Spanish Journal of Agricultural Research
Not a member yet
2067 research outputs found
Sort by
Short communication: Virulence of Puccinia triticina in the North Caucasus region of Russia
No full textAim of study: To analyze the structure of P. triticina populations by a virulence survey in the North Caucasus region of Russia from 2011 to 2015.Area of study: The North Caucasus region is a leading grain production region in Russia where wheat leaf rust causes losses in yield.Material and methods: Uredinial samples of leaf rust were collected in all agro-climatic zones of the North Caucasus on the production sites of winter wheat and on the plots of official state trials. Single uredinial isolates (a total of 564) were tested for virulence with 41 ˈThatcherˈ near isogenic lines with Lr resistance genes.Main results: Clones virulent to Lr9, Lr42, Lr47 and Lr50 were not found. Isolates virulent to the Lr19, Lr24, Lr29, Lr41, Lr43 + 24, Lr45, Lr52 genes were characterized by low frequencies. The 564 fungal isolates studied were represented by 564 virulence phenotypes, the majority of them with a virulence complexity from 9 to 19. A high level of intrapopulation fungus diversity in virulence was noticed during the whole period of research (Shannon diversity index from 2.994 to 3.314). The differences in the frequencies of virulences in the years of research were small (Rogers distance from 0.001 to 0.160).Research highlights: Due to the fact that the North Caucasus region is a zone of epiphytotic danger and high variability of the P. triticina population, the analysis of the genetics of the fungus population is important for the strategy of varietal distribution in the region and development of rust-resistant varieties
The development of the radicular and vegetative systems of almond trees with different rootstocks following the application of biostimulants
No full textAim of study: Recently, the development of almond crops on a global scale has increased their area under cultivation. The demand for both plants and products that stimulate the growth of almond trees has therefore become increasingly necessary. Accordingly, in this project we have studied the response in the vegetative and root systems of almond trees with different rootstocks to varying inputs of several root stimulants.Area of study: Valencia (Spain)Material and methods: Several different organic biostimulants were studied in isolation, i.e. not combined with synthetic chemical fertilizers, in order to ascertain if chemical fertilizers could be at least partially replaced.Main results: Good results were obtained by applying a biostimulant composed of organic matter rich in saccharides and carboxylates. Using an approach that enabled a distinguishing between them, plant radicular systems were shown to respond differently according to the biostimulant applied and the rootstock tested. The best results were obtained with a biostimulant composed of organic matter from corn hydrolysis and containing free amino acids and extracts from algae, as well as 0.07% zeaxanthins.Research highlights: Although biostimulants are promoters of young almond tree growth, they should be applied to only partially replace chemical fertilizers. The present paper shows the importance of using an organic-origin biostimulant, as a complement to chemical nutrition
Effects of fan volute structure on airflow characteristics in rice combine harvesters
No full textAim of study: Selecting a proper fan for the rice combine harvesters to get a good cleaning performance when harvesting high yield rice. Area of study: Jiangsu Province, China.Material and methods: Three potential multi-duct fans were designed, and the computational fluid dynamics and hot wire anemometer technology were utilized to learn the airflow and pressure variation inside the fan with perforated plates at the outlet ducts as cleaning loads. Then, the fan with the best performance was selected and a multi-duct cleaning test-bed was developed. The variation of the corresponding airflow velocity in the cleaning system was analyzed and the ideal airflow velocity in different section of the sieve was clarified. Finally, a field experiment was carried out.Main results: For a rice combine harvester with a feed rate of 7 kg/s (material other than grain + grain), the requested airflow rates inside the cleaning shoe was about 3.0 m3/s. The ideal airflow velocity in different section of the cleaning shoe was 8-9 m/s at upper duct, 4-6 m/s at the middle section, and 3-4 m/s at the tail section; large improvement in cleaning performance was achieved with the designed fan.Research highlights: The airflow velocity decreased as the cleaning loads at the duct increased. The fan with the averaged airflow velocity ≥7 m/s at the upper duct under different cleaning loads, and the airflow velocity at the lowest duct ≥ 9 m/s, is favorable for forming a blowing airflow in the tail sieve and is good for grain stratification
Determining the radiation use efficiency of potato using sunshine hour data: a simple and costless approach
