Introduction. The methods of fruit disinfestation against fruit flies use processes (physical methods) which differ according to the export country and fruit which must be disinfested. The term definitions are made clear and the various treatments are presented. Heat treatments. For mango, treatments usable for disinfestation can only utilize heat, because of the strong sensitivity of this fruit to cold temperatures. The heat treatments in general consist of using an immersion in hot water by a system of batches or an uninterrupted bath. These treatments are then followed or not by a fruit fast cooling which can be carried out by ventilation (cold air) or hydrocooling (water). Heat can also be obtained by use of forced hot air or hot vapor, because a higher temperature than 45 °C kills fly eggs and larvae. Microwave treatments. The use of microwaves is also a technique which makes it possible to increase the temperature in the fruit heart. Irradiation. The last possible solution is the use of irradiation, which uses a principle different from the preceding treatments. Conclusion. In comparison with the most current treatments (vapor heat treatment and forced hot-air treatment), the hot water treatment has many advantages: it is easy to implement, it is quick, it kills surface parasitic organisms, it makes it possible to clean the fruit surface and its cost only corresponds to approximately 10% of the cost of one vapor heat treatment. It would thus be recommended for mango disinfestation.

Introduction. Mango producers of two important growing areas of the states of Guerrero and Michoacán, Mexico, reported extensive damage in mango trees caused by an abundant mycelial growth covering most diseased panicles of mango trees cv. Haden. Materials and methods. The fungus was isolated from panicles of mango. Pathogenicity was evaluated in the orchard by inoculating 20 inflorescences protected by cellophane paper bags. In vitro characterization was evaluated on monosporic cultures; conidial morphology and rate of growth were determined. A molecular characterization by DNA extraction was carried out to identify the microorganism. Results. Cladosporium tenuissimum caused necrosis of flowers, pedicels and small fruits on inoculated mango panicles cv. Haden in the long coast of Guerrero and Michoacan States of Mexico. The affected organs were covered with grey cottony mycelia and an olivaceous, green to grey sporulation. In vitro, young colonies were also olive green and velvety, turning dark green to grey with a whitish outer margin. The growth rate of colonies was 0.46 cm·day–1. Conidia were subspherical, lime-shaped and fusiform, olivaceous in color with visible scars and denticle-like extensions. The mean size of conidia was (5.85 × 2.93) µm with variations of 3.2–23 µm × 1.98–5.47 µm. The molecular characteristics rendered C. tenuissimum after identification. Symptoms of inoculated or naturally infected tree organs were similar. A diagrammatic scale was developed for the evaluation of disease severity, which varied from 69% to 100% in infected panicles. The organs were susceptible from blooming to fruit set. Discussion. Further research is proposed to evaluate the geographical distribution of C. tenuissimum in the production areas of mango with the concomitant evaluations of strategies of control.

Introduction. Citrus is the most important fruit crop widely grown by small-scale and commercial farms in Ethiopia. However, productivity of citrus in many parts of the country is threatened by Phaeoramularia leaf and fruit spot disease caused by Phaeoramularia angolensis. Surveys and field experiments were conducted to map the geographical distribution, and to study the efficacy of different fungicides for the control of this disease. Materials and methods. Surveys were conducted in the major citrus-growing areas (south, south-west and north-west) of Ethiopia. Random sampling techniques were used for sample collection. The efficacy of different fungicides against P. angolensis was studied under a hot-spot area, based on disease incidence and severity, and marketable fruit yield. Results and discussion. Phaeoramularia leaf and fruit spot disease of citrus has been widespread throughout the south, south-west, and north-west of Ethiopia, causing complete crop failure. This disease was more severe in smallholder farmers' fields as compared with the commercial orchards. The severity of P. angolensis was varied between different citrus species and areas with different agro-ecologies. The south and south-west part of the country, characterized by high and frequent rainfall with high humidity, were severely affected by the disease. Field application of Benlate, Score and Cuproxat significantly reduced the incidence and severity of the disease and, thereby, increased marketable fruit yield. Conclusion. Phaeoramularia leaf and fruit spot disease of citrus has become widespread in many parts of Ethiopia within a short period. Further investigation on P. angolensis biology and detailed epidemiological studies are mandatory to develop a model, and, thereby, to facilitate forecasting systems for effective and sustainable management of leaf and fruit spot disease of citrus in Ethiopia.

