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1.
PLoS One ; 16(3): e0248655, 2021.
Article in English | MEDLINE | ID: mdl-33725027

ABSTRACT

Agricultural non-point source pollution refers that substance such as nitrogen and phosphorus cause water environment pollution through surface runoff and underground leakage in agricultural production activities. Water environment pollution related to agricultural non-point source pollution in the Huaihe River Basin is becoming more and more prominent. Therefore, it is necessary to analyze the characteristic of soil nutrient in cultivated land and explore the spatial variation and influencing factors of soil nutrients at the watershed scale. A total of 239 topsoil samples were collected from the Guo river basin, and the related factors of soil organic matter (SOM), total carbon (TC), total nitrogen (TN), total phosphorous (TP), total potassium (TK) and potential of hydrogen (PH) were studied by using descriptive statistics and geostatistical methods. The results showed that TK and PH were weak variation, while SOM, TC, TN and TP were medium variation. Soil pH, TP, TK, TC and SOM had moderate spatial variability, which was caused by both random factors and structural factors such as soil texture, soil type, fertilization and local ecological restoration management. Soil TN showed a strong spatial correlation, mainly due to soil texture and soil type. If the recommended fertilization amount is still given based on the average value of soil nutrients ignoring the spatial heterogeneity, it will not only affect crop production efficiency and fertilizer utilization, but may also cause greater environmental pollution. This study can provide a theoretical basis for the management of agro-ecological environments throughout the basin area.


Subject(s)
Crop Production/standards , Non-Point Source Pollution/prevention & control , Rivers/chemistry , Soil/chemistry , China , Nitrogen/analysis , Phosphorus/analysis , Seasons , Spatial Analysis
2.
Pak J Biol Sci ; 24(12): 1269-1277, 2021 Jan.
Article in English | MEDLINE | ID: mdl-34989204

ABSTRACT

<b>Background and Objective:</b> Bakasang is a typical food of North Sulawesi and its surroundings, made from fermented fish viscera. This food is made by fermentation so that it is rich in amino acids and polypeptides. This study aimed to determine the optimum processing conditions for Bakasang with Peroxide Value (PV) parameters based on Response Surface Methodology (RSM) with Central Composite Design (CCD). <b>Materials and Methods:</b> Viscera from fresh Skipjack tuna consisting of intestines, liver, heart and eggs were mixed with salt and left in a fermenter for varying times and temperatures to obtain Bakasang. The fermentation temperature, salt content, and fermentation time, determined based on the Central Composite Design (CCD), were variables in this study. Thus, 20 experiments consisted of eight quadratic points, six centre points and six axial points. <b>Results:</b> The results showed that the correlation test between temperature, salinity and fermentation time variables on PV were 0.521, 0.305 and 0.591. The regression test resulted in an R<sup>2</sup> value of 0.988. The model equation obtained was y = 4.35194 - 0.11363x<sub>1 </sub>- 0.07459x<sub>2 </sub>- 0.25300x<sub>3 </sub>+ 0.00157x<sub>12 </sub>+ 0.00310x<sub>22</sub> + 0.01571x<sub>32</sub> - 0.00064x<sub>1</sub>x<sub>2 </sub>+ 0.00172x<sub>1</sub>x<sub>3</sub> + 0.00340x<sub>2</sub>x<sub>3</sub>. The contour plot graph obtained from the experiment using CCD showed that the optimum processing conditions for Bakasang were at a temperature of 32.9324°C, salinity 10.2631% and fermentation time of 4.7793 days, which will produce Bakasang with an optimum PV of 1.51256 meq kg<sup>1</sup> sample. <b>Conclusion:</b> According to the findings of this study, the optimum temperature, salinity and fermentation time for producing Bakasang with a PV of 1.51256 meq kg<sup>1</sup> sample were 32.932°C, 10.263% and 4.779 days, respectively.


