Introduction. Banana and plantains rank fourth among the most important food crops of the world, and India holds the position of the largest producer. A study was undertaken to evaluate the potential yield of new synthetic banana hybrids based on bunch weight and fruit quality. It also assessed the nematode damage, Sigatoka leaf spot disease and parthenocarpy stability. Materials and methods. Thirteen new hybrids and eleven parental bananas of dessert type were used and evaluated in the first vegetative generation. Plant growth parameters, viz., pseudostem height and girth, number of leaves, and suckers per plant were measured at the flowering stage and the damage of roots by nematode and intensity of the Sigatoka leaf spot disease were assessed at the harvest stage. The content of total soluble solids, and reducing, non-reducing and total sugars in the fruit was estimated. Results. All the hybrids exhibited parthenocarpy and there was no reversion from parthenocarpy to non-parthenocarpy. The plant height and girth and the leaf number varied among the hybrids significantly. The maximum bunch weight was recorded for H-212 (ABB) which showed a regular suckering habit, very high content of total soluble solids and reducing sugars, and more leaves without leaf spot infection than the other hybrids; moreover, H-212 is a female sterile dessert-type banana and it is tolerant to nematode and resistant to Sigatoka. The reproduction factor of Radopholus similis on H-211 (AA), H-213 (ABB) and H-02-01 (AA) was significantly lower than on H-203 (AA), H-209 (ABB) and H-205 (AA). Conclusions. Our studies distinguished one triploid ABB hybrid H-212 with high yield and fruit quality, and no sanitary problems; it can be released for commercial cultivation to banana growers.

Introduction. Au Maroc, le parasitoïde A. melinus constitue l’agent de lutte biologique le plus efficace contre les pullulations d’A. aurantii, ou pou de Californie, insecte très nuisible à l’agrumiculture marocaine. Or, cet hyménoptère est présent naturellement dans la région du Tadla, grande région agrumicole du centre du Maroc (325 295 ha). De ce fait, la protection intégrée des agrumes contre A. aurantii pourrait constituer une possibilité de lutte prometteuse par rapport à la seule lutte chimique raisonnée. Note étude a été un préalable à la mise en place d’une stratégie de lutte intégrée sur agrumes au Tadla par la surveillance du pou de Californie et de son principal parasite A. melinus. Matériel et méthodes. Nos expérimentations ont été conduites en 2000 et 2001 dans un verger non traité, constitué d’un mélange de variétés d’agrumes. L’évolution de la dynamique des populations d’A. aurantii et d’A. melinus a été suivie et les périodes d’abondance des stades réceptifs vivants du ravageur coïncidant avec les périodes d’activité de son parasitoïde ont été repérées. Résultats. Dans la région du Tadla, le pou de Californie a présenté quatre générations par an, une génération printanière (avril–mai), une génération estivale (juin–juillet) et deux générations automnales (octobre et novembre–décembre). Les stades du ravageur susceptibles d’être parasités par A. melinus ont été observés tout au long de l’année. L’analyse de ces stades a révélé deux périodes (printanière et automnale) particulièrement favorables à la ponte des femelles du parasitoïde. Ses populations se sont révélées importantes dès le début de l’automne et jusqu’à la fin du printemps suivant. Conclusion. Des lâchers d’A. melinus effectués durant l’automne, l’hiver et le printemps pourraient donc être efficaces.

Introduction. The Tephritidae Ceratitis capitata is one of the most important agricultural pests in the world. Eradication programmes need as much genetic information as possible to be efficient. It is vital to know the genetic variation that exists in the areas thought to have been important in the expansion of the species, such as the Iberian Peninsula. The aim of this study was to determine the genetic structure of Spanish C. capitata populations and the relationships between them. Materials and methods. We studied the genetic variability of populations of C. capitata (eight wild samples and one laboratory strain) through the use of the horizontal starch gel electrophoresis technique and the assay of fifteen enzyme-coding loci chosen at random. Results. The quantity of variability detected in this polyphagous species was not high. Of the 15 loci studied, only four were clearly polymorphic. No significant differences were found in any comparison of populations collected from different hosts. Discussion. The distribution patterns of this variation seem to be the result of gene flow and selection in the form of agricultural practices.