Introduction. In São Paulo State in Brazil, there is a demand for pear tree varieties that present fruit complementary characteristics and high adaptation for a subtropical-tropical climate. Thus, our study aimed at evaluating variety selections with better fruit quality and mainly adapted to the different areas of the São Paulo State. Materials and methods. Crosses among Asian [Pyrus pyrifolia (Burm.f.) Nakai] and European (P. communis L.) pear cultivars were made in Brazil from 1992 to 1998 aiming at finding new pear types for subtropical areas of the country. The first interspecific hybrids of the IAC pear breeding program were planted in various regions of São Paulo State, at latitudes from 21° 11’ S to 24° 11’ S and (11 to 200) chilling units (CU). About 20 phenological characteristics were evaluated. The hybrids and their parents were genetically characterized through RAPD markers. Results and discussion. In the progeny of ‘Okusankichi’ × ‘D'água’, the mean age for the first bearing and fruit development period (FDP) were 3.8 years and 137 days, respectively. The fruit characters early ripening, rounded shape, russet-brown skin and crisp flesh were dominant in all crosses of Asian × Asian and Asian × European pear trees. Twenty-six hybrids were selected, of which twelve are still being tested in a subtropical-tropical climate (0–80 CU). Their main characteristics are fruit with rounded, oblate, oblong or pyriform shapes, russet-brown or green skin, and crisp or soft flesh, and plants with medium-high vigor, an upright-spreading form and a fruit development period of from (110 to 160) days. Conclusion. The precocity of hybrids is highly dependent on the parental characteristics and the environmental conditions. A fruit development period close to that of the earliest parent was obtained. In F1 generations from crossings among Asian and European pears, certain characteristics were dominant. The RAPD analysis was efficient at identifying cultivar genotypes, selections and hybrids of pear from different botanical groups.

Introduction. The grapefruit tree has a long production period. In the Jordan Valley, harvest lasts from November to March. Many Jordanian farmers tend to harvest their fruit early to get high prices, regardless of its quality. Thus, the effect of the harvesting date on fruit quality of grapefruit cv. ‘Red Blush’ was evaluated under Jordan Valley conditions for two seasons, 2002 and 2003. Materials and methods. Fruit quality of uniform 25-year-old grapefruit cv. ‘Red Blush’ trees budded on sour orange rootstock was studied during the 2002 and 2003 seasons. Fruits were harvested from October 15 in both seasons with 15-day intervals with a total of eight harvests. The studied data were total soluble solids (TSS), titratable acidity (TA), the [TSS/TA] ratio and juice percentage. Results and discussion. Fruit total soluble solids and fruit juice percentages were at a minimal level during early harvesting dates and increased with time, reaching the maximum level on January 1 for TSS and January 15 for fruit juice percentage in the first season and on December 15 and February 1, respectively, in the second season, after that TSS decreased. Fruit titratable acidity values were at maximal levels during early harvesting dates (October 15) and decreased with time, reaching the minimum level on February 1 in the first season and on January 15 in the second season. The [TSS/TA] ratio ranged from 5.5 to 6.0 between January 1 and February 1 in the first season, and between December 1 and January 15 in the second season. Conclusion. Our study displayed that Jordan Valley growers are harvesting their grapefruits much too early to provide acceptable eating quality fruits to local markets.

