Spanish Journal of Agricultural Research
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Modeling pesticide translocation injected by endotherapy into the stem of coconut tree (Cocos nucifera L.)
No full textAim of study: To present a mathematical model to simulate the translocation of pesticides injected into coconut trees. Pesticide residues in water and coconut pulp were also evaluated.
Area of study: The data were obtained in coconut plants of the Itaporanga Experimental Field, located in the Municipality of Itaporanga d'Ajuda, Sergipe State, Brazil.
Material and methods: To estimate the effect of pesticide site-sap coefficients and retardation factors on translocation and its phytosanitary behavior and risk of contamination of coconut fruits, the stipe was modeled by a classic dispersion-advection equation. The pesticides cyproconazole, azoxystrobin, dimethoate, imidacloprid, metalaxyl, and thiamethoxam were injected into the coconut palm stipe. The method used to extract pesticide residues from pulp, water and coconut sap samples was based on the QuEChERS methodology with modifications.
Main results: Simulations showed that (i) the pesticides dimethoate, metalaxyl, and thiamethoxan were the active ingredients showing the greatest potential for translocation in the sap of the coconut tree stem; (ii) the pesticides imidacloprid and metalaxyl translocated upward in the stipe, and more rapidly than pesticides abamectin and cyproconazole, which moved slower to the aerial part of coconut plants. In chromatography analysis, no pesticide residues were quantified in water and coconut fruit pulp samples of coconut trees injected with pesticides, after the evaluated intervals.
Research highlights: The proposed model allowed us to observe that the translocation is inversely proportional to the sorption of the pesticide in the stem of coconut trees
Short communication: Comparison of hemato-immunological parameters in rainbow trout (Oncorhynchus mykiss): Palomino vs naturally pigmented varieties
No full textAim of the study: To evaluate hemato-immunological parameters in the Palomino trout compared to naturally pigmented rainbow trout.
Area of study: Fars province (SW Iran).
Material and methods: Sixty fish of both varieties (30 Palomino and 30 naturally pigmented) were sampled from the same pond. After blood sampling, hematological parameters, total serum protein and immunoglobulin (Ig), phagocytic activity, respiratory burst activity, serum lysozyme, and bactericidal activity were measured.
Main results: Number of white blood cells, total protein, total immunoglobulins, lysozyme, and bactericidal activities in serum of Palomino trout were significantly higher than those in naturally pigmented rainbow trout. However, no significant changes were observed in no. of red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, differential leukocyte count, phagocytic, and respiratory burst activity.
Research highlights: The immune system performance of Palomino trout was similar to naturally pigmented fish. However, in some cases, the immune response of Palomino fish may be even more robust than that of naturally pigmented fish. This finding helps us to favor Palomino trout in breeding programs and genetic modification
In vitro anthelmintic activities of three ethnomedicinal plant extracts against Haemonchus contortus
No full textAim of study: To investigate the in vitro anthelmintic efficacies of three plants, Annona senegalensis (AS), Cochlospermum planchonii (CP), and Sarcocephalus latifolius (SL), used by livestock farmers in Northern Nigeria, to treat gastrointestinal nematode infections in ruminants.
Area of study: Makurdi, Benue State, Nigeria.
Materials and methods: The plants were selected through a structured questionnaire administered to livestock farmers in Northern Nigeria. Aqueous and acetone leaf (AS and SL) and root (CP) extracts of these plants were investigated for their anthelmintic activity against Haemonchus contortus using the egg hatch inhibition assay at concentration levels of 0.3125 to 10 mg/mL in 2.5% dimethyl sulfoxide.
Main results: A probit log-dose response analysis showed that acetone extract of CP achieved 100% egg hatch inhibition similar to the commercial drug at all tested concentrations after 48 hours of incubation, while AS demonstrated 88.7% egg hatch inhibition. Acetone extract of SL had less than 50% egg hatch inhibition at all tested concentrations. On the other hand, the aqueous extract of CP and SL both exhibited 100% inhibition at 5 and 10 mg/mL of the tested concentrations, while AS had less than 50% egg hatch inhibition at all tested concentrations.
Research highlights: This study identified CP, AS, and SL as medicinal plants with rich sources of molecules that have potential value in the development of novel anthelmintic drugs
Phenology, growth, and yield of almond cultivars under organic and conventional management in southwestern Spain
No full textAim of study: To advance implementation of sustainable agriculture from organic production system on almond crop by means of the assessment of physiological and agronomical responses of commercial almond cultivars.
Area of study: Irrigated almond in the Guadalquivir River Valley.
Material and methods: Physiological and agronomic aspects of almond such as defoliation, phenology, tree growth, N and P leaf reserves, susceptibility to aphids and fruit yield were assessed on five almond cultivars under organic and conventional production management during four consecutive seasons from 2017 to 2021.
