Sole Cultures Research Articles

Biological Nitrogen Fixation of Cowpea in a No-Till Intercrop under Contrasting Rainfed Agro-Ecological Environments

Nitrogen (N) availability under no-till intercropping systems has not been widely investigated in diverse agro-ecological regions in Limpopo Province. Two seasons of rainfed experiments were conducted during 2018/19 and 2020/21 in a 2 × 4 × 2 factorial design to measure the biological nitrogen fixation (BNF) ability of cowpea in an intercropping system with four grain sorghum cultivars at two test locations, Ofcolaco and Syferkuil, of Limpopo Province using the natural abundance technique. The cowpea nitrogen isotope composition (δ 15N‰) ranged from 0.2 ‰ to 4‰ at Ofcolaco, whereas at Syferkuil, the range was 2 ‰ to 7 ‰. The N derived from air (Ndfa) was from 35% to 92% at Ofcolaco and 4% to 70% at Syferkuil during the two cropping seasons. The amount of N2 fixed across locations and seasons ranged from 1 kg ha−1 to 71 kg ha−1. In the intercropping system, cowpea fixed more N at higher densities compared with lower densities at the two experimental sites. Biomass was significantly correlated with N accumulated by cowpea (r2 > 0.9) at all locations and across seasons. N accumulated in sole cultures was 30% more at Ofcolaco and 36% more at Syferkuil compared with binary cultures. Furthermore, the treatment combination, cowpea density, as well as cropping system, significantly affected N fixation and accumulation. For high productivity, cowpea intercrop with grain sorghum cultivar Enforcer is recommended, as both crops complemented each other when intercropped. The research should investigate further the root distribution and biomass production of sorghum and cowpea, as well as their impact on N intake.

Yield Responses of Grain Sorghum and Cowpea in Binary and Sole Cultures under No-Tillage Conditions in Limpopo Province

Climate change is severely disrupting ecosystem services and crop productivity, resulting in lower crop growth and yields. Studies have emphasized the importance of assessing conservation practices through crop modelling to improve cropland productivity. There is a lack of accurate information in the performance of conservation practices as well as data for improved crop modelling. No-tillage sorghum–cowpea intercrop experiments were established to assess the productivity of four sorghum cultivars and cowpea at two densities of 37,037 and 74,074 per plants and generate data for improved crop modelling. The leaf area index (LAI) varied in sorghum cultivars and cowpea densities during the two growing seasons. Cultivars Enforcer and NS5511 produced the highest grain yields of 4338 kg per ha and 2120 kg per ha, respectively, at Syferkuil. Ofcolaco’s Enforcer and Avenger were the highest yielding cultivars at Ofcolaco, with mean yields of 2625 kg per ha and 1191 kg per ha, respectively. At Syferkuil, cowpea yield was 93% and 77% more in sole compared to binary cultures during the growing seasons at Syferkuil. At Ofcolaco, sole yielded approximately 96% more grain than binary. The findings confirm that for the sorghum–cowpea intercrop to improve overall system productivity, cowpea density should be increased.

Forage potential of sorghum-clover intercropping systems in semi-arid conditions

ABSTRACT To identify the optimum intercropping system of sorghum and clover in terms of quantity and quality of forage yield, a two-year experiment was conducted in a semi-arid region of Iran, during the 2016 and 2017 growing seasons. Treatments consisted of eight cropping systems: S75C25 (75% sorghum + 25% clover), S50C50 and S25C75, as replacement series; S100C50, S50C100, and S100C100 as additive series; and sole cultures of sorghum and clover. The highest and lowest dry matter (DM) yield (29.17 and 10.71 Mg·ha-1) were found in the S100C100 and clover monoculture systems, respectively. Although the highest content of crude protein (CP) and digestible dry matter (DDM) were recorded from clover monoculture, the maximum yield of CP and DDM were obtained from the S100C100. Increasing the proportion of clover in intercropping decreased the acid detergent fiber and neutral detergent fiber, increased the relative feed value, net energy for lactation and dry matter intake. Increasing the proportion of sorghum in intercropping improved the yield of DM, CP and DDM. The land equivalent ratio for DM yield was higher than one in all intercropping treatments but were significantly higher in the additive intercropping systems. Overall, it could be concluded that sorghum and clover additive intercropping systems increased forage yield and quality, however if simultaneous increase of the quantity and quality of forage is the interest of this study then the S100C100 system had a significant advantage over other treatments and can be a suitable alternative for sorghum and clover monoculture systems in semi-arid regions.