Introduction. Breeding studies for acerola (Malpighia glabra) improvement aim at obtaining plants that produce fruits with uniform chemical and physical attributes, including high levels of vitamin C, which can provision the market with fresh fruit and frozen pulp. High variability in fruit quality is observed in Brazilian acerola crops, especially those propagated by seeds. In this context, the objective of our research was to evaluate the physical and chemical characteristics of Brazilian acerola genotype fruits. Materials and methods. Sixteen acerola genotypes were studied in Jaboticabal, São Paulo State, Brazil. A completely randomized design with sixteen treatments and six replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quality, such as width, length, weight, pulp percentage, soluble solids (SS), titratable acidity (TA), [SS / TA] ratio and vitamin C content, were evaluated in fruits of the acerola genotypes. The results were submitted to variance analyses, the Tukey test and cluster analysis. Results and discussion. There was a statistical difference between the acerola genotypes studied.Three of them stood out as natural sources of vitamin C.In spite of fruit size, two acerola genotypes were found to have potential for fresh fruit production. In a general form, genotypes that presented a high [SS / TA] ratio had low vitamin C content. Conclusion. The acerola genotypes studied in Jaboticabal presented high variability, forming eleven groups in relation to fruit quality parameters.

Introduction. Mamey (Mammea americana L., Clusiaceae) was present in Martinique before the Spanish colonization. Its distribution area includes tropical America and the Caribbean. A significant phenotypical diversity is observed on the island, with fruits of very uneven quality as well as various agronomic, pomological and biochemical characteristics. The aim of our work was to localize, identify and characterize trees considered of superior quality. Materials and methods. A survey carried out between April and September 2005 allowed the selection of 10 trees renowned by the people as bearing high-quality fruits. These fruits present a small number of seeds and nonadhesive pulp, and develop a sweet taste as well as a strong flavor. During the year 2006, pomological description and biochemical analysis (total soluble solids and total titrable acidity) were carried out on the fruits. Results and discussion. The biometric and biochemical characteristics measured were generally better than those cited in the literature. Some accessions stand out and present great assets for their promotion for the fresh market as well as for processing. Moreover, some tendencies emerged from the variability observed for a few characters: thus, the variability of the biochemical characteristics measured within one accession, as well as between accessions originating from the same land, is low. It is null for the seed adhesion to the pulp for fruits belonging to the same accession. Conclusion and perspectives. Our work is one of the first relating to identification and characterization of phenotypical diversity of the M. americana L. species, especially in Martinique Island. Our results are likely to promote the development of a diversification network. Some highlighted trends suggest new research to be able to distinguish the role of the environmental versus genetic components in the performance of the phenotypes observed.

Introduction. Pour introduire Ricinodendron heudelotii (Euphorbiacée) dans les agrosystèmes, des plantules ayant un système racinaire pivotant peuvent être produites par embryogenèse somatique in vitro. Nous avons étudié l’effet de quelques phytohormones exogènes sur certains paramètres biochimiques caractéristiques de l’embryogenèse somatique de l’espèce. Matériel et méthodes. Des cals et des embryons somatiques ont été induits par culture de fragments de feuilles sur un milieu de base enrichi en (1, 2 ou 3) mg 2,4-D·L–1 ou de combinaisons [2,4-D / kinétine] ou [2,4-D / BAP] impliquant différentes concentrations des hormones. Les extractions et analyses des sucres totaux, phénols, protéines totales et activité des peroxydases ont été faites après (30, 50 et 70) j de développement des cals. Résultats. Après 30 j de culture, les meilleurs pourcentages d’explants formant des cals ont varié de 72,1 % à 100 % selon les phyto-hormones utilisées. Après 50 j de culture, ces cals ont formé des amas globulaires de cellules en division (nodules embryonnaires). Après 70 j de culture, 17,4 % des cals ont différencié les embryons somatiques multiformes en présence de 3 mg 2,4-D·L–1; 23,1 %, en présence de [1 mg 2,4-D·L–1 + 1 mg kinétine·L–1] et 27,6 %, [1 mg 2,4-D·L–1 + 2 mg BAP·L–1]. La teneur en sucres a été la plus élevée à 30 j (formation des cals) et 50 j (formation des nodules embryonnaires sur cals), alors que les teneurs en phénols, en protéines et l’activité des peroxydases ont été plus élevées à 70 j (différenciation des embryons somatiques sur cals). Discussion et conclusion. À l’instar de ce qui se passe chez d’autres espèces végétales, chez R. heudelotii, les phytohormones exogènes interviendraient dans le contrôle du métabolisme des paramètres biochimiques impliqués dans la formation des embryons somatiques et de leur développement.