Main results: A lower flower density, tree growth, and almond production, an earlier and more intense defoliation degree, and a higher susceptibility to aphids were observed in the organic plot compared to the conventional orchard. 'Lauranne' was the cultivar that showed the best productivity under organic and conventional management. 'Marcona' showed the higher flower density and medium vigor, although was the most susceptible cultivar to aphids and the less productive cultivar under both managements.
Research highlights: Cultivation of irrigated almond still presents numerous difficulties, especially the control of pests and diseases due to the use of environmentally friendly pesticides which are less effective than chemicals. These pathogenic factors and others such as nutrition especially affect the yield of the crop, although the differences with the conventional system are reduced over time. Despite these difficulties, the high added value of organic almonds together with the increasing demands by consumers of healthy environmental practices and food safety are a stimulus to continue and develop research on sustainable agriculture
Impact of nutritional and sanitary management on Apis mellifera colony dynamics and pathogen loads
No full textAim of study: The aim of this study was to assess the impact of the mite control strategies combined with nutritional management on honey bee colony dynamics and survival during winter, the following spring, and summer.
Area of study: Santa Fe province in central Argentina.
Material and methods: We set two apiaries with 40 colonies each and fed one apiary with high fructose corn syrup (HFCS) and the other with sucrose syrup (SS). Within each apiary, we treated half the colonies against Varroa mites and half of these treated colonies also received a pollen patty. The other half of the colonies remained untreated and did not received pollen patties. All colonies were sampled for Varroa infestation level, Nosema ceranae abundance and colony strength seven times during a year (from summer 2016 to autumn 2017). We computed autumn mite invasion and colony losses at each sampling time.
Main results: Colonies fed with HFCS had more brood cells during the study that those fed with SS and treated colonies had fewer adult bees and Varroa infestation than untreated colonies. No significant effect of the protein supplementation was observed on any of the response variables. , SS colonies from all groups had significantly more mites drop counts than HFCS colonies.
Research highlights: Considering that a reduced frequency of application is desirable, our results suggested that nutrition management could enhance chemical treatment effectiveness since honey bees might profit from improved nutrition. However, a better understanding of the nutritional requirements of the colonies under field conditions is needed
Effectiveness of the entropy weight method to evaluate abiotic stress tolerance in citrus rootstocks
No full textAim of study: The entropy weight method (EWM) is considered one of the most reliable and scientific approaches when decision making is influenced by multiple factors. However, there are no reports on the application of EWM in the evaluation of abiotic and biotic stress tolerance in crops. In this study, abiotic stress via saline water irrigations was imposed on different citrus rootstocks. The relative stress tolerance levels of rootstocks were ascertained using EWM and compared with standard fuzzy membership approach and the factor analysis.
Area of study: Punjab Agricultural University Regional Research Station Abohar, India, 2017-2019.
Material and methods: In a pot culture study, about 1½ yr-old rootstock seedlings were exposed to saline water irrigations with 4 and 6 dS m-1 electrical conductivity (EC) for 60 days. Saline water response index for mineral composition of plant parts, physiological and biochemical attributes of rootstocks were calculated for each salinity level over 2 dS m-1 conductivity water, considered as control and subjected to further analysis.
Main results: At 4 EC, the entropy weight and membership function value of the rootstocks ranged 0.758-0.998 and 0.682-0.731, respectively. The corresponding values at 6 EC ranged between 0.759-0.991 and 0.391-0.728, respectively. Following EWM, the rootstocks were rated for their relative tolerance levels as: Rangpur Lime>Cleopatra>Volkamer Lemon=Rough Lemon>Carrizo at 4 EC salinity level. At 6 EC, the order was: Cleopatra>Rangpur Lime>Volkamer Lemon>Rough Lemon>Carrizo. The results were consistent between EWM and standard principle component analysis approaches.
Research highlights: The study suggests that the comprehensive evaluation of crop genotypes for abiotic stress tolerance is also feasible with the EWM
Quality of Santa Inês × Dorper sheep meat submitted to different levels of inclusion of sunflower cake
No full textAim of study: To evaluate the physicochemical and sensory quality of meat from Santa Inês × Dorper lambs fed diets with increasing levels of sunflower cake.
Area of study: Rio Grande do Norte (Brazil).
Material and methods: Twenty-four castrated lambs (initial weight of 18.9 ± 2.17 kg) were distributed in a completely randomized design with four treatments (0, 5, 10 and 15% sunflower cake in diet) with six repetitions and kept in confinement until reaching the average body weight of 32.1 ± 2.6 kg. The Longissimus lumborum muscle was used for proximate composition and physicochemical analyzes, and the Semimembranosus muscle was used for pH (after 24 h of slaughter) and sensory analysis assays.
