On-farm Testing Research Articles

Immunological quality of colostrum and specific antibodies against enteropathogens in the colostrum and transition milk of crossbred Gir × Holstein cows.

Colostrum management is crucial for enhancing the immune response against enteropathogens and the survival of dairy calves during the first few weeks of life. However, few physiological studies have investigated the dynamics of general and specific immunoglobulin G (IgG) content in cow milk during early lactation stages, particularly in that of crossbred Gir × Holstein dairy cows, the most predominant dairy cattle population in tropical countries, such as Brazil. Therefore, this study evaluated the effects of parity and milking order on the volume and quality of colostrum, transition milk, and mature milk in crossbred Gir × Holstein cows using three traditional on-farm tests. The dynamics of IgG in the mammary secretions and the specific antibody levels against enteropathogens were also determined using sandwich enzyme-linked immunosorbent assay (ELISA) during the early stages of lactation. Fifty healthy Gir × Holstein cows were divided into two groups based on parity number, i.e., primiparous (n = 18) and multiparous (n = 33). They were monitored from the first to the 43rd milking. The colostrum volume and quality were evaluated using a colostrometer, Brix refractometer, and Colostro Balls after the first milking, in addition to the colostral IgG levels measured using sandwich ELISA as a reference standard. On-farm tests showed that the colostrum samples obtained from Gir × Holstein cows exhibited an optimal colostrum quality based on the literature criteria, regardless of parity number; however, the IgG mass was higher in the colostrum of multiparous (201 ± 67.03g) cows than in that of primiparous (144 ± 32.40g) cows. The volume and composition of transition and whole milk were also assessed at the second to ninth, 11th, 13th, 15th, 29th, and 43rd milkings. Multiparous cows produced higher volumes of transition milk than primiparous cows. In addition, multiparous cows exhibited a higher total solids percentage in their postpartum mammary secretions than primiparous cows. A higher percentage of inhibition of specific antibodies against Escherichia coli K99 was observed in the blood serum of multiparous cows than in that of primiparous cows. The volume and composition of mammary secretions changed over time; milk production increased, whereas total solids, total IgG, and specific antibody levels against most enteropathogens decreased, regardless of parity. Additionally, an association between parity and time was observed with respect to milk yield, the Brix score (%), and specific antibody levels against the Clostridium perfringens alpha toxin in mammary sections and against coronavirus and rotavirus in blood samples. This association indicated higher values in multiparous cattle than in primiparous cattle at specific time points. In conclusion, this study reveals postpartum time-dependent changes in the physiological and immunological components in the mammary secretions and blood of crossbred Gir × Holstein cows from the first to the 43rd milking. These results will contribute to the development of future research in Gir × Holstein-specific neonatology, which is genetically adapted to tropical and subtropical countries.

Agronomic Performance and Resistance to Maize Lethal Necrosis in Maize Hybrids Derived from Doubled Haploid Lines

Maize (Zea mays L.) is one of the most widely cultivated grain crops globally. In sub-Saharan Africa (SSA), it plays an important role in ensuring both food and income security for smallholder farmers. This study was conducted to (i) assess the performances of testcross hybrids constituted from maize lethal necrosis (MLN) tolerant doubled haploid (DH) lines under various management conditions; (ii) estimate the combining ability effects and determine the nature of gene action in the DH lines; and (iii) identify DH lines and testcross hybrids for resistance to MLN, high grain yield, and other important traits. Eleven DH lines were crossed with 11 single-cross testers using the line-by-tester mating design, and 115 successful testcross hybrids were generated. These hybrids, along with five commercial check hybrids, were evaluated across four optimum management conditions, two MLN artificial inoculations, and one managed drought environment in Kenya. Under each management condition, the effects of genotypes, environments, and genotype-by-environment interactions were significant for grain yield (GY) and most other traits. Hybrids T1/L3, T10/L3, and T11/L3 exhibited higher grain yields under at least two management conditions. A combining ability analysis revealed that additive gene effects were more important than non-additive effects for GY and most other traits, except for leaf senescence (SEN) and MLN disease severity score. DH line L3 exhibited a desirable general combining ability (GCA) effect for GY, while L5 was the best general combiner for anthesis date (AD) and plant height (PH) across all management conditions. DH lines L2, L6, and L7 showed negative GCA effects for MLN disease severity. Single-cross testers T11 and T10 were good general combiners for GY under all management conditions. Hybrids T2/L11, T9/L10, and T2/L10 demonstrated high specific combining ability (SCA) effects for GY under all conditions. This study identified DH lines and testers with favorable GCA effects for grain yield, MLN resistance, and other agronomic traits that can be used in breeding programs to develop high-yielding and MLN-resistant maize varieties. Better-performing testcross hybrids identified in the current study could be verified through on-farm testing and released for commercial production to replace MLN-susceptible, low-yield hybrids grown in the target ecologies.

