Higher Economic Returns Research Articles

Dryland crop production and economic returns for crop residue harvest or grazing

AbstractWhile crop residues could provide an additional source of revenue for agricultural producers, there are concerns that harvesting these residues could have negative effects on productivity and economic returns. Although crop residue harvest effects have been studied in wetter areas, including the U.S. Corn Belt and Southeast, there have been few studies in more arid areas. The objective of this analysis was to quantify intermediate‐term (6‐yr) effects of crop residue harvest on crop productivity and economic returns for different biomass harvest intensities and methods, and for different practices aimed at mitigating negative effects of residue harvest in the U.S. Northern Great Plains. Crop rotation treatments included spring wheat (Triticum aestivum L.)–dry pea (Pisum sativum L.), W–P; spring wheat–dry pea/cover crop mix, W–P/CC; and spring wheat–dry pea–corn (Zea mays L.), W–P–C. Biomass removal treatments included no biomass removal, bale and remove wheat straw, bale and remove residues from each crop, and graze all crop residues. Significant corn yield reductions occurred when baling crop residues, but not with grazing. However, significant spring wheat yield reductions occurred with grazing in the W–P rotation. Grazing may be more suited to the W–P–C rotation than the W–P or W–P/CC rotations as the breakeven grazing price was lower in this rotation, and the grazing treatment in this rotation had both relatively high economic returns and low economic risk over the study period.

Simulating Araucaria angustifolia (Bertol.) Kuntze Timber Stocks With Liocourt’s Law in a Natural Forest in Southern Brazil

This paper presents a simulation of the regulation of Araucaria angustifolia (Bertol.) Kuntze timber stocks using Liocourt’s law. Although this species is currently protected by law, recent government initiatives are being considered to propose sustainable forest management practices by selecting small rural properties in Southern Brazil. Here, we simulate the applicability of Liocourt’s law in a typical rural property, the size of which is approximately 85 ha. Forest inventory measurements were conducted by estimating the diameter at the breast height (d), total height (h), and annual diameter increments of 308 trees that fit the criteria of d ≥ 10 cm, distributed on 35 permanent plots of 400 m2 each. As a result, a reverse J-shaped d distribution was found. On average, 303 trees can be found per hectare (ha). Local allometric equations showed their basal area (G) to be 21.9 m2∙ha−1, and their commercial volume (V) to be 172 m3∙ha−1, whereas Liocourt’s quotient (q) was 1.31. Based on these attributes, nine different forest management scenarios were proposed by simulating a remaining basal area (Grem) of 10.0, 14.0, and 18.0 m2∙ha−1, and Liocourt’s quotient was changed to 1.1, 1.3, and 1.5. All scenarios consider a d of 62.5 cm. In the less intensive scenario (i.e., q value = 1.5 and larger basal area of 18.0 m2·ha−1) there is greater optimization of space, and higher economic return is ensured to rural producers due to the definition of shorter cutting cycles. This also allows a faster growth rate in both d and h for smaller trees, due to the higher incidence of light onto the lower canopy layer, increasing the natural regeneration implementation of other native species. Forest management should thus be considered a goal in addition to consumer market characteristics for defining the ideal timber stock scenario.

Silicon as an acidity corrective associated with Azospirillum brasilense to improve nitrogen management and wheat profitability

This research aimed to study a possible synergistic effect with inoculation with A. brasilense and N doses, associated with the application of silicon in acidity corrective form, evaluating the grain yield of irrigated wheat in Cerrado region. The experiment was conducted in Selviria, MS, Brazil, under a no-till system, on a Latossolo Vermelho distrofico (Oxisol). The experiment was set up as a randomized block design with four replications, in a 2 × 5 × 2 factorial arrangement consisting of two soil corrective sources (dolomitic limestone and Ca and Mg silicate as source of Si); five N doses (0, 50, 100, 150, and 200 kg ha-1) applied in topdressing; and with and without inoculation with A. brasilense. Inoculation makes wheat production more profitable, irrespective of N doses and corrective sources. The N dose of 139 kg ha-1 with dolomitic limestone associated with inoculation of A. brasilense provided the greatest grain yield. However, the highest economic return was obtained at the N dose of 100 kg ha-1, with dolomitic limestone application and inoculation.

