantly different from that of N3. Under croppingpatterns with N2 fertilizer dose, the second yielding combinations werebarley/chickpea (12.18 ard) and then barley/lupin (11.08 ard) whichrepresented 61 and 55% of yield of soled barley fertilized with N3.These results indicating that chickpea was of better effect than lupin onbarley yielding ability and fertilization with the intermediate nitrogendose (N2) was quite enough for intercropping. Also, with N2barley/chickpea and barley/lupin yielded 49% chickpea together with61% barley with LER of 1.15 as well as 46% lupin together with 55%barley with LER 1.21, respectively, compared with sole culture of eachcrop. These two intercropping –N2 combinations increased totalproduction by 15% and 21% respectively.

Preference of cultured sole (Solea senegalensis) for different substrates differing in material, texture and colour

Sole (Solea solea and Solea senegalensis) culture has been intensely investigated but their special benthonic and nocturnal habits still pose specific challenges to develop appropriate husbandry methods. In nature sole remain buried in the sand, but in culture the use of sand as a substrate has been considered a serious obstacle for hygienic conditions. In the present work different materials, plastic and concrete, are evaluated compared with sand, using different textures and colours. The methodology used relies on the fish itself for the assessment of preference. Images of tagged fish that could freely choose between different substrates are taken continuously during 72h and further analyzed to assess frequency of preference and immobility time in each substrate. Promisingly sole showed a similar frequency of preference for sand and plastic, when plastic is dark and rough, but there seems to be still a lack of comfort in the plastic substrate since the fish do not remain immobile in it. There is not a clear hierarchy between colour and texture as far as preference is concerned. Sole seem to prefer light sand whatever the texture, and rough plastic whatever the colour, so the preference should be assessed for each specific combination. Results obtained with concrete do not permit to conclude a special preference. Further experiments should be developed to improve the texture of plastic and thus increase immobility and to assess the long-term consequences on growth, stress and health.

Radical Reform

Tariq Ramadan’s latest book, Radical Reform: Islamic Ethics and Liberation,consists of sixteen chapters divided into four major sections: “OnReform,” “ClassicalApproaches of the Fundamentals of Law and Jurisprudence,”“For a New Geography of the Sources of Law and Jurisprudence,”and “Case Studies.”The author commences by criticizing the process of ijtihad as it currentlyexists. Although it made things progress for centuries, he finds thatijtihad is highly inadequate, has not resolved the crises faced by Muslims,and has not produced the expected renewal. As far as taqlid is concerned,Ramadan argues that imitating past scholars makes Muslims believe thatthey can avoid today’s challenges by taking refuge in the past. Ijtihad, hebelieves, has always been behind the times, simply seeking to interpretIslamic law in light of new changes and developments in society. He is criticalof literalist, traditionalist, conservative, and culturally based interpretationsof Islam. Arab culture, he points out, is not Islam’s sole culture. Thusif Islam is truly a universal religion, it must provide its followers with themeans to approach cultural diversity.The author provides an intelligent criticism of Salafism, which confuseseternal principals with historical models and thereby reduces Islam’s universalityto the dream of an impossible return to the past and an irresponsible“nostalgia of origins.”As he points out, many Salafi reductionists cannot distinguishbetween religion and culture and therefore view diversity and socioculturalevolution as religious innovations. Not only is he critical of mosttraditional approaches to ijtihad, he is critical of virtually every Islamicmovement when it comes to their methods of implementing Islamic law ...

TRAP CROPPING AND INTERCROPPING OF PIGEONPEA (CAJANUS CAJAN L. MILLSP.) IN PEST MANAGEMENT OF COWPEA (VIGNA UNGUICULATA L. WALP.) IN SOUTHERN BENIN : COMPETING RISK AND PEST STATUS IN POD ATTACK

In the present study, five treatments arranged in a Randomized Complete Block Design with four replications were considered : sole culture of cowpea (T1); cowpea plot surrounded by pigeonpea culture (T2); alternate row intercropping of cowpea and pigeonpea (T3); intercropping of two cowpea rows for one pigeonpea row (T4) and intercropping of one cowpea row for two pigeonpea rows (T5). Only Treatments T1, T2 and T4 were followed up to the end of the experiment because of the unexpected agronomical interactions in treatments T3 and T5. The study is therefore based ontreatments T1, T2 and T4. Larval population densities of Maruca vitrata (Fabricius) (Lepidoptera, Pyralidae) were relatively low as well on cowpea pods as on those of pigeonpea. Concerning the pod sucking bugs (PSB) (Heteroptera), none of them was found on cowpea pod during the experiment whereas they were present on pigeonpea pods. The population distribution of these bugs was bimodal showing two periods of relative abundance with a succession of low and high population densities in T2 and T4. As well on cowpea in T1 as on pigeonpea and cowpea in both T2 and T4, highest attacks of M. vitrata were registered on pod stages II and III. Thus pigeonpea functioned as an excellent trap crop for the heteropteran species in pest management of cowpea. Thepods of stage I were green without visible seeds; in the stage II, pods were green with visible seeds; the pods of stage III were yellowish and in the stage IV, pods were dry

Dietary lipid level affects growth performance and nutrient utilisation of Senegalese sole (Solea senegalensis) juveniles

Over the last few years, several aspects of Senegalese sole (Solea senegalensis) culture have been developed and optimised but the dietary lipid level for optimal growth has never been determined. Hence, five isonitrogenous diets (56 % dietary protein) with increasing dietary lipid levels (4, 8, 12, 16 and 20 % DM) were fed to satiation to triplicate groups of twenty fish (mean initial weight 10 g). Fifteen tanks were randomly assigned one of the five diets. Feed was distributed using automatic feeders, and fish were fed over a 16-week period. At the end of the experiment the fish fed on diets containing the two lowest dietary lipid levels (4 and 8 %) showed a 3-fold body-weight increase with a significantly higher daily growth index than fish fed higher lipid levels (1.2 v. 0.8). Moreover, these fish displayed a significantly lower dry feed intake (12 g/kg per d) and feed conversion ratio (1.0) compared with fish fed higher lipids levels (16-19 g/kg per d; feed conversion ratio 2.0). Low dietary lipid levels ( < 12 %) significantly improved nutrient retention and gain and hence growth, without major effects on whole-body composition. Despite the slight alteration in n-3 PUFA muscle content in the fish fed low-fat-diets, this fish fed low dietary lipid still remains a rich n-3 PUFA product and generally maintained its nutritional value. These results evidenced a low lipid tolerance of Senegalese sole juveniles and suggest a maximal dietary inclusion level of 8 % lipids for both optimal growth and nutrient utilisation without compromising flesh quality.