Applied Research in Science and Technology

Response of Fluted Pumpkin (Telfairia occidentalis Hook. F) to Wood Ash Rates in An Ultisol, Southeastern Nigeria

Janet Oliver Orji — 2026-05-01

Background: Fluted pumpkin is a major leafy vegetable widely cultivated and consumed in Nigeria and other rainforest ecological zones of West and Central Africa. The cultivation of this crop faces challenges due to the low soil fertility of the ultisols found in southeastern Nigeria, making it difficult for farmers in the region to achieve bumper harvests of both foliage and pods.
Aims: The experiment aimed to evaluate the response of fluted pumpkin (Telfaria occidentalis Hook. F) to varying rates of wood ash application in ultisol soils. This study seeks to determine the optimal wood ash level that improves soil fertility and enhances the growth and yield of fluted pumpkin, thereby providing sustainable agricultural practices for farmers in southeastern Nigeria.
Methods: The field experiment was conducted to evaluate the effect of wood ash application on growth and yield of fluted pumpkin (Telfaria occidentalis Hook. F). The experimental treatments were four wood (dried oil palm rachis) ash rates; 0, 2, 4 and 6 t/ha. The treatment was laid in a randomized complete block design, replicated four times.
Results: The results showed that the application of wood ash enhanced growth and yield of fluted pumpkin. The treatment of 6t/ha wood ash produced 19.71 t/ha foliar yield. The treatment of 4t/ha produced 18.63 t/ha foliar yield. The least foliar yield, 8.81 t/ha was recorded in the control treatment. Comparing the number of pods per plant, the treatment of 6t/ha wood ash produced significant number of pods per plant; 3.60, followed by 3.43 fluted pumpkin pods per plant recorded in the treatment of 4t/ha wood ash. The least number of pods per plant; 1.12 was recorded in the control treatment. The treatment that received 6t/ha oil palm rachis ash (OPRA) produced 26.81 t/ha pod, followed by 25.01 t/ha recorded in 4t/ha wood ash rate. The least pod yield; 7.44 t/ha was recorded in the control treatment. The study revealed that application of wood ash to fluted pumpkin could assist farmers in achieving bumper harvest in the study area. Farmer in the study area should adopt the application of 4t/ha of wood ash to fluted pumpkin.

Optimizing Plant Spacing and Mulching for Enhanced Weed Control and Cucumber Yield (Cucumis sativus) under Varied Sowing Conditions

Janeth Oliver Orji — 2026-05-02

Background: Weeds pose a significant challenge to crop farming, particularly in cucumber production in Nigeria. They compete with cucumber plants for essential resources such as water, nutrients, and sunlight, which can lead to reduced crop yields. They harbor insects and disease organisms, serve as alternate host to pests, and compete with crops for nutrients, moisture, light, and space. Weeds cause damage to crops, reduce the yield and quality by competing with the crops, and cause harm to animals that feed on them. The production of cucumber has increased in Nigeria due to its importance, but it is still in short supply because of poor yield, which could be attributed to weed infestation.
Aims: This study was conducted to investigate the impact of spacing and mulching on weed control and fruit quality of cucumber (Cucumis sativus) at various sowing dates in humid ecology.
Methods: The experiment was carried out using a split-split plot arrangement layout in a Randomized Complete Block Design. The treatments consisted of three factors (time of planting, spacing, and mulching). The main plot was sowing dates (April, May, June, July, August and September), the sub plot was spacing (20cm x 50cm, 40cm x 50cm and 60cm x 50cm), sub-sub plot was mulching (no mulch, black plastic mulch, transparent plastic mulch, wood shaving) all were replicated 3 times.
Result: The sowing date had a significant effect (p<0.05) on weed dry weight at 4 and 6 weeks after emergence. Sowing in April recorded the lowest weed dry weight (0.31g at 4 WAE and 0.79g at 6 WAE) in 2015 and (3.84g at 4 WAE; 3.16g at 6 WAE) in 2016. Cucumbers that were spaced at 20 cm x 50 cm recorded the lowest weed dry weight (8.53g at 4WAE and 4.60g at 6WAE) in 2015 and also in 2016 (10.36g at 4WAE and 5.33g at 6WAE). Black polythene recorded the lowest weed dry weight (2.87g at 4WAE; 1.79g at 6WAE) in 2015 and (2.95g at 4WAE and 1.88g at 6WAE) in 2016.
Conclusion: The study revealed that effective weed control and high fruit quality were achieved by sowing early in April and May at closer spacing, combined with black polythene mulching. These practices recorded the lowest weed dry weight, while early sowing also produced better fruit quality. Therefore, the study recommends sowing early in April and May at closer spacing and using black polythene mulch for optimal cucumber production

Sensitivity-Based Critical Bus Ranking for Available Transfer Capability Assessment of the Nigeria 330 kV Transmission Network under N−1 Contingencies