KOJIC ACID PRODUCTION USING MIXED CULTURES OF ASPERGILLUS ORYZAE AND ASPERGILLUS TAMARII

Objective: This study aimed to find the optimum kojic acid fermentation conditions using combination cultures of Aspergillus oryzae and Aspergillustamarii.Methods: Screening of the best mixed cultures was performed using yeast extract medium with 5% (w/v) glucose. Fermentation conditionswere optimized by varying carbon and nitrogen sources, pH of medium, inoculum ratio, and aeration. Aeration was varied using 50 and 100 mLof medium in 100 and 250 mL Erlenmeyer flasks, respectively. Kojic acid was analyzed using thin-layer chromatography-densitometry and UV-Visspectrophotometry.Results: Kojic acid produced from mixed cultures yielded 0.1396 gg−1, while sole cultures of A. oryzae and A. tamarii yielded 0.0329 gg−1 and0.1001 gg−1, respectively. Of the nine fermentation mediums, the best carbon and nitrogen sources were sucrose and yeast extract. From the threevariations of pH, pH 3.5 was the optimum pH value. From the three ratios of inoculum concentration, a ratio of 2:3 (A. oryzae:A. tamarii) was the bestratio. Aeration was varied using 50 and 100 mL of medium in 100 and 250 mL Erlenmeyer flasks, respectively. Aeration of 100 mL medium in 250 mLErlenmeyer flask was selected as the best aeration that produced 6.559 g/L kojic acid.Conclusion: The highest concentration of kojic acid was obtained by mixing cultures of A. oryzae and A. tamarii in a ratio of 2:3, using sucrose andyeast extract as the substrates at pH 3.5 and semiaerobic condition.

The Ingenious Interactions Between Macrophages and Functionally Plastic Retinal Pigment Epithelium Cells.

The purpose of this study was to clarify the interactions between macrophages (MPs) and RPE cells in coculture systems to investigate the functional plasticity of RPE cells. Adherent peritoneal cells or murine MP cell line Raw 264.7 was cocultured with primary RPE cells taken from C57BL/6 mice, with or without lipopolysaccharide (LPS) or TNF-α stimulation. The cytokine levels of the culture supernatants (CSs) were then analyzed with the Bio-Plex murine 23-Plex Panel Assay Kit (Bio-Rad Laboratories). Monocyte chemoattractant protein-1 (MCP-1), IL-6, VEGF, and TNF-α in CS were further quantified by ELISA. The expression profiles, in cocultures, of complement-associated genes, TNF-α, and angiogenesis-associated genes were analyzed by quantitative real-time PCR. The production of MCP-1, IL-6, and VEGF was synergistically elevated when primary MPs or RAW264.7 cells and RPE cells were cocultured compared with those derived from sole cultures of MPs and RPE cells. The synergistic effect was confirmed without direct cell contact and was more prominent in the presence of LPS or TNF-α. TNF-α production by MPs was suppressed by RPE cells. Coculture of RPE cells with RAW264.7 cells increased the gene expression of C3, CFB, and VEGF genes, whereas it reduced those of complement regulatory factors CFH, CD59, clusterin, and TNF-α and antiangiogenic pigment epithelium-derived factor (PEDF). Our findings indicate the presence of ingenious interactions between MPs and RPE cells that forces the inflammation and complement activation in the vicinity of RPE cells under pathologic conditions.

