Spanish Journal of Agricultural Research
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Short communication: Antimicrobial activity of indoleacetic, gibberellic and coumaric acids against Paenibacillus larvae and its toxicity against Apis mellifera
No full textAim of study: To explore three isolated phytomolecules: indoleacetic acid (IAA), gibberellic acid (GA), and the secondary metabolite p-coumaric acid (CUM): (1) evaluating their toxicity against Apis mellifera larvae and adults under controlled conditions in the laboratory; (2) searching for antimicrobial activity against Paenibacillus larvae.Area of study: Honey bee larvae and adults were collected from the experimental apiary of the “Centro de Investigación en Abejas Sociales (CIAS)” (-37.9348798, -57.682817), Institute of the National University of Mar del Plata (UNMdP), Argentina.Material and methods: Paenibacillus larvae strains were isolated from beehives from different provinces of Argentina (Buenos Aires, Córdoba and Entre Ríos) showing clinical symptoms of the American foulbrood. All strains (S1, S2, S3, S4) were genotypically identified using PL5 and PL4 primers and characterized as genotype ERIC1. Then standard essays were performed to determined toxicity of phytomolecules in honey bees and antimicrobial activity through the broth microdilution method.Main results: The diet with GA, IAA and CUM did not present toxic effects in larvae or adult bees, and only CUM showed antimicrobial activity against P. larvae. In this study, we obtained in vitro values of MNIC (minimum non-inhibitory concentration) of 500 μg mL-1 and a MIC (minimum inhibitory concentration) of 650 μg mL-1 for CUM.Research highlights: The obtained results remark its potential as a natural alternative for the control of P. larvae, avoiding the problems generated by the use of synthetic antibiotics such as the resistance phenomena and the contamination of hive’s products
Leaf nutrient status of some grafted-pear rootstocks influenced by different soil types
No full textAim of study: Determining leaf nutrient status of some grafted-pear rootstocks grown under different calcareous soil types.Area of study: The Horticultural Research Station of Kamalabad, Karaj, Iran.Material and methods: Leaf mineral element concentrations were determined in 2015, 2016, 2017, and 2018. Leaf sampling was carried out about 90 days after full bloom. The N-content was estimated by the Kjeldahl method. Total concentration of calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and boron (B) were also determined by the atomic absorption spectrophotometry, and phosphorus (P) and potassium (K) were analyzed using the flame photometry. The deviation from optimum percentage (DOP) and its correlation with the ΣDOP of macro- and micro-nutrients were used to determine the nutritional status of the studied plants.Main results: In clay loamy soil pyrodwarf rootstock, which was grafted with 'William Duchess' scion, presented a more suitable balanced nutritional index than other rootstocks/scion combinations. The OHF69 rootstock grafted with 'Daregazi' offered better balanced nutritional values in fairy lime silt-loamy soil, whereas the pyrodwarf rootstock grafted with 'Louise Bonne' scion in less lime silt-loamy soil was found to have higher values than other studied rootstocks/scion combinations in terms of nutrient concentration.Research highlights: The study determined effective solutions to the field problems of calcium carbonate equivalent which distinctly affect the soil properties related to plant growth. It also revealed the most suitable pear rootstock/scion combinations in different calcareous soil types for orchard establishment in arid and semi-arid regions
Pollen tube growth and fruit set in quince (Cydonia oblonga Mill.)
No full textAim of study: To determine the self-compatibility level of eight quince cultivars.Area of study: The region of Belgrade (Central Serbia).Material and methods: Pollen tube growth in vivo and fruit set in two pollination variants (self- and open-pollination) were studied in eight quince cultivars. The quantitative parameters of pollen tube growth (average number of pollen tubes in the upper and middle third of the style, base of the style and in the ovary; the dynamics of pollen tube growth through these parts of the pistil) was determined using the fluorescence microscopy.Main results: The parameters of pollen tube growth and fruit set were primarily dependent on the genotype and variants of pollination. All studied parameters were significantly higher in the open-pollination variant compared with the self-pollination in all cultivars. In the self-pollination variant, ʻLeskovackaʼ and ʻVranjskaʼ had the highest number of pollen tubes that penetrated the ovary (2.10 and 0.54 in average, respectively), as well as the largest percentage of pistils with the penetration of pollen tubes in the nucellus of ovules six days after pollination (40.09% and 14.74%). Also, they had the highest percentage of initial fruit set (17.01% and 28.52%) and final fruit set (9.32% and 9.86%). Based on this, ʻLeskovackaʼ and ʻVranjskaʼ can be classified as self-compatible cultivars, while the others are self-incompatible.Research highlights: The majority of quince cultivars were self-incompatible. When establishing new orchards with these cultivars, care should be taken about the choice of pollenisers in order to achieve high yields
Effect of short-term conservation temperature, with or without centrifugation, on the survival and motility of Catalonian donkey spermatozoa
