Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
Not a member yet
3042 research outputs found
Sort by
Population dynamics and integrated control of the damson-hop aphid Phorodon humuli (Schrank) on hops in Spain
Get PDFThe hop aphid Phorodon humuli (Schrank) (Hemiptera: Aphididae) is a serious pest in most areas where hops are grown. A field trial was performed on a hop yard throughout 2002, 2003 and 2004 in León (Spain) in order to analyse the population development of Phorodon humuli and its natural enemies, as well as to determine the most effective integrated program of insecticide treatments. The basic population development pattern of P. humuli was similar in the three years: the population peaked between mid to late June, and then decreased in late June/early July, rising again and reaching another peak in mid-July, after which it began to decline, rising once more in late August; this last rise is characteristic of Spain and has not been recorded in the rest of Europe. The hop aphid’s main natural enemy found on the leaves was Coccinella septempunctata (Coleoptera: Coccinellidae). The multiple regression analysis showed that aphids are positively related with the presence of beetle eggs and mean daily temperatures and negatively related with maximum daily temperature integral above 27ºC in plots without insecticide treatment. The most effective program of insecticide (imidacloprid) treatments consisted of an initial treatment in June and a second treatment in the second half of July or at the beginning of August. However, a single treatment in June would be sufficient when in this last period the maximum daily temperatures were higher than 27ºC for at least 15 days, avoiding in this way the harmful effects of imidacloprid on predators
NIRS determination of non-structural carbohydrates, water soluble carbohydrates and other nutritive quality traits in whole plant maize with wide range variability
Get PDFThe aim of this work was to study the potential of near-infrared reflectance spectroscopy (NIRS) to predict non-structural carbohydrates (NSC), water soluble carbohydrates (WSC), in vitro organic dry matter digestibility (IVOMD), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and starch in samples of whole plant maize with a wide range of variability. The samples were analyzed in reflectance mode by a spectrophotometer FOSS NIRSystems 6500. Four hundred and fifty samples of wide spectrum from different origin were selected out of 3000 scanned for the calibration set, whereas 87 independent random samples were used in the external validation. The goodness of the calibration models was evaluated using the following statistics: coefficient of determination (R2), standard error of cross-validation (SECV), standard error of prediction for external validation (SEP) and the RPDCV and RPDP indexes [ratios of standard deviation (SD) of reference analysis data to SECV and SEP, respectively]. The smaller the SECV and SEP and the greater the RPDCV and RPDP, the predictions are better. Trait measurement units were g/100g of dry matter (DM), except for IVOMD (g/100g OM). The SECV and RPDCV statistics of the calibration set were 1.34 and 3.2 for WSC, 2.57 and 3 for NSC and 2.3 and 2.2 for IVOMD, respectively. The SEP and RPDP statistics for external validation were 0.74 and 4.7 for WSC, 2.14 and 2.5 for NSC and 1.68 and 1.6 for IVOMD respectively. It can be concluded that the NIRS technique can be used to predict WSC and NSC with good accuracy, whereas prediction of IVOMD showed a lesser accuracy. NIRS predictions of OM, CP, NDF, ADF and starch also showed good accuracy
Isolation of table olive damage causes and bruise time evolution during fruit detachment with trunk shaker
Get PDFThe high sensitivity of table olives to mechanical damage limits mechanical harvesting with trunk shakers. The objective of this study was the identification, evaluation and temporal evolution assessment of the sources of damage caused to the fruits. To do this, digital image analysis was used for the objective determination of damage produced to table olives. Harvesting tests were performed in an intensive olive orchard with trees of the ‘Manzanilla’ variety in Seville, Spain. Mechanical harvesting with trunk shakers and subsequent detachment of the fruits to the ground produced a level of interference 12 times greater than the levels obtained from manual harvesting. Fruit-fruit and fruit-branch impacts and friction from the movement of the fruit in the tree canopy during vibration and detachment were the main causes of damage to the fruits. These causes represented a mean value of 60% of the damage produced to the fruits from mechanical harvesting. In addition, most bruising from mechanical damage occurred in the first hour after harvesting and followed an exponential tendency. The information obtained about table olive damage causes and bruise time evolution during fruit detachment with trunk shaker can be used by the producers to determine how to reduce and prevent bruising during harvesting operations.The high sensitivity of table olives to mechanical damage limits mechanical harvesting with trunk shakers. The objective of this study was the identification, evaluation and temporal evolution assessment of the sources of damage caused to the fruits. To do this, digital image analysis was used for the objective determination of damage produced to table olives. Harvesting tests were performed in an intensive olive orchard with trees of the ‘Manzanilla’ variety in Seville, Spain. Mechanical harvesting with trunk shakers and subsequent detachment of the fruits to the ground produced a level of bruise 12 times greater than the levels obtained from manual harvesting. Fruit-fruit and fruit-branch impacts and friction from the movement of the fruit in the tree canopy during vibration and detachment were the main causes of damage to the fruits. These causes represented a mean value of 60% of the damage produced to the fruits from mechanical harvesting. In addition, most bruising from mechanical damage occurred in the first hour after harvesting and followed an exponential tendency. The information obtained about table olive damage causes and bruise time evolution during fruit detachment with trunk shaker can be used by the producers to determine how to reduce and prevent bruising during harvesting operations