Insecticide resistance management against thrips (Thysanoptera: Thripidae) on onion in the central Rift Valley of Ethiopia

Two field experiments were conducted in the Central Rift Valley of Ethiopia in the hot and cool dry seasons of 2016/2017 with the objective to develop an insecticide resistance management program on thrips infesting onion. The first experiment dealt with the evaluation of four different insecticides namely profenofos, λ–cyhalothrin, imidacloprid, and spinetoram in different sequences on thrips population and their effect on yield. The second experiment examined the effect of admixing the surfactant organosilicone with imidacloprid, spinetoram and dimethoate. A Randomized Complete Block Design with three replications was used for both experiments. Data on number of thrips, bulb yield and economic returns were collected. The insecticide imidacloprid and spinetoram resulted in fewer numbers of thrips and higher yields than profenofos and λ –cyhalothrin. Application of the more effective insecticides when the thrips population was high followed by less effective insecticides resulted in better control and higher economic return. Surfactant added insecticides gave a fewer numbers of thrips and higher yields than the corresponding insecticides applied without surfactant. The sequential application of spinetoram and imidacloprid with less effective λ-cyhalothrin and profenofos by mixing with adjuvant are recommended for thrips control as an integral component of thrips management in the Central Rift Valley of Ethiopia.

Joining forces to strengthen European health research.

Joining forces to strengthen European health research.

GROWING POSSIBILITIES OF MEDICINAL AND AROMATIC PLANTS IN GREENHOUSES CLIMATIZED BY BIOGAS POTENTIAL IN TEKIRDAĞ REGION

Medicinal and aromatic plants that are generally grown in natural environment and obtained by collection from these natural environments cannot meet the need.In this respect, it is possible to increase the possibility of growing medicinal and aromatic plants by providing the necessary climatic conditions especially with greenhouse systems. In the greenhouse, the highest cost is the provision of air conditioning. In this respect, greenhouse air conditioning system can be provided with renewable energy or waste materials. In this study, information on some medicinal and aromatic plants that can be grown in greenhouses conditioned by biogas which can be produced from wastes of bovine and ovine animal production structures in Tekirdağ region where agriculture and animal husbandry are carried out intensively in our country and waste evaluation can be obtained without being subject to low cost medical and aromatic plants. intended. For this purpose, biogas potential and energy production opportunities of each district of Tekirdağ were determined and medicinal and aromatic plants that can be grown by providing greenhouse air conditioning were determined. As a result of the research, Capers (Capparis spinosa) (Barbera and Lorenzo, 1984), Rosemary (Rosmarinus officinalis) (Ayanoğlu et al., 2016), Poppy (Papaver somniferum linnaeus) (Erdurmuş and Öneş, 1990), Mint (Mentha piperita) (Anonim, 2019), which can be easily provided with biogas production potential in Tekirdağ region and which have high economic returns with demand. Medicinal Sage (Salvia officinalis) (Bağdat, 2008), Gojiberry (Lycium barbarum) (Anonim, 2015a; Anonim 2015b), St. John's Wort (Hypericum perforatum) (Bayram ve ark., 2002), Lemon Balm (Melissa officinalis) (Anonim,2019) has been concluded that medicinal and aromatic plants such as can be grown.

Sustainable Recycling Technology for Li-Ion Batteries and Beyond: Challenges and Future Prospects.

