Sole Culture Research Articles

Deployment of fine and coarse grain rice cultivars in time and space for increased productivity

To examine the impact of mixture ratio and temporal deployment of fine and coarse grain cultivars on rice productivity and profitability, two experiments were carried out at Bangladesh Agricultural University. In both investigations, two monsoon rice cultivars viz., Binadhan-13 (a tall, late-maturing, fine-grained) and Dhani Gold (a semi-dwarf, mid-maturing, coarse-grained) were utilized. In the 1st experiment, rice cultivars were planted in different mixture ratios viz., sole Binadhan-13, sole Dhani Gold, 1:1, 2:3, 3:2, 2:4 and 4:2 ratio of Binadhan-13 to Dhani Gold. The second study included the introducing time of Dhani Gold viz., seven days before or after or same day of Binadhan-13, sole Binadhan-13 and sole Dhani Gold. Three replications of the randomized complete block design were used for both trials. In the first experiment, both cultivars produced more when grown in mixtures as opposed to solitary cultures. Even though Dhani Gold's sole culture had the greatest yield, it was statistically equivalent to combined yields when Binadhan-13 and Dhani Gold were grown together in mixtures at 2:1, 3:1, or 4:1 ratios. The maximum net return and benefit cost ratio (BCR) were achieved when Binadhan-13 and Dhani Gold were planted in mixture following a 4:2 ratio as opposed to when Binadhan-13 was grown solely. In the second experiment, a sole cultivar generated less yield than cultivars that were transplanted on the same day, before, and after another cultivar. Cultivation of sole Binadhan-13 produced the lowest net return and minimum BCR (1.37), while the highest net return and BCR (1.81) was recorded when Dhani Gold was planted seven days before Binadhan-13 in mixture. A clear economic advantage of mixed culture with temporal deployment over the sole culture of either cultivar was evident. Therefore, transplanting Dhani Gold in a 1:1 ratio seven days before Binadhan-13 may be advised for greater output and economic return.

Trap crop selection and economic threshold based ecological management of Spilosoma obliqua Walker (Lepidoptera, Arctiidae) for sesame

The stage-specific life table and nutritional ecology of a Spilarctia obliqua (Walker) along with respective economic thresholds (ETs) on four different crops such as sesame (Sesamum indicum), castor (Ricinus communis), jute (Corchorus capsularis) and sunflower (Helianthus annuus) were studied during 2020-2022. The feeding and population dynamics of S. obliqua were significantly affected by the hosts in terms of host suitability or susceptibility (sunflower>jute>castor>sesame). The ET of S. obliqua on sesame (40.59±2.12 pests m-2 area) was significantly (F3,8=4.72, P=0.031) higher than the other crops (sunflower<jute<castor). Subsequently, the three most suitable hosts (sunflower> jute>castor) were tested in a multi trap cropping system for sesame as main crop in a specific pattern depending on respective susceptibility. Data from the model trap cropping (without pesticide) supported minimum infestation of S. obliqua and other pests along with more predators on sesame with higher benefit cost ratio (BCR) and more (11.82%) carbon sequestration (CS) in same area relative to monoculture (with pesticide) of sesame. It supports pesticide free high production and better CS than sole culture of sesame for climate smart agriculture.

Production efficiency and properties of bacterial cellulose membranes in a novel grape pomace hydrolysate by Komagataeibacter melomenusus AV436T and Komagataeibacter xylinus LMG 1518

The microbial production of cellulose using different bacterial species has been extensively examined for various industrial applications. However, the cost-effectiveness of all these biotechnological processes is strongly related to the culture medium for bacterial cellulose (BC) production. Herein, we examined a simple and modified procedure for preparing grape pomace (GP) hydrolysate, without enzymatic treatment, as a sole growth medium for BC production by acetic acid bacteria (AAB). The central composite design (CCD) was used to optimise the GP hydrolysate preparation toward the highest reducing sugar contents (10.4 g/L) and minimal phenolic contents (4.8 g/L). The experimental screening of 4 differently prepared hydrolysates and 20 AAB strains identified the recently described species Komagataeibacter melomenusus AV436T as the most efficient BC producer (up to 1.24 g/L dry BC membrane), followed by Komagataeibacter xylinus LMG 1518 (up to 0.98 g/L dry BC membrane). The membranes were synthesized in only 4 days of bacteria culturing, 1 st day with shaking, followed by 3 days of static incubation. The produced BC membranes in GP-hydrolysates showed, in comparison to the membranes made in a complex RAE medium 34 % reduction of crystallinity index with the presence of diverse cellulose allomorphs, presence of GP-related components within the BC network responsible for the increase of hydrophobicity, the reduction of thermal stability and 48.75 %, 13.6 % and 43 % lower tensile strength, tensile modulus, and elongation, respectively. Here presented study is the first report on utilising a GP-hydrolysate without enzymatic treatment as a sole culture medium for efficient BC production by AAB, with recently described species Komagataeibacter melomenusus AV436T as the most efficient producer in this type of food-waste material. The scale-up protocol of the scheme presented here will be needed for the cost-optimisation of BC production at the industrial levels.