Short communication. Evaluation of a commercial kit based on acridine orange/propidium iodide to assess the plasma membrane integrity of ram sperm
Get PDFThis study was designed to develop a semiautomatic computer assisted methodology to evaluate the membrane integrity of ram spermatozoa using a commercial kit based on acridine orange/propidium iodide (AO/PI) labelling and ImageJ software. The study was divided into two experiments. In the first trial, the new computer-assisted method was validated by mixing fresh semen samples with different volumes of freeze killed spermatozoa to determine proportions of damaged spermatozoa in the final samples. The proportion of damaged spermatozoa in each sample determined by the automated procedure where highly correlated (R2=0.97, p<0.001) with the predicted theoretical values. In the second trial, the new method was compared with a previously validated method of membrane integrity assessment based on phase-contrast/propidium iodide (PH/PI) methodology. Measurements by AO/PI were, on average, 4.0% larger than measurements by PH/PI (SD=7.02%) and 1.79% smaller than measurements of sperm motility determined by CASA (SD=4.83). The AO/PI method was also more repeatable than the PH/PI. The double staining methodology coupled with the routine for image analysis allowing automatic determination of sperm membrane integrity means a reduction in processing time of 75% compared to the previously developed method using a single fluorochrome (3 vs 12 min on average if the incubation period was included). This facilitates its use when a large number of samples are analysed. Our results validate the new computer assisted method for assessing sperm membrane integrity in sheep. The new method developed, in addition to being a free tool, allows quick automatic determination of sperm viability, which facilitates its use in routine semen analysis
Side effects of different pesticides used in citrus on the adult stage of the parasitoid Aphytis melinus DeBach (Hymenoptera Aphelinidae) and its progeny
Get PDFTwelve pesticides commonly used in citrus in Spain were tested on adults of Aphytis melinus DeBach to determine their effects on parasitoid survival and fecundity, and the duration of the residue of each pesticide. Six of these pesticides were found to be harmless to moderately harmful to this parasitoid in a laboratory assay in closed Petri dishes: spinosad (bait formulation), azadirachtin, fenbutatin, fosetyl-Al, copper oxichloride, and mancozeb, with their scores on the reduction of beneficial capacity (RBC) index being between 21.4 and 94.6% after one week. The other six pesticides classified as harmful were tested on citrus plants to study their persistence over time under greenhouse conditions: Pirimicarb, pyriproxifen, paraffinic oil, abamectin, chlorpyrifos, and lambda-cyhalothrin. Most of these products reduced their negative effect on adults of A. melinus between one and six weeks after treatment, although lambda-cyhalothrin was still harmful to parasitoids 11 weeks after application. This information can help growers and consultants to make decisions about pesticide selection and application timing in citrus in order to support IPM implementation when A. melinus is present
Short communication. In vitro embryo production can be modified by the previous ovarian response to a superovulatory treatment in sheep
Get PDFThirty-two ewes were used to study how the ovarian response to a superovulatory treatment determines quality of oocytes recovered from ovaries after embryo collection, and their developmental capacity after in vitro maturation (IVM) and fertilization (IVF). Ewes were superovulated, and seven days after oestrus, embryos were collected and ewes divided into three groups: (+ +), n=19, ewes responding to the treatment with embryos collected after flushing; (+ –), n=8, ewes responding, but only oocytes were found; and (– –), n=5, ewes not responding to the treatment and no embryos collected. Ovaries were recovered and oocytes collected from the three groups. A significant effect of the response to the treatment was observed for oocyte quality, so that (– –) ewes presented the higher number of oocytes per ewe (p<0.001). Total number of oocytes selected for IVM and IVF was significantly higher in the same group, in comparison with (+ +) and (+ –) (p<0.001). Group (+ –) ewes presented the lowest maturation (p<0.001), fertilization (p<0.05) and cleavage rates (p<0.001). In conclusion, the ovarian response to a superovulatory treatment determines the number and quality of the oocytes recovered 7 days after the oestrus induced by the hormonal treatment. In vitro techniques could be an important tool to increase embryo production by particular ewes when they are not able to produce a significant amount of in vivo embryos
Endozoochorus seed dispersal by goats: recovery, germinability and emergence of five Mediterranean shrub species
Get PDFHerbivores can play an important role as seed dispersal vectors, ungulates constituting potential seed dispersal agents of Mediterranean grasses and shrubs. We evaluated the role of domestic goats as seed dispersers of five representative Mediterranean forage shrub species (Cistus albidus L., Phillyrea angustifolia L., Calicotome villosa (Poir.) Link., Rhamnus lycioides L. and Atriplex halimus L.). Following seed ingestion by goats, total faeces were collected at 24-h intervals for five days. The total number of seeds recovered varied among species, with R. lycioides showing the minimum recovery percentage (1.3%) and C. albidus (35.8%), the maximum. Seed recovery was significantly related to seed hardness and length. In most species, the maximum amount of seeds recovered occurred 48-72 h after ingestion. The passage through the goat gut significantly depressed seed germination in C. albidus, C. villosa and A. halimus; inhibited it in R. lycioides and increased it in P. angustifolia. Seedling emergence was significantly lower in intact dung pellets than in broken-down ones, and both significantly lower than in uneaten seeds (control). The results of this study show that goats can potentially favor or inhibit seed dispersal of browsed Mediterranean shrub species. Therefore, goat grazing could be a potential management tool for expanding target shrub species populations or preventing shrub encroachment in undesired areas
Short communication. Impact of the amino acid proline on the cold hardiness of honey bee, Apis mellifera L.