Subject(s)
Crop Production/standards , Fermented Foods/standards , Fishes/metabolism , Animals , Crop Production/methods , Fermented Foods/supply & distribution , Fishes/microbiology , Indonesia
3.
Sci Rep ; 10(1): 8351, 2020 05 20.
Article in English | MEDLINE | ID: mdl-32433494

ABSTRACT

Mercury (Hg) exposure poses serious health risks to humans, resulting in extensive investigations examining Hg accumulation, biotransformation and uptake in crops. In this investigation, Hg accumulation in potato tubers due to bioaccumulation processes was determined and bioconcentration factors affecting bioaccumulation were identified using a greenhouse experiment. Our results showed that the percentage of available Hg concentrations from total Hg in soil samples were less than 1.2%, indicating that soils used in our experiment exhibited a high binding strength for Hg, with alkaline soil recording the lowest available Hg/total Hg ratio. Results indicated that soil type and Hg treatment, as well as their interactions, significantly affected Hg accumulation in potato tubers (P < 0.01). Importantly, our results also indicated that potatoes grown in soil with a Hg concentration two times higher than the Chinese Environmental Quality Standard exhibited no obvious toxic effects on humans; Bioconcentration factors (BCF) values (<0.04) suggested that potatoes can be considered as a low Hg accumulating species and suitable for human consumption. Potato yields in acidic soil were lower than those in neutral or alkaline soils, making this medium unsuitable for growth.


Subject(s)
Bioaccumulation , Environmental Pollution/adverse effects , Mercury/analysis , Soil Pollutants/analysis , Solanum tuberosum/chemistry , China , Crop Production/standards , Crops, Agricultural/chemistry , Crops, Agricultural/growth & development , Crops, Agricultural/metabolism , Crops, Agricultural/standards , Foodborne Diseases/etiology , Foodborne Diseases/prevention & control , Humans , Mercury/metabolism , Mercury/standards , Mercury/toxicity , Plant Tubers/chemistry , Plant Tubers/growth & development , Plant Tubers/metabolism , Plant Tubers/toxicity , Soil/chemistry , Soil Pollutants/metabolism , Soil Pollutants/standards , Soil Pollutants/toxicity , Solanum tuberosum/growth & development , Solanum tuberosum/metabolism , Solanum tuberosum/standards
4.
PLoS One ; 15(4): e0224588, 2020.
Article in English | MEDLINE | ID: mdl-32236110

ABSTRACT

Nitrogen (N), phosphorus (P), potassium (K), and water are four crucial factors that have significant effects on strawberry yield and fruit quality. We used a 11 that involved 36 treatments with five levels of each of the four variables (N, P, and K fertilizers and water) to optimize fertilization and water combination for high yield and quality. Moreover, we used the SSC/TA ratio (the ratio of soluble solid content to titratable acid) as index of quality. Results showed that N fertilizer was the most important factor, followed by water and P fertilizer, and the N fertilizer had significant effect on yield and SSC/TA ratio. By contrast, the K fertilizer had significant effect only on yield. N×K fertilizer interacted significantly on yield, whereas the other interactions among the four factors had no significant effects on yield or SSC/TA ratio. The effects of the four factors on yield and SSC/TA ratio were ranked as N fertilizer > water > K fertilizer > P fertilizer and N fertilizer > P fertilizer > water > K fertilizer, respectively. The yield and SSC/TA ratio increased when NPK fertilizer and water increased, but then decreased when excessive NPK fertilizer and water were applied. The optimal fertilizer and water combination were 22.28-24.61 g plant-1 Ca (NO3)2·4H2O, 1.75-2.03 g plant-1 NaH2PO4, 12.41-13.91 g plant-1 K2SO4, and 12.00-13.05 L water plant-1 for yields of more than 110 g plant-1 and optimal SSC/TA ratio of 8.5-14.