Introduction. Grewia coriacea is a widespread plant species that occurs spontaneously in tropical forests of Central Africa. It is one of the most important commercial spontaneous fruit crops in the Republic of Congo (Brazzaville), where it is harvested, sold and consumed on a rather large scale. However, similar to many other spontaneous products of the tropical rain forest in Africa, G. coriacea remains poorly studied and its nutritional potential is unknown. Because the fruit of G. coriacea is an important food for indigenous people in a large portion of the Congo River Basin, we studied the evolution of some compounds of this fruit starting from its fruit setting until its maturation. Materials and methods. The contents of various pigments (chlorophyll a and b, and carotenoids), and concentrations of soluble sugars, ascorbic acid and soluble proteins of the fruit pulp of G. coriacea were analyzed in the laboratory and they were followed during maturation. Results and discussion. The curves of evolution of the studied parameters followed some anticipated trends: increasing, decreasing or relative stability. Increasing applied to the carotenoids (3,0 mg·g–1 at the beginning of the fruit development up to 8.2 mg·g–1 at the end of its maturation), soluble sugars (9,9 µg·g–1 up to 75,4 µg·g–1), ascorbic acid (25 mg·100 g–1 up to 230 mg·100 g–1) and soluble proteins (7 µg·g–1 up to 40 µg·g–1). In contrast, the two chlorophyll pigments (chlorophyll a and b) showed an overall decreasing trend. Finally, the concentration of soluble proteins remained rather constant in the later stages, despite an initial increase in the early stage of development. Conclusion. To our knowledge, these results are the first data published concerning the temporal changes in physico-chemical parameters of G. coriacea fruits in tropical Africa. The study shows that the studied fruits have high nutritional potentials, and that their ability to accumulate rather high levels of ascorbic acid could make them a potential source of vitamin C.

The plant. The aguaje (Mauritia flexuosa L. f.) is an Amazonian palm which grows naturally on flooded soils, forming dense gatherings called aguajales in Peru. It can reach a height of 35–40 m. Each tree has an average of 8 inflorescences per year and each inflorescence produces about 900 fruits. This palm is in the domestication process. A dwarf form, recently discovered, could permit the improvement of the methods of production. The fruit. The fruit is an ellipsoid oval-shaped drupe, covered by red or dark red-coloured cornea scales. It measures (5 to 7) cm long and (4 to 5) cm in diameter. The pulp has a high content of β-carotene (260 mg·100 g–1 of pulp). Marketing. Marketing is carried out for fruits coming from the natural environment. There is a local consumption of approximately 150 t·month–1 and it can be of raw or processed fruit. For this fruit’s demand, it is necessary to cut down approximately 24 000 palms a year. Discussion. The aguaje has big social and economical importance to these regions' inhabitants. It represents great potential for the national as well as the international market. The Research Institute of the Peruvian Amazon (IIAP) is devel-oping technologies for agronomical management of the species, and for production and proc-essing of the fruit. Studies on aguaje growth and genetic diversity in the natural conditions also have to be carried out.

