Introduction. A study was carried out to investigate the proximate and mineral composition of plantain and banana fruits of new hybrids selected in Nigeria, compared with those of a local cultivar, Agbagba. Our aim was to assess their nutritional value and to enhance the adoption and utilization potential of these new selected hybrids. Materials and methods. Five new Musa hybrids developed at the IITA, Nigeria, were investigated. Proximate values of fat, carbohydrate and protein of the samples were determined and the energy content of each sample was calculated. Fruit mineral analysis was performed for each cultivar studied. The data were statistically analyzed. Results and discussion. All the new hybrids were higher than the local cultivar Agbagba in protein and crude fiber content. Conversely, Agbagba fruit had the highest level of carbohydrate. A significant difference was observed between the PITA 14 hybrid and the rest of the cultivars in total energy and fat content. Both the BITA 3 and PITA 26 hybrids contained the highest levels of ash. The PITA 17 hybrid contained the highest moisture. The PITA 14 and PITA 24 hybrids were different from all other cultivars in phosphorus and copper contents. The calcium concentration in the PITA 14 and PITA 17 hybrids differed regarding the rest of the cultivars assessed. Also, the levels of potassium and manganese found in all the hybrids were different from those obtained in Agbagba, while the latter differed from all the hybrids in magnesium and sodium levels. Conclusion. The new Musa hybrids assessed are superior to the Agbagba plantain in nutritional value, which could enhance the adoption and utilization potential of these new hybrids by the local population.

Introduction. Banana and plantain (ban+plant) play a substantial role in people’s diet in Cameroon. A survey was carried out in 240 households in four localities to determine the daily consumption of (ban+plant)-derived foods and the contribution of these foods to iron (Fe), zinc (Zn) and vitamin A intake by children of less than 5 years of age and mothers. Materials and methods. The daily consumption level was assessed by a 24-h dietary recall during three consecutive days. The Fe, Zn and β-carotene (precursor of vitamin A) contents of (ban+plant) products were determined and the bioavailability of these micronutrients was estimated using the [phytate:Fe] and [phytate:Zn] molar ratios. Results. On a dry-weight basis, Fe content in (ban+plant)-based foods ranged from (0.78 to 1.32) mg·100 g–1; Zn content from (0.22 to 0.41) mg·100 g–1 and β-carotene content from (336 to 724) µg·100 g–1. Phytate content was between (0.17 and 1.23) g·100 g–1, with [phytate:Fe] and [phytate:Zn] molar ratios above the estimated bioavailability thresholds of 10–14 and 15, respectively, for all dishes. The daily quantities consumed by rural and urban subjects were not significantly different. The daily supply of Fe by (ban+plant) to children and mothers was 5% and 2%; Zn supply was 3% and 4%, respectively. In contrast, the daily vitamin A supply by (ban+plant) foods was relatively significant, reaching 13% on average per day for both children and mothers. In certain cases, this contribution was as high as 20%. Conclusion. Estimated bioavailability of Fe and Zn is low in (ban+plant) that, therefore, poorly contribute to Fe and Zn intake in the households. However, (ban+plant) are a good source of β-carotene and can make a substantial contribution to meeting vitamin A requirements of children and their mothers.

