Agro-ecological Zones Research Articles

Effect of Date of Sowing and Nitrogen Level on the Yield of Wheat

An experiment to evaluate the growth and production of BARI Gom-26 was carried out at Bangladesh Agricultural University's Agronomy Field Laboratory from November 2022 to March 2023. The experiment compared various nitrogen amounts and planting dates. Five nitrogen levels (90, 100, 110, 120, and 130 kg N ha-1) were taken into consideration along with three planting dates (November 15, November 25, and December 5, 2022). Three replications of a Randomized Complete Block Design (RCBD) were used in the trial. On March 1, March 18, and March 28, 2023, respectively, harvesting was done independently. According to the findings, November 25th with 110 kg N ha-1 produced the highest grain yield (3.92 t ha-1). Furthermore, on November 25, 2022, 110 kg N ha-1 produced the highest scores of tillers per hill (6.11), effective tillers per hill (5.74), number of spikelets per spike (12.46), number of grain-1 (23.89), straw yield (7.07 t ha-1), and biological yield (11.00 t ha-1). On the other hand, on December 5 with 130 kg N ha-1, the lowest number per total tiller (3.54), number of effective tillers per hill (3.36), straw yield (3.46 t ha-1), and biological yield (6.22 t ha-1) were noted. As a result, November 25, 2022, was linked to the highest grain yield. On November 25, 2022, it was also observed that all three planting dates and all five nitrogen treatments worked effectively with 110 kg N ha-1. The best date to sow wheat was determined to be November 25, 2022, and this date is advised for wheat cultivation in Bangladesh in different agro-ecological zones.

Comparison of methodologies for estimating enteric methane emission factors from sheep in smallholder systems in Africa: A case study from Ethiopia

In Ethiopia, enteric methane emissions from sheep contribute around 7 % to the national greenhouse gas (GHG) budget. This study examined the gross energy intake (GEI) and enteric methane emission factors (EFs) of sheep in smallholder systems in North Shewa, Ethiopia, using locally derived data via household surveys. The surveys encompassed two agroecological zones (AEZs) and analyzed various sheep classes across seasons. The study followed the Commonwealth Scientific Industrial Research Organization (CSIRO) Tier 2 methodology, which had previously been used in Kenya, and compared the results with those derived from the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC Tier 2) methodology. The EFs from the two Tier 2 methodologies were compared with IPCC default Tier 1 EF. The ranges of GEI and EF estimated for the different sheep classes showed similarity with larger variations observed for IPCC Tier 2 estimates. The estimated GEI for the various sheep classes ranged from 11.1 to 13.8 MJ day−1 (‘CSIRO’ Tier 2) and 10.2–14.7 MJ day−1 (IPCC Tier 2). The estimated EFs ranged from 4.8 to 5.9 kg CH4 animal−1 year−1 (‘CSIRO’ Tier 2) and 4.5–6.5 kg CH4 animal−1 year−1 (IPCC Tier 2). The flock-level EF was computed by aggregating the EFs of the different sheep categories. The flock level EF estimated by the IPCC Tier 2 (6.0 ± 0.1 kg CH4 animal−1 year−1) was significantly higher compared to both the 'CSIRO' Tier 2 and IPCC Tier 1 methods. Based on the findings, we can say that variations in EF values emphasize the significance of taking different Tier 2 approaches into account when evaluating and comparing CH4 emissions estimates in smallholder sheep farming systems. However, there is a need for further investigations to compare the two Tier 2 methodologies against actual intake and emission measurements to decide which methodology is better.

Effect of Chemical Pesticides on the Growth and Yield of Two Industrial Potato Varieties (Asterix and Courage) in Bangladesh

Experiments were conducted to find out suitable disease management practices to produce quality potato seeds in processing the varieties of Asterix and Courage in Bangladesh. A set of two field experiments was conducted in two different Agroecological zones of Bangladesh. A Factorial Randomized Completely Block Design with 2 potato varieties, 4 treatments, and 4 replications for each were used. A significant difference was found in the plant height and number of tubers per hill. In contrast, days to tuberization and the number of stems per hill of both varieties in response to pesticide application were insignificant. The highest tuber yield and better A and B-grade tubers were recorded, in which fungicides and insecticides were applied. The primary viral infection had been identified in the control and fungicide-treated plots only while there was no viral disease incidence was observed in the insecticide-treated plots. The incidence of post-harvest disease and disorder was found to be negligible. J. Bio-Sci. 32(2): 13-22, 2024

