Developing scoring functions for soil quality to assess land suitability for irrigated wheat in Southern Algeria

Efficient land-use management could be optimized through appropriate advice regarding land suitability and achieving a reasonable yield while preserving soil and environmental conditions. The main objective of this study was to determine and define those locations capable of wheat cultivation with irrigation in the municipality of N’goussa (Southern Algeria). Expert opinion (EO) method was used for selecting minimum soil data set (MDS_-EO), where six influencing soil properties (sand, pH, salinity, organic matter, gypsum and lime) and other three key parameters (slope, land use/land cover, and proximity to roads and electricity network) were considered important for irrigated wheat cultivation in the study area. Indicators were weighted according to principal component analysis (PCA) loadings and summed. PCA revealed that the selected nine indicators are appropriate for accounting 73.63% of the total variance. Two maps of land suitability were created here (expressed as a soil quality index within a range from 0 to 1) from multivariate analysis and already known standard scoring functions (SSFs) by using two data sets (pure and scored). The distribution of soil quality index (IQI) showed that above 70% of the land was moderately (MS) to highly suitable (HS) for irrigated wheat. The estimation accuracy of soil quality classes has been evaluated using random forests (RF), having as a dependent variable the final class of land suitability used in each map. It was determined that estimation accuracy could reach 60% (pure data set) and 65% (scored data set) at 0.5 cut-off value for soil quality classes. Final prioritizing according to ranks of sensitivity index (SI) and efficiency ratio (ER) showed that IQI obtained from scored data set is the most suitable approach in soil quality assessment of arid areas. Therefore, it could be applied in southern Algeria for land management, integrated planning and environmental assessments.     

Physiological races of Fusarium oxysporum f.sp. melonis in Tunisia

Fusarium wilt of melon, caused by Fusarium oxysporum f.sp. melonis (Fom), is an important disease; races of the pathogen were identified by inoculating differential standard host cultivars. A total of ten isolates that were obtained from 23 fields located in four different geographical regions were identified as pathogenic. Results indicate that all four known Fom races, namely, 0, 1, 2 and 1.2, were found in north and middle Tunisia. Race 1.2 was the most prevalent.     

QUARTZ PORPHYRY TREATMENT ALTERS IRRIGATION WATER CHEMISTRY,AFFECTING HYDROPONIC VEGETABLE PRODUCTION

This study focused on using quartz porphyry (QP) as a water treatment to improve hydroponic production of komatsuna (Brassica rapa L. nothovar; Japanese mustard spinach). We compared the chemistries of the control and QP-treated nutrient solutions and found that magnesium (Mg²⁺) and calcium (Ca²⁺) concentrations increased linearly up to day 21 following sowing in both conditions, then declined slightly. The QP treatment reduced sodium (Na⁺) and chloride (Cl^?) concentrations for the whole cultivation period. In both the control and QP-treated solutions, nitrate (NO^? ₃) and sulfate (SO^2? ₄) showed the same trend to a daily increase. In spite of these similarities, however, komatsuna production was better with the QP-treated nutrient solution compared to control. Treatment with QP during cultivation in August–September reduced the harmful effects of Na⁺, chloride (Cl^?), nitrite (NO^? ₂), and SO^2? ₄ by reducing concentrations of these ions, possibly leading to decreased salinity and toxicity effects in the plants. Mineral concentrations during October–November differed from those of August/September, resulting in variation among the different growth parameters for komatsuna.     

Significance of extrinsic factors for the optimization of dietary cobalt supplementation in Tor putitora fingerlings

Fish Physiology and Biochemistry - Extrinsic factors play a significant role during aquaculture feed manufacturing practices. Herein, a 90-day feeding trial was designed in triplicate under...     

Identification et répartition géographique des fusarioses affectant l'épi et le pied du blé dans certaines régions du Nord de la Tunisie

Des prospections ont été réalisées durant les mois d'Avril et de Mai dans certaines parcelles de blé situées au Nord de la Tunisie dans l'objectif d'identifier les espèces de Fusarium associées à la pourriture du collet et à l'échaudage des épis de blé. Les résultats ont montré que Fusarium culmorum , Fusarium graminearum et Microdochium nivale ( Fusarium nivale ) sont les plus fréquemment isolées. Leur gravité varie selon les régions. En effet, les champs localisés dans les gouvernorats de Béja, Jendouba et Bizerte ont montré l'existence principalement de six espèces de Fusarium : Fusarium culmorum , Fusarium graminearum , Fusarium avenaceum , Fusarium solani , Microdochium nivale ( Fusarium nivale ) et Fusarium equiseti .     

Détection des races 0, 1 et 2 de Fusarium oxysporum f. sp. niveum et leur distribution dans les régions de production de la pastèque en Tunisie

La détermination des races physiologiques de Fusarium oxysporum f. sp. niveum dans les régions de production de la pastèque en Tunisie a révélé la présence des 3 races 0, 1 et 2. A partir des 90 isolats obtenus à partir des plantes flétries de pastèque, 13%, 42% et 45% ont été identifiés respectivement comme étant de la race 0, de la race 1 et de la race 2. La race 0 a été trouvé dans 17% des parcelles prospectées, alors que les races 1 et 2 ont été signalées dans 70% des parcelles. La race 2 a été présente en association avec une ou les deux races au sein de la même parcelle. Notons également la dominance de la race 2 au sein de certaines régions du Sud (Gafsa et Métouia) et du Nord (Testour). Les races 1 et 2 ont été aussi détectées à partir du sol et des graines de pastèque.     