Subject(s)
Agricultural Irrigation/methods , Crop Production/methods , Fertilizers/standards , Fragaria/growth & development , Agricultural Irrigation/standards , Biomass , Crop Production/standards , Fragaria/drug effects , Fruit/growth & development , Fruit/standards , Nitrogen/pharmacology , Phosphorus/pharmacology , Potassium/pharmacology
5.
PLoS One ; 15(4): e0231377, 2020.
Article in English | MEDLINE | ID: mdl-32298316

ABSTRACT

Lentil (Lens culinaris Medik.) is a cool-season pulse grown in winter cropping cycle in South Asia and provides a major source of nutrition for many low-income households. Lentil productivity is perceived to be sensitive to high rainfall, but few studies document spatial and temporal patterns of yield variation across climate, soil, and agronomic gradients. Using farm survey data from Nepal, this study characterizes patterns of lentil productivity and efficiency for two cropping seasons. Additional insights were derived from on-farm trials conducted over a 5-year period that assess agronomic, drainage, and cultivar interventions. To contextualize the inferences derived from farm surveys and trials, the Stempedia model was used to simulate the severity of Stemphylium blight (Stemphylium botryosum) risk-the principal fungal disease in lentil-with 30 years of historical climate data. Although development efforts in Nepal have prioritized pulse intensification, results confirm that lentil remains a risky enterprise highlighting the prevalence of crop failures (16%), modest yields (353 kg ha-1), and low levels of profitability (US$ 33 ha-1) in wet winters. Nevertheless, site factors such as drainage class influence responses with upland sites performing well in wet winters and lowland sites performing well in dry winters. In wet winters, a phenomena perceived to be increasing, 76% of surveyed farmers reported significant disease pressure and simulations with Stempedia predict that conditions favoring Stemphylium occur in >60% of all years. Nevertheless, simulation results also suggest that these risks can be addressed through earlier planting. Based on the combined results, gains in yield, yield stability, and technical efficiency can be enhanced in western Nepal by: 1) ensuring timely lentil planting to mitigate climate-mediated disease risk, 2) evaluating new lentil lines that may provide enhanced resistance to diseases and waterlogging, and 3) encouraging the emergence of mechanization solutions to overcome labor bottlenecks.


Subject(s)
Biomass , Climate , Crop Production/methods , Crops, Agricultural/growth & development , Lens Plant/growth & development , Computer Simulation , Crop Production/standards , Nepal
7.
Sci Rep ; 9(1): 11648, 2019 08 12.
Article in English | MEDLINE | ID: mdl-31406178

ABSTRACT

The dissipation patterns of cyantraniliprole and its metabolite IN-J9Z38 were investigated using proso millet (Panicum miliaceum) under open-field conditions to establish a pre-harvest interval. A simple and sensitive analytical method was developed for analyzing residues using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) for multiple reaction monitoring of target compounds. The analytical method was validated in terms of the instrumental limit of quantitation, method limit of quantitation, linearity, accuracy, and precision. The method was successfully applied to the analysis of cyantraniliprole and IN-J9Z38 residues in the field samples of four plots, which were treated twice with an oil dispersion formulation, according to the date of pesticide treatment before harvest. In the case of cyantraniliprole in grain and straw, there was a 91.1 and 89.1% decrease, respectively, from the initial residues (14-7 days) to the final plot (40-30 days before harvest). However, IN-J9Z38 gradually increased over time, indicating that cyantraniliprole transformed into IN-J9Z38 during cultivation. The biological half-lives of total cyantraniliprole were 11.3 and 9.4 days for grain and straw, respectively. The results obtained in this study will inform regulation and management of pesticide use for the minor crop proso millet.


Subject(s)
Insecticides/analysis , Panicum/chemistry , Pesticide Residues/analysis , Pyrazoles/analysis , ortho-Aminobenzoates/analysis , Chromatography, High Pressure Liquid/methods , Crop Production/methods , Crop Production/standards , Edible Grain/chemistry , Edible Grain/standards , Half-Life , Insecticides/metabolism , Pesticide Residues/metabolism , Plant Stems/chemistry , Pyrazoles/metabolism , Tandem Mass Spectrometry/methods , ortho-Aminobenzoates/metabolism
8.
An Acad Bras Cienc ; 90(1): 415-424, 2018.
Article in English | MEDLINE | ID: mdl-29641765