Effect of Integrated Nutrient Management (INM) on Soil Physico-chemical Properties in Wheat (Triticum aestivum L.) Intercrop under Beul (Grewia optiva Drummond.) Based Agroforestry System and Open Condition

The raising human health hazards due to excessive use of chemical fertilizers and pesticides in India leads cancer patients. To overcome such problems there is need of Integrated Nutrient Management (INM) in our major crop wheat and further to improve soil fertility under agroforestry system. Therefore, the present investigation was carried out to study the impact of INM on the physical and chemical properties of soil when wheat intercropped under Beul (Grewia optiva) based agroforestry system in the mid-hill region of Himachal Pradesh at Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan, HP (India). INM practices were applied to evaluate their effectiveness in enhancing soil fertility, crop yield, and overall soil health. The experimental setup included various treatment combinations of organic and inorganic fertilizers viz., T1: RDF, T2: FYM, T3: Vermicompost, T4: Goat manure, T5: 50% RDF+50% FYM, T6: 50% RDF+50% VC, T7: 50% RDF+50% GM, and T8: Control to determine their synergistic effects on the soil and cereal crop. These treatments were randomly assigned to plots under two planting conditions: S1 (under Beul based agroforestry system) and S2 (open condition), with three replications each, following in a factorial randomized block design (RBD). The key physical parameters such as bulk density (g/cm3), particle density (g/cm3), porosity (%), and soil moisture (%) were measured along with chemical properties of soil including soil pH, EC (dS/m1), organic carbon content (%), and nutrient availability of N, P and K in kg per hectare. The soil data of two consecutive years and pooled data were analyzed in R Statistical Software. The results demonstrated that INM significantly improved both the physical and chemical soil properties in agroforestry system as compared to control treatment i.e. open condition. The use of 100 % FYM found to be best treatment during the course of study among various treatments of INM for soil porosity, soil moisture, soil pH, available N, P and K. The soil structure and nutrient availability were increased in second year as compared to first year which will lead to improve the growth and yield of wheat crop. The study underscores the importance of adopting INM practices in agroforestry system to achieve sustainable agriculture as well as chemical free agriculture in hilly regions of Himachal Pradesh which will be helpful for human health. Thus, the use 100% FYM fertilizer is recommended for farmers in hilly area of Himachal Pradesh for sustainable agriculture and natural farming. The findings provide valuable insights for farmers and policymakers aiming to optimize crop production and maintain soil health in similar agro-ecological zones.

Historical Analysis of Climate Variability and Agricultural Production in Nigeria (1931-2020)

This study investigates the historical dynamics of climate variability and its impacts on agricultural production in Nigeria from 1931 to 2020. Utilizing a robust analytical framework that integrates climatic data analysis, statistical modelling, and geographic information system (GIS) techniques, the research explores trends in temperature and precipitation across different agro-ecological zones. Key findings reveal a consistent upward trend in average annual temperatures, with more pronounced warming observed in northern Nigeria, notably the Sahelian zone. Concurrently, precipitation patterns exhibit regional disparities, characterized by increased rainfall in southern regions and variable patterns in the north, including periods of severe droughts during the 1970s and 1980s. Statistical analyses employing Mann-Kendall trend tests and regression models confirm significant temperature increases and varying precipitation trends, underscoring their direct impacts on agricultural productivity. The study highlights the sensitivity of crop yields to climatic factors, demonstrating that rising temperatures adversely affect staple crops such as maize, millet, and sorghum, while adequate precipitation plays a critical role in enhancing yields. Socio-economic factors, including disparities in resource access between northern and southern regions, influence farmers’ adaptive capacity and resilience to climate variability. Adaptation strategies adopted by Nigerian farmers, such as adjusted planting schedules, crop diversification, and irrigation practices, are explored within the context of socio-economic constraints and infrastructural limitations. Spatial analysis using GIS provides insights into the differential impacts of climate variability across Nigeria, emphasizing the vulnerability of northern regions to climate shocks compared to the relative resilience of southern regions. Policy implications underscore the urgency of promoting climate-resilient agricultural practices, improving resource access, enhancing rural infrastructure, and implementing targeted capacity-building initiatives. These measures are essential for enhancing adaptive capacity, resilience, and sustainable agricultural development amidst on going climate variability and change in Nigeria.