Introduction. Bananas are traditionally propagated by suckers: nevertheless, the advantage of using tissue-cultured plants for banana production has been demonstrated in recent years. Despite the large-scale use of micropropagated plants in the subtropical regions, little information is available on the performance of these crops in tropical countries. So we compared the yield potential of some Cavendish banana cultivars propagated either by traditional suckers or by tissue culture. Materials and methods. A randomized complete block experiment was established in a commercial plantation in Cameroon to compare the performance of three tissue-cultured banana plants of Grand Nain, Williams and Zelig cultivars and two conventionally-propagated plants of Grand Nain and Williams. Morphological, phenological and yield component data were collected for six crop cycles. Results. All the plants grew vigorously and produced quality exportable fruits. However, the tissue-cultured plants consistently produced heavier bunches and higher yields than the conventionally-propagated plants. The highest yields (65.92 t·ha–1 for Grand Nain, 64.60 t·ha–1 for Williams and 65.58 t·ha–1 for Zelig) were obtained for the tissue-cultured plants in the third crop cycle compared with 51.43 t·ha–1 and 59.02 t·ha–1 obtained for the traditionally-propagated Grand Nain and Williams plants, respectively. There were no significant yield differences between the plants of different origin in the second and fourth cycles, respectively. However, the tissue-cultured Williams and Zelig plants outperformed the other plants in the sixth crop cycle. Conclusion. The tissue-cultured plants of the three Cavendish cultivars studied performed better than the plants resulting from conventional suckers. The best cultivar for commercial plantation used, that is located in a tropical environment, was Williams. In general, to obtain an optimum benefit, we would recommend the use of tissue-cultured plants over a period of 6–7 years with good management practices.

Introduction. Le plantain constitue une importante denrée alimentaire pour de nombreuses populations au sud du Sahara. Sa production dans les systèmes traditionnels de culture par les petits paysans est menacée par la maladie des raies noires, une maladie foliaire due à Mycosphaerella fijiensis Morelet responsable de pertes importantes de récolte. Pour faire face à cette maladie, des hybrides tétraploïdes de type plantain, résistants à la maladie, ont été créés au Cameroun puis sélectionnés à l’issue d’une première phase d’évaluation. Après multiplication végétative, les hybrides ainsi sélectionnés ont été évalués en station de recherche afin de déterminer leurs caractéristiques agronomiques et leur rendement potentiel en conditions de culture semi-intensive. Matériel et méthodes. De 1996 à 2000, trente hybrides sélectionnés ont été évalués, en comparaison avec leurs parents femelles, sur deux cycles de production à la faveur de trois essais mis en place suivant un dispositif expérimental en blocs de Fisher complètement randomisés avec deux répétitions de 10 bananiers chacun. Chacun des bananiers a été étudié à partir de caractéristiques agronomiques portant sur la croissance et la production. Résultats et discussion. Sept hybrides ont été sélectionnés sur la base de leur rendement potentiel élevé, de leur précocité de floraison et de leur pouvoir rejetonnant. Cependant, ce matériel végétal tétraploïde présente plusieurs défauts qui constituent un frein à leur diffusion. Certains de ces hybrides sont utilisés comme produits intermédiaires dans un nouveau schéma d’amélioration variétale au CARBAP.

Introduction. Chips or crisps are the most important foods usually fried; they are presented in the form of thin discs (chips) or sometimes in the form of sticks (French fries). Materials and methods. Chips were prepared starting from pulp samples resulting from five hybrids of plantain and banana newly released in Nigeria and from a local cultivar used as reference. The iron, zinc and pro-vitamin A contents were investigated in the chips to unveil their micronutrient content. Results and discussion. The results showed that there was no significant difference (p < 0.05) in the iron content of the chips produced from the new plantain and banana hybrids, while a significant difference (p < 0.05) existed in both zinc and total carotenoid contents of the hybrids. Chips made from BITA 3, a hybrid cooking banana, couldcontribute 2.61 retinol equivalent (RE)e [1 (RE)e = 6 µg β-carotene (precursor of vitamin A)] daily, if a small packet of chips (45 g) is consumed, based on the Recommended Daily Dietary Allowance. A 45-g packet of chips made from PITA 26 can contribute 14.6% and 20.1% of the daily requirements of zinc per day, and 30.1% and 22.3% of the requirements of iron per day, for a man and a woman, respectively. Conclusions. The new plantain and banana hybrids may therefore significantly participate in a food strategy aiming at combating the lack of micronutrients in the sub-Saharan African diet.