On-farm multi-location testing of synthetic dual-purpose chicken breed (DZ-white) at Lowland area of Kaffa Zone of Ethiopia

A study evaluated synthetic dual purpose DZ-white’s adaptability and production performance in lowland agro-ecology. A total of 900 day-old chicks were distributed to fifteen (15) participant farmers (sixty chicks per farmer). Vaccines for Newcastle and Gumboro were administered as per veterinarian recommendations. Initially, chicks were supplemented with commercial feed and gradually shifted to locally available feed resources. Data on body weight, age at first egg, egg production, egg weight and farmers’ perception were recorded. On average, the adult male and female chicken body weight recorded at 20 weeks of age were 331.2 grams and 273.3 grams per chicken, respectively. Moreover, in the present study, the adult male and female chicken body weight recorded at 20 weeks of age were 1541.3 grams and 476.9 grams per chicken, respectively. The result also showed that an average egg weight at initial laying stage 5%, 50% and peak production stage were 44.09 grams, 48.33 grams and 55.45 grams, respectively. In the current study, chickens produced 296 eggs annually. Based on the adaptability, production performance and social acceptance, participant farmers preferred synthetic dual purpose DZ- white chicken breed to commonly used local and exotic breeds. As a result of their moderate growth and production performance, scavenging ability and social acceptance, demonstration and scaling up of the breed in the rural smallholder production system are highly recommended.

PSIV-29 Efficacy of a chute-side pregnancy test on early pregnancy determination in mature Rambouillet ewes

Abstract Distinguishing pregnant from non-pregnant ewes in early pregnancy allows for more efficient flock management by producers. While early pregnancy detection techniques like ultrasonography and hormone quantification are well established, these techniques are often not adaptable to field conditions or require specialized equipment and training. The objective of this study was to evaluate a validated bovine commercial on-farm pregnancy test on efficacy for detecting early pregnancy in distinct blood constituents of ewes. Rambouillet ewes [n = 30; average body weight (BW) = avg 60.9 ± 1.1 kg; age 2 to 8 yr) were estrous synchronized using a 5 d CIDR protocol followed by 2 injections of PGF2α at 0 and 4 h. A rattle-painted ram was subsequently placed with ewes for a 35-d breeding season. Blood constituents including whole blood (WB), plasma (PL), and serum (SE) were collected via jugular venipuncture prior to synchronization (d 0) and on d 20, 35, and 70 after breeding. Blood constituents were individually evaluated using the IDEXX Alertys OnFarm pregnancy test for pregnancy detection. Trans-abdominal ultrasonography was performed on d 35 and d 70 post-breeding. Serum progesterone (P4) was quantified on d 100 of gestation to confirm pregnancy status. Progesterone concentrations ≥ 4 ng/mL were considered pregnant. On d 20 of gestation, IDEXX tests agreed with P4 concentrations on d 100 (χ2 = 0.30) in WB, SE and PL at 35.7, 53.6, and 53.6%, respectively. Pregnancy detection accuracy increased on d 35 of gestation as IDEXX tests agreed with P4 at d 100 (χ2 = 1.00) in WB, SE, and PL at 60.7, 60.7 and 60.7% accuracy, respectively. On d 70 of gestation, IDEXX tests agreed with P4 at d 100 (χ2 = 0.81) in WB, SE, and PL at 90.7, 93.3 and 93.3% accuracy, respectively indicating similarity in pregnancy diagnosis in the two methods. Detection of pregnancy using ultrasonography at d 35 identified 33% of pregnant ewes, while d 70 ultrasound detected 93% of pregnant ewes when compared with d 100 serum P4. Results suggest that the IDEXX pregnancy test provides early diagnosis of pregnancy with d 70 results comparable to d 100 serum P4 quantification regardless of blood constituent type.