No full textAim of study: Radiation parameters and photoperiod influence potato biomass and tuber yield significantly. Lack of instrument facilities in developing countries is the main hindrance to estimate global solar radiation (GSR) and radiation use efficiency (RUE). Considering these facts, an experiment was conducted to estimate light extinction coefficient (K) and RUE using a simple but indirect approach that can be implied in any location lacking sophisticated instruments.Area of study: Field experiments were conducted in Kalyani, West Bengal, representing the Indo-Gangetic Plains.Material and methods: Angstrom-Prescott (A-P) equation was used to calculate GSR. The experiment was laid out in a split-plot design with three dates of planting (DOP), 15th Nov, 29th Nov and 13th Dec, as main plot treatment and three potato cultivars (ˈKufri Suryaˈ, ˈKufri Chandramukhiˈ and ˈKufri Jyotiˈ) as sub-plot treatment. Leaf area indices and K values were used to determine intercepted PAR (IPAR) as well as RUE.Main results: The cumulative IPAR from emergence to harvest ranged 246-429 MJ m-2 depending on planting time and varieties. Irrespective of DOPs, the highest mean RUE (4.19 g MJ-1) was calculated in ˈKufri Chandramukhiˈ, showing that it used the radiation more efficiently that the other two cultivars (ˈKufri Suryaˈ= 3.75 g MJ-1 and ˈKufri Jyotiˈ= 3.14 g MJ-1).Research highlights: Statistical indices confirmed that the A-P model can be reliably used in the study region for estimation of GSR. This simple way to estimating RUE using bright sunshine hours data can be used in developing countries, where costly radiation instruments are not available
Short Communication: Laboratory assessment of ammonia volatilization from pig slurries applied on intact soil cores from till and no-till plots
No full textAim of study: Agricultural activities are the main source of volatilized ammonia (NH3). Maximum rates are reached within a few hours after slurry application. This study aimed to evaluate the influence of soil texture, tillage and slurry dry matter (DM) on NH3 volatilization.Area of study: Mediterranean semiarid environments (NE Spain).Material and methods: Ammonia volatilization from pig slurry directly applied on the soil surface was quantified in the laboratory, in soil samples from two experimental sites with different soil textures: silty loam and sandy loam. Field treatments consisted of two tillage management practices: till by disc-harrowing or no-till. At topdressing (cereal tillering), tillage treatments were combined with slurries of different DM contents applied onto the silty loam soil. Measurements were done for two cereal cropping seasons and during the period of maximum NH3 flux (12 h after slurry application). A photoacoustic analyzer was used.Main results: Slurry spreading at sowing resulted in low volatilization (0.7-9% of NH4+-N applied) as it also did at topdressing (0.3-1.4% of NH4+-N applied). At sowing, ammonia volatilization from high DM slurry (>7.5%) was significantly enhanced by no-till in both soils. At topdressing, this result was also found in records on silty loam soil. No differences were found between tillage systems when slurry of low DM content was applied, whatever the soil texture and application moment. Although NH3 volatilization was probably affected by the laboratory conditions, the comparisons between treatments were still valuable.Research highlights: Ammonia volatilization abatement can be improved (<1 kg NH3-N ha-1) if fertilization is done after crop establishment using low DM slurries (<3.5%)
Food restriction in Nile tilapia juveniles (Oreochromis niloticus)
No full textAim of study: To evaluate if dietary restriction influence muscle and intestinal morphology as well as the production performance of juvenile Nile tilapia (Oreochromis niloticus).Area of study: State University of Western Paraná (Universidade Estadual do Oeste do Paraná – Unioeste), Toledo Campus, Brazil.Material and methods: The experimental design was completely randomized with four treatments and five replicates. The treatments were: 7:0 (fed daily; control); 6:1 (fed 6 consecutive days followed by 1 day of fasting); 5:2 (fed 5 consecutive days followed by 2 days of fasting); and 1:1 (fed 1 day followed by 1 day of fasting). A commercial ration with 33.70% crude protein and 4.60% lipid was used, and fish were fed four times daily until apparent satiety for 60 days.Main results: The following parameters were found to have differences among treatments (p<0.05): final weight, weight gain, final length, hepatosomatic index, visceral fat, intestinal quotient, protein efficiency rate, protein retention, ash, and frequency of muscle fiber diameters within the classes of<20 μm and between 20 and 50 μm. The intestinal villi height and hepatic glycogen content did not differ (p>0.05) among treatments. The cost of food and partial net revenue were higher in the 7:0 treatment compared to the experimental treatments.Research highlights: Dietary restriction for Nile tilapia in the juvenile phase negatively influences productive performance, centesimal composition, and muscle growth, which demonstrates that this practice is economically unfeasible for commercial production
Should the impact factor of the year of publication or the last available one be used when evaluating scientists?