Introduction. Research was conducted at the Pistachio Research Institute in Rafsanjan, Iran, to evaluate the effects of ‘Badami’ (Pistacia vera L.), ‘Sarakhs’ (wild P. vera) and ‘Beneh’ (P. mutica F. & M.) seedling rootstocks on the nut quality of ‘Owhadi’, ‘Kalleh-ghuochi’ and ‘Ahmad-aghaie’ pistachio cultivars. Twenty-year-old trees of these nine rootstock/scion combinations were used in a two-year study done in 2003 and 2004. Materials and methods. Growth parameters [trunk cross-sectional area (TCA), tree height, canopy diameter, shoot growth, leaf area and number of suckers], yield parameters (cumulative yield and yield efficiency), and nut quality (blankness, splitting, nuts per ounce and weight of 100 nuts) were measured. Results and discussion. TCA was significantly lower on ‘Sarakhs’ rootstock than on the two other rootstocks and ‘Sarakhs’ was the least vigorous among the tested rootstocks and gave the lowest leaf area of scion cultivars. ‘Sarakhs’ rootstock consistently influenced the formation of the highest number of suckers. ‘Badami’ rootstock allowed us to obtain the greatest cumulative production and yield efficiency, the lowest blankness of pistachio nuts, and the highest percentage of splitting of pistachio nuts. Conclusion. Our study showed that genetic variability among pistachio rootstocks may influence scion vigour, yield, extent of shell splitting, blankness and nut weight.

Introduction. Simple, accurate and non-destructive models determining leaf area of plants are important in many experimental comparisons. Determining the individual leaf area (La) of A. deliciosa (A. Chev.) vines involves the measurements of leaf parameters such as leaf length (Ll) and width (Lw), or some combinations of these parameters. Materials and methods. A 2-year investigation was carried out in Italy during 2005 (calibration experiments) and 2006 (validation experiment) under open field conditions. It aimed at comparing existing predictive leaf area models for A. deliciosa leaves using non-destructive measurements, and assessing the accuracy of the optimum model selected using an independent dataset. Results and discussion. Regression analyses of (La) vs. (Ll) and (Lw) revealed several models that could be used for estimating the area of individual A. deliciosa leaves. A linear model with (Ll × Lw) as the independent variable [La = 0.82 (Ll × Lw) – 0.28] provided the most accurate estimate (R2 = 0.985, mean standard error = 25) of A. deliciosa leaf area. Validation of the model with (Ll) and (Lw) measured on leaves from other orchards grown in different locations showed that the correlation between calculated and measured areas was very high. Conclusions. With the model selected, agronomists and physiologists can estimate accurately and reliably the leaf area of A. deliciosa plants without the use of expensive instruments, e.g., a leaf area planimeter or digital camera with image measurement software.

Introduction. La zone sahélienne se caractérise par des sécheresses récurrentes, une dégradation accrue des sols, des rendements agricoles faibles et des périodes de famines fréquentes. Il serait dès lors nécessaire d’introduire des cultures moins tributaires de la pluviométrie et pouvant participer à l’autosuffisance alimentaire. Dans ce contexte, nous avons testé la culture de cultivars améliorés de jujubier (Ziziphus mauritiana Lam.) au nord du Burkina Faso. Matériel et méthodes. Cinq cultivars domestiqués de jujubier d’origine israélienne (cultivar Ben Gurion), ou indienne (Gola, Kaithali, Seb et Umran) ont été plantés en station de recherche à partir de jeunes plants greffés (environ 500 plants·ha–1) ; ils ont été irrigués soit manuellement par une technique traditionnelle, soit par un système de goutte-à-goutte. Le poids et la dimension des fruits (longueur et largeur) récoltés après 2 et 3 ans de plantation ont été étudiés. Résultats. La production fruitière des cultivars en deuxième et troisième années, tous cultivars confondus, a donné respectivement 0,48 t·ha–1 et 3,54 t·ha–1 avec une production moyenne de (0,97 et 7,08) kg par an et par pied. Les cultivars, Ben Gurion, Gola et Seb ont produit environ 500 fruits par pied, Umran, 300 fruits par pied, et Kaithali, 200 fruits par pied. Le cultivar Ben Gurion a présenté le poids moyen de fruit le plus élevé (15 g) et Kaithali, le poids le plus faible (6 g). Les cultivars les plus productifs se sont révélés être Ben Gurion et Gola qui, avec le cultivar Umran, ont donné les plus gros fruits. Discussion et conclusion. Les récoltes observées pour les plants de 2 et 3 ans pourrait faire espérer, par extrapolation, un rendement de près de 13 t·ha–1 en neuvième année. Ces premiers résultats obtenus dans une région peu propice à la production agricole permettent d’envisager la possibilité d’un développement de la culture du jujubier en zone sahélienne, pouvant déboucher à terme sur une source de revenus substantiels pour les populations locales.