Performance of on farm testing (OFT) on application of zinc solubilizing bacteria (ZSB) on yield of rice

Performance of on farm testing (OFT) on application of zinc solubilizing bacteria (ZSB) on yield of rice

On Farm Testing of a High Yielding and Nitrogen Responsive Rice Variety MTU (Maruteru) 1212 in West Godavari District of Andhra Pradesh, India

The On Farm Testing (OFT) has been taken up on rice MTU 1212 variety in three different locations during Kharif season for two consecutive years to find out the performance of rice variety on yield and economics of rice. The higher yield i.e., 7669, 7574 kg/ha was noticed with MTU 1212 rice variety as compared to MTU 7029 (6607 and 6625 kg/ha) during both the years of experimentation. Net returns and B:C ratio were higher with MTU 1212 rice variety (Rs. 84,343, 95,090 and 89,717/ha) when compared to farmers practice (Rs. 60,246, 71,603 and 65,925/ha) during 2022-23, 2023-24 and in pooled data, respectively.

Development of an animal health testing tool to reduce antimicrobial use on farms: perceptions, implications, and needs of Irish dairy farmers and farm veterinarians

BackgroundThe threat of antimicrobial resistance is triggering the need for behavioural change towards antimicrobial use on Irish farms. Newly introduced veterinary medicine regulations are mandating the restricted and more prudent use of antimicrobials in the animal health sector. The need to reduce antimicrobials has placed a greater emphasis on the importance of animal health testing, however, issues with current testing practices are affecting diagnosis and subsequent drug usage. There is potential for digital technologies to address these issues and reduce antimicrobial use on farms, however, for these tools to be successful, they would need to be developed in collaboration with future end users.ResultsUsing qualitative approaches (focus groups), this study engages with dairy farmers and farm veterinary practitioners to detail current challenges with animal health diagnosis and to explore the initial development of a rapid, on-farm animal health testing tool to address these challenges. Issues with timing and testing, the role of knowledge and experience, and veterinarian availability all affect the ability of farmers and veterinarians to diagnose animal health issues on farm. These issues are having negative implications including the increased and unnecessary use of antimicrobials. An on-farm testing tool would help mitigate these effects by allowing veterinarians to achieve rapid diagnosis, facilitating the timely and targeted treatment of animal illnesses, helping to reduce overall antimicrobial use on farms. However, engagement with end users has highlighted that if a tool like this is not developed correctly, it could have unintended negative consequences such as misdiagnosis, increased antimicrobial use, challenges to farmer-veterinarian relationships, and data misuse. This study outlines initial end user needs and requirements for a testing tool but suggests that in order to successfully design and develop this tool, co-design approaches such as Design Thinking should be applied; to mitigate future negative impacts, and to ensure a testing tool like this is designed specifically to address Irish dairy farmers and farm veterinarians’ values and needs, ensuring responsible and successful uptake and use.ConclusionsDigital tools can be effective in reducing antimicrobial use on farms, however, to be successful, these tools should be designed in a user centred way.