Introduction. The worldwide production of banana and plantain, which is estimated to 106 Mt·year–1, relies on a narrow genetic basis. Thus, banana production is fragile regarding emergent diseases, and creation of new varieties of banana stands out as a real necessity for its sustainability. In banana, various improvement strategies aim to create triploid hybrids. The objective of this report is to present a simple in vitro methodology to induce stable tetraploid plants by colchicine treatment, usable as parent for obtaining triploid varieties. Materials and methods. Twenty-one diploid M. acuminata clones and three interspecific M. acuminata / M. balbisiana diploid clones were treated as proliferating culture in liquid medium with 1.25 mM of colchicine for 48 h. Plant screening has been performed by morphological identification in greenhouse, chromosome counts on root tips and flow cytometry on leave blades on vitroplants using propidium iodide staining. Results. Chromosome counts led to distinguish diploid and tetraploid plants but did not afford to detect chimeras. Flow cytometry allowed an early screening of a larger number of plants leading to detect rapidly chimerical plants. It was observed that some stable 2x / 4x cytochimeras are periclinal. Tetraploid clones were obtained with all diploid genotypes. General behaviour of tetraploids in the field was globally weaker than the corresponding diploids. Nevertheless, all the doubled-diploids flowered and crossed with diploid plants to obtain triploid progenies. Conclusion. This study has clearly shown that induction of stable doubled-diploid plants can be obtained from a wide range of genetically different bananas. These results open the way to the systematic use of doubled-diploids by banana breeding programs for the release of enhanced triploid varieties.

Introduction. Many shoots or bud-like structures are lost in the final stage of plant micropropagation because of being too short for handling. Yellow and red lights induce in vitro plant growth of some species, and blue light reduces it instead. Yellow cellophane film passes through from the yellow to red light spectrum but cuts off the blue one. Growth of banana in vitro shoots was thus compared with or without yellow-cellophane-film shading. Materials and methods. Field-grown banana normal and dwarf variant plants of Nanicão cv. (Musa sp., AAA group, Cavendish subgroup) derived from micropropagation were re-established in vitro. They were then transferred to MS medium without growth regulator in test tubes covered by yellow cellophane film under cool white fluorescent lamps at a light intensity of 46 μmol·m–2·s–1. Shoot growth was measured as height was evaluated after (20 and 30) days of culture. Results and discussion. The yellow-cellophane-film shading stimulated the growth of banana in vitro shoots. When cultured under the yellow-cellophane-film shading for 20 days, the normal true-to-type plants showed an increase of about 25% in shoot height compared with the plants cultured without cellophane film. Similar growth response was also observed on the in vitro shoots of the dwarf plants but the increment was only about 12%. This shading technique can aid shoot elongation and consequently reduction of plantlet loss at the final stage of plant micropropagation. The differing sensibility of the normal true-to-type plants and dwarf variants to the yellow-cellophane-film shading may be used for reduction of the dwarf variant population in banana micropropagation. Conclusion. Yellow-cellophane-film shading stimulates growth of banana in vitro shoots.

Introduction. Citrus canker, caused by the bacterium Xanthomonas axonopodis pv. citri, is a serious disease of most commercial citrus cultivars and some citrus relatives. Surveys were conducted in small-scale farms, commercial plantations, backyard orchards and nurseries in order to quantitatively study the occurrence and distribution of the disease and determine the intensity and field host range. Materials and methods. Seventeen locations in four regional states of Ethiopia were surveyed. Incidence on leaves was determined by counting total number of leaves and expressed as a proportion of leaves with at least one lesion. Incidence on fruits was determined on attached fruits, recorded as presence or absence of the symptoms. Severity was also measured on leaves and fruits. The identity of the pathogen was confirmed by morphological, biochemical and physiological characterization and detached leaf tests of representative isolates. Results. The surveys indicated the occurrence of citrus canker in Ethiopia. Overall incidence on leaves was 71.4% of leaves with at least one lesion and severity was 26.8% of leaf area infected. Incidence on fruits was 30% of fruits infected and severity was 21.25% fruit area infected. Morphological, biochemical and physiological characterization and detached leaf tests of isolates indicated characteristics similar to X. axonopodis pv. citri. The host range for citrus canker in Ethiopia was limited to Mexican lime (C. aurantifolia) and sour orange (C. aurantium). Based on the field host range and detached leaf tests, it appears that the X. axonopodis pv. citri variant that occurs in Ethiopia has similar host ranges to that of atypical Asiatic (Xac-A*) form. Canker severity significantly correlated with temperature but not with rainfall, elevation or tree age. Conclusion. This is the first confirmed report of the disease in Ethiopia.