Study of the Toxic Contaminants Cadmium and Lead in Sardines (Sardina pilchardus) in the Bay of Algiers (Algeria)

The study of the discharge of metallic pollutants into the marine environment through biological material such as sardines makes it possible to evaluate the quality of the biological resources and of the marine environment. The sardine (Sardina pilchardus) is the most popular species for fishing and the most consumed species by the Algiers population. Two toxic metals that can affect human health are studied in this fish. A year of sampling with fishermen was conducted. Sampling was done in the spring, in the autumn, and in April between April 2014 and April 2015. Sampled sardines were grouped by size classes. The gills and muscle were recovered by size classes. The results were explored using a principal components analysis and compared by a Mann-Whitney distribution test. An atomic absorption spectrophotometer was used in the laboratory for analysis. The most important results show that lead levels were higher than those of cadmium in the gills and muscle. For sardines, lead contamination appears to have both gill and food origins. Mann-Whitney comparison tests confirmed this homogeneous distribution of lead between the gills and muscle. The correlation between cadmium in the gills and height or weight is more substantial than that with muscle. The origin of cadmium in sardines is branchial. The food origin appears secondary. From our point of view, the effect of season, i.e., winter (December) and spring (April), favors an increase in metal levels in parallel to the production reserves planned for spawning. The effect of season was observed by use of a biplot. A significant reduction in cadmium and lead content was observed in September. The high temperature, an environmental factor, induced stress that reduced the metal concentrations and the decontamination induced by the issuance of genital products in early summer.     

Detection of <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subsp. <Emphasis Type="Italic">paratuberculosis</Emphasis> in tissue samples of cattle and buffaloes

Tissue samples were collected at random from cattle (Bos taurus) and buffalo (Bubalus bubalis) from an abattoir of the district of Lahore and were analyzed for the presence of Mycobacterium avium subsp. paratuberculosis and Mycobacterium bovis through acid-fast staining and polymerase chain reaction (PCR). Body condition of animals and diarrhea were recorded. Most of the animals were emaciated. Diarrhea was noticed in 15.6% of buffaloes and 19.2% of cattle. Intestinal pathology was observed in 29% of buffaloes and 32.8% of cattle. Number of mesenteric lymph node (MLN) showing gross lesions was a bit higher (35.6%) in cattle than buffalo (31.2%). Acid-fast staining of tissue scraping smears revealed the presence of acid-fast bacilli (AFB) in 17.4% intestinal and 16.4% MLN tissue samples in buffalo, while in cattle 19.2% intestinal and 17.8% MLN were found positive for AFB. In buffaloes, PCR confirmed 12.8% intestinal and 12.4% MLN positive samples for M. avium subsp. paratuberculosis. However, in cattle, PCR analysis demonstrated 14.2% positive results for M. avium subsp. paratuberculosis in both MLN and intestinal tissue samples. PCR also confirmed M. bovis in 5.8% of cattle and 5% of buffalo MLN and intestinal tissues. PCR positive tissue samples for M. avium subsp. paratuberculosis were from those animals which were emaciated, having diarrhea, and severe gross lesions. AFB were also detected in tissue scraping smears of these animals. It is concluded that infection by various mycobacterium species can be differentiated by PCR, which is not possible by acid-fast staining technique.     

Genetic diversity of Grapevine rupestris stem pitting-associated virus isolates from Tunisian grapevine germplasm

Grapevine rupestris stem pitting-associated virus (GRSPaV) is one of the most widespread grapevine viruses and is transmitted mainly by grafting. GRSPaV presence was tested in 487 samples representative of the Tunisian grapevine germplasm (including autochthonous, table, wine, wild grape, and rootstock varieties) from different Tunisian regions. GRSPaV infection was detected in 51.3% of samples from different Tunisian regions, among which the table grapevine cultivars were the most commonly infected (68.7%). Genetic variability of GRSPaV isolates from wild and cultivated grapevines was assessed by sequencing the partial capsid protein (CP) gene of 19 Tunisian isolates and 1 Italian GRSPaV isolate from Sicily, and the partial RNA-dependent RNA polymerase (RdRp) gene of 13 Tunisian GRSPaV isolates. According to phylogenetic analysis of CP nucleotide sequences obtained in this study and sequences retrieved from GenBank, Tunisian isolates fell into four phylogenetic groups already described (I, II, III, and IV) and two new phylogenetic groups (VI and VIII). Phylogenetic analysis of the partial RdRp gene revealed that Tunisian isolates of GRSPaV are distributed into four phylogroups. This study highlights the importance of regular monitoring of GRSPaV infections in Tunisia, with special regard to those grapevine accessions employed in conservation and selection programmes. In particular, the presence of new GRSPaV genetic variants and infection of wild grapevines must be taken into account in order to choose a correct control strategy.