Development and evaluation of a lateral flow-based portable optical system for determination of the pregnancy status of dairy cows

Our objectives were to develop and evaluate an integrated system consisting of a lateral-flow immunoassay (LFIA) and an electronic portable imaging device for determination of pregnancy status of cows based on plasma concentrations of pregnancy-specific protein B (PSPB). Experiment 1 was conducted to test the performance of the LFIA for PSPB (PSPB-LFIA) whereas experiment 2 was conducted to evaluate the performance of the integrated system including both the LFIA and imaging device. The PSPB-LFIA strips were made of nitrocellulose membrane with polystreptavidin, anti-mouse antibody, Europium-anti-PSPB conjugates, and biotin-PSPB. After adding buffer and plasma in a 96-well plate, strips were dipped to initiate flow and were read in a fluorescence microscope to estimate PSPB concentrations based on the test-to-control line signal (T/C ratio). The T/C ratio of standards was linearly associated with PSPB (R2 = 0.99 in both experiments) concentrations. To test the ability to identify pregnant cows of the PSPB-LFIA only or the integrated system, plasma samples were collected and transrectal ultrasonography (TUS) was conducted 29 to 35 d post AI in lactating Holstein cows (Experiment 1: n = 83; Experiment 2: n = 205). A cow was considered pregnant (Preg) if concentrations of PSPB in plasma obtained by ELISA were ≥2 ng/mL or if an embryo was visible by TUS. In Experiment 1, the accuracy of the PSPB-LFIA compared with ELISA was 92.7% (91.2% Se; 96.1% Sp; 98.1% PPV; 83.3% NPV) and compared with TUS was 90.4% (100% Se; 78.9% Sp; 84.9% PPV; 100% NPV). The agreement between LFIA and ELISA (kappa = 0.84; 95%CI 0.71-0.96) or LFIA and TUS (kappa = 0.80; 95%CI 0.67-0.93) as methods to classify cows as Preg or Non-Preg was high. In Experiment 2, the accuracy of the PSPB-LFIA compared with ELISA was 96.1% (93.8% Se; 100% Sp; 100% PPV; 90.5% NPV) and compared with TUS was 92.2% (99.0% Se; 84.7% Sp; 87.6% PPV; 98.8% NPV). The agreement between LFIA and ELISA (kappa = 0.92; 95%CI 0.86-0.97) or LFIA and TUS (kappa = 0.84; 95%CI 0.77-0.92) as methods to classify cows as Preg or Non-Preg was high. We conclude that a system integrating a fluorescence-based LFIA and an optical reader was effective for classifying cows as pregnant or not pregnant based on estimations of plasma concentrations of PSPB. This novel system serves as a platform for further development of on-farm pregnancy testing tools based on measurement of biomarkers of pregnancy in bodily fluids of cattle.

Community-based breeding programs can realize sustainable genetic gain and economic benefits in tropical dairy cattle systems.

Implementing an appropriate breeding program is crucial to control fluctuation in performance, enhance adaptation, and further improve the crossbred population of dairy cattle. Five alternative breeding programs (BPs) were modeled considering available breeding units in the study area, the existing crossbreeding practices, and the future prospects of dairy research and development in Ethiopia. The study targeted 143,576 crossbred cows of 54,822 smallholder households in the Arsi, West Shewa, and North Shewa zones of the Oromia Region, as well as the North Shewa zone of the Amhara Region. The alternative BPs include conventional on-station progeny testing (SPT), conventional on-farm progeny testing (FPT), conventional on-station and on-farm progeny testing (SFPT), genomic selection (GS), and genomic progeny testing (GPT). Input parameters for modeling the BPs were taken from the analysis of long-term data obtained from the Holetta Agricultural Research Center and a survey conducted in the study area. ZPLAN+ software was used to predict estimates of genetic gain (GG) and discounted profit for goal traits. The predicted genetic gains (GGs) for milk yield (MY) per year were 34.52 kg, 49.63 kg, 29.35 kg, 76.16 kg, and 77.51kg for SPT, FPT, SFPT, GS, and GPT, respectively. The GGs of the other goal traits range from 0.69 to 1.19 days per year for age at first calving, from 1.20 to 2.35 days per year for calving interval, and from 0.06 to 0.12 days per year for herd life. Compared to conventional BPs, genomic systems (GPT and GS) enhanced the GG of MY by 53%-164%, reduced generation interval by up to 21%, and improved the accuracy of test bull selection from 0.33 to 0.43. The discounted profit of the BPs varied from 249.58 Ethiopian Birr (ETB, 1 USD = 39.55696 ETB) per year in SPT to 689.79 ETB per year in GS. Genomic selection outperforms SPT, SFPT, and FPT by 266, 227%, and 138% of discounted profit, respectively. Community-based crossbreeding accompanied by GS and gradual support with progeny testing (GPT) is recommended as the main way forward to attain better genetic progress in dairy farms in Ethiopia and similar scenarios in other tropical countries.