Tremendous efforts are being made to develop electrode materials, electrolytes, and separators for energy storage devices to meet the needs of emerging technologies such as electric vehicles, decarbonized electricity, and electrochemical energy storage. However, the sustainability concerns of lithium-ion batteries (LIBs) and next-generation rechargeable batteries have received little attention. Recycling plays an important role in the overall sustainability of future batteries and is affected by battery attributes including environmental hazards and the value of their constituent resources. Therefore, recycling should be considered when developing battery systems. Herein, we provide a systematic overview of rechargeable battery sustainability. With a particular focus on electric vehicles, we analyze the market competitiveness of batteries in terms of economy, environment, and policy. Considering the large volumes of batteries soon to be retired, we comprehensively evaluate battery utilization and recycling from the perspectives of economic feasibility, environmental impact, technology, and safety. Battery sustainability is discussed with respect to life-cycle assessment and analyzed from the perspectives of strategic resources and economic demand. Finally, we propose a 4H strategy for battery recycling with the aims of high efficiency, high economic return, high environmental benefit, and high safety. New challenges and future prospects for battery sustainability are also highlighted.

Performance of Direct-Seeded Rice as Influenced by Dual Cropping with Nitrogen Levels and Weed Management Practices in Prayagraj Region of Eastern Uttar Pradesh

A field experiment was conducted at Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Prayagraj (U.P.), India, to evaluate the performance of direct-seeded rice (DSR) as influenced by dual cropping with nitrogen levels and weed management practices. Dual cropping of Sesbania with 100% recommended dose of nitrogen gave comparable yields with higher net returns and C/B ratio for both the years. Pretilachlor plus (@ 0.3 kg a.i./ha) as pre-emergence application followed by hand-weeding (HW) at 45 days after sowing (DAS) was effective in controlling weeds and increasing yields of DSR which resulted in higher economic returns than HW twice at 20 and 45 DAS. The results showed that farmers could save 56% human labour, 73% machine labour and 25% irrigation water as compared to transplanted rice; thus, DSR technology has the potential to increase farmers’ income and save natural resources.

Rapid detection of adulteration of minced beef using Vis/NIR reflectance spectroscopy with multivariate methods.

High economic returns induce the continuous occurrence of meat adulteration. In this study, visible/near-infrared (Vis/NIR) reflectance spectroscopy with multivariate methods was used for the rapid detection of adulteration in minced beef. First, the reflectance spectra of different adulterated minced beef samples were measured at 350-2500nm. Standardization and Savitzky-Golay (SG) smoothing were applied to reduce spectral interference and noise. Then, support vector machine (SVM), random forest (RF), partial least squares regression (PLSR), and deep convolutional neural network (DCNN) were adopted for adulteration type identification and level prediction. Moreover, principal component analysis (PCA), locally linear embedding (LLE), subwindow permutation analysis (SPA), and competitive adaptive reweighted sampling (CARS) were performed to eliminate redundant information. SG smoothing performed better on interference reduction. DCNN and PCA identified adulteration type with the accuracy above 99%. In adulteration level prediction, the RF with spectra of important wavelengths selected by CARS provided optimal performance for beef adulterated with pork, and coefficient of determination of prediction (R2P) and the root mean square error of prediction (RMSEP) were 0.973 and 2.145. The best prediction for beef adulterated with beef heart was obtained using PLSR and CARS with R2P of 0.960 and RMSEP of 2.758. Accordingly, Vis/NIR reflectance spectroscopy coupled with multivariate methods can provide the rapid and accurate detection of adulterated minced beef.

Comparative Economic Analysis of Organic and Inorganic Fertilizers on Grain Yield of Tropical Maize Varieties

Increasing demand for maize in Nigeria has resulted in high use of inorganic fertilizers and these fertilizers are expensive for peasant farmers who dominate farming in the country. The use of inorganic fertilizers also results in hidden cost borne by man and the ecosystem. In a search for a cost-effective and safer alternative, six maize varieties were evaluated using moringa, banana-peel, maize-stalk fertilizer (MBM) both in solid and foliar forms. Gross benefit, net benefit and benefit-cost ratio (BCR) were used to determine enterprises with the highest economic returns. The results showed that maize varieties treated with 90 kg/ha of NPK had the highest grain yield which was significantly comparable with MBM. The application of 120N+50P+40K rate of MBM to single cross hybrid, SCH LY1312-1, resulted in the highest benefit-cost ratio (15.16). MBM is economically more viable than NPK Fertilizer and its application in the solid (powdered) form before planting produced double economic returns compared to foliar application. Single cross hybrids gave better economic returns when the fertilizer was applied in solid form.