ABSTRACT

Organic fertilizers are a viable alternative to increase oilseed productivity in family agriculture systems. The study aimed to evaluate the effects of timing and placement of cattle manure and/or gliricidia (Gliricidia sepium Jacq. Walp) prunings on cotton (Gossipium hirsutum L.) and sunflower (Helianthus annuus L.) nutrient accumulation and biomass productivity. Experiments were carried out in 2010 and 2011 in Taperoá, Paraíba, Brazil. The organic fertilization treatments were: GI - gliricidia incorporated before planting; GS - gliricidia applied on surface 45 days after planting (DAP); MI + GI - manure and gliricidia incorporated before planting; MI + GS - manure incorporated before planting and gliricídia applied on the surface 45 DAP; MI - manure incorporated before planting; and T - with no organic fertilization. In 2010, treatment MI + GS increased N, P, and K accumulation in cotton (12 and 7 kg ha-1) as well as in sunflower (20 and 29 kg ha-1). In 2011, GI and GS treatments resulted in higher N, P, K accumulations in both crops. The highest cotton productivity in 2010 was obtained with MI + GS treatment (198 kg ha-1) and in 2011 with GS treatment (594 kg ha-1). For sunflower, MI + GS treatment yielded the highest productivity in 2010 (466 kg ha-1) and GI treatment in 2011 (3542 kg ha-1). GI and MI + GS treatments increased total biomass productivity for cotton and sunflower. The treatment that combined both cattle manure incorporated into the soil before planting and gliricidia applied on the surface 45 days after planting was the most viable management strategy.


Subject(s)
Fabaceae/chemistry , Fertilizers , Gossypium/growth & development , Helianthus/growth & development , Manure , Absorption, Physiological/physiology , Animals , Biomass , Brazil , Cattle , Crop Production/methods , Crop Production/standards , Efficiency , Soil/chemistry , Time Factors
9.
Article in English | MEDLINE | ID: mdl-29401727

ABSTRACT

As a major part of farming sustainability, the issues of grain production and its quality improvement have been important in many countries. This paper aims to address these issues in China. Based on the data from the main production provinces and by applying the stochastic frontier analysis methodology, we find that the improvement of transportation and the use of agricultural machinery have become the main driving forces for grain quality improvement in China. After further studying different provinces' potentials of grain quality improvement, we show that grain quality has increased steadily. Therefore, we can conclude China's grain quality improvement is indeed sustainable. Furthermore, different grains like rice, wheat, and corn share similar characteristics in terms of quality improvement, but the improvement rate for rice is relatively low, while those of corn and wheat are relatively high. Moreover, the overall change of efficiency gain of grain quality improvement is not significant for different provinces. The efficiency gains of the quality improvements for rice and wheat even decrease slightly. In addition, we find that only expanding grain quality improvement potential can simultaneously achieve the dual objectives of improving grain quality and increasing yield.


Subject(s)
Crop Production/standards , Edible Grain , Quality Improvement/statistics & numerical data , Sustainable Development , China , Crop Production/instrumentation , Crop Production/methods , Farmers/statistics & numerical data , Models, Theoretical , Transportation/statistics & numerical data
10.
J Sci Food Agric ; 98(1): 12-17, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28898466

ABSTRACT

The application of agricultural biotechnology attracts the interest of many stakeholders. Genetically modified (GM) crops, for example, have been rapidly increasing in production for the last 20 years. Despite their known benefits, GM crops also pose many concerns not only to human and animal health but also to the environment. Malaysia, in general, allows the use of GM technology applications but it has to come with precautionary and safety measures consistent with the international obligations and domestic legal frameworks. This paper provides an overview of GM crop technology from international and national context and explores the governance and issues surrounding this technology application in Malaysia. Basically, GM research activities in Malaysia are still at an early stage of research and development and most of the GM crops approved for release are limited for food, feed and processing purposes. Even though Malaysia has not planted any GM crops commercially, actions toward such a direction seem promising. Several issues concerning GM crops as discussed in this paper will become more complex as the number of GM crops and varieties commercialised globally increase and Malaysia starts to plant GM crops. © 2017 Society of Chemical Industry.