Influences of Some Preceding Winter Crops and Nitrogen Fertilizer Rates on Yield and Quality of Intercropped Maize with Cowpea

A field study was conducted in Mallawi Agricultural Experiments and Research Station, Agricultural Research Center (ARC), El-Minia governorate, Egypt to decrease mineral nitrogen (N) inputs of maize with good yield quality and increase farmers' benefit. Local maize cultivar T.W.C. 310 was grown under intercropping and sole cultures in one row/ridge that received three mineral N fertilizer rates (75, 87.5 and 100% of the recommended N rate of maize), while local cultivar of cowpea seeds Keraim ‐ 1 were drilled in one row and two rows/ridge under intercropping and sole cultures, respectively. A split split plot design with three replicates was used. Quality of maize grains was tested in the laboratories of Seed Technology Research Department, Field Crops Research Original Research Article

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.

Evolution of Leaching Products on the Surface of Chalcopyrite by Mesophiles and Thermophiles Based on SR-XRD and XANES Spectroscopy

The bioleaching experiments of chalcopyrite were conducted with single and mixed mesophiles (30 °C) and moderate thermophiles (45 °C) and extreme thermophile (65 °C), respectively, and analyzed by synchrotron radiation (SR) based X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES) spectroscopy. The results showed that the copper extraction of chalcopyrite could be significantly promoted by bioleaching microorganisms, and the promotion effects for both the mixed cultures grown at different temperature and the different cells grown at the same temperature were significantly different. The surface of chalcopyrite after bioleached by the mixed or sole cultures are serious corroded and became complicated. More S0 was found to form in the sole cultures of specific iron-oxidizing microorganism L. ferrooxidans and L. ferriphilum and sulfur-oxidizing microorganisms A. thiooxidans and A. caldus cultures. Jarosite and secondary minerals (chalcocite and covellite) were detected for the mixed cultures and sole cultures of iron/sulfur-oxidizing microorganisms. The evolution of chalcocite and covellite were just relevant to the potential of leaching solution, no matter which cultures were used, where chalcocite could be formed at Eh value less than 500 mV and then converted to covellite at Eh value ~550 mV.

Identification of Vibrio harveyi proteins involved in the specific immune response of Senegalese sole (Solea senegalensis, Kaup).

Senegalese sole cultures are frequently affected by Vibrio harveyi disease outbreaks. Vaccines in aquaculture are one of the most successful methods of preventing fish pathologies; however, these vaccines are usually composed of inactivated whole cells containing a wide pool of antigens, and some do not induce any protection against pathogens. Thus, the aim of this study was to identify immunogenic proteins of V. harveyi involved in the specific antibody production by Senegalese sole. S. senegalensis specimens were immunized, by intraperitoneal injection, with V. harveyi bacterin supplemented with inactivated extracellular polymeric substances (ECP) and Freund incomplete adjuvant to obtain polyclonal antiserum. One month later, specimens were re-inoculated with the same antigens. Sera from immunized fish were collected two months post first immunization. Strong specific immune response to V. harveyi antigens was detected by ELISA using bacterin (limit dilutions of sera were 1:64000), ECP (1:4000) and outer membrane proteins (OMP) (1:4000) as antigens. Presence of immunogenic proteins in V. harveyi ECP and OMP were determined by 2D-PAGE. For Western Blot analysis some gels were transferred onto nitrocellulose membranes and incubated with sera from S. senegalensis specimens immunized against V. harveyi. 2D-PAGE and Western Blot showed at least five reactive proteins in the ECP and two in the OMP fraction. The spots that clearly reacted with the sole antiserum were excised from stained gel, and analyzed by mass spectrometry (MALDI/TOFTOF). A database search was then performed, using MASCOT as the search method. According to the results, the five ECP spots were identified as Maltoporine, protein homologous to Metal dependent phosphohydrolase, two porins isoforms of V. harveyi and a protein homologous to the cell division protein FtsH. Reactive proteins in the OMP fraction were identified as the protein 3-hydroxyisobutyrate dehydrogenase and a protein homologous to acid phosphatase.