Assessment of Biometric Characteristics and Yield of Two Onion Cultivars in Soils of Anantapur District, Andhra Pradesh, India

In order to identify suitable onion varieties for Ananthapur district of Andhra Pradesh, an On Farm Testing (OFT) was conducted during the Rabi seasons of 2022-23 and 2023-24 at Krishi Vigyan Kendra operated mandals of Ananthapur district. Two high yielding onion varieties were tested with five locations during each year in comparison to that of farmers variety of being grown by the farmers of the area. Different treatments included onion varieties of NHRDF Red 4 (TO1), NHRDF Red 3 (TO2) and Bellary local variety as farmers practice. The results revealed that highest plant height (58.25 cm), maximum number of leaves (8.35), lesser duration (123 days), maximum weight of bulb (77.76 g) and bulb yield (26.45 t/ha) was reported from NHRDF Red 4 than NHRDF Red-3 and farmers local variety (Bellary local). Similarly, NHRDF Red 4 variety recorded higher gross returns (Rs. 2,49,066/ha), net returns (Rs. 1,11,407/ha) and B:C ratio of 1.81 as compared to other two varieties. From the study, it is concluded that onion variety NHRDF Red-4 had better performance in the trial and can be recommended for cultivation in Ananthapur district of Andhra Pradesh.

Onfarm testing of Sorghum variety NTJ-5 in semi-arid regions of Andhra Pradesh

Onfarm testing of Sorghum variety NTJ-5 in semi-arid regions of Andhra Pradesh

Selecting an appropriate statistical model for estimating genetic parameters: A case study of pig maternal breeds in Czechia

A three-trait statistical model was designed for backfat thickness (BFT) and loin eye muscle depth (LMD) with accompanying variable average daily gain (ADG). Data from 82,507 Czech Large White and 37,556 Czech Landrace pigs were collected during on-farm performance testing from 2013 to 2022. Several animal models were tested with different combinations of effects and complexity. Model performance was evaluated by the linear regression (LR) method and predictivity. In Czech Large White, the preferred model comprised fixed effects of sex, birth year, herd, and ultrasound device, as well as random effects of herd-year-season (HYS), litter, and animal. In Czech Landrace, HYS was treated as fixed instead. The inclusion of maternal effects was not supported due to questionable impact on the main statistics. The selected model yielded mean absolute bias of 0.11 and 0.19, mean determination of 0.39 and 0.21, mean population accuracy of 0.36 and 0.31, and mean predictivity of 0.13 and 0.08 in Large White and Landrace, respectively. Heritability estimates were overall lower than those reported by other authors: 0.23, 0.10, and 0.10 in Large White and 0.26, 0.10, and 0.09 in Landrace for ADG, BFT, and LMD, respectively. Genetic correlations, on the other hand, reached relatively high values: 0.61, 0.61, and 0.66 in Large White and 0.71, 0.92, and 0.70 in Landrace for ADG-BFT, ADG-LMD, and BFT-LMD, respectively.