Subject(s)
Crop Production/legislation & jurisprudence , Crops, Agricultural/genetics , Food, Genetically Modified/standards , Plants, Genetically Modified/genetics , Consumer Product Safety , Crop Production/organization & administration , Crop Production/standards , Crops, Agricultural/chemistry , Crops, Agricultural/metabolism , Food, Genetically Modified/economics , Humans , Malaysia , Plants, Genetically Modified/chemistry
11.
Naturwissenschaften ; 104(11-12): 86, 2017 Oct 05.
Article in English | MEDLINE | ID: mdl-28983648

ABSTRACT

The inefficient use of resources always poses risks of maize (Zea mays L.) yield reduction in China. We performed this research to monitor the effects of increasing plant density and reducing nitrogen (N) rate on radiation-use efficiency (RUE), N efficiency traits, grain yield (GY) and their inter-relationships. Besides, whether GY and resource-use efficiency can both be maximized was examined. Hence, a 2-year field experiment was conducted using a widely grown variety "Denghai 618" in Shandong, China. Treatments contained two different plant densities [67,500 (D1) and 97,500 (D2) plant ha-1] and three N levels [0 (N-2), 180 (N-1), 360 (Nck) kg ha-1], set D1Nck as control. Significant increases in grain yield, biomass, RUE, above-ground N uptake (AGN) and N efficiency were observed when density increased from D1 to D2. Declining N application was accompanied by reductions in yield, RUE and AGN especially under high density, yet an obvious improvement in N recovery efficiency (NRE), agronomic N efficiency and N partial factor productivity. The increased GY was positive related with population biomass (r = 0.895**), RUE (r = 0.769**) and AGN (r = 0.923**), whereas it has no significant correlation with N efficiency. In this study, D2Nck obtained 18.8, 17.9, 24.8 and 29.7% higher grain yield, RUE, AGN and NRE respectively, compared to control, optimizing both yield and the efficiencies of radiation and N use. Furthermore, higher yield and RUE with more desirable N efficiency may be possible via optimizing density and N rate combination.


Subject(s)
Agriculture/standards , Biomass , Crop Production/standards , Fertilizers , Nitrogen/metabolism , Zea mays/growth & development , Zea mays/metabolism , China , Nitrogen Cycle , Population Density , Seasons
12.
Environ Sci Pollut Res Int ; 24(29): 23236-23249, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28831706

ABSTRACT

Round-Bohai Bay (RBB)-Region is an important crop production area in China, where vegetables are mainly produced in solar greenhouses. However, excessive fertilization and monoculture have caused serious deterioration of soil quality in this region. Soil microbial communities play pivotal roles in many ecosystem processes and are recognized as integrative components of soil quality. Therefore, in this study, we investigated bacterial and fungal diversity in solar greenhouse soils covering a wide range of cultivation year (CY) and sampling site (SS), by using pyrosequencing technology. Surprisingly, CY and SS had little influence on bacterial and fungal relative abundance and diversity. However, environmental factors (EF) and soil available potassium (K) in particular made a significant contribution to the variation of soil bacterial and fungal communities. Specifically, K showed significant (P < 0.05) correlations with dominant bacterial phyla Bacteroidetes, Acidobacteria, Chloroflexi, and Planctomycetes and fungal phyla Ascomycota and Basidiomycota. These results suggested that soil EF appeared more important than CY and SS in shaping the compositions of bacterial and fungal communities. In addition, since fertilizer K has been in the long-term abused in RBB-Region, future vegetable production should pay more attention to K input to reduce the negative effect on soil microbial communities.