Residual zinc improves soil health, productivity and grain quality of rice in conventional and conservation tillage wheat-based systems

Zinc (Zn) deficiency in rotations of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) impedes the productivity of both component crops. Fertilisation with Zn and switching to conservation tillage systems may help to improve soil health and the productivity of both rice and wheat. However, it is not clear whether, in conservation tillage systems, Zn application to either crop will fulfil the requirement of the following crop through a residual effect. This study was designed to evaluate the influence of Zn applied to wheat on the performance of rice under conventional (puddled transplanted rice, PuTR) and conservation (direct-seeded aerobic rice, DSAR) tillage. As a part of a long-term experiment, Zn was applied as foliage spray (FA, 0.025 M), by seed priming (SP, 0.5 M) and by soil application (SA, 10 kg ha–1) in plough-till wheat (PTW) and no-till wheat (NTW). Controls without Zn application were included (PTW-C, NTW-C). After wheat harvest, rice was planted as PuTR and DSAR in each of the eight Zn application × wheat tillage treatment combinations. Compared with PuTR, DSAR significantly improved soil fertility (nitrogen, phosphorus, Zn), soil organic matter (1.5–4.5%), soil organic carbon (3%), soil microbial biomass carbon (2.5%) and grain yield (5.6%). Overall, DSAR preceded by NTW had higher soil organic carbon (4.3%), soil microbial biomass nitrogen (1.6%) and soil microbial biomass carbon (3.7%) than PuTR sown after either PTW or NTW. Residual Zn enhanced grain Zn concentration by 15% in rice planted after PTW-SA and 12% after NTW-SA. Overall order of improvement in rice-grain Zn concentration was PTW-SA = NTW-SA > NTW-C = NTW-SP. Likewise, higher grain yield with residual Zn availability was in the order DSAR-NTW-SA > PuTR-PTW-SA during 2018. Highest economic return with high benefit:cost ratio was recorded for DSAR-NTW-SA. Zinc application to the wheat crop effectively improved crop performance and grain quality of the following rice crop in both conventional and conservation tillage systems. However, the conservation system DSAR-NTW-SA may be chosen for improved soil health, and for increased harvest grain yield with better grain quality.

Strategic priorities for the development of middle regions in Russia

Relevance. The key factor in the development of any region is its geographical position in the socio-economic and geopolitical space of the country. In this respect, middle regions are of particular interest. Unfortunately, their unique qualities remain largely underexplored in research literature, which is the gap this article seeks to address. Research objective. The purpose of the study is to provide a definition of the concept ‘middle region’, describe its key characteristics and align them with the strategic priorities in the development of such regions. Data and methods. The research methodology centres around the notion of cumulative effect of the middle region and the tools for its assessment. This effect is associated with enhanced socio-economic efficiency of a territorial capital resulting from the advantages of its middle position. Among other things, this effect manifests itself through higher economic returns on investment. The empirical part of the study relies on the data on 36 Russian middle regions, their missions and priorities of strategic development. Results. The article summarizes the Russian and international theoretical approaches to the definition of the middle regions, their place and role in the territorial structure of a country and its socio-economic development. It is shown that most authors assign middle regions the role of the country’s epicenter, highlighting their key role in economy, culture, politics and other spheres of life. The approach proposed in this study focuses on middle regions’ position in space, on the one hand, and, on the other, sees them as systems of interactions in the socio-economic space. Based on this understanding of the middle region, several groups of Russian middle regions are identified: integrators, sustainable middle regions and developing middle regions. Conclusions. The mission of middle regions is one of the fundamental concepts of strategic management, comprising a hierarchy of goals. It is shown that although the mission of middle regions should be to become integrators of the country’s socio-economic space through the network of inter-territorial and global interactions, not all Russian middle regions are ready to pursue this ambitious goal and prefer to focus on addressing internal goals of their own.