Field Performance of Sesame Varieties under Rainfed Ecosystem in Southern Tamil Nadu, India

In Pudukottai district, sesame is cultivated in 3,000 ha and farmers are predominantly growing very old sesame variety TMV 3. This variety is more susceptible to pest and diseases which leads to increased cultivation cost towards plant protection measures as well as reduced yield and income. To overcome this problem, Krishi Vigyan Kendra, Tamil Nadu Agricultural University, Pudukkottai conducted On Farm Testing (OFT) in sesame varieties for promoting the high yielding varieties. Fifteen farmers were selected in different locations of Thiruvarankulam block, Pudukkottai district in Tamil Nadu. Critical inputs of seeds of sesame varieties like TMV 7 and G.Til 10 were distributed to the farmers. The plant physiological and yield parametersviz., plant height (cm), No. of branches, No. of capsules/ branch, capsule length (cm), seeds per capsule, Yield (q/ha) and BC ratio were recorded. The results revealed that, Among the sesame varieties tested, TMV 7 was recorded the maximum plant height (125 cm), number of branches (6.6), number of capsules per plant (43.5), capsules length ( 3.3 cm), No of seeds per capsule ( 57) which resulting in the highest yield of 7.8 q/ha followed by sesame G.Til 10 which recorded more plant height (120 cm), number of branches (6.0), number of capsules per plant (38.2) capsules length ( 3.1 cm), No of seeds per capsule ( 51) and yield of 7.3 q/ha compared to farmers variety cultivating variety TMV 3 which registered the lowest plant physiological parameters and yield (6.4 q/ha). The maximum B:C ratio was recorded in sesame variety TMV 7 (3.12) followed by G.Til 10 ( 2.92) over the variety TMV 3 (2.84). From this trial, it was concluded that, farmers are satisfied with the sesame TMV 7 variety for cultivation due to its low pest and disease incidence, higher yield and BC ratio.

Leveraging digital agriculture for on-farm testing of technologies

The Precision Nitrogen Project (PNP) worked with more than 80 corn and winter wheat producers to inexpensively design and implement randomized, replicated field strip trials on whole commercial farm fields, and to provide site-specific testing of current nitrogen (N) technologies. This article proposes a conceptual framework and detailed procedure to select the N technology to be tested; design and implement field trials; generate, process, and manage field trial data; and automatically analyze, report, and share benefits from precision N technology. The selection of the N technology was farmer-driven to ensure a good fit and to increase the likelihood of future technology adoption. The technology selection method was called the “N tiered approach”, which consisted of selecting a technology that progressively increases the level of complexity without exceeding the farmer’s learning process or farm logistic constraints. The N tools were classified into (1) crop model-based, (2) remote sensing-based, (3) enhanced efficiency fertilizers, and (4) biologicals. Field strip trials comparing producers’ traditional management and the selected N technology were combined with site-specific N rate blocks placed in contrasting areas of the fields. Yield data from the N rate blocks was utilized to derive the site-specific optimal N rate. The benefits of current N technologies were quantified by comparing their yield, profit, and N use efficiency (NUE) to growers’ traditional management and to the estimated site-specific optimal N rate. Communication of the trial results back to the growers was crucial to ensure the promotion and adoption of these N technologies farm wide. The framework and overall benefits from N technologies was presented and discussed. The proposed framework allowed researchers, agronomists, and farmers to carry out on-farm precision N experimentation using novel technologies to quantify benefits of digital ag technology and promote adoption.

RNA and protein biomarkers for detecting enhanced metabolic resistance to herbicides mesosulfuron-methyl and fenoxaprop-ethyl in black-grass (Alopecurus myosuroides).

The evolution of non-target site resistance (NTSR) to herbicides leads to a significant reduction in herbicide control of agricultural weed species. Detecting NTSR in weed populations prior to herbicide treatment would provide valuable information for effective weed control. While not all NTSR mechanisms have been fully identified, enhanced metabolic resistance (EMR) is one of the better studied, conferring tolerance through increased herbicide detoxification. Confirming EMR towards specific herbicides conventionally involves detecting metabolites of the active herbicide molecule in planta, but this approach is time-consuming and requires access to well-equipped laboratories. In this study, we explored the potential of using molecular biomarkers to detect EMR before herbicide treatment in black-grass (Alopecurus myosuroides). We tested the reliability of selected biomarkers to predict EMR and survival after herbicide treatments in both reference and 27 field-derived black-grass populations collected from sites across the UK. The combined analysis of the constitutive expression of biomarkers and metabolism studies confirmed three proteins, namely, AmGSTF1, AmGSTU2 and AmOPR1, as differential biomarkers of EMR toward the herbicides fenoxaprop-ethyl and mesosulfuron in black-grass. Our findings demonstrate that there is potential to use molecular biomarkers to detect EMR toward specific herbicides in black-grass without reference to metabolism analysis. However, biomarker development must include testing at both transcript and protein levels in order to be reliable indicators of resistance. This work is a first step towards more robust resistance biomarker development, which could be expanded into other herbicide chemistries for on-farm testing and monitoring EMR in uncharacterised black-grass populations. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Microbiological analysis strategies for detecting pathogens and assessing biosecurity practices in outdoor earthen shrimp farms