Introduction. Aroma is often used as a fruit quality marker. Several researchers have used the analysis of volatile compounds to characterize dates (Phoenix dactylifera). Nevertheless, it is difficult to analyze this subtle aroma in spite of the many techniques available, such as liquid-liquid extractions and headspace analysis. The global approach of the e-nose with a minimum handling of the sample is a fast and efficient alternative to these techniques. This rather new tool, simulating the behavior of the human nose, thus aroused our interest for application to dates. Materials and methods. Dates were harvested, in 2005, at the Tamar stage from nine date varieties, in Zagora, Morocco. They were frozen after harvest and sent by air to the laboratory of CIRAD (Montpellier, France). All data were collected at the same time. Five hundred g of dates were taken at random, pitted and cut into small pieces. After homogenization, an aliquot of 3.0 g was put into a 10-mL headspace flask and immediately sealed. Six replicates per sample were prepared for later electronic-nose analysis. An electronic nose (e-nose) from Alpha MOS, equipped with Metal Oxide Sensors (MOS), was used. Data were analyzed using Principal Component Analysis (PCA). The Discrimination Index (DI), created by Alpha MOS, was used to describe the discriminatory power of the groups’ separation. Alpha MOS considers that good discrimination and reliability are achieved for DI over 80%. Results. Discrimination indexes > 88% and means of the coefficients of variation obtained for each sensor < 4% demonstrate the high performance and good reproducibility of the e-nose. Conclusion. The e-nose is sensitive to date volatile emissions. All the date varieties studied were well separated. This fast screening technique, creating a specific olfactory fingerprint as a genuine identity card, could be used to follow changes in maturity, assure the identity of lots of dates and detect adulteration.

Introduction. Insect pest identification and understanding of insect pest ecological relationships constitute a basic step for any control measure needed. Some native fruit trees occur naturally in southern Mozambique and the edible fruits are sought after by local communities. Our study aimed at assessing the activity of native fruit tree insect pests during the year and their ecological relationships, providing, for the first time, a faunistic analysis of insect species affecting fruit trees in the region of Maputo, Mozambique. Materials and methods. Entomological surveys were carried out between June 2002 and December 2003 in the Districts of Manhiça, Marracuene, Namaacha and Matutuíne (southern Mozambique). Quadrangular 900-m2 plots were established in fields where Annona senegalensis, Garcinia livingstonei and Vangueria infausta native fruit trees naturally occurred. The number of individual insect pests per fruit, tree and plot was recorded to estimate ecological fauna measurements: the affinity index, association index and simultaneous constancy. Results and conclusion. A total of 1648 insect specimens, belonging to eight insect species, were found while conducting the ecological observations on Annona senegalensis Pers (Annonaceae), Garcinia livingstonei T. Anders (Clusiaceae) and Vangueria infausta Burch (Rubiaceae). Two groups of pests were observed: defoliators and insects attacking the fruits, which represented the majority. Affinity between insect species was observed, with the relationship between Ceratitis capitata Wiedemann and one unidentified species of the Cosmopterigidae family reaching the highest values. C. capitata was also found to have the highest association index with Spatulipalpia monstrosa Balinsky (Lepidoptera: Pyralidae), as well as Carpophilus sp. (Coleoptera: Nitidulidae) and Araecerus sp. (Coleoptera: Curculionidae). C. capitata and Araecerus sp. had the highest simultaneous occurrence in different locations. Cluster analysis also indicated that Ceratitis capitata and Carpophilus sp. had the highest similarity percentage in all samples.