English

Garlic (Allium sativum L.) is an important vegetable crop in Ethiopia. The yield of the crop is often constrained by low and unbalanced nutrient supply in the soil. This study was undertaken to assess effect of vermicompost (VC) on growth, quality and economic return of garlic variety Chelenko I during 2016 main rainy season in Haramaya University main campus, Ethiopia. The treatment consisted of four levels of vermicompost (0, 2.5, 5 and 7.5 tons ha-1) laid out in a randomized complete block design in three replication. Data were collected and analyzed on days to emergency, plant growth, quality, and economic return of garlic. Results revealed early emergency (8.07 days) with application of 7.5 tons ha-1 of vermicompost while late emergency (10.13 days) was at nil application of vermicompost. Significant (P<0.05) maximum leaf area (37.05 cm2), leaf area index (1.36) and biomass (61.54 g) were recorded with application of 7.5 tons ha-1. Besides to this, maximum total dry matter (32.71%) and total soluble solid (12.72 Brix°) were also recorded at the rate of 7.5 tons ha-1. Due to application of 7.5 tons ha-1 fertilizer, the economic analysis showed the highest net benefit cost of 431,188 ETB ha-1 and marginal rate of return (168.87%) with incurred highest total variable cost of 79,350 ETB ha-1. Thus, it can be reasonably generalized that on short time basis, the application of high amounts of VC fertilizers can result in higher economic return than the low dose of VC fertilizer. Therefore, it can be concluded that, the maximum growth and quality and economic return of garlic was obtained with application of 7.5 tons of VC ha-1 fertilizer as it gave the highest net benefit cost. However, since the experiment was done only once and at one location, similar experiments should be carried out using additional higher rates of VC fertilizer over several seasons and locations to make a conclusive recommendation. Key words: Chelenko I, economic return, marginal rate return, net benefit, total soluble solids.

Effects of different fertilizers on the growth and yield of okra (Abelmoschus esculentus L.) in summer season in Chitwan, Nepal

An experiment was conducted in the Horticulture Farm of Agriculture and Forestry University to demonstrate the effects of different fertilizers on the yield and yield parameters of okra (var. Arka Anamika). The experiment was laid out in Randomized Complete Block Design (RCBD) consisting of seven treatments and three replications. The various treatments used in the experiment were goat manure, sesame cake, mustard cake, synthetic fertilizer (NPK), poultry manure, vermicompost and untreated control. The required dose of nitrogen was fulfilled by the fertilizer itself whereas insufficient amount of phosphorous and potassium was fulfilled by addition of single super phosphate and muriate of potash respectively. The fertilizers were applied on the basis of recommendation given by the Nepal Agriculture Research Council (NARC). The effect of poultry manure on number of open flowers and number of fruits at 40 DAS was found superior. The effect of poultry manure on plant height, number of leaves, plant diameter was found superior at 50 DAS. Goat manure produced the superior result on number of open flowers at 50 DAS. Poultry manure on the number of leaves and plant height produced the significant result at 60 DAS. Synthetic fertilizer responded well to number of fruits at 60 DAS. Sesame cake produced the superior results at 70 DAS on number of buds. Poultry manure responded well to all the parameters and produced the yield of 200 qt./ha with the BC ratio of 1.77. This experiment suggests the farmers to use the poultry manure to get the highest economic return. Vermicompost and mustard cake producing the superior and significant yield in this research are not recommended as they have low BC ratio unless effective measures are encouraged to reduce the cost of this fertilizers.