The need for rapid and reliable on-farm bacteriological test methods to detect pathogens and assess the success of biosecurity practices in fish and shrimp farms has been increasing. This study compared on-farm and in-laboratory (after refrigerated transportation) analyses for black tiger shrimp (Penaeus monodon) cultured in two outdoor earthen ponds in low-resource settings on the southeastern coast of Bangladesh, using basic bacteriological facilities. Water quality parameters, including temperature, dissolved oxygen (DO), pH and salinity were determined at monthly intervals during summer (April to June). Water temperature in two farms ranged from 26.3°C to 29.3°C (27.7±1.6°C in Farm-1 and 27.4±0.9°C in Farm 2), within suitable limits for shrimp culture. DO levels varied from 5.1±0.2 to 5.4±0.5 mg/l, pH from 7.1±0.2 to 7.1±0.6, and salinity from 14.7±1.2 to 15.7±0.6 ppt, all within optimal ranges for shrimp farming. Bacterial loads showed slight variations between sampling periods. On-farm analyses consistently showed lower bacterial loads in shrimp samples compared to in-laboratory analyses with bacterial counts increasing over transportation time. Water temperature significantly influenced bacterial load as reflected by different sampling periods. The total bacterial load in farm water, sediment and shrimp samples showed notable differences between on-farm and in-laboratory analyses, reflecting the impact of environmental conditions, handling practices and time delays. It is concluded that on-farm microbiological analysis strategy is an effective method for detecting pathogens and assessing biosecurity practices in shrimp farms cultured in outdoor earthen ponds.

Construction of a Scale to Measure Correlates of Adoption of Sustainable Domains in On-Farm Testing Interventions

The study was conducted in 2023 with an aim to identify SRDs and develop a reliable scale for adoption correlates within these domains. The development of the scale follows a systematic Likert scale development methodology involving identification of SRDs of OFT interventions, delineation of different dimensions of each correlate of adoption, dimension analysis and selection, and its standardisation by reliability and validity assessment. The final scale comprises 32 dimensions under seven adoption correlates, selected via exploratory factor analysis (EFA) and item discrimination index calculation. The scale demonstrated strong content, construct, and convergent validity, with an average variance extracted (AVE) value of 0.69 and composite reliability (CR) score of 0.97. It also exhibited high internal consistency, with a Cronbach’s alpha of 0.97 and a split-half reliability coefficient of 0.963. The standardized scale is effective for measuring factors related to the adoption of improved technologies and practices, providing a valuable tool for researchers in various fields. The administration of the developed scale and the subsequent correlation analysis revealed significant relationships, with human resource correlates showing the highest correlation (r = 0.895), followed closely by technological (r = 0.872) and economic correlates (r = 0.87), underscoring the critical factors influencing farmers’ adoption behaviour.

