Bayoud caused by Fusarium oxysporum f.sp. albedinis (Foa), is the most destructive disease of the date palm (Phoenix dactylifera L.) in Morocco and Algeria and there is no effective control strategy. We found that although Foa isolates vary morphologically, Foa strains can be identified by species-specific primers. PCR analysis revealed that the strains that we isolated from infected date palm rachis were the Bayoud pathogen Foa. We used these strains to evaluate the antifungal activity of tar extracted from Acacia tortilis subsp. raddiana. The A. raddiana tar had a density of 1.15, a refraction index of 1.3850, a pH of 5.2 and a dried matter ratio of 48.75%. The A. raddiana tar effectively inhibited the growth of Foa in vitro with a minimum inhibitory concentration of 3 µg/ml.

The biological activities of medicinal plants have been recognized for centuries. Among them, Juniperus phoenicea is very commonly used for its medicinal virtues (respiratory, hepatic and renal infections). Its wood is used for heating and manufacture of coal and its vegetable tar is used to treat certain cases of eczema. The aim of the present study is focused on the evaluation of the in vitro antifungal activity of a tar extracted from Juniperus phoenicea L. The physicochemical analysis was performed first; then, the evaluation of antifusarial activity of the Juniperus phoenicea L. was carried out by using the dilution and the direct contact method to determine the minimum inhibitory concentration (MIC). Results of the physicochemical analysis show a density value of 1.10, a refraction index of about 1.5112, an acid pH (4.02) and the dries matter ratio of 36, 34% for the tested tar. The antifungal activity of the tar under study against six strains of Fusarium oxysporum f.sp. albedinis (FOA; S1, S2, S3, S4, S5, S6) revealed that Juniperus phoenicea L. tar has a great antifungal activity against all the investigated strains. The antifungal activity results reveal that the fungal growth was inhibited by the tar. S3 proved to be the most sensitive strain with a minimal inhibition concentration value of 0.006 mg/ml. The present study indicates that Juniperus phoenicea L. tar has antifungal activity against the different tested fungal strains.

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Purpose: To investigate the intra-specific variations in eleven Fusarium oxysporum isolates from infected date palm using pathogenicity and molecular methods. Methods: Eleven isolates of Fusarium oxysporum obtained from infected date palms in the southwest region of Algeria were subjected to confirmatory test using a specific polymerase chain reaction (PCR) technique with the primer pairs, TL3-FOA28 and BIO3-FOA1. Polymorphism in the 5' domain of the large subunit rRNA was investigated. Small libraries of the domain, amplified by the primer pair, LR3/LROR, were constructed and the inserts sequenced. Results: The 11 isolates of Fusarium oxysporum collected from the infected date palm were confirmed as Fusarium oxysporun f. sp albedinis. Results from the investigation of polymorphism in the 5' domain of the large subunit rRNA revealed that the sequences were 100 % homologous or extremely close (> 99.4 %, differing by no more than one to three nucleotides) to several Fusarium oxysporum sequences. In addition, F. inflexum (U34548.1) was highly homologous to one of the F. oxysporum f. sp. albedinis. Conclusion: The sequences of the 11 isolates are almost 100 % homologous to several F. oxysporum species. It is noteworthy that a sequence highly homologous to one of the F. oxysporum f. sp. albedinis is obtainable from a different species, F. inflexum (U34548.1).

Vegetable tars are newly formed resinous products extracted by pyrolysis from wood or bark. Since prehistoric times, they have been used for their adhesive, water-repellent, repellent and finally medicinal properties. This work investigated the use of these vegetable tars as sources of bio-fungicides. The physicochemical properties of the tars obtained in the labor-atories showed a significant yield of 1.22%, 0.66% and 0.51% respectively for the wood of (Jeniperus phoenicea, Olea europeae sylvestris and Acacia torti-lis Sub raddiana). They also showed a density value of 1.22 and a refractive index of about 1.5115 for J.phoenicea, an acid number of 0.39 and a dry matter ratio of 19.86% for A. tortilis Sub raddiana. Considerable antifungal activity of the acetate of three tars against certain fungal phytopathogens (Fusarium) was observed with the most remarkable MIC values ranging from 0.1 mg / ml to 0.46 mg / ml. The J. phoenicea extracts were more active against F. oxysporum f sp albedinis (FOA) strains. The growth of F. solani was more sensitive to acetate extracts from O. europeae. Dichloromethane ex-tracts of A. tortilis Sub raddiana yielded with an average MIC of 0.16 and 1.02 mg / ml, respectively for strains of F. oxysporum and F. graminearum. The bioautography test revealed the presence of 3 antifusaric molecules of interest. These MIC results further merit in vivo tests for the development of future biofungicides.

Saoura, is an Algerian desert region, characterized by a height density of date palm trees (more than 300000).Despite this high density, the produc-tion of dates has seen a continuous decrease due to multiple reasons includ-ing increasing water salinity, the spread of many fungal diseases and insect pests where the most serious is Parlatoria blanchardi. The random use of Malathion during the invasions of desert locusts caused an ecological imbal-ance, where the majority of the natural enemies of date palm scale (DPS) disappeared, as consequence the population of DPS expanded increasingly. This study aims to find alternative methods to control pests taking into con-sideration the ecological balance. For this purpose, three entomofauna in-ventories were carried out to study the dynamics of insect populations and for introduction and acclimatization of new auxiliary insects to biocontrol the large infestation of DPS. we also looked to find a biodegradable insecticide extracted from Citrullus colocynthis (desert plant pariah by insects due to its toxicity). By comparing the results we noticed that effectiveness of the colo-cynth aquatic extracts on the target insect was as high as 65.99 % however it’s side effects on ecosystem were negligible unlike Malathion which exter-minated over than 301 non-target insects where 68% are useful such as bees, butterflies, some entomophagous insects and even some vertebrate such as Oenanthe leucopyga. Finally, a phytochemical screening and toxico-logical studies are recommended to determine exactly which component in colocynth is more effective on DPS and its undesirable effect on human health.