Subject(s)
Crop Production/methods , Metals, Heavy/analysis , Soil Microbiology/standards , Soil Pollutants/analysis , Soil/chemistry , Acidobacteria/isolation & purification , Ascomycota/isolation & purification , Basidiomycota/isolation & purification , Biodiversity , China , Crop Production/standards , Ecosystem , RNA, Ribosomal, 16S , Vegetables/growth & development
14.
PLoS One ; 11(5): e0155926, 2016.
Article in English | MEDLINE | ID: mdl-27195497

ABSTRACT

Compared with CO2, methane (CH4) and nitrous oxide (N2O) are potent greenhouse gases in terms of their global warming potentials. Previous studies have indicated that land-use conversion has a significant impact on greenhouse gas emissions. However, little is known regarding the impact of converting rice (Oryza sativa L.) to vegetable fields, an increasing trend in land-use change in southern China, on CH4 and N2O fluxes. The effects of converting double rice cropping to vegetables on CH4 and N2O fluxes were examined using a static chamber method in southern China from July 2012 to July 2013. The results indicate that CH4 fluxes could reach 31.6 mg C m-2 h-1 under rice before land conversion. The cumulative CH4 emissions for fertilized and unfertilized rice were 348.9 and 321.0 kg C ha-1 yr-1, respectively. After the land conversion, the cumulative CH4 emissions were -0.4 and 1.4 kg C ha-1 yr-1 for the fertilized and unfertilized vegetable fields, respectively. Similarly, the cumulative N2O fluxes under rice were 1.27 and 0.56 kg N ha-1 yr-1 for the fertilized and unfertilized treatments before the land conversion and 19.2 and 8.5 kg N ha-1 yr-1, respectively, after the land conversion. By combining the global warming potentials (GWPs) of both gases, the overall land-use conversion effect was minor (P = 0.36) with fertilization, but the conversion reduced GWP by 63% when rice and vegetables were not fertilized. Increase in CH4 emissions increased GWP under rice compared with vegetables with non-fertilization, but increased N2O emissions compensated for similar GWPs with fertilization under rice and vegetables.


Subject(s)
Carbon Cycle , Carbon Footprint , Crop Production/methods , Nitrogen Cycle , Oryza/growth & development , Vegetables/growth & development , Crop Production/standards , Global Warming , Methane/analysis , Nitrous Oxide/analysis , Oxides/analysis
15.
J Sci Food Agric ; 96(9): 3007-16, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26399449

ABSTRACT

BACKGROUND: Recent studies have reported the potential of near infrared (NIR) spectral analysers for monitoring the ripeness of grape berries as an alternative to wet chemistry methods. This study covers various aspects regarding the calibration and implementation of predictive models of total soluble solids (TSS) in grape berries using laboratory and in-field collected NIR spectra. RESULTS: The performance of the calibration models obtained under laboratory conditions indicated that at least 700 berry samples are required to assure enough prediction accuracy. A statistically significant error reduction (ΔRMSECV = 0.1°Brix) with P < 0.001 was observed when measuring berries without epicuticular wax, which was negligible from a practical point of view. Under field conditions, the prediction errors (RMSEP = 1.68°Brix, and SEP = 1.67°Brix) were close to those obtained with the laboratory dataset (RMSEP = 1.42°Brix, SEP = 1.40°Brix). CONCLUSION: This work clarifies several methodological factors to develop a protocol for in-field assessing TSS in grape berries using an affordable, non-invasive, portable NIR spectral analyser. © 2015 Society of Chemical Industry.


Subject(s)
Crops, Agricultural/chemistry , Food Inspection/instrumentation , Food Quality , Fruit/chemistry , Models, Statistical , Vitis/chemistry , Calibration , Crop Production/standards , Crops, Agricultural/growth & development , Crops, Agricultural/metabolism , Data Accuracy , Databases, Factual , Food Inspection/standards , Fruit/growth & development , Fruit/metabolism , Guidelines as Topic , Materials Testing , Principal Component Analysis , Quality Control , Refractometry , Reproducibility of Results , Signal Processing, Computer-Assisted , Solubility , Spain , Spectroscopy, Near-Infrared , Vitis/growth & development , Vitis/metabolism , Waxes/adverse effects , Waxes/chemistry , Waxes/metabolism , Wine/analysis , Wine/standards
16.
Talanta ; 148: 216-28, 2016.
Article in English | MEDLINE | ID: mdl-26653443