Get PDFLike many insects, honey bee can increase its cold tolerance through freeze avoidance, using antifreeze proteins (AFPs) to lower its supercooling point (SCP). Proline is the most dominant amino acid in honey bee hemolymph, which can be obtained by the insect through feeding. In the current study the antifreeze activity of this amino acid was evaluated on worker honey bees, immediately before the start of cold season. The experiment was established on four treatments including three different concentrations of proline (1%, 3% and 4.35%) diluted in 1:1 water sucrose syrup, and the syrup without proline (control). Newly emerged worker honey bees were fed on the mentioned diets for 2 weeks, under cage condition, and then 20 bees from each treatment (cage) were selected randomly for determination of cold hardiness inside a cooling bath. Using a CHY data logger, equipped with a K100 sensor attached to the bee’s gaster, the SCP, the amount of released heat and the rate of this release as measures of insect cold hardiness were recorded. Proline significantly reduced honey bees’ SCP. The lowest point, -7.67±0.2646°C, was observed in the concentration of 1% proline. The amount of released heat and the rate of this release were not significantly different across the treatments
Relationship between udder morphology traits, alveolar and cisternal milk compartments and machine milking performances of dairy camels (Camelus dromedarius)
Get PDFA total of 22 dairy dromedary camels under intensive conditions in late lactation (275±24 days) were used to study the relationship between external and internal udder morphology and machine milking performances. Measurements of udder and teat morphology were obtained immediately before milking and in duplicate. Individual milk yield, lag time and total milking time were recorded during milking, and milk samples were collected and analyzed for milk composition thereafter. Cisternal and alveolar milk volumes and composition were evaluated at 9 h milking interval. Results revealed that dairy camels had well developed udders and milk veins, with medium sized teats. On average, milk yield as well as milk fat and protein contents were 4.80±0.50 L d-1, 2.61±0.16% and 3.08±0.05%, respectively. The low fat values observed indicated incomplete milk letdown during machine milking. Lag time, and total milking time were 3.0±0.3, and 120.0±8.9s, on average, respectively. Positive correlations (p<0.05) were observed between milk yield and udder depth (r=0.37), distance between teats (r=0.57) and milk vein diameter (r=0.28), while a negative correlation was found with udder height (r=-0.25, p<0.05). Cisternal milk accounted for 11% of the total udder milk. Positive correlations were observed between total milk yield and volume of alveolar milk (r=0.98; p<0.001) as well as with volume of cisternal milk (r=0.63, p<0.05). Despite the low udder milk storage capacity observed in dairy camels, our study concluded that the evaluated dromedary sample had adequate udder morphology for machine milking. Finally, positive relationships were detected between milk yield and udder morphology traits of dairy camels
Effect of increasing lysine supply during last third of gestation on reproductive performance of Iberian sows
Get PDFNinety purebred Iberian (IB) sows in second or third parity were used to determine the effects of dietary lysine (Lys) concentration during last third of pregnancy on sow and litter performance. The sows were randomly assigned to one of three dietary treatments: 5.5 (LLys, Control), 7.4 (MLys) and 8.7 (HLys) g Lys kg-1 diet. Feed allowance was 2.30-2.33 kg d-1. Close to farrowing a conventional lactation diet was used. Dietary Lys did not affect body-weight (BW) gain in late gestation of second-parity sows. However, in third-parity sows, a strong tendency was observed for BW gain to increase during late pregnancy with dietary Lys levels higher than 5.5 g kg-1 (p=0.061). Body-weight losses during lactation were never influenced by Lys supply. A strong tendency (p=0.064) for a lower ratio between piglets born alive and total piglets born was observed in second-parity sows fed the Control gestation diet. Litters and piglets from sows on this diet had the lowest weight at birth (p0.05). In conclusion, under moderate energy supply, adequate reserves for subsequent lactation can be achieved in second- and third-parity IB sows with a daily provision of at least 17.2 g lysine over the last third of pregnancy, what implies a substantial increase in protein supply respect to traditional practices