Introduction. L’olivier (Olea europaea L.) est la principale espèce fruitière exploitée au Maroc. L’embryogenèse somatique de la Picholine marocaine a été jusqu’à présent très peu étudiée malgré l’importance de cette variété au Maroc. L’objectif de nos recherches a été d’étudier les effets de divers milieux de culture sur l’induction et le développement d’embryons somatiques chez cette variété. Matériel et méthodes. Des cotylédons entiers de graines d’olivier ont été excisés après désinfection et mis en culture. L’initiation des cals embryogènes a eu lieu sur un milieu de culture de Murashige et Skoog, solidifié par de l’agar et contenant 0,5 mg de zéatine·L–1 combinée à différentes concentrations en acide naphtalène acétique (ANA) [(1, 2, 5, 10 et 40) mg·L–1], les cultures témoins étant sans régulateurs de croissance. Après 3 semaines, les cals ont été transférés dans un milieu soit liquide, soit solidifié par de l’agar ou de la gélerite. Après 6 semaines sur le milieu d’induction, les cals ont été transférés sur un milieu maintenu liquide ou solidifié par de l’agar ou de la gélerite, et contenant 0,5 mg·L–1 de zéatine, afin de favoriser le développement des embryons somatiques et, par la suite, leur régénération en plantules. Le taux de cals induits et le poids moyens des cals formés sur les différents milieux ont été mesurés après 6 semaines de culture sur le milieu d’induction. Une analyse histologique des cals embryogènes et non embryogènes a été effectuée. Résultats. L’induction des cals a significativement été influencée par la concentration en ANA. Les meilleurs résultats ont été obtenus avec 2 mg ANA·L–1 pour l’induction des cals (82,3 %) et 5 mg ANA·L–1 pour le développement de ces cals (150 mg). Le milieu liquide s’est révélé être le meilleur pour l’induction des cals et le milieu avec agar a favorisé le développement des cals et la régénération de plantules par embryogenèse somatique. L’utilisation de la gélerite n’a permis aucune morphogenèse. Les plantules régénérées et acclimatées ont présenté une croissance normale en serre. Conclusion. L’embryogenèse somatique serait exploitable pour la micropropagation de l’olivier au Maroc.

Introduction. Black pepper (P. nigrum L.), the major world spice, is a climbing vine of historical, religious and economic importance. Landraces or farmer’s cultivars constitute the major component of this tropical vine's diversity. Normal spike formation. Berries of P. nigrum are produced in solitary, unbranched, axillary spikes. The apical bud of the plagiotropic branches transforms into an inflorescence (spike). Spike variant. Mutation in the floral meristem of black pepper could result in inflorescence proliferation. A variant with 100% of proliferating spikes was collected from a farmer’s plot, and then propagated by cuttings. The proliferating spikes are of indeterminate growth habit. Benefits. This natural mutant of Piper nigrum resulted in improved socioeconomic status of the farmer through sale of the rooted cuttings at a premium price. The variant can also be used as a donor for improvement of black pepper, besides as a novelty in potted pepper culture. Since berries of varying maturity are produced due to indeterminate growth, and since immature berries are rich in oleoresin, a single harvest will be yielding matured berries, which can be traded as black pepper of commerce, and half-matured berries suited to the value-added industry. Discussion. Mutations in the floral organ identity genes and their effect on altered flower/inflorescence development have been reported in the literature. In the case of spike proliferation, the transformation of the floral primordia in the mutant spike into inflorescence primordia has resulted in the modified spike architecture.