Interaction of Cropping Pattern and Fertility Treatments on Yield and Sustainability of Mixed Cropping System under Moisture Regime

The farmers in most regions of Pakistan are heavily reliant on traditional farming approaches all year round and tend to cultivate exhaustive crops like wheat, cotton, maize, and sugarcane in most areas of the country. Consistently adopting this system leads to depleting the soil fertility status, which they overcome by instigating an uneconomical way of using excessive chemical fertilizers to maximize crop yields. These fertilizers are truly acidic and adversely affect soil health. Adopting sustainable farming approaches by the incorporation of legumes into the farming system with an integrated nutrient supply restores soil fertility and maintains the sustainability of the agro-ecosystem. A field experiment was performed to determine the significance of the integrated source of nutrient management on the growth and yield of sole and mixed cultures of sorghum and mungbean crops in areas with moisture regimes. The fertility treatments applied to the sole and intercrops of sorghum and mung-bean in a given sequence; i) Control, ii) Compost @ 10 t/ha, iii) FYM @ 20 t/ha, iv) NP @ 40 kg N + 30 kg P2O5 ha-1, v) ½ of recommended Compost @ 5 t/ha + ½ of recommended NP @ 20 kg N & 15 kg P2O5 ha-1, vi) ½ of recommended FYM @ 10 t/ha + ½ of recommended NP @ 20 kg N & 15 kg P2O5 ha-1. The sole crop of mungbean gave a maximum grain yield of 2229.1 kg/ha over an intercrop of 1779.7 kg/ha. Similarly, the highest grain yield of 2779.8 kg/ha of sorghum was obtained in sole culture over its intercrop of 2150.9 kg/ha. The interaction effect of cropping pattern and fertility treatments showed that sorghum and mungbean gave significant results for growth and yield parameters where a combined dose of organic & mineral fertilizers were provided in comparison to the plots where these fertilizers were applied in split doses.

Influence of Skin Commensals on Therapeutic Outcomes of Surgically Debrided Diabetic Foot Infections-A Large Retrospective Comparative Study.

In diabetic foot infections (DFI), the clinical virulence of skin commensals are generally presumed to be low. In this single-center study, we divided the wound isolates into two groups: skin commensals (coagulase-negative staphylococci, micrococci, corynebacteria, cutibacteria) and pathogenic pathogens, and followed the patients for ≥ 6 months. In this retrospective study among 1018 DFI episodes (392 [39%] with osteomyelitis), we identified skin commensals as the sole culture isolates (without accompanying pathogenic pathogens) in 54 cases (5%). After treatment (antibiotic therapy [median of 20 days], hyperbaric oxygen in 98 cases [10%]), 251 episodes (25%) were clinical failures. Group comparisons between those growing only skin commensals and controls found no difference in clinical failure (17% vs. 24 %, p = 0.23) or microbiological recurrence (11% vs. 17 %, p = 0.23). The skin commensals were mostly treated with non-beta-lactam oral antibiotics. In multivariate logistic regression analysis, the isolation of only skin commensals was not associated with failure (odds ratio 0.4, 95% confidence interval 0.1-3.8). Clinicians might wish to consider these isolates as potential pathogens when selecting a targeted antibiotic regimen, which may also be based on oral non-beta-lactam antibiotic agents effective against the corresponding skin pathogens.