No full textAim of study: To analyze the effect of three short-term storage temperatures with or without removing seminal plasma on the survival and motility of donkey sperm and the response to refrigeration and centrifugation of the different spermatozoa subpopulations.Area of study: North-eastern Spain (Catalonia).Material and methods: Semen from seven Catalonian jackasses was diluted with a skimmed milk-based (Kenney) extender and different treatments were obtained: FRESH semen, FRESH semen immediately centrifuged to remove the seminal plasma before resuspension in Kenney extender (FRESH+CENTRIFUGATION), FRESH semen stored at 5/15/20ºC for 2 h (STORAGE 5/15/20ºC), and STORAGE 5/15/20ºC semen then centrifuged (STORAGE 5/15/20ºC+CENTRIFUGATION). Survival was examined using eosin-nigrosin stained smears. Motion was assessed by means of a computer-assisted sperm analyzer (CASA).Main results: The spermatozoa of the STORAGE 5ºC and 20ºC showed an overall motility similar to that seen in FRESH samples. However, the STORAGE 15ºC led to an important motility reduction. No differences were seen between the FRESH and STORAGE 5/15/20ºC with respect to progressive motility. However, STORAGE 5/15/20ºC+CENTRIFUGATION all reduced total motility, and STORAGE 15ºC+CENTRIFUGATION led to reduced survival. The sperm motile subpopulations structure of donkey semen was maintained after STORAGE 5/15/20ºC+CENTRIFUGATION, although STORAGE 15ºC+CENTRIFUGATION led to important changes. STORAGE 5/20ºC+CENTRIFUGATION, in contrast, only induced slight changes. STORAGE 20ºC+CENTRIFUGATION was associated with no change in the percentage of sperm cells belonging to each Subpopulation compared to FRESH sperm.Research highlights 2 h of storage at 20ºC followed by centrifugation is suitable for the short-term storage of donkey semen
The impacts of agricultural support on enhancing the efficiency, competitiveness and sustainability of sheep breeding: The case of Niğde and Aksaray provinces, Turkey
No full textAim of the study: The sheep breeding sector in Turkey has lost its potential to become a highly competitive and efficient sector despite a number of policies being implemented over the years. Therefore, the objective of the study was to empirically evaluate the competitiveness of sheep breeding and the determinants of the technical efficiency of the sector as well as the current impacts of agricultural policies on the performance of the sector.Area of study: Niğde and Aksaray provinces of TR71 region in Turkey.Material and methods: The required primary data were obtained through a face-to-face survey from 110 sheep breeders. Two methodological approaches, namely Stochastic Frontier Analysis and Policy Analysis Matrix, were used.Main results: The support policies caused an inefficiency in allocation of already scarce resources in sheep breeding, but not ensure to increase the competitiveness at both national and international levels. Sheep farms could increase their income by up to 50% without changing the level of input by taking into account the factors that caused inefficiency in sheep breeding. The major determinants that decreased efficiency were current subsidies for sheep breeding, herd size and the excessive utilization of family labour, while the factors that increased the efficiency were sheep race, access to extension services, grazing period and location. Besides, Domestic Resource Cost (DRC) value in the efficient farms decreased to 0.88, implying that they had a comparative advantage.Research highlights: Implementation of structural support policies with long term would enhance efficiency of sheep farms and ensure the sustainability and competitiveness of the sector
Does the proposed CAP reform allow for a paradigm shift towards a greener policy?
No full textAim of study: The paper explores whether the legislative proposal for the EU Common Agricultural Policy (CAP) after 2021 and the novelty of comprehensive strategic planning at Member State (MS) level can bring about a greener, more multifunctional policy paradigm. While existing research has explored long-term policy change over the entire decision-making process, this study aims to demonstrate the usefulness of conducting policy analysis at the inception of the legislative procedure.Area of study: The study applies to the European Union.Material and methods: The research employs a qualitative method of policy analysis, using a combination of three theoretical frameworks – social learning, path dependency and intergovernmentalism. Extensive document analysis and in-depth interviews were applied to evaluate the proposed reform and gauge the responses of key interest groups.Main results: The proposal holds potential for a substantial overall greening of the policy but will be strongly dependent on implementation at the MS level; the institutional framework provides space for increased environmental ambition, but does not guarantee it, as the proposed safeguards are too weak.Research highlights: More accountability is required during the formulation and implementation of Strategic Plans. Due to strong elements of path dependency and intergovernmentalism, an overall paradigm shift at EU level is unlikely. Strengthening the role of MSs is weakening the commonality of the policy that guarantees at least minimal environmental standards
Comparison of the technical and economic performances of two different shredders on pomegranate pruning residues