Introduction. Dans plusieurs pays, le psylle Cacopsylla pyri (Hemiptera, Psyllidae) est considéré comme le ravageur majeur du poirier. Afin de préserver les ennemis naturels de ce ravageur, la lutte contre C. pyri passe actuellement par l’utilisation de matières actives aptes à préserver les auxiliaires de l’insecte, voire de substances préventives, dont la kaolinite. Pour la première fois en Tunisie, nous avons testé l’efficacité de ce produit en traitement d’hiver, en comparaison avec l’huile minérale traditionnellement utilisée. Matériel et méthodes. Pour déterminer le moment opportun d’un traitement contre C. pyri, les adultes présents en hiver dans un verger de poiriers ‘Williams’ ont été échantillonnés par frappage des branches. Les femelles récoltées ont été disséquées pour déterminer le stade de développement de leurs ovaires. Ces observations ont permis de déclencher, au moment opportun, une application hivernale à base de kaolinite, dont les résultats ont été comparés à ceux obtenus par un traitement à l’huile minérale. L’impact de ces deux traitements sur la ponte des femelles d’hiver et les larves qui en ont été issues a été étudié ; conjointement, la phénologie du poirier a été évaluée par plusieurs contrôles. Résultats. Les applications hivernales de kaolinite ont évité la ponte des femelles de psylle sur poirier. En conséquence, ce produit a réduit significativement les populations larvaires de C. pyri jusqu’au stade de chute des pétales. En outre, la kaolinite n’a pas eu d’impact sur le déroulement de la floraison. Conclusion. En Tunisie, la kaolinite s’est révélée très performante dans la prévention des pontes des femelles hivernantes de C. pyri ; elle pourrait donc être insérée dans un programme de lutte intégrée contre ce ravageur.

Introduction. Two Turkish fig cultivars, Alkuden and Bursa Siyahi, were propagated by meristem culture to eliminate the fig mosaic virus. The technique of dsRNA analysis was conducted on the in vitro propagated plants to test for virus-free status. Materials and methods. Four different Murashige and Skoog (MS) media complementedwith different concentrations of growth hormones (GA3, BA and IBA) were compared to study the cultured meristems’ survival rate, shoot formation and rooting. Short- and long-term thermotherapy treatments were also applied. Results. For survival rate, 0.2 mg GA3·L–1 + 0.5 mg BA·L–1 gave the most favorable results; for shoot formation, it was the medium with 0.2 mg GA3·L–1 + 2.0 mg BA·L–1 which was the best, while rooting rate was the highest for meristems cultured on MS medium with only 0.1 mg GA3·L–1. Conclusion. Meristem culture, together with thermotherapy treatment, is recommended to obtain virus-free fig plant material. Although cultured plants seemed to be very healthy, dsRNA virus tests are recommended for sensitive evaluation of the sanitary status of the plants obtained.

Introduction. Le rythme de croissance des végétaux ligneux est un critère essentiel dans l'établissement de l’architecture de l'arbre et, par conséquent, le port futur de l’arbre. Nous avons réalisé une étude portant sur une analyse dynamique de la croissance primaire et secondaire de l’olivier, tout au long d’une saison de végétation. Matériel et méthodes. La croissance de méristèmes terminaux d’oliviers issus de semis a été suivie. L’étude a porté sur la croissance primaire (allongement et édification de métamères) et sur la croissance secondaire (diamètre basal) de différents types de rameaux. Cette croissance a été modélisée, ce qui nous a permis de développer des courbes de modèles théoriques. Résultats. Les croissances relatives primaire et secondaire ont été caractérisées par des courbes en triple sigmoïde, indiquant trois vagues de croissance principales : deux printanières et une automnale. Elles ont été modélisées par des équations théoriques à neuf paramètres et trois logistiques. La validité de ces modèles a été vérifiée par certains critères de performance des modèles, dont la racine carrée de la moyenne des carrées des erreurs et le critère du maximum de vraisemblance. Conclusion. Le caractère rythmique de la croissance l’olivier a été confirmé.