Sustainable ruminant nutrition in West Africa by in vitro characterization of cashew apple by-products

Cashew trees (Anacardium occidentale L.) are planted for primarily their nuts, but they also generate apples which are mostly thrown away due to their astringent taste. The current study aimed to explore the possible utilization of cashew apple by-products (CABP) in West Africa as an alternative feedstuff for small ruminants’ nutrition. To achieve this aim, five parts of cashew apple by-products (whole, up, down and middle part, and pomace) of two cashew varieties (red and yellow) were collected in two different agroecological zones (Sudanian Zone, SZ and Sudano-Guinea Zone, SZ) to be characterized for the chemical composition, including polyphenols and sugars, and the in vitro fermentation pattern. In general, the results showed that CABP characteristics depend more on sampling area than on variety. The dry matter (DM) in SZ and SGZ varied from 12.76 to 26.10 % and 7.41–22.9 %, respectively. The pomace showed the highest crude protein, lipids, and neutral detergent fiber (NDF) content (SZ: 9.48, 3.94 and 31.66 % DM; SGZ: 14.03, 4.94 and 34.12 % DM, respectively) but the lowest nonstructural carbohydrate (NSC) and sugar for both zones. Regarding the in vitro fermentation, the organic matter degradability (dOM) was higher in the middle part (73.73 %) and whole apple (61.62 %) of SZ and SGZ, respectively. In contrast, the pomace from both zones showed the lowest in vitro fermentation parameters. The total polyphenols were more concentrated in the CABP from SZ (whole: 2736 μg/g DW; pomace: 3813 μg/g DW) compared to those from SGZ (whole: 1755 μg/g DW; pomace: 1374 μg/g DW). Results suggest that CABP should be collected in each cultivation zone regardless of variety, separating pomace from other by-products and may be used as alternative feedstuff for small ruminants during the dry season in the West Africa region.

Determination of Adoption Traits and Key Production Constraints of Improved Maize Varieties Using Participatory Research Appraisal

Introduction: Maize is a staple crop critical to the food security and livelihoods of millions of smallholder farmers in Sub-Saharan Africa. Despite the availability of improved maize varieties, adoption rates among farmers remain suboptimal. Understanding the traits that drive adoption and identifying key production constraints is essential for the development and dissemination of varieties that meet farmers' needs. Aims: This study aimed to identifying the most valued traits of improved maize varieties from the farmers' perspective, assessing the socio-economic and biophysical factors influencing the adoption of these varieties and identifying the main production constraints faced by farmers in different agro-ecological zones. Study Design: The study was conducted in three regions representing diverse agro-ecological zones. A multi-stage sampling technique was used to select a representative sample of maize farmers. Data collection involved focus group discussions (FGDs), key informant interviews (KIIs), and household surveys. PRA tools such as pairwise ranking and matrix scoring were employed to capture qualitative and quantitative data on adoption traits and production constraints. Place and Duration of Study: The study took place at Ejura Sekyeredumasi, Nkoranza South District and Wenchi Municipal district, between June 2017 and December 2017. Methodology: Descriptive statistics were used analyzed the demographic characteristics of maize farmers as well as socioeconomic factors influencing the adoption of improved maize farming technology using SPSS 16 version. Data collected included; socio-demographic characteristics, adoption of improved maize varieties and constraints to maize production. Results: The results showed that about 78 % and 18 % of farmer respondents perceived that both fertilizers and improved seed were too expensive. Other constraints to maize production were drought, high cost of other agro-inputs, lack of improved cultivars and poor soil fertility significantly influenced the adoption of improved maize farming technologies in the area Conclusion: The study underscores the importance of incorporating farmers' preferences and addressing context-specific production constraints in maize breeding programs. Enhanced extension services, improved seed distribution systems, and tailored agronomic practices are recommended to increase adoption rates and improve productivity. Participatory approaches in agricultural research are vital for aligning breeding objectives with the real-world needs of smallholder farmers, ensuring the relevance and impact of improved maize varieties in the Ghana.

Family flock size and age-sex structure of indigenous village chickens.