ClimMob: Software to support experimental citizen science in agriculture

Experimental citizen science offers new ways to organize on-farm testing of crop varieties and other agronomic options. Its implementation at scale requires software that streamlines the process of experimental design, data collection and analysis, so that different organizations can support trials. This article considers ClimMob software developed to facilitate implementing experimental citizen science in agriculture. We describe the software design process, including our initial design choices, the architecture and functionality of ClimMob, and the methodology used for incorporating user feedback. Initial design choices were guided by the need to shape a workflow that is feasible for farmers and relevant for farmers, breeders and other decision-makers. Workflow and software concepts were developed concurrently. The resulting approach supported by ClimMob is triadic comparisons of technology options (tricot), which allows farmers to make simple comparisons between crop varieties or other agricultural technologies tested on farms. The software was built using Component-Based Software Engineering (CBSE), to allow for a flexible, modular design of software that is easy to maintain. Source is open-source and built on existing components that generally have a broad user community, to ensure their continuity in the future. Key components include Open Data Kit, ODK Tools, PyUtilib Component Architecture. The design of experiments and data analysis is done through R packages, which are all available on CRAN. Constant user feedback and short communication lines between the development teams and users was crucial in the development process. Development will continue to further improve user experience, expand data collection methods and media channels, ensure integration with other systems, and to further improve the support for data-driven decision-making.

Enhancing Blackgram Yield: Validating a Soil Test-driven Fertilizer Prescription Equation for Alfisol

Background: On-farm testing of fertilizer prescription equations is imperative to demonstrate the efficacy of technology implementation for the benefit of the stakeholders. The current research was conducted on a farmer’s holding, using blackgram (Vigna mungo L. Hepper), to evaluate the fertiliser prescription equations (FPEs) in the Thondamuthur block of Coimbatore district, Western Zone of Tamil Nadu. The treatments included control, blanket, blanket + FYM, Soil Test Crop Response (STCR) based fertilizer dose for an yield target of 1.0, 1.2 and 1.4 t ha-1, STCR-IPNS based fertilizer dose for an yield target of 1.0, 1.2 and 1.4 t ha-1 and farmer’s practice. Methods: Using the data of yield and fertilizer doses applied, parameters viz., per cent achievement, response ratio (RR), benefit: Cost ratio (BCR) were computed. Result: STCR-IPNS with a targeted yield of 1.4 t ha-1 consistently displayed the most substantial growth, superior yield and yield-related characteristics, with the per cent achievement falling within ±10 per cent variation. Furthermore, it exhibited a higher response ratio (RR) and a more favourable Benefit Cost Ratio (BCR) when compared to both farmer’s practice and blanket fertilizer recommendations. The results revealed that the target yield has been achieved within ±10 per cent variation proving the validity of the equations.

Assessing the Performance of Latest Greengram Varieties under Improved production Packages in Thiruppur, Tamil Nadu, India

On Farm Testing (OFT) in Mungbean Yellow Mosaic Virus (MYMV) resistant and high yielding greengram varieties was conducted by Krishi Vigyan Kendra, Tamil Nadu Agricultural University, Tirupur in farmers field during kharif 2020. Totally 15 farmers each with one acre were selected in three villages of Pongalur Block in Tirupur district of Tamil Nadu. Critical input viz., seeds of greengram varieties CO 8 and DGG 1 were distributed to the farmers and the varietal performance were assessed along with the existing variety under cultivation VBN 2. The plant physiological parameters viz., plant height, number of nodules / plant and yield attributing parameters such as number of pods / plants, number of branches/plant, Mung bean Yellow Mosaic Virus (MYMV) disease incidence (%), yield (q ha-1) and B:C ratio were recorded. The results revealed that, among the three varieties, Greengram CO 8 was recorded more number of pods (42) and minimum incidence of Mungbean Yellow Mosaic Virus (MYMV) disease incidence of 3.2 per cent resulting in the highest yield of 9.5 q ha-1 followed by DDG 1 with 34 pods/plant, MYMV disease incidence of 7.3 per cent and yield of 8.4 q ha-1 compared to the existing variety VBN 2, which recorded the lowest number of pods (31 Nos.), yield (7.6 q ha-1) with the highest MYMV disease incidence (12.5%). The highest B:C ratio was recorded in greengram variety CO 8 (2.92) which was followed by DDG 1 (2.58). It was concluded that, farmers of Tirupur district in Tamil Nadu were satisfied with cultivation of greengram CO 8 variety due to the lowest disease incidence, higher yield and Benefit Cost Ratio.