Agro-economical Evaluation for Intercropping Sugar Beet and Barley under Combinations of Barley Cutting and Nitrogen Level Treatments

This study was conducted to investigate the agro-economic effect of intercropping sugar beet and barley under combinations of barley cutting and Nitrogen levels. Field trials conducted using a split plot design with three replications at the Farm of Gemmeiza Agricultural Research Station, Egypt during 2018/2019 and 2019/2020 seasons. Sugar beet planted on both sides of the bed and barley plant on the top of all beds at the rate of 25%of the sole culture. Sugar beet with companion barley under three cut treatments (no cut, cut before heading (C1) and cut after heading (C2)) and three nitrogen fertilization levels (80, 100 and 120kgN/feddan (feddan=4200m2)) were studied, as well as to study competitive relationships land equivalent ratio (LER). Results from this study revealed that cut and nitrogen treatments had significant (0.05%) effects on most traits of sugar beet and barley in both seasons. Significant cuts*N interaction effects were found for sugar beet and barley traits in both seasons. LER. were greater than unit (1.15 and 1.16) by intercropping sugar beet with barley under N fertilizer rate 120kg N/feddan with both no cut and C1. The effect of cuts and nitrogen interaction on LER across the two seasons increase the land usage. The highest yield advantage for RCC (89.49 and 73.54) was recorded with C1 at 120Kg N/feddan in both seasons respectively, indicating the effect of barley cuts and N fertilizer rates on yield and aggressivity (AG) values of sugar beet and barely. The highest values Total income (L.E.), Net return and economic return (L.E.) obtained from sugar beet under 120kgN rate * no cut or C1 treatments in both seasons. Agro-economically biplot graph recommended that intercropping barley with sugar beet under 120kg N rate * no cut or C1 drive the maximum values of productivity of sugar beet and competitive relationships and yield of both crops.

Innovative application of brackish groundwater without the addition of nutrients in the cultivation of Spirulina and Chlorella for carbohydrate and lipid production

Brackish groundwater is promising for the cultivation of economically important microalgae; however, its effects have been evaluated only after nutrient supplementation. In this study, 100% brackish groundwater was evaluated as a culture medium for Spirulina sp. (BGWS) and Chlorella fusca (BGWC). In addition, the effects of supplementation with 25% of the nutrients from Zarrouk (BGWS25) and BG-11 (BGWC25) culture media were evaluated. BGWS and BGWC increased the concentration (68.1% w w−1) and productivity of carbohydrate (35.3 mg L−1 d−1) in Spirulina sp. and increased the concentration (56.4% w w−1) and productivity (13.5 mg L−1 d−1) of lipids in C. fusca biomass, when compared to that in the respective controls. The use of brackish groundwater as the sole culture medium is an innovative alternative for the economic production of biomass rich in carbohydrates and lipids. This has potential applications for biofuel production.

Fusarium wilt and Southern Blight Diseases of Tomatoes: Trichoderma spp. as Antagonists of the Causative Organisms

Fusarium wilt ( Fusarium oxysporum f. sp . lycopersici ) and southern blight ( Sclerotium rolfsii ) are two of the soil borne diseases limiting tomato cultivation globally and are difficult to manage. This study evaluated biocontrol agents, Trichoderma harzianum and T. viride for antagonistic efficacy against these pathogens in vitro . The dual culture technique was adopted using two approaches; namely, pre-inoculation of Trichoderma spp. into culture medium at 24 and 48 hours ahead of the pathogen and simultaneous inoculation of Trichoderma spp. and pathogen. The Trichoderma spp. were evaluated singly against each pathogen. The sole culture of each pathogen was the control. Each treatment was replicated thrice and laid out in a completely randomized design. Inoculated Petri plates were incubated at 27 o C ± 2 o C. Data collected were subjected to statistical analysis and mean separation using Minitab software. Results showed that the inhibition of the mycelial growth of both pathogens by the biocontrol agents were days dependent. Furthermore, prophylactic evaluations gave significantly higher inhibition of the mycelial growth of the pathogens as against therapeutic evaluation. Additionally, F. oxysporum was more susceptible to antagonism by both biocontrol agents as higher percentages of mycelial growth inhibition were recorded for it in all treatments. Finally, T. harzianum was a better antagonist of the two pathogens, recording 84.62% and 69.01% inhibition of mycelial growth of F. oxysporum and S. rolfsii, respectively at 9 days after inoculation. Trichoderma spp . maybe exploited as biocontrol agents for the management of these pathogens.