ABSTRACT

This study presents a systematized method for predicting water content, fat content and free acidity in olive fruits by on-line NIR Spectroscopy combined with chemometric techniques (PCA, LDA and PLSR). Three cultivar varieties of Olea europaea - Hojiblanca cv., Picual cv. and Arbequina cv. - were monitored. Five olive cultivation areas of Southern Spain (Andalucia) and Southern Portugal (Alentejo) were studied in 2011 and 2012. 465 olive samples were collected during the ripening process (non-mature olives) and compared with other 203 samples of mature olives collected at the final ripening stage. NIR spectra were measured directly in the olive fruits in the wavelength region from 1000 to 2300 nm in reflectance mode. The reference analyses were performed on the olive paste by oven drying for the moisture, by mini-Soxhlet extraction for the fat content and by acid titration of the oil extracted from the olive paste. Calibrations and predictive models were developed by Partial Least Square Regression (PLSR) previous Principal Component and Linear Discriminant analyses (PCA and LDA) were employed as exploratory and clean-up tools of data sets. The final models obtained for the total samples showed acceptable statistics of prediction with R(2)=0.88, RMSEV%=4.88 and RMSEP%=4.98 for water content, R(2)=0.76, RMSECV%=19.5 and RMSEP%=20.0 for fat content and R(2)=0.83, RMSECV%=36.8 and RMSEP%=38.8 for free acidity. Regression coefficients were better for only one maturity state (ripe period) than for olive fruit with different composition (ripening period). All models obtained were applied to predict LQPs on a new set of samples with satisfactory results, a good prediction potential of the models.


Subject(s)
Crop Production/methods , Olea , Olive Oil/analysis , Online Systems , Spectroscopy, Near-Infrared/methods , Crop Production/standards , Least-Squares Analysis , Online Systems/standards , Spectroscopy, Near-Infrared/standards , Time Factors
17.
Lima; s.n; 1994. 126 p. tab, graf. (3702).
Monography in Spanish | LILACS | ID: lil-187047

ABSTRACT

Se ha comparado 4 medios de enriquecimiento selectivo y la influencia de 2 temperaturas de incubación para la recuperación de salmonella de muestras de verduras irrigadas con aguas residuales. Se determinó también el grado de contaminación de estas verduras. Se emplearon:caldo selenito-cistina, caldo tetrationato según Muller Kaufmann, Caldo Rappaport y Caldo Rappaport-Vassiliadis. Se concluyó que el Caldo Rappaport es el que mejor recupera serotipos de salmonella, asi mismo que la temperatura de 43ºC ofrece mejor recuperación de serotipos de salmonella.


Subject(s)
Crop Production , Crop Production/standards , Salmonella/isolation & purification , Wastewater , Culture Media
18.
Lima; s.n; 1994. 106 p. tab, graf. (3703).
Monography in Spanish | LILACS | ID: lil-187048

ABSTRACT

Se ha cuantificado arsénico por el método espectrofotométrico de Vasac y Sedivec en tubérculos de papas de cultivos expuestos. Las muestras proceden del Valle del Mantaro (Junín) y de las zonas de Cañete, Barranca, Puente Piedra y Huachipa (Lima). La investigación se realizó en 50 tubérculos de diferentes variedades y formas de riego. El nivel medio de Arsénico en las muetras fue de 0,2572 ppm ñ 0,0132, con una desviación standard de 0,0927ñ0,0093 y cifras extremas de 0,095-0.500 ppm. Los valores promedios obtenidos de arsenico en los tubérculos es menos que los valores máximos aceptables de Canadá ya que solo constituyen el 25,72 por ciento de 1ppn, que es la cantidad máxima de arsénico aceptada en la papa, ya que a partir de ella produce efectos nocivos y tóxicos.


Subject(s)
Crop Production , Crop Production/standards , Arsenic/isolation & purification , Arsenic/analysis , Arsenic/adverse effects , Arsenic/pharmacokinetics , Arsenic/pharmacology , Arsenic/toxicity , Solanum tuberosum/chemistry , Solanum tuberosum/drug effects , Solanum tuberosum/toxicity
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