Effect of Olive Leaves and Propolis Extracts on Growth Performance, Immunological Parameters and Economic Efficiency using Nile Tilapia (Oreochromis niloticus)

This study aimed to evaluate the effects of olive leaves ether extract (EEOL) and ethanol extract of propolis (EEP) on growth performance, body composition, nutrient digestibility, immunological parameters and economic efficiency in Nile tilapia, Oreochromis niloticus. Three Isonitrogenous (crude protein 35%), isocaloric (Digestable energy, 2900kcal) diets were fed to Nile tilapia averaging 19.7 ±0.94 g. A basal control diet had no additives, second and third diets containing 0.1% EEOL (1g/kg) and 0.4% EEP (4 g/kg) for successive 12 weeks. Results revealed that the dietary addition of EEOL and EEP had significant effects on growth performance parameters and protein utilization (P≤0.029). In addition, dietary supplement of EEP was more prominent than with EEOL and propolis extracts on fish final body gain and protein utilization. The carcass content from dry matter, protein and fat contents recorded higher values in EEOL or EEP supplemented groups. Furthermore, nutrient digestibility was improved by adding EEOL and EEP. The total leucocytes count, lymphocytes %, monocytes %, phagocytic activity, plasma total protein and globulin showed higher levels in fish groups with dietary addition of EEOL and EEP extracts than in fish fed the control diet. In terms of economic analysis, EEOL and EEP extract diet revealed the lowest cost per kg live weight of fish, along with the highest economic return and net profit. Addition of EEOL or EEP extracts to diet resulted in a more economically efficient production than in fish fed the control diet. Our results suggested that the dietary inclusion of EEOL (1g/kg) or EEP extracts (4g/kg) markedly enhanced growth performance, body composition, feed digestibility, immune status and economic efficiency using Nile tilapia.

Effect of weeding regime on the performance of boro rice cultivars

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from December 2016 to May 2017 to investigate the effect of weeding regime on the performance of boro rice cultivars. The experiment comprised of two factors, Factor A- Rice cultivars: BRRI dhan28, BRRI dhan29, and BRRI dhan74, Factor B: Methods of weeding- no weeding, two hand weedings at 15 and 35 DATs, application of pre-emergence herbicide Commit, application of early post-emergence herbicide Pediplus, application of pre-emergence herbicide Commit followed by application of early post-emergence herbicide Pediplus, application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT, and application of early post-emergence herbicide Pediplus followed by one hand weeding at 35 DAT. The experiment was laid out in a split plot design assigning rice cultivars in the main plots and weed management practices in the sub-plots with three replications. Fourteen weed species infested the experimental field belonging to six families. Among the weed species, four were grasses, four were broad leaves and six were sedges. Cultivar exerted significant effect on weed density and dry weight. Both the highest weed density and dry weight were found in BRRI dhan28 and the lowest ones were observed in BRRI dhan29 rice cultivar. Weed density and weed dry weight were significantly influenced by weeding regime. The highest weed density and dry weight were observed in no weeding condition and application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT showed the best performance. BRRI dhan29 produced the highest grain and straw yields among the cultivars. Weed control had pronounced influence on yield of rice. The highest grain yield was obtained in application of pre-emergence herbicide Pretilachlor (Commit)followed by one hand weeding at 35 DAT and the lowest one was obtained in control (no weeding) treatment. From the results of the study it may be concluded that rice cultivar BRRI dhan29 with application of pre-emergence herbicide Commit followed by one hand weeding at 35 DAT might be the best treatment for controlling weed effectively as well as obtaining highest yield and highest economic return.&#x0D; J Bangladesh Agril Univ 17(3): 265–273, 2019

Urban Expansion and the Loss of Prairie and Agricultural Lands: A Satellite Remote-Sensing-Based Analysis at a Sub-Watershed Scale