Evaluation of Essential Oil Yield and Ecological Indices in the Intercropping of thyme (Thymus vulgaris L.) and soybean (Glycine max L.) with Application of Arbuscular Mycorrhizal Fungus

AbstractBackground and Objectives :In order to using sustainable agricultural methods and entering new species for increasing biodiversity, a field experiment performed to evaluate the effect of thyme (Thymus vulgaris L.) and soybean (Glycine max L.) with application of biofertilizer on the essential oil productivity, essential oil yield and ecological indices. Material and Methods: A field experiment was carried out as split split plot based on the randomized complete blocks design (RCBD) with 12 treatments and three replication at the faculty of Agriculture, University of Maragheh during 2019 growing season. The main factor was different planting patterns including thyme sole culture, soybean sole culture, intercropping of one row soybean+ one row thyme (1:1) and intercropping of two rows of soybean+ one row thyme (2:1). The sub plot and sub- sub plot factor were inoculation and non-inoculation of arbuscular mycorrhizal fungus and harvest time (first harvest and second harvest), respectively. Results: The results demonstrated that the highest dry yield of thyme (634.5 g.m-2) was achieved in the sole culture of plants with application of AMF. Also, the highest essential oil yield of thyme (9.45 g.m-2) was observed in the first harvest and intercropping ratio of 1:1. In addition, the essential oil yield and essential oil yield of thyme with AMF inoculation increased by 30.86 and 11.95% compared with control. Moreover, the highest ecological indices (LER, AHER, ATER and LUE) and monetary indices (IA, MAI and SPI) were achieved in the intercropping ratio of 1:1 with AMF application. Conclusion: The intercropping ratio of 1 row soybean+ 1 row thyme along with biofertilizer could be suggested to farmers for enhancing economic income and land use efficiency.

Comprehensive CircRNA Profiling and Selection of Key CircRNAs Reveal the Potential Regulatory Roles of CircRNAs throughout Ovarian Development and Maturation in Cynoglossus semilaevis.

Simple SummaryCircRNAs: as molecules involved in gene regulation, have become a new research hotspot in the non-coding RNA field. CircRNAs show tissue- or developmental stage-specific patterns of expression and can influence the expression levels of their parental genes. Recent studies have documented the potential biological roles of circRNAs in the growth, development, reproduction and health of humans and animals. Tongue sole (Cynoglossus semilaevis) is a marine flatfish that is an economically important farmed species in China. The commercial aquaculture of tongue sole has developed in the last few years because wild resources have decreased. Reproduction is regulated by brain-pituitary-gonad-liver axis which limits the development of artificial tongue sole culture. However, the roles of circRNAs in the ovarian development and maturation of tongue sole has never been reported. The identification of the potential functions of circRNAs provides a foundation for understanding the genetic mechanisms that regulate oocyte growth and maturation, which will allow the efficiency of tongue sole reproduction to be improved. Moreover, our findings extend the knowledge about a new type of endogenous RNA involved in regulating the ovarian development and maturation of tongue sole.CircRNAs are novel endogenous non-coding small RNAs involved in the regulation of multiple biological processes. However, little is known regarding circRNAs in ovarian development and maturation of fish. Our study, for the first time, provides the genome-wide overview of the types and relative abundances of circRNAs in tongue sole tissues during three ovarian developmental stages. We detected 6790 circRNAs in the brain, 5712 in the pituitary gland, 4937 in the ovary and 4160 in the liver. Some circRNAs exhibit tissue-specific expression, and qRT-PCR largely confirmed 6 differentially expressed (DE) circRNAs. Gene Ontology and KEGG pathway analyses of DE mRNAs were performed. Some DE circRNA parental genes were closely associated with biological processes in key signalling pathways and may play essential roles in ovarian development and maturation. We found that the selected circRNAs were involved in 10 pathways. RNase R digestion experiment and Sanger sequencing verified that the circRNA had a ring structure and was RNase R resistant. qRT-PCR results largely confirmed differential circRNA expression patterns from the RNA-seq data. These findings indicate that circRNAs are widespread in terms of present in production-related tissues of tongue sole with potentially important regulatory roles in ovarian development and maturation.