Chinonso S Ezeonye — 2026-06-06

Background: Increasing loadings and recurring contingency of the 330 kV transmission system in Nigeria have led to concerns about voltage stability and available transfer capability (ATC). The determination of these critical buses, which have a great influence on the network performance, is an important issue for planning, operation, and focused reinforcement.
Aims and Methods: In this study, a sensitivity oriented approach is developed to rank critical bus and ATC assessment for 330 kV Nigerian grid under N−1 contingency conditions. The framework combines voltage deviation evaluation, ATC calculation, sensitivity ranking, cumulative sensitivity contribution analysis, voltage-ATC coupling evaluation, and post-contingency recovery analysis with a first order exponential model.
Result: The findings indicate that system vulnerability is highly location dependent and varies significantly over the network. Bus 22 (Alagbon TS) was identified as the most critical bus with the highest normalised sensitivity index of 1.000 and the most reduction in ATC of 1.65 MW. The cumulative sensitivity analysis showed that the top 15 buses contributed approximately 42% of the total network sensitivity, confirming that vulnerability is concentrated within a relatively small number of locations. The voltage–ATC coupling analysis indicated a strong relationship between the voltage degradation and the transfer capability reduction while the post-contingency recovery assessment proved recovery stability with a recovery time constant of 2.5 s.
Conclusion: The proposed sensitivity based approach is used to identify critical buses and to make targeted reinforcement decisions to enhance the reliability and operational security of the Nigeria 330 kV transmission system.

Effects of Different Silicate Concentrations on Growth Performance of Thalassiosira sp. as Live Feed for Shrimp Larvae

Andri Hendriana — 2026-06-29

Background: Diatoms require silicate for frustule formation and optimal cell division, making silicate availability a critical factor in improving microalgal production for aquaculture. Thalassiosira sp. is one of the most widely used live feeds in shrimp hatcheries because of its high nutritional value and suitable cell size for larval consumption.
Aims: This study evaluated the effects of different silicate concentrations on the growth performance of Thalassiosira sp. by simultaneously assessing cell density, specific growth rate (SGR), and division rate (DR).
Methods: A completely randomized design with four treatments was employed: control (without silicate), 15 ppm (SL15), 20 ppm (SL20), and 25 ppm (SL25), each with three replicates. Cell density was monitored daily for 14 days using a haemocytometer, while SGR and DR were calculated from the exponential growth model.
Results: The results showed that silicate supplementation significantly affected all growth parameters (p < 0.05). The highest cell density (4.60 × 10⁶ cells mL⁻¹) was obtained in the SL25 treatment on day 12, whereas the highest SGR (29.17 ± 0.32% day⁻¹) and DR (0.422 ± 0.005 divisions day⁻¹) were recorded in SL20. However, Duncan's Multiple Range Test indicated no significant differences between SL20 and SL25 for SGR and DR, suggesting comparable physiological responses at these silicate concentrations. These findings indicate that silicate concentrations between 20 and 25 ppm provide the optimal range for enhancing the growth performance of Thalassiosira sp. and may improve the efficiency of live-feed production for shrimp hatchery applications.
Conclusion: Silicate supplementation significantly improve the growth performance of Thalassiosira sp., as reflected by increased cell density, specific growth rate, and division rate.

Gut Microbiota Modulation by Phytobiotics in Pacific White Shrimp (Litopenaeus Vannamei): A Literature Review

Sheny Permatasari — 2026-06-30

Background: The Pacific white shrimp (Litopenaeus vannamei) is one of the most economically important aquaculture species worldwide. However, intensive farming practices have increased the incidence of disease outbreaks, environmental stress, and gut microbiota dysbiosis, resulting in reduced productivity and sustainability. Phytobiotics have emerged as promising natural feed additives due to their antimicrobial, antioxidant, and immunostimulatory properties, with increasing evidence suggesting their role in modulating gut microbial communities. Nevertheless, current findings remain fragmented across different phytobiotic sources and experimental approaches.
Aims: This systematic literature review aimed to synthesize current evidence regarding the effects of phytobiotics on gut microbiota composition, growth performance, immune responses, and disease resistance in L. vannamei.
Methods: Literature published between 2015 and 2025 was retrieved from Scopus, ScienceDirect, and Google Scholar following predefined inclusion criteria, and 20 eligible studies were included in the qualitative synthesis.
Results: The reviewed studies consistently demonstrated that phytobiotics promote beneficial gut bacteria while suppressing opportunistic pathogens, particularly Vibrio spp., thereby improving intestinal microbial balance and hepatopancreatic health. These microbial changes were associated with enhanced nutrient utilization, improved feed efficiency, stronger innate immune responses, increased antioxidant capacity, and greater resistance to bacterial infections, ultimately resulting in better growth performance. Although the available evidence supports the potential of phytobiotics as sustainable alternatives to antibiotics, microbiome-based studies remain limited. Future research integrating high-throughput sequencing and multi-omics approaches is required to elucidate the mechanisms underlying phytobiotic–microbiota interactions and optimize their application in sustainable shrimp aquaculture.