Indigenous village chickens (IVCs) significantly contribute to rural development. There is considerable variation in family flock size and age-sex structure of IVCs. This study reports the family flock size, age-sex group structure, and demographic history of IVCs. This work involved a cross-sectional study conducted using face-to-face general informants' individual interviews with 119 smallholder farmers in highland and lowland agroecological zones. The average family flock size of the sampled households was small (mean = 7.28, range: 1-38). Female birds (hens and pullets) represented the largest proportion of the family flocks (50.2%). The proportion of chicks (26.4%) and pullets (14.4%) was lower than that of hens (35.8%), which creates a considerable challenge in producing replacement breeding flocks. Similarly, the proportion of cockerels (9.1%) was lower than that of cocks (14.3%). The average cock-to-hen ratio (one cock to seven hens) was better than the commonly recommended proportion (1 cock to 8-10 hens). As a result, smallholder farmers have not faced the problem of producing infertile eggs. The estimated effective population size (Ne) of 4.02 and the corresponding inbreeding coefficient of 0.12 at the family flock level show that to some extent inbreeding may occur at the family flock level; besides, the estimated Ne represents 55.2% of the census size. However, inbreeding could be offset by the high rate of flock turnover and uncontrolled mating among scavenging birds. Family flocks contain a few birds, which may lead to consanguineous mating. Inbreeding is, however, considerably reduced by uncontrolled breeding among birds that share a common scavenging ground. The driving factors behind the low proportion of chicks and juvenile birds and the family flock size need to be further investigated to improve the contribution of local chickens to rural livelihoods.

Multi-Scale analysis of the impacts of soil and water conservation practices and landscape on grain yield and return on investment in the sub-humid ethiopian highlands

Ethiopia's sub-humid highlands face a critical challenge in balancing agricultural productivity with land degradation. This study explores the effectiveness of soil and water conservation practices (SWCPs) in addressing this challenge. We investigated the interaction effects of types of SWCPs, landscape positions, and location on Teff (Eragrostis teff) and wheat (Triticum aestivum) yield. In addition, we assessed the economic viability of SWCPs using cost-benefit analysis with farmer-funded and cost-sharing scenarios. The results indicated that yield was significantly affected by the interactions between factors like SWCP type and landscape position. Soil bunds consistently increased crop yield across diverse locations and landscapes, indicating superior erosion control benefits. Lower landscape positions on foot slopes benefited most from SWCP implementation. Teff yield increased by 188 % and wheat yield by 181 % under soil bunds. The cost-benefit analysis confirmed the financial viability of SWCPs, particularly for Teff (NPV = 4499.35 USD, IRR = 50 %, and BCR = 1.51) and wheat (NPV = 544.35 USD, IRR = 16 %, and BCR = 1.06) grown on lower landscapes with farmer-funded investment scenarios. Positive return on investment was observed in both scenarios, with cost-sharing offering greater economic benefits for farmers. These findings highlight the importance of an integrated approach to SWC implementation for achieving multiple Sustainable Development Goals (SDGs) by enhancing food security, improving farmer incomes, and promoting sustainable and productive landscape management practices. Future research should explore the long-term sustainability of SWCPs, their adaptation across diverse agroecological zones and landscapes, the incorporation of various crops, the broader socioeconomic impacts, and the development of effective extension programs for wider adoption by farmers.

Prevalence of bluetongue virus disease in a small ruminant population in Kalat, Balochistan, Pakistan.

Bluetongue is a vector-borne, emerging disease that poses a severe threat to most domesticated animals. A cross-sectional study was conducted to estimate the prevalence of bluetongue virus (BTV) disease in apparently healthy sheep and goats in Kalat, Balochistan. A total of 270 serum samples (sheep: 150 and goat: 120) were collected and screened for the detection of anti-BTV antibodies using a competitive enzyme-linked immunosorbent assay. The data regarding different contributory risk factors were also collected using a predesigned questionnaire. It revealed that overall, 27.4% (74/270, 95% confidence interval, χ2 = 1.71, p = 0.12) prevalence in both sheep and goat populations. The highest prevalence of 47% (32/68) was recorded in Surab city with the lowest prevalence of 15.49% (11/71) in the Manguchar area. In contrast, in Kalat 28.1% (9/32), Daan area 24% (12/50), and Marap area 22.44% (11/49), seropositivity was recorded. Upon sex bases, antibodies were almost equally found in both male 28.57% (8/28) and female 27.27% (66/242) animal populations. Moreover, all four breeds (Balochi, Khurasani, Lehri, and Rakhshani) were equally and potentially seropositive. The Khurasani breed was the most susceptible to 34.69% (17/49), followed by the Balochi breed, 45/145 (31%) seropositivity. The prevalence of BTV was 16.66% (1/6) in Rakhshani breed and 15.71% (11/70) in Lehri breed., Ticks were found in almost 21% of animals, while 93% of animals were reared on open grazing in rangelands. This study clearly indicates widespread BTV infection in small ruminants in the study area that may pose serious threats to livestock farming. Further extensive studies are recommended to study the prevalence of disease in different agroecological zones of the province. This also warns the high-ups to manage concrete efforts to eradicate and control the disease in the area.