Funneliformis mosseae inoculation under water deficit stress improves the yield and phytochemical characteristics of thyme in intercropping with soybean

Intercropping of medicinal plants/legumes along with bio-fertilizer application is a relatively new sustainable practice for improving the yield and secondary metabolites production. Here, a 2-years field experiment was performed to evaluate the effects of water deficit stress and arbuscular mycorrhizal fungi (AMF) application (as bio-fertilizer) on nutrients concentration, dry matter yield, essential oil quantity and quality of thyme in intercropping with soybean. Three irrigation levels, including (i) irrigation after depletion of 20% (I20) as non-stressed, 50% (I50) as moderate water deficit and 80% (I80) available water as severe water deficit were applied as the main factor. The sub-factor was represented by different cropping patterns including thyme sole culture, replacement intercrop ratio of 50:50 and 66:34 (soybean: thyme) and the third factor was non-usage (control) and usage of AMF. According to our results, the thyme dry yield under moderate and severe water deficit stress decreased by 35 and 44% in the first year, and by 27 and 40% in the second year compared with non-stressed (I20) plants, respectively. Also, the macro- and micro-nutrients of thyme leaves increased significantly in intercropping patterns after application of AMF. The maximum essential oil percentage of thyme was achieved in 50:50 intercropping ratio treated with AMF. Under moderate and severe water deficits, the major constituents of thyme essential oil including thymol, p-cymene and γ-terpinene were increased in intercropping patterns treated with AMF. Generally, AMF application in intercropping ratio of 50:50 may be proposed to farmers as an eco-friendly approach to achieve desirable essential oil quality and quantity in thyme under water deficit stress conditions.

ارزیابی شاخصهای رشد و سودمندی در کشت مخلوط لوبیاسبز و ریحان بذری

Background and objectives: Intercropping of basil with legumes due to morphological differences and more importantly, their biological stabilization can be a step towards sustainability in agriculture and also to avoid the use of chemical inputs and therefore produce healthier products. Therefore, the objectives of this experiment were to evaluate and compare different indicators of growth, yield and ecological and economic usefulness of basil with green bean in pure crops and mixed replacement ratios in Mashhad climatic conditions. Materials and Methods: An experiment was conducted in RCBD design at the research farm of Ferdowsi University of Mashhad in the growing year 2018 19. The treatments were: 1) sole cropping of green bean (P), 2) and also basil (O) and different ratios of intercropping of these two plants, including 3) 1:3 ratio of green bean and basil (P1O3), 4) ratio 2:2 green bean and basil (P2O2) and 5) 3:1 ratio green bean and basil (P3O1). Daily values of growth indices during the growth period of plants were estimated using the specific functions, and at the end of the growing season, the final yield of intercropped species (fresh green pods of green bean and basil dried seeds) was measured and indicators related to the advantage of intercropping including land equivalent ratio (LER), actual yield loss (AYL) and the monetary advantage index (MAI) were calculated. Function fitting, statistical analysis of data and drawing of figures were performed using Slide Write ver2.0, SAS v 9.2 and MS Excel 2016, respectively. Results: The highest LAI recorded in sole cropping of green bean and basil (3.4 and 3 respectively) and the lowest was for green bean in P1O3 (0.2) and for basil in P3O1 (2). Also, highest TDM in sole cropping of green bean was 973 g m2 and in sole cropping of basil was 1654 g m2 and the lowest ones for intercropped green bean was in P1O3 (44 g m2) and in the intercropped basil in P3O1 (755 g m2). The highest CGR of green bean and basil in their sole cropping were 20.56 and 17.92 g m2 day-1, respectively. The mean RGR of green bean was 0.03 g g-1 in P1O3 and the highest RGR was in basil in the sole cropping treatment (0.03 g g-1) The highest NAR in green bean was in its sole cropping (8.3 g m2 day-1) and basil (8.5 g m2 day-1). No economic yield was achieved for green bean in P1O3 and P2O2 treatments, so all the advantage indices of intercropping including LER, AYL and MAI in these treatments were negative. Also, the highest yield of basil was obtained in P1O3, which was not significantly different from its sole culture, and only in this treatment the intercropping advantage indices studied were positive and preferred to sole culture. Conclusion: The results truly showed incompatibility of basil with green bean in intercropping due to low competitiveness and weakness of green bean in intercropping with basil. Although intercropping in P3O1 treatment was economically and ecologically beneficial, but by considering all the conditions such as the possibility of implementing this cultivation ratio, it is suggested that while examining more different aspects of intercropping of basil with green bean such as weed competition and mechanisms of basil competition with green bean, another legume crop that has more desirable characteristics in terms of ecological compatibility and non-interference of ecological niches with this plant to replace green bean in basil production systems.