Introduction. Le manguier est l’un des arbres fruitiers les plus répandus en Afrique de l’Ouest. Un historique de son introduction dans la zone a été publié récemment. Pour faire suite à ce document, l’analyse présentée a été consacrée aux principales variétés qui y sont cultivées aujourd’hui et à l’impact des facteurs historiques et commerciaux sur la composition variétale des vergers. Quelques définitions. En préalable à un inventaire des variétés, certains termes permettant de les caractériser ont été précisés (précocité, monoembryonie et polyembryonie) et quelques informations sur l’origine des variétés floridiennes ont été fournies. Les principales variétés cultivées en Afrique de l’Ouest. Quatre catégories ont été distinguées : les variétés de mangues locales ou polyembryonnées (mangots, mangue du Cameroun), les premières variétés monoembryonnées propagées par greffage (Amélie, Julie, Sabot, Djibelor, Cuisse Madame), les variétés floridiennes, également monoembryonnées et propagées par greffage, introduites plus tardivement et utilisées soit pour l’exportation (Kent, Keitt, Palmer, Zill, Valencia, Smith, Irwin, Haden), soit pour les marchés régionaux (Brooks, Davis-Haden, Miami Late, Springfels, Beverly, Eldon, Ruby). Chaque variété a été décrite, de même ses caractéristiques culturales et ses débouchés. La composition des vergers de manguiers greffés. La composition des vergers greffés est influencée par l’évolution historique et la destination des fruits qui peuvent être autoconsommés, vendus sur le marché local, national ou sous-régional, exportés sur le marché international ou transformés dans des unités artisanales ou industrielles. Cette composition a été précisée pour la Guinée, le Mali, le Burkina-Faso, la Côte d’Ivoire, le Sénégal et le Togo.

Introduction. In saline soils, the water absorption process of the plants is negatively affected, due to the permeability of the roots, leading to hydric stress. Plants under saline stress close their stomas earlier than plants not in these conditions; this causes an increase in stomatal resistance due to the decrease in water potential. The aim of the present research was to detect alterations in the stomatic behaviour and leaf water potential in young plants of Annona squamosa submitted to saline stress. Materials and methods. Sixty-day-old seedlings of A. squamosa were acclimated for 15 days in a greenhouse, before being submitted to different saline treatments. Five treatments (T0 = 0 mM; T1 = 25 mM; T2 = 50 mM; T3 = 75 mM and T4 = 100 mM of NaCl in a nutritive solution) were applied with six replications. The evaluations of the stomatic response occurred on the 20th, 30th, 40th, 60th, 80th and 90th days after the beginning of the saline treatments. The transpiration measures, diffusive resistance and leaf temperature were registered in the first mature leaf. The photosynthetically active radiation, relative humidity and air temperature within the greenhouse were simultaneously assessed 60 and 90 days after the beginning of treatments; then the leaf water potential (Rleaf) was also measured. Results. During the time of the experiment the leaf temperature and its difference from the air temperature was not affected by NaCl levels, but only 90 days after the beginning of the treatments the values observed in the control plants were lower than those observed in the 25 mM treatment. The diffusive resistance after 40 days was increased in all NaCl treatments. The transpiration, independent of treatment, was reduced by 44.1% (at 60 days) and 13.4% (at 90 days) with the 100-mM treatment compared with the control treatment. The increment in NaCl induced a decrease in Rleaf in all treatments, but an equal reduction was observed for each treatment after 60 and 90 days. Conclusion. The NaCl levels affected the transpiration and leaf water potential; however, the leaf water potential showed an equal reduction in all treatments on the 60th and 90th days.

Introduction. Our work aimed at reporting the occurrence of an anomaly in pineapple fruit in the state of Acre. Materials and methods. Fruit observations were accomplished in the pineapple experimental area of Embrapa Acre, in Rio Branco, AC, Brazil, from 1987 to 1998. Results and discussion. Typical symptoms of the studied anomaly were observed in the varieties Pérola, Quinari and Abacaxi de Tarauacá: an early yellowing of the skin of the superior half of the fruit was noted, while the skin of the lower half retained its green color, as if the fruit was not ripe yet. In the interior of the fruit, a cavity or crack was present in the area of the main axis. No plant pathogenic organism was isolated from the cavity inside the fruits. Also, it was not possible to relate the occurrence of abnormal fruits with climatic factors, considering that fruit with normal ripening of the same varieties were picked at about the same time from nearby pineapple plants. The occurrence of fruit with abnormal ripening was not observed in other pineapple varieties, such as Rio Branco, Cabeça-de-Onça and SNG-3, cultivated in Acre. Conclusions. It was not possible to associate the anomaly with biotic or non-biotic factors. Thus, it could be of physiological cause.

Introduction. Some fruit characteristics are very important for cherry marketing. This study aimed at determining relationships between some of them to help researchers on fruit quality. Materials and methods. The relationships between fruit cracking, fruit weight and diameter, soluble solid and acidity content, and fruit stalk thickness were determined on 35 sweet cherry cultivars in Amasya in Turkey. Results and discussion. There was a positive polynomial relationship between the fruit stalk thickness and fruit cracking; between fruit weight and fruit stalk thickness; and between fruit weight and fruit firmness. There was a positive relationship between the fruit weight and the acidity content, and between the fruit firmness, acidity and soluble solid. There was a negative relationship between fruit firmness and pH. Conclusions. Some relationships between cherry characteristics exist, which may help researchers to solve some problems such as fruit cracking. These studies may contribute to producing fruit with a good quality and help to evaluate new cultivars.