No full textAim of study: The study aimed to examine the technical and economic performances of two different shredders for three windrow densities of pomegranate residues.Area of study: The study was conducted in the Serik District of Antalya Province, Turkey.Material and methods: Two different pruning residue shredders driven by tractor power take off (PTO) were used. Machine‑I has pick‑up, shredding, screen units. Machine‑II only has a shredding unit. The experiment was conducted at windrow densities of 1.49, 2.10, and 2.41 kg/m2 in a pomegranate orchard; the study used a completely randomized split‐plot design with two treatments and three replications.Main results: The power values for the increasing windrow densities were 8.00, 11.73, and 18.47 kW/m for Machine-I and 5.08, 5.68, and 6.48 kW/m for Machine-II. Moreover, the average particle length of 68.6 mm shredded by Machine‑I was approximately 20 mm smaller than that of Machine‑II. The minimum unit energy value of Machine-II was 2.53 kWh/t at the maximum windrow density of 2.41 kg/m2. This value for Machine-I was 5.58 kWh/t at the medium windrow density of 2.10 kg/m2. The lowest unit cost for Machine-I and Machine-II was calculated as 27.2-7.1 US/t (at maximum density), respectively.Research highlights: The appropriate windrow densities for Machine-I and Machine-II were different in terms of energy requirements and total unit cost. Machine-I is more effective at consistently chopping the residues than Machine-II, but it requires more energy and a higher unit cost
The importance of disease incidence rate on performance of GBLUP, threshold BayesA and machine learning methods in original and imputed data set
No full textAim of study: To predict genomic accuracy of binary traits considering different rates of disease incidence.Area of study: SimulationMaterial and methods: Two machine learning algorithms including Boosting and Random Forest (RF) as well as threshold BayesA (TBA) and genomic BLUP (GBLUP) were employed. The predictive ability methods were evaluated for different genomic architectures using imputed (i.e. 2.5K, 12.5K and 25K panels) and their original 50K genotypes. We evaluated the three strategies with different rates of disease incidence (including 16%, 50% and 84% threshold points) and their effects on genomic prediction accuracy.Main results: Genotype imputation performed poorly to estimate the predictive ability of GBLUP, RF, Boosting and TBA methods when using the low-density single nucleotide polymorphisms (SNPs) chip in low linkage disequilibrium (LD) scenarios. The highest predictive ability, when the rate of disease incidence into the training set was 16%, belonged to GBLUP, RF, Boosting and TBA methods. Across different genomic architectures, the Boosting method performed better than TBA, GBLUP and RF methods for all scenarios and proportions of the marker sets imputed. Regarding the changes, the RF resulted in a further reduction compared to Boosting, TBA and GBLUP, especially when the applied data set contained 2.5K panels of the imputed genotypes.Research highlights: Generally, considering high sensitivity of methods to imputation errors, the application of imputed genotypes using RF method should be carefully evaluated
Bifenthrin toxicity, inheritance of resistance, cross-resistance to insecticides in Helicoverpa armigera
No full textAim of study: It is first report to sort out resistance development; its mode and inheritance in Helicoverpa armigera against bifenthrin till several generations using progeny reciprocal crosses and back crosses, combined with observing the cross resistance of bifenthrin against pyrethroid, organophosphate, pyrazole and new chemistry insecticides.Area of study: This study was conducted at agriculture fields of University of Agriculture, Faisalabad, Pakistan.Material and methods: Bifenthrin selected strain of H. armigera was reciprocally crossed to bifenthrin susceptible strains. Resulting F1 progeny was back-crossed to resistant strain. Cross resistance of bifenthrin to six insecticides (cypermethrin, triazophos, emamectin benzoate, fipronil, lambda-cyhalothrin, profenofos) was observed.Main results: Resistance ratio was higher in bifenthrin selected strain. h value showed that resistance was autosomal with incomplete dominance. Polygenic mode of resistance; resistance controlled by more than one gene; was found against bifenthrin in H. armigera. Cross resistance of bifenthrin selected strain against different insecticides was found higher.Research highlights: Reciprocal crosses of F1 progeny combined with LC50 exhibits that resistance can be controlled using multiple insecticides at different intervals against H. armigera. These results can be implicated to develop an integrated pest management strategy to control H. armigera
Toxicological and ecotoxicological pressure due to pesticide use in Sancti Spíritus, Cuba
No full textAim of study: To quantify the toxicity and ecotoxicological pressure of pesticides in Sancti Spíritus province, Cuba, between 2011 and 2014.Material and methods: A longitudinal descriptive study was designed for the study period, to identify potential risks to the environment and human health associated with the use of pesticides. In order to determine the toxicity and ecotoxicity of pesticide use, ƩSeq (Spread equivalents), POCER (Pesticide Occupational and Environmental Risk) indicator, and the Toxic Load (TL) methodology of the Plant Health Cuban Institute were used.Main results: Corresponding to 62 chemical families, 124 active ingredients were applied in the province during the study period. Organophosphates, carbamates, pyrethroids, inorganic compounds (such as copper), dithiocarbamates, aryloxyphenoxypropionates, neonicotinoids, sulfonylurea, triazoles, and organochlorines predominated due to their frequency of use. Use of toxic-pesticides, lack of personal protection equipment amount others made workers, residents and applicators the toxicological modules with the highest risk of exposure. From the POCER results we found that aquatic organisms, persistence, and groundwater are the modules with the highest ecotoxicological pressure.Research highlights: With the use of the POCER indicator as well as ƩSeq, a more accurate assessment of toxicity and ecotoxicity from certain pesticide can be done instead of the TL equation currently used in Cuba. In addition substitution of the most toxic pesticides by less toxic ones could help to reduce synthetic pesticide pressure on humans and the environment. This study can help to develop policies and management practices to reduce the hazards of synthetic pesticide use in Cuba