Phosphorus Adsorption as Affected by Concretionary Nodules of Oxic Rhodustalf in Southern Guinea Savannah Agroecological Zone of Nigeria

Hard, rounded masses of mineral matter, known as concretionary nodules, can be found in soil or sedimentary rock. These nodules are typically made up of minerals like iron oxides, hydroxides, and carbonates that have been deposited in groundwater. Their sizes can range from small pebbles to large boulders, and they often differ in composition or hardness compared to the surrounding rock or soil. Nodules act as a highly effective storage space for extra P, leading to a significant increase in overall P requirements. Phosphorus, although an essential element for all living organisms, including plants and animals, is scarce. Despite its importance, only a small fraction of the total phosphorus available can be readily absorbed by plants. Given the worldwide demand for phosphorus in food production, it is crucial to devise techniques for extracting it from different sources. However, there has been limited research on the understanding of phosphorus availability and adsorption mechanisms in these areas. Therefore, the study focused on exploring the impact of concretionary nodules on phosphorus sorption and the characteristics of low-activity clay soil in the Guinea savannah of Nigeria. Soil samples collected from the study area were used to investigate the soil’s ability to absorb phosphorus at depths ranging from 0 to 30-60-90-120-150 cm in different soil and concretion locations. Various soil and concretion types demonstrated distinct capacities for phosphorus adsorption, as indicated by the adsorption isotherm. The maximum monolayer adsorption capacities (Qmax values) were 161.0, 154.5, 149.6, 141.7, 139.8, and 139.3 mg/g for OBC, OBS, OC, OIS, OS, and OIC, respectively. At equilibrium with a 50-ppm solution, the pseudo-second-order rate constants for P sorption were 1.180 x 10<sup>–4</sup>, 9.740 x 10<sup>–5</sup>, 1.120 x 10<sup>–4</sup>, 1.140 x 10<sup>–4</sup>, 1.000 x 10<sup>–4</sup>, and 8.010 x 10<sup>–5</sup> g mg<sup>–1</sup> min<sup>–1</sup> for OIS, OIC, OBS, OBC, OS, and OC, in that order. In the 300-ppm equilibrium solution, the OIS, OIC, OBS, OBC, OS, and OC pseudo-second-order rate constants were 1.250 x 10<sup>–4</sup>, 1.130 x 10<sup>–4</sup>, 9.550 x 10<sup>–5</sup>, 1.040 x 10<sup>–4</sup>, 2.750 x 10<sup>–4</sup>, and 1.420 x 10<sup>–4</sup> g mg<sup>–1</sup> min<sup>–1</sup>, respectively. At the 500-ppm equilibrium, the pseudo-second-order rate constants for OIS, OIC, OBS, OBC, OS, and OC were 1.240 x 10<sup>–4</sup>, 1.090 x 10<sup>–4</sup>, 1.020 x 10<sup>–5</sup>, 1.100 x 10<sup>–4</sup>, 2.730 x 10<sup>–4</sup>, and 1.180 x 10<sup>–4</sup> g mg<sup>–1</sup> min<sup>–1</sup>, respectively. Consequently, the soil adsorption capacity increased with higher pseudo-second-order rate constants.

Leveraging genetic resource diversity and identification of trait-enriched superior genotypes for accelerated improvement in linseed (Linum usitatissimum L.)

