Introduction. Black Leaf Streak Disease (BLSD) is the most important foliar disease affecting banana production worldwide. A forecasting system has been developed and implemented in various countries aiming at optimal control of BLSD through minimum applications of fungicide. In Dominican Republic, favorable dry climatic conditions contrast with serious organizational issues for BLSD control. Our objective was to evaluate the adaptation of this forecasting strategy in these specific conditions. Materials and methods. Fungicide resistance analyses were carried out in the northwestern region of Dominican Republic, in order to determine the appropriate spectrum of systemic fungicides for the forecasting strategy. Three field experiments were set up on commercial farms where disease evolution was monitored every week, on reference plots, in order to decide the pertinence of fungicide applications. Results. Fungicide resistance to QoI fungicides and strong sensitivity reduction to DMI (Demethylation Inhibitor) fungicides were detected in all farms. In spite of these limitations in the use of some fungicide groups, disease control was achieved with a limited number of fungicide applications (6–9), as compared with 13–26 applications in most commercial farms of Dominican Republic over the same period. Discussion. The calculation of an indicator of the efficiency of the chemical control confirmed the potential of the forecasting strategy, underlining the influence of crop management as well as the neighboring environment of the farms on its efficiency. The requirements for further generalization of this system to commercial farms of this country are discussed.

Introduction. Many fruit trees with a hard seed coat exhibit seed dormancy, posing problems for their regeneration. Vitex doniana, an indigenous multipurpose but threatened fruit and vegetable tree that supports the livelihoods of many households in West Africa, is a typical example. Materials and methods. In our research, we evaluated five dormancy-breaking treatments. We tested the effects of sulphuric acid at 95% concentration (T1); 3 d sun-drying + 48 h soaking in tap water (T2); 3 d alternation of 8 h sun-drying + 1 h soaking in tap water (T3); 2 weeks sun-drying with regular watering in the daytime (T4); and physical shock (T5). These treatments were compared with two controls (T0 and Tc), with seeds from two different sources. The germination percentage, mean germination time, time to first germination and time to threshold germination (20%) were compared; the seedling height, diameter and biomass produced were monitored for 15 weeks. We used generalised linear models and correlation tests to compare the effects of the various treatments on germination and seedling growth. Results and discussion. T3 significantly enhanced seed germination in V. doniana (72% after 12 months). T4 best promoted homogeneity in germination (p < 0.01), followed by T3. The best seedling growth was obtained with T4 and T3. Alternation of sun-drying followed by soaking of seeds, a technique with almost no cost, improved seed germination in V. doniana and, in 33 d, just over 1 month, 20% germination can be achieved. Vitex doniana is a fast-growing species (at the nursery stage), in contrast to the common opinion. Conclusion. Our method should be further investigated to assess the adequate soaking and drying length so as to speed up germination and reach homogenous cohorts.

Introduction. L’anacardier (Anacardium occidentale L.) est surtout cultivé pour la production de l’amande ou noix de cajou mais aussi pour le pseudofruit. Les insectes nuisibles à cette plante ont été étudiés au Pérou où celui-ci est consommé. Matériel et méthodes. Des prélèvements ont été réalisés de 1998 à 2005 dans différentes localités du département de Loreto en Amazonie péruvienne afin d’identifier les insectes ravageurs de l’anarcadier. Des observations de terrain et des élevages au laboratoire ont permis de caractériser leurs dégâts et des éléments de la bio-écologie pour chacun de ces insectes. Résultats. Sept espèces d’insectes ont été identifiées, qui commettent des dommages notables : cinq espèces s’attaquent au pseudofruit : Acanthocephala parensis (Hemiptera : Coreidae), Anastrepha obliqua (Diptera : Tephritidae), Conotrachelus sp. (Coleoptera : Curculionidae), Trigona amalthea et T. amazonensis (Hymenoptera : Apidae). L’espèce Aphis gossypii (Hemiptera : Aphididae) infeste l’inflorescence ainsi que le fruit. Les larves de Macrocopturus cf. tristis (Coleoptera : Curculionidae) se développent dans les bourgeons et les jeunes rameaux. Trois espèces parmi celles qui ont été identifiées sont de nouveaux ravageurs qui n’avaient pas été encore signalés. Sept espèces d’importance secondaire ont également été observées. Conclusion. Compte-tenu du potentiel que représente la production de pomme cajou et du développement possible de la culture de l’anacardier en Amazonie péruvienne, une étude plus approfondie des insectes nuisibles à cette production est souhaitable.