Evaluation of yield, yield components and nutritive value in intercropping of Barley with Vetch

To evaluate some agronomic properties and forage characteristics in the intercropping of barley (Hordeum vulgare L.) and vetch (Vicia ervilia L.), an experiment was conducted during 2014-2016 cropping seasons. A randomized complete block design with four replications was used. Intercropping patterns included 80% barley+ 20% vetch, 60% barley+ 40% vetch, 40% barley + 60% vetch and 20% barley + 80% vetch along with the sole culture of both crops (100% barley and100% vetch). The result showed that the highest value of plant height, grain number, thousand-grain weight, biological yield, grain yield and harvest in barley was observed from 80% barley + 20% vetch intercropping ratio, however, for vetch, it was detected from 100% vetch. Furthermore, the highest land equivalent ratio was obtained from 80% barley+ 20% vetch. Based on the results, the highest crude protein content and dry matter digestibility were observed in sole cropped vetch, whereas the highest neutral detergent fiber and acid detergent fiber were recorded in sole cropped barley. These results suggested that intercropped barley and vetch as 80% barley + 20% vetch ameliorated the grain yield and yield components, and forage quality compared to other intercropping ratios.

Redefining the field to mobilize three-dimensional diversity and ecosystem services on the arable farm

In this article we explore the concept and implications of three-dimensional (spatial, temporal, and genetic) in-field crop diversification to inform systems redesign towards ecological intensification. We first present a conceptual framework for classifying diversity in arable contexts. We then apply the framework to analyse two long-term systems experiments in The Netherlands where spatial and genetic diversity measures were implemented via strip and mixed intercropping with the aim to increase ecosystem service delivery: incidence and spreading rate of late blight (Phytophthora infestans) in potato (Solanum tubersosum L.), and biocontrol control potential in wheat (Triticum aestivum L.). In the case of late blight, potatoes planted in strips had significantly lower disease incidence than the monoculture reference across all years, and adding cultivar mixing within the strip was more powerful in mitigating late blight than spatial diversification alone. In the case of biocontrol in wheat, strips supported significantly larger (for all but one taxonomic group) and significantly more diverse epigeic natural enemy populations than the sole culture reference in all years. However, the addition of species mixing within strips did not further increase biocontrol indices compared to sole-wheat strips. These results imply that compromises between management complexity and ecosystem service enhancement are achievable through strip cropping, an operable practice with current machinery, and one that does not require a thorough reconfiguration of the production system. The three-dimensional diversity framework proved useful for unpacking experimental outcomes in terms of diversity-mediated mechanisms, however it requires further development before it can be used to facilitate multi-objective optimization.

Growing tall and dwarf rice cultivars in mixture for better weed management and higher yield

Growing two or more cultivars of same crop species in mixture reduces intra-specific competition for natural resources and increases competitive ability of crops against weeds and thus enhances crop yield. The objective of this study was to evaluate the potentiality of growing rice cultivars in mixtures for minimizing weed pressure and increasing rice yield. The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during Aman season (July-December) 2017. Two transplant Aman rice cultivars viz. Binadhan-13 (tall, late- maturing and fine grain aromatic cultivar) and BRRI dhan49 (semi-dwarf, mid-maturing and coarse grain cultivar) were grown following two spatial arrangements viz., alternate row and alternate hill, and nine different cultivar mixture (Binadhan-13:BRRI dhan49) row ratios viz., 1:0, 1:2, 2:1, 2:3, 3:2, 2:4, 4:2,1:1 and 0:1. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Results confirmed the positive influence of spatial arrangement and cultivar mixture ratio on rice productivity. Both the cultivars showed better growth and higher yield when grown in mixture irrespective of ratios compared to their sole culture performances. But cultivar mixture ratio showed no advantages over sole culture in suppressing weeds. Based on the total yield Binadhan-13 and BRRI dhan49 inter-planted in 1:1 row ratio following alternate hill performed the best resulting in 50% and 12% yield advantages over sole culture of Binadhan-13 and BRRI dhan49, respectively. Therefore, growing tall and dwarf rice cultivars in mixture can be adopted as a tool for increasing rice productivity.
 J. Bangladesh Agril. Univ. 17(2): 133–141, June 2019