Linseed or flaxseed, native to the Indian subcontinent, had undergone domestication, edaphic selection and evolutionary processes that may have resulted in huge genetic variability in Indian genotypes. To understand the hitherto unexplored genetic diversity for sustainable flaxseed production amid challenges of climate fluctuation and identify trait-specific high-yielding genotypes, 2576 unique linseed accessions were comprehensively evaluated for 36 traits for up to six environments representing two major agroecological zones in India. A wide range of variability was recorded for days to initiation of flowering (42.86–114.99), plant height (43.31–122.88 cm), capsules/plant (64.62–375.87), seed size (6.06–14.44 cm2), thousand seed weight (2.80–11.86 g), seed yield (2.93–17.28 g/plant), oil content (30.14–45.96%) and fatty acid profile especially the key constituent omega-3 fatty acid (25.4–65.88%). Most of the traits such as plant height, flowering time, seed yield, seed and capsule size showed a high or moderately high level of variance coupled with high broad sense heritability indicating precise capturing of less heritable quantitative traits. The infraspecific classification of the tested collection revealed the seed/oil type (2498 accessions) as the dominant morphotype over dual-purpose/fiber flax (78 accessions) in the conserved collection. Correlation analysis indicated a significant positive association between flowering time, plant height, days to maturity and oil content. Trait-specific superior genotypes for earliness (50% flowering in < 60 days, maturity in < 122 days), bold seeds with high thousand seed weight (> 11 g), capsules/plant (> 350), oil content (> 45%) and fatty acid composition (> 65% alpha-linolenic acid) were identified to aid genetic improvement of linseed and to broaden the narrow genetic base.

Determinants of Information Needs on Climate-Smart Agriculture Among Male and Female Farmers Across Farming Systems and Agroecological Zones in Sierra Leone: Implications for Anticipatory Actions

Determinants of Information Needs on Climate-Smart Agriculture Among Male and Female Farmers Across Farming Systems and Agroecological Zones in Sierra Leone: Implications for Anticipatory Actions

Genetic Diversity of Whiteflies Colonizing Crops and Their Associated Endosymbionts in Three Agroecological Zones of Cameroon.

Bemisia tabaci (Gennadius) is as a major pest of vegetable crops in Cameroon. These sap-sucking insects are the main vector of many viruses infecting plants, and several cryptic species have developed resistance against insecticides. Nevertheless, there is very little information about whitefly species on vegetable crops and the endosymbionts that infect them in Cameroon. Here, we investigated the genetic diversity of whiteflies and their frequency of infection by endosymbionts in Cameroon. Ninety-two whitefly samples were collected and characterized using mitochondrial cytochrome oxidase I (mtCOI) markers and Kompetitive Allele Specific PCR (KASP). The analysis of mtCOI sequences of whiteflies indicated the presence of six cryptic species (mitotypes) of Bemisia tabaci, and two distinct clades of Bemisia afer and Trialeurodes vaporariorum. Bemisia tabaci mitotypes identified included: MED on tomato, pepper, okra, and melon; and SSA1-SG1, SSA1-SG2, SSA1-SG5, SSA3, and SSA4 on cassava. The MED mitotype predominated in all regions on the solanaceous crops, suggesting that MED is probably the main phytovirus vector in Cameroonian vegetable cropping systems. The more diverse cassava-colonizing B. tabaci were split into three haplogroups (SNP-based grouping) including SSA-WA, SSA4, and SSA-ECA using KASP genotyping. This is the first time that SSA-ECA has been reported in Cameroon. This haplogroup is predominant in regions currently affected by the severe cassava mosaic virus disease (CMD) and cassava brown streak virus disease (CBSD) pandemics. Three endosymbionts including Arsenophonus, Rickettsia, and Wolbachia were present in female whiteflies tested in this study with varying frequency. Arsenophonus, which has been shown to influence the adaptability of whiteflies, was more frequent in the MED mitotype (75%). Cardinium and Hamiltonella were absent in all whitefly samples. These findings add to the knowledge on the diversity of whiteflies and their associated endosymbionts, which, when combined, influence virus epidemics and responses to whitefly control measures, especially insecticides.