Introduction. Elaeagnus latifolia Linn. is a type of wild edible fruit found in northeast India, Thailand and also in Vietnam. Although the fruit is reported to be a source of vitamins, minerals, essential fatty acids and other bioactive compounds, only a few studies have been concerned with the antioxidant activity of this plant. Materials and methods. Our study revealed in vitro antioxidant and free radical scavenging activity of 70% methanolic extract of Elaeagnus latifolia Linn. (ELME). Various tests including identification and quantification of phytochemicals, total antioxidant activity, hydroxyl radical, superoxide radical, singlet oxygen, hypochlorous acid scavenging, reducing power and DNA protection assays were performed. Results and discussion. Among the tests, ELME scavenged superoxide radical [IC50 = (150.78 ± 4.2) μg×mL–1], hydroxyl radical [IC50 = (238.09 ± 11.63) μg×mL–1] and protected pUC18 DNA [P50 = (695.91 ± 15.84) μg×mL–1]; P50 signifies the concentration for 50% protection . The fruit is found to be a source of minute amounts of carbohydrates, ascorbic acid, tannins, phenolics and flavonoids. HPLC data showed that purpurin, tannic acid, quercetin, catechin, reserpine and rutin are present in ELME. Conclusion. Our results provide evidence that 70% methanol extract of E. latifolia Linn. acts as a promising antioxidant as well as DNA protector, which is partly due to the phenolic and flavonoid compounds present in it.

Introduction. The genus Phoenix has 13 species. Dates from P. dactylifera and P. theophrasti are the only ones that have been characterised so far. The aim of our study was to evaluate the physico-chemical and functional characteristics of date fruits in the Khalal and Rutab stages of P. loureiroi, P. canariensis, P. reclinata and P. roebelenii, and compare them with P. dactylifera. Materials and methods. Two samples of 15 date fruits in the Khalal stage and another 15 date fruits in the Rutab stage were chosen from each species for analyses and quality parameters. Results and discussion. Significant differences in the measured parameters were observed among the different species. Dates of P. dactylifera were larger than those of the other species and had the lowest [seed weight/fruit weight] proportion. In the Khalal stage, dates from P. canariensis and P. dactylifera were yellow, P. loureiroi and P. reclinata were dark yellow to orange, and those of P. roebelenii were brown purple. Dates of P. dactylifera (Rutab stage) showed higher sugar and lower organic acid contents than those of the other dates. Dates of P. reclinata, P. roebelenii and P. canariensis presented values of antioxidant activity and total phenols in the Khalal stage that were very high compared with those of P. dactylifera. These species are used as ornamental palms but their fruits are consumed locally as food. These dates presented high nutritional quality and can be used as novel foods for different purposes, such as snacks or food fortification, especially due to their high value in functional properties.

Introduction. Chlordecone (CLD), an organochlorine formerly used to control the banana black weevil, is strongly adsorbed on soils, particularly on andosols. A simplified analytical procedure for the quantitative determination of chlordecone residues in water and micro-samples of soil and plants was compared with a standard method. Materials and methods. The procedure combines a simplified sampling protocol and a 10-min solid phase microextraction (SPME), followed by gas chromatographic separation (GC) and mass spectrometric (MS and MS/MS) identification. Quantitation of CLD used a standard addition method with zero extrapolation. First, seventy samples were analysed using the proposed method and the standard method based on hot solvent extraction. Second, fifteen soil samples were analysed with two SPME methods followed by GC-MS but using CLD labelled with C13 as an internal standard or the proposed method. Results and discussion. The detection (LOD) and quantitation (LOQ) limits of our SPME extraction procedure were determined for GC-MS and GC-MS/MS with water, plant (pineapple roots) and soil samples: in water for MS/MS, LODMS/MS-water = 0.5 ng×L–1, LOQMS/MS-water = 2.0 ng×L–1; in andosol for MS/MS, LODMS/MS-soil = 15.0 ng×kg–1 dw, LOQMS/MS-soil = 80.0 ng×kg–1 dw. Data from the seventy contaminated soils obtained with the proposed method and the standard method showed a correlation coefficient of r = 0.86. Data obtained by the two SPME/GC-MS quantitation procedures showed a correlation of r = 0.8073. Conclusion. The method proposes a simplified sample preparation and extraction of CLD in water, plant and soil samples, with no solvent manipulation and which is not time-consuming. The LOD and LOQ were similar to those obtained with other currently used methods. The method is reliable and accurate and may be considered as a good tool for research purposes.