EVALUATION OF THE CULTIVAR MIXTURE STRATEGY AS A SUSTAINABLE TOOL FOR MANAGING WEEDS AND ENHANCING RICE YIELD

The study was conducted to evaluate the potentiality of rice cultivar mixtures as a strategy for managing weeds and increasing the rice yield under different weeding regimes. Two rice cultivars having different plant stature and maturity periods viz. Binadhan-13 and BRRI dhan56 were used in this study. Factors included six cultivar mixture ratios viz. sole Binadhan-13, sole BRRI dhan56, 2:3, 3:2, 2:4 and 4:2 Binadhan-13 to BRRI dhan56, and four weed management practices viz. no, one, two and three weeding. The experimental design was randomized complete block with three replicates. Both the cultivars showed better growth, higher weed suppression and increased yield when grown in mixture irrespective of ratios compared to their monoculture performances. Based on the total rice grain yield, different mixture ratios performed in the order 4:2, 3:2, 2:3 and 2:4 Binadhan-13 to BRRI dhan56. Binadhan-13 and BRRI dhan56 inter-planted in 4:2 row ratio appeared as the best mixture ratio which resulted in 136% and 7% yield advantages and 17% and 24% weed dry matter reduction over sole culture of Binadhan-13 and BRRI dhan56, respectively. Hence, cultivar mixture strategy can be adopted as an effective tool for better weed management and increased yield of rice.

Reduced Tillage and Intercropping as a Means to Increase Yield and Financial Return in the Drylands of Tigray, northern Ethiopia: A Case Study under Rainfed and Irrigation Conditions

Intensive tillage is a major sustainability concern in cereal dominated cropping systems in the drylands of Tigray, Ethiopia. Hence, on-farm trials were conducted to investigate the yield and economic advantage of reduced tillage and intercropping for two seasons. A factorial experiment in a complete randomized block design was carried out at Adigudom located in Hintalo-Wajirat district in South-Eastern Tigray in 2014 (rain-fed) and 2015 (irrigated). The experiment consisted of four tillage frequencies (zero, one, two and four) and three types of cropping systems (sole maize, sole soybean and maize-soybean intercropping) in three/four replications. Maize, variety “Melkassa 2”, and soybean, variety “Awassa 91” were used. Grain and biomass yields, and harvest index of both crops were analysed. Yield advantage of intercropping was evaluated using land equivalent ratio (LER) and partial budget analysis was used for the financial evaluation. The grain and biomass yields of both crops were significantly increased (p<0.05) as the tillage frequencies increased from zero to four in both seasons but the frequent tillage with sole cropping was not economically viable as the two times tillage with maize-soybean intercropping gave 126% greater net benefit compared to the four times tillage sole maize, which is practiced by farmers in the study area. The net benefit was strongly influenced by the main effects of tillage and intercropping in both seasons (p<0.001) and by their interaction in 2014 (p<0.05). Significantly higher LER (1.87-2.12) was recorded from maize-soybean intercropping over sole cropping in all the tillages and both seasons. Hence, two alternative options are suggested that farmers could apply in the drylands of Tigray: (i) keeping the sole cropping culture of maize production, and reducing number of tillages from 4 to 2 that would give 374%and 705% Marginal Rate of Return (MRR), respectively, under the rainfed and irrigated conditions compared to zero tillage sole maize; or (ii) intercropping maize with soybean and reducing tillage frequency from 4to 2 that would give 608% and 585% MRR in the respective growing seasons, compared to zero tillage maize-soybean intercropping. Taking these results into account, two times tillage combined with maize-soybean intercropping can be a good option in dryland areas of Tigray to achieve higher total intercrop yield at a low cost and larger LER. Moreover, reduced tillage can minimize soil degradation and benefit farmers with poor access to draft power or female-headed households constrained with labour for ploughing. Keywords : Tillage; Intercropping; Maize; Soybean; Tigray; Ethiopia. Please find erratum for this article here: https://dx.doi.org/10.4314/mejs.v11i1.10

Photosynthetic pigments accumulation and some growth indices of cowpea, maize and tomato in response to interspecific and intraspecific competition stress