Grain yield performance of spring maize under different agroecological zones

Maize is an important cereal crop which ranks second in production after rice in Nepal with an increasing demand for livestock and poultry ration but declining in production. This experiment was conducted to screen top- and stable yielding maize hybrids in various agroecological zones of Nepal during the spring season. In this study, nine maize genotypes were evaluated across six environments in randomized complete block design with three replications. The additive main effect and multiplicative interaction (AMMI) ANOVA revealed that environment, genotype, and their interaction had a substantial effect on the grain yield and all five principal components (PCs) were significantly different (P < 0.0001). AMMI stability value revealed that genotypes Rampur composite and Kanchan 101 were the most stable genotypes in all environments. The specific adaptation of genotype as explained by Which-won-where model suggest that Godavari in environment E2, Rajkumar in E4 and E5, and Bisco gold 941 in E1, E3 and E6 were the winning genotypes. Furthermore, the mean-versus-stability model revealed that genotype Kanchan 101 had above average yield with greater stability. In addition, biplot analysis revealed that 78.32% of variation is explained by PC1 and 11.41% by PC2 of the interaction effect. The genotype ranking based on revealed that genotype Kanchan 101 was close to the ideal line and Sano ghogha was at the greatest distance. Conclusively, AMMI and genotype and genotype by environment interaction (GGE) model explicates that genotype Kanchan 101 has both the high yield and stability across all agroecological zones. In future research on multi-year trial with emphasis other agronomic traits to assess the stability and priorities for the development of package of practices for maximizing the grain yield is recommended.

Study of the Biodemographic Parameters of Two Genetically Distinct Strains of Callosobruchus maculatus from Two agroecological Zones of Senegal

During this study, we determined different biological parameters of Callosobruchus maculatus populations from two agro-ecological zones of Senegal (the ZSP and the ZVFS). To do this, strains of C. maculatus were collected in two localities, each representing an agro-ecological zone. The analysis of the results obtained shows that fecundity is greater for the strain coming from the silvopastoral zone (55.60 ± 19.144 eggs per female) than for that coming from the Senegal River valley zone (45 ± 18.577 eggs per female.). Furthermore, the evolution of egg laying shows that whatever the strain or population, more than 95% of eggs are laid during the first four days of the infestation with a peak on the second. In addition, the strains are characterized by an egg fertility rate exceeding 65% with a larval survival rate of over 75% and the Fouta strain has the highest rates. However, the emergence rate of the strain from the silvopastoral zone is lower at 49%. The longevity of adults in the Senegal River valley zone is significantly longer (11.035 ± 1.527 days) than that of adults in the silvopastoral zone. The sex ratio is in favor of males for both populations. The total development time and the oviposition-emergence time are relatively the same in the two strains with an average of 31 days and 21 days respectively.

EVALUATING REMOTE SENSING-BASED DROUGHT INDICES: STRENGTHS, LIMITATIONS, AND APPLICABILITY ACROSS SUB-SAHARAN AFRICA'S AGRO-ECOLOGICAL ZONES: A REVIEW

This study reviews the application and effectiveness of various remote sensing (RS) indices for drought monitoring in Sub-Saharan Africa (SSA). Given the region’s diverse climatic zones and frequent drought occurrences, accurate and timely assessment tools are crucial. The study examines indices from different spectral regions, including optical, thermal infrared, and microwave bands, focusing on their spatial and temporal resolutions, data availability, strengths, and limitations. Optical indices such as the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Water Index (NDWI) are effective in semi-arid and sub-humid zones where vegetation density varies. Thermal infrared indices, including the Temperature Condition Index (TCI), the Vegetation Health Index (VHI), and the Temperature Vegetation Dryness Index (TVDI), provide insights into thermal anomalies and vegetation health, with TCI particularly suited for semi-arid zones and TVDI useful in both semi-arid and sub-humid zones. Microwave indices, such as the Normalized Backscatter Moisture Index (NBMI), Vegetation Optical Depth (VOD), and the Microwave Polarization Difference Index (MPDI), excel in capturing soil moisture and vegetation water content, proving useful in humid forest and semi-arid zones. The integration of these indices with other meteorological and hydrological data enhances drought monitoring and management strategies. Recommendations are made for the optimal use of these indices across different SSA agroecological zones.

Prediction of spatial heterogeneity in nutrient-limited sub-tropical maize yield: Implications for precision management in the eastern Indo-Gangetic Plains