No full textAim of study: A common procedure when evaluating scientists is considering the journal’s quartile of impact factors (within a category), many times considering the quartile in the year of publication instead of the last available ranking. We tested whether the extra work involved in considering the quartiles of each particular year is justifiedArea of study: EuropeMaterial and methods: we retrieved information from all papers published in 2008-2012 by researchers of AGROTECNIO, a centre focused in a range of agri-food subjects. Then, we validated the results observed for AGROTECNIO against five other European independent research centres: Technical University of Madrid (UPM) and the Universities of Nottingham (UK), Copenhagen (Denmark), Helsinki (Finland), and Bologna (Italy).Main results: The relationship between the actual impact of the papers and the impact factor quartile of a journal within its category was not clear, although for evaluations based on recently published papers there might not be much better indicators. We found unnecessary to determine the rank of the journal for the year of publication as the outcome of the evaluation using the last available rank was virtually the same.Research highlights: We confirmed that the journal quality reflects only vaguely the quality of the papers, and reported for the first time evidences that using the journal rank from the particular year that papers were published represents an unnecessary effort and therefore evaluation should be done simply considering the last available rank
A whole row automatic pick-up device using air force to blow out vegetable plug seedlings
No full textAim of study: To develop a whole row automatic pick-up device using air force to blow out plug seedlings, to avoid the damage to seedlings that the current way of seedling picking by needle insertion induces.Area of study: Jiangsu Province, China.Material and methods: We designed a pick-up device which mainly consists of a seedling transporting device, a seedling air loosening device, a seedling clamping device and an automatic control system. The damage rate of seedling was significantly reduced and the success rate of seedling picking was increased by using the new seedling air loosening method and the new designed end-effectors. A prototype of the new pick-up device was produced according to the calculation results, and the performance tests were arranged under actual production conditions in an indoor laboratory.Main results: The calculation showed that when the diameter of the blowhole in air nozzle is 3.5 mm, and the air pressure is between 0.146 MPa and 0.315 MPa, the seedlings can be blown out successfully. Besides, the clamping strain test showed that the new designed end-effector can meet the requirements of seedling picking. The orthogonal test showed that both the air pressure and water content significantly affected the success ratio. The success ratio reached 96.64% when air pressure was 0.4 MPa, water content was 55%-60% and airflow rate was 100%, what meets the current requirements of transplanting.Research highlights: This research can provide some references for the automatic transplanting technology
Short communication: Presence of Fusarium graminearum sensu stricto associated with triticale (× Triticosecale Wittmack) in Argentina
No full textAim of study: To report the occurrence of Fusarium graminearum sensu stricto (s.s.) on triticale grains from field samples in Argentina and the potential mycotoxin production for these isolates.Area of study: Buenos Aires province, ArgentinaMaterial and methods: A total of 40 samples from different crops (barley, rye, triticale, and wheat) showing Fusarium head blight symptoms were taken during 2017/2018 harvest season. Colonies with colour and mycelium similar to Fusarium were taken and were morphologically and molecularly identified. The potential to produce deoxynivalenol, 15-acetyl deoxynivalenol and zearalenones was determined. Also, the Koch´s postulates were used to evaluate the pathogenic capacity of the F. graminearum s.s. isolates in triticale.Main results: Two Fusarium isolates were identified morphologically as F. graminearum, which were confirmed molecularly by PCR using the specific Fg16 F/R primers pair and by sequencing red and tri101 genes. The sequences obtained were compared with those available in the NCBI database using BLAST tools, showing 99-100% homology with those belonging to F. graminearum s.s. The results demonstrated that F. graminearum s.s. isolates were pathogenic when triticale spikes were inoculated by spraying under greenhouse conditions.Research highlights: To our knowledge, this is the first time that the presence of F. graminearum s.s. is reported associated with triticale in Argentina