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.

First Isolation and Characterization of Tenacibaculum soleae from Sea Bass Dicentrarchus labrax

Tenacibaculum soleae is a recently described pathogen that has been reported as the causative agent of considerable losses in sole cultures in Spain. This report documents the first case of T. soleae as an etiological agent of tenacibaculosis in farmed sea bass Dicentrarchus labrax. Its identification was performed employing phenotypical, serological and molecular methods. Although the sea bass isolates were homogeneous from a biochemical, chemotaxonomic and molecular point of view, they belonged to a serological group different from the type strain CECT7292, which can be of great importance in the development of future vaccines and other methods of disease prevention in sea bass industry. Virulence assays with a representative isolate confirmed the pathogenic potential for sea bass. The disease was experimentally reproduced by prolonged bath, while no mortalities could be recorded by intraperitoneal injection. The results presented here show that T. soleae must be taken into account as an important pathogen in the marine aquaculture industry.

Forage yield, quality and economic benefit of intercropped barley and annual medic in semi-arid conditions: Additive series

Production of high-yielding quality forage remains a challenge in arid and semi-arid conditions. Cereal–legume mixture may be a viable option to improve forage yield and increase on-farm protein production. A two-year experiment was conducted in 2009 and 2010 to determine if mixtures of barley (Hordeum vulgare L.) and annual medic (Medicago scutellata L.) could increase forage quality and forage dry matter. A randomized complete block design with two additive intercropping systems (100B:20M) (100% of barley pure stand seeding rate with 20% of annual medic pure stand seeding rate) and (100B:40M) with sole cultures of barley and annual medic. Total dry matter yield produced by intercrops averaged 3385kgha−1 and was similar to that of barley sole crop (3590kgha−1). The land equivalent ratio was highest (1.07) when barley was intercropped with annual medic in the 100B:40M intercrop indicating that 7% more area would be required by a sole cropping system to produce a similar yield. Based on results from LER, relative crowding coefficient (RCC) and monetary advantage index (MAI), it was concluded that 100B:40M was superior to either barley or annual medic monocropping. The highest protein yield (893kgha−1) was obtained from the 100B:40M intercrop. When both forage yield and quality were considered, the 100B:40M intercropping system was superior and could be recommended as an alternative to barley alone.

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.

Grain yield response and Chilo partellus infestation in diverse sorghum-cowpea intercrop arrangements

Yield improvement and insect pest control in intercropping systems relative to sole cultures has been variable and inconsistent over habitats, component species, varieties, density, row arrangement, soil fertility and moisture. This study was initiated to quantify yield response of two sorghum varieties (Macia and SV-2) and a cowpea variety, PAN311 to different crop arrangements and to assess the level of Chilo partellus infestation in sorghum in the intercropping system. Superior intercropped sorghum yield was obtained when component crops were arranged in alternate rows at a 0.90 m spacing whereas cow- pea yields were similar to or lower than sole crop yield in the different component crop arrangements. The overall land use efficiency, assessed by the land equivalent ratio (LER), was improved by an average of 11% with intercropping at a row spacing of 0.90 m. However, no yield benefit was observed when crops were arranged in an alternate row pattern at a narrow row spacing of 0.45 m. Intercropping reduced C. partellus infestation in mixed and alternate intercropping systems, relative to the sole cultures.

Effect of substrates on the malonate inhibitory pattern and brefeldin A formation in Curvularia lunata.

The extracellular level of brefeldin A fluctuates with the length of malonate inhibition. Following treatment with malonate, mycelial multiplication as opposed to brefeldin A formation, was preferentially increased in the maleate, fumarate, succinate, citrate, methyl palmitate and glucose replacement cultures. Competitive maleate--malonate, fumarate--malonate, succinate--malonate and citrate--malonate-inhibited replacement cultures gave significantly higher mycelial and brefeldin A yields than the sole malonate-inhibited replacement cultures.