Introduction. Le charançon du noyau de la mangue, Sternochetus mangiferae (Fabricius), est un ravageur spécifique du manguier, classé comme insecte de quarantaine dans de nombreux pays producteurs de mangues où il n’est pas présent. Distribué dans toute la zone de production du manguier, il a été identifié en Guadeloupe en 1986 et s’y est largement développé depuis. Il existe peu de solutions en matière de lutte. Sur la base de données bibliographiques et de compléments d’observations réalisées en Guadeloupe, nous avons essayé de proposer de nouvelles méthodes de contrôle des populations du charançon. Matériel et méthode. Le cycle larvaire de S. mangiferae a lieu entièrement dans le fruit, de l’éclosion de l’œuf au stade adulte. Il dure de (1 à 2) mois. Les pontes altèrent l’aspect de l’épiderme des mangues. La larve se nourrit de leur amande. Les dégâts des larves sur les graines compromettent leur viabilité. Une prospection de l’insecte a été effectuée sur l’ensemble de l’île de la Guadeloupe. Le comportement de six variétés de manguier a été observé face aux attaques du charançon. Pour deux variétés de manguiers, Julie et Irwin, un suivi des pontes bihebdomadaire a été réalisé du 11 avril au 2 juin 2005. Résultats. L’insecte est présent sur la totalité de l’île. Il attaque indifféremment toutes les variétés, mais, dans le cas de la variété Julie, les larves atteignent difficilement le stade adulte. Nous avons pu caractériser la période de développement du fruit la plus sujette aux attaques. Un intervalle optimum de taille de fruit a été défini pour recevoir le traitement qui a été situé par rapport au stade de développement de la mangue. Discussion. Des recherches plus poussées sur la variété Julie pourraient être intéressantes pour le développement de variétés tolérantes.

Introduction. After harvest, litchi fruits (Litchi chinensis Sonn.) rapidly lose their bright red skin color. Peel browning of harvested litchi fruit has largely been attributed to rapid degradation of red anthocyanin pigments associated with the oxidation of phenolic compounds by polyphenol oxidase (PPO) and/or peroxidase (POD). An anthocyanase has been also identified in litchi peel. Our work aimed at characterizing two specific litchi varieties that differ greatly in their color and browning behavior. Materials and methods. The anthocyanins, polyphenol oxidase (PPO), peroxidase (POD) and anthocyanase in the pericarp of two litchi cultivars, Kwai May and Wai Chee, grown in Reunion Island and Spain, respectively, were studied. Results and discussion. The qualitative composition of major anthocyanins (cyanidin-3-rutinoside and cyanidin-3-glucoside) was identical for the two cultivars studied, but, quantitatively, the variety Kwai May had a lower concentration than Wai Chee (64% less) of cyanidin-3-rutinoside. This component represented more than 90% of total anthocyanins in both cultivars. The activity of PPO was 6 times greater in the variety Kwai May than in Wai Chee and the activity of POD 30 times greater. The activity of POD was greater than that of PPO in both varieties. These differences help to explain the different behaviors of the cultivars during subsequent postharvest studies.

Introduction. Fruit and vegetable consumption is now more than ever before understood, along with physical exercise, to be among the factors