Knowledge of the factors influencing nutrient-limited subtropical maize yield and subsequent prediction is crucial for effective nutrient management, maximizing profitability, ensuring food security, and promoting environmental sustainability. We analyzed data from nutrient omission plot trials (NOPTs) conducted in 324 farmers' fields across ten agroecological zones (AEZs) in the Eastern Indo-Gangetic Plains (EIGP) of Bangladesh to explain maize yield variability and identify variables controlling nutrient-limited yields. An additive main effect and multiplicative interaction (AMMI) model was used to explain maize yield variability with nutrient addition. Interpretable machine learning (ML) algorithms in automatic machine learning (AutoML) frameworks were subsequently used to predict attainable yield relative nutrient-limited yield (RY) and to rank variables that control RY. The stack-ensemble model was identified as the best-performing model for predicting RYs of N, P, and Zn. In contrast, deep learning outperformed all base learners for predicting RYK. The best model's square errors (RMSEs) were 0.122, 0.105, 0.123, and 0.104 for RYN, RYP, RYK, and RYZn, respectively. The permutation-based feature importance technique identified soil pH as the most critical variable controlling RYN and RYP. The RYK showed lower in the eastern longitudinal direction. Soil N and Zn were associated with RYZn. The predicted median RY of N, P, K, and Zn, representing average soil fertility, was 0.51, 0.84, 0.87, and 0.97, accounting for 44, 54, 54, and 48% upland dry season crop area of Bangladesh, respectively. Efforts are needed to update databases cataloging variability in land type inundation classes, soil characteristics, and INS and combine them with farmers' crop management information to develop more precise nutrient guidelines for maize in the EIGP.

Evaluating the Response of Watermelon (Citrullus lanatus (L.) to Organic and Inorganic Fertilization in Makurdi, Southern Guinea Savannah, Nigeria

Watermelon consumption in Nigeria is on the increase due to increasing awareness of its nutritional value while its production is on the decrease due to inefficiency of resource management (inputs like fertilizers). This study aims to optimize watermelon (Citrullus lanatus L.) production through the use of organic and inorganic fertilizers. The field experiment was conducted at the Teaching and Research Farm of Joseph Sarwuan Tarka University, Makurdi in the 2019 cropping season under rain-fed conditions. The site falls within the Latitude 7°4'1N and Longitude 8°3'7E at an elevation of about 97m above sea level in the Southern Guinea Savanna Agro-ecological Zone of Nigeria. The experiment treatments, namely and they were T1 (Control 0kg/ha), T2 (150 kg/ha Compost), T3 (200 kg/ha Compost), T4 (250 kg/ha Compost) and T5 (300 kg/ha NPK 20:10:10) laid out in Randomized Complete Block Design with three replications. The study revealed that in comparison with control treatments, 300 kg/ha NPK 20:10:10 produced (31.04t/ha) fruit yield, the application of 250 kg/ha compost enhanced growth and yield parameters of watermelon with fruit yield of (17.65t/ha). The research findings suggest that using compost manure at the rate of 250 kg/ha for watermelon production is viable since it is economical and environmentally friendly alternative to NPK fertilizer due to it cheap and easy to prepare methods, its beneficial effects on soil, groundwater and the environment. It is further recommended that, in Makurdi, smallholder farmers, should adopt the application of compost at the rate of 250 kg/ha for optimum yield

Edaphic influences on soil organic carbon in the forest systems of southern Western Ghats, India.

Spatial distribution and edaphic influences on soil organic carbon (SOC) are key determinants of carbon sequestration potential, and analysis of aggregate-protected SOC gives an in-depth understanding of the stability of carbon stored in soils. The present study evaluated the edaphic effects on the SOC in four different forest types-tropical evergreen forest, tropical moist deciduous forest, tropical dry deciduous forest and shola forest-in the southern high hills agro-ecological zone of Western Ghats, India. SOC stocks at depths of up to 1m varied significantly across forest types, with the highest levels observed in the shola forest type (441.08Mg C/ha) and the lowest in the dry deciduous forest (138.17Mg C/ha). Around 70% of SOC was found in upper layers (0-30cm) in all the studied forest types. Evaluation by a fixed-effect model showed that forest type, soil depth and aggregate size significantly affected SOC storage in these systems. An assessment of the relative importance and effect of 14 edaphic factors on SOC content in different forest types using the random forest model showed that the algorithm could explain 93.68%, 41.72%, 45.53% and 75.2% variability of SOC concentration across shola, dry deciduous, moist deciduous and evergreen systems, respectively. Across all forest types, except for dry deciduous forests, soil texture was found to be the primary factor influencing SOC, surpassing all other edaphic parameters. Ionic interactions by way of metal oxides like Ca2+, Al3+, Fe3+, Mg and H+ influenced the SOC in tropical forest systems. The insights into SOC dynamics and the edaphic factors regulating them offer valuable guidance for forest management in tropical regions, particularly regarding climate change mitigation.