Main results: The increasing levels of sunflower cake did not affect the composition or physicochemical properties. Sensory analysis also did not reveal significant differences in meat obtained from animals in different diets. Principal Components Analysis indicated that juiciness, color, odor and flavor were positioned opposite to protein, texture, and ash.
Research highlights: The use of sunflower cake in diets for crossbred sheep Dorper × Santa Inês as soybean meal and corn replacer, up to 15% inclusion of soybean meal and corn, does not affect the proximate composition, physicochemical or sensory characteristics of the meat
Freezing preservation procedure of caecal inoculum for microbial fermentation studies in pigs
No full textAim of study: To define freezing conditions that preserve fermentative capacity of microbial inoculum for in vitro studies in pigs.
Material and methods: Caecal contents from three slaughtered pigs were obtained for being used as inoculum. Part of it was immediately frozen in liquid N and stored at -80ºC, whereas the rest was directly used as fermentation inocula. Incubation substrate was pre-digested in pepsin and pancreatin to simulate the processes occurring before the caecum. Pre-digested substrate was incubated alone or supplemented by three additives consisting of two commercial additives based on essential oils mixtures (CRINA-TEP and CRINA-TMEC) and riboflavin. Gas production at 2, 4, 6, 8, 10, and 12 h, and methane, short chain fatty acids (SCFA), and ammonia concentration at 6 h and 12 h were recorded.
Main results: No differences (p>0.05) were recorded along the 12 h incubation between both preservation methods of inocula regarding gas production, methane or total SCFA or their molar proportions. Only a trend for a higher ammonia concentration was detected with frozen than fresh inocula (p=0.062). Although not a main objective of the paper, gas production from the substrate alone (control) was lower than with riboflavin from 8 h onwards, and with CRINA-TEP from 4 to 10 h incubation (p>0.05).
Research highlights: Caecal inoculum from pigs for in vitro fermentation studies can be preserved by freezing, provided that freezing and thawing processes are carried out under favorable conditions, especially in terms of time and temperature
Simulation modelling of mechanical systems for intra-row weeding in a precision farming approach
No full textAim of study: To test new approaches to perform mechanical weeding inside the row in horticulture and tree fruit fields. The idea is to weed the row by skipping the crop by means of a rotating system instead of a traditional crosswise one.
Area of study: North of Italy.
Material and methods: Numerical models have been developed to simulate mechanical weeding over time by generating numerical maps to quantify the different kind of worked areas.
Main results: Considering the efficiency of weed control on the row, the rotating plant-skipping system with vertical axis (RPSS-VA model) with two working tools gives the best performance index (1.1.RWA% = 95.9%). A similar performance can be obtained by the crosswise displacement plant-skipping system, but with very high crosswise translation velocity (with va/vr ratio = 1/5, 1.1.RWA% = 94.5%). With regard to the outwards worked area the RPSS-VA models give the best performances (2.2.%OWAR index from 127.2% up to 282.3%). To reduce the worked area outside the row, the FBTS models give lower index (2.1.OWAR%), while the RPSS-HA works only on the row, but with the lower 1.1.RWA% index among all tested models (55.8%).
Research highlights: Rotating systems resulted more efficient than traditional ones, and provide considerations on the use of electric drive power instead of hydraulic one. This study highlights also the need of new approaches in designing lighter working tools. Lastly, the proposed classification of the worked areas could be used as reference standard
Exploring the economic impact of carbonic fertilisation in greenhouses in western Almería (Spain)
No full textAim of study: To assess the economic viability of implementing carbon fertilisation (CF) on the Campo de Dalías greenhouse agricultural sector.
Area of study: Agricultural area of Campo de Dalías (Southeast of Spain), the highest density of greenhouses for horticulture in Europe, with an area of 21,285 ha of greenhouses, spread over an entire area of 33,000 ha.
Material and methods: Based on the technology currently used in the Campo de Dalías, we estimated the impact of introducing technology that could incorporate CF (multi-span greenhouses) and that of CF itself. The main indicators analysed were value added, employment, gross output, and input use, and especially water consumption.
Main results: The results show an improvement in the most important indicators analysed, making CF an economically viable technique that will help the development process of the agricultural sector in Campo de Dalías.
Research highlights: Campo de Dalias production competes in Central European markets with others coming from areas with lower costs (North Africa) or those with higher technical standards (mainly the Netherlands). Species traditionally grown in the Campo de Dalías greenhouses have disappeared due to their low profitability. Technological innovation is the only way out to prevent this important sector from continuing losing value