This study aimed at investigating the photosynthetic pigment accumulation and some growth indices of cowpea, maize and tomato in response to interspecific and intraspecific competition stress. The study was carried out under a screen-house to minimize extraneous factors such as pests and rodents using a randomized complete block design (RCBD). Seeds of cowpea, maize and tomato were collected from the Department of Crop Production and Protection, Faculty of Agriculture, Obafemi Awolowo University, Ile Ife, Osun state, Nigeria. These seeds were planted at a depth of about 3 mm below the soil. The seeds were sown at the rate of six seeds per pot in the monoculture, while in the pots designed for the mixed culture of maize and cowpea, maize and tomato, cowpea and tomato, three seeds of each plant were sown. Two seeds of each plant were sown in the pots with the three crops. The treatments were then supplied with 500 mL of tap water in the morning and in the evening respectively until the seedlings become fully established. The photosynthetic pigments were determined spectrophotometrically with three replicates. Plant growth indices were determined according to Hunts (1978) using leaf area and dry matter data collected at four and six weeks after planting. Statistical analysis was performed using statistical analytical software SAS version 9.2. The results indicated that photosynthetic pigments accumulation (Chlorophyll a, b and carotenoid) in maize (15.98, 23.92 and 44.72 μM), Chlorophyll b and carotenoid in tomato plants (12.48 and 1,178.7 μM) in the sole stands were more than the mixed culture of maize with cowpea and tomato (7.195, 14.74 and 0.00 μM). Also, total Chlorophyll in maize (1,127.8 μM), Chlorophyll a and total Chlorophyll in tomato (3.95 and 1,317.5 μM) in the mixed culture were more than in the sole culture of maize (1,030.9 μM) and tomato plants (−9.40 and 546.3 μM). The different photosynthetic pigments accumulated in cowpea were greatly enhanced in the mixed culture than in the sole culture. All the photosynthetic pigments of maize, cowpea and tomato in all the treatments analysed in this study were significantly different at P >0.05. Plant growth indices such as net assimilation rate, relative growth rate, crop growth rate and tissue water contents of these plants had higher value in the intercropped than the check crop (sole). These plant growth indices were significantly different to one another at P >0.05. This study concluded that competition for shared resources in the mixed culture of tomato, maize and cowpea enhanced growth and accumulation of photosynthetic pigments.

MiR-429 suppresses neurotrophin-3 to alleviate perineural invasion of pancreatic cancer

Perineural invasion (PNI) potentially increases the risk of relapse and abdominal pain in patients with pancreatic ductal adenocarcinoma (PDAC). However, the underlying mechanisms of PNI of PDAC is incompletely revealed. Our study aimed to investigate roles of miR-429 in modulating PNI in PDAC. We found that miR-429 was downregulated in PDAC cancer tissues and was profoundly decreased in tissues with PNI. It was reduced in nine of the ten examined pancreatic cancer cell lines. MiR-429 mimics restored its cellular expressions in MIA PaCa-2 and BxCP3 cells and significantly suppressed cell viability and invasion of the cancer cells. The online bioinformatic software predicted that neurotrophin-3 (NT-3) was a potential target gene of miR-429. It was showed that NT-3 mRNA elevated in PC cancer tissues, especially in patients presenting PNI. MiR-429 upregulation substantially suppressed the NT-3 mRNA and secretion in cancer cells. Also, the dual luciferase reporter assays confirmed the interaction between miR-429 and NT-3. When co-culturing the two PDAC cells with PC-12 cells, the invaded cell counts significantly increased comparing with the sole culture of cancer cells. However, miR-429 mimic transfection or NT-3 blocking retarded the cancer invasion in the co-culture system. Besides, we found that cancer cells conditioned medium (CM) treatment significantly increased the neurite outgrowth percentage in PC-12 cells, which was suppressed by culturing with CM from miR-429 mimics-transfected cells. In the CM cultured PC-12 cells, NT-3 receptor TrkC as well as pain-related proteins TRPV1 and TRPV2 significantly elevated. Collectively, miR-429 potentially suppressed neurotrophin-3 to alleviate PNI of PDAC.

Possibility of co-culturing Euglena gracilis and Lactuca sativa L. with biogas digestate

ABSTRACTThe goal of this study was to establish a system for co-culturing microalgae and crop plants with biogas digestate. We examined growth performances of E. gracilis and L. sativa co-cultured using a commercial liquid fertilizer designed for soilless culture supplemented with vitamins and ammonium. This solution simulated the filtrate of nitrified biogas digestate derived from the organic fraction of municipal solid waste but was supplemented with insufficient plant nutrients (Mg, Fe and Mn). The specific growth rate of the co-cultured E. gracilis was 0.761 ± 0.081 d−1 (mean ± SE), which was the same rate that E. gracilis achieved when grown as a sole culture. There were no significant differences between L. sativa cultured with E. gracilis until the stationary growth phase of E. gracilis was reached and those cultured alone relative to biomass, RGRs (relative growth rates), or relative to SPAD values of leaves. These results suggest that E. gracilis and L. sativa could be co-cultured with the biogas digestate after being nitrified and filtered. In addition, considering concentrations of plant macronutrients in the residual solution after the co-culturing E. gracilis and L. sativa, it could be re-used as the nutrient solution for co-culturing E. gracilis and L. sativa.