Prairies or grasslands together with areas designated as agricultural lands are one of the largest types of land cover and land use that exist today. While prairies provide habitat to a wide variety of animals and organisms, and agricultural lands support human populations, these lands, especially those in the immediate vicinities of large urban areas, are giving way to urbanization at alarming rates. In particular, prairies are often viewed as wastelands because their benefit to the effective functioning of the urban ecosystem is often not fully understood. On the other hand, many agricultural lands are being converted for several urban uses because of the high economic returns from their sale. In this study, we classified SPOT (Satellite Pour l’Observation de la Terre) satellite data of the study area using the supervised maximum likelihood classification approach in order to investigate the loss of prairies and agricultural lands due to urban expansion in six sub-watersheds in the Kansas City metropolitan area of the States of Kansas and Missouri in the U.S. Based on the classified maps, we computed the magnitude and rate of urban expansion, and the proportion of loss in prairies and agricultural lands that was a result of urban expansion. Results from the 22-year study revealed that in all six sub-watersheds, agricultural lands and grassland were depleted at alarming rates with no sustainable effort to conserve them. These results provide baseline information that can support a data-driven and sustainable path for urban expansion in the examined sub-watersheds.

2019–2020 Florida Citrus Production Guide: Rootstock and Scion Selection

When preparing for new planting or replanting, an important factor to consider is the choice of rootstock. Choosing the right rootstock and scion combination can result in higher economic returns without any additional cost. Rootstocks affect scion vigor, yield, fruit size and quality, and pest tolerance. However, tree growth, yield, and fruit quality interact strongly with climate, soil type, tree spacing, and other factors, often producing contradictory reports on rootstock performance in different areas. This 3-page fact sheet is part of the 2019–2020 Florida Citrus Production Guide. Written by Ute Albrecht, Fernando Alferez, and Mongi Zekri, and written by the Horticultural Sciences Department, March 2019. HS1308/HS1308: 2022–2023 Florida Citrus Production Guide: Rootstock and Scion Selection (ufl.edu)

Rebuilding global fisheries under uncertainty

Current and future prospects for successfully rebuilding global fisheries remain debated due to uncertain stock status, variable management success, and disruptive environmental change. While scientists routinely account for some of this uncertainty in population models, the mechanisms by which this translates into decision-making and policy are problematic and can lead to unintentional overexploitation. Here, we explicitly track the role of measurement uncertainty and environmental variation in the decision-making process for setting catch quotas. Analyzing 109 well-sampled stocks from all oceans, we show that current practices may attain 55% recovery on average, while richer decision methods borrowed from robotics yield 85% recovery of global stocks by midcentury, higher economic returns, and greater robustness to environmental surprises. These results challenge the consensus that global fisheries can be rebuilt by existing approaches alone, while also underscoring that rebuilding stocks may still be achieved by improved decision-making tools that optimally manage this uncertainty.

Economic evaluation of puberty induction of nulliparian Nellore heifers using intravaginal device and melengestrol acetate

The present study evaluates the economic viability of puberty induction in nulliparous Bos taurus indicus Nellore breed heifers using an intravaginal device of fourth-use and melengestrol acetate (MGA®). The experiment was undertaken in the Nossa Senhora Aparecida Farm, Terenos city, Mato Grosso do Sul, Brazil, and was utilized a completely randomized experimental design in a 2 × 3 factorial scheme. Two age classes were included in the study, which were divided into 348 precocious (early-cycle) heifers, aging 16-18 months, weighting an average of 264.6 kg and 543 conventional-cycle heifers aging 24-26 months averaging 346.8 kg. The three treatments were as follows: control without the induction of follicle formation (treatment 1); treatment 2: induction with an intravaginal implant (intravaginal implantation with a fourth-use progesterone implant on Day 0, withdrawal on Day 12, and application of 1 ml of intramuscular estradiol cypionate [ECP®]); and treatment 3, 2.3 g of MGA® during 12 days with supplement followed by 1 ml of intramuscular ECP® at the end of the treatment. Heifers induced via implantation had a higher rate of ovarian activity (presence of corpus luteum) during the early cycle (63.8% animals) while the conventional cycle (72.4%). This effect influenced the frequency of early stage anestrus (56%). Among the treatments evaluated, 72% of control heifers had no ovarian activity (absence of corpus luteum). In the group with implant induction the conception rates were 65.5% and 62.4% in early and conventional-cycle females, respectively. Puberty induction in Nellore heifers provides a high economic return. The protocol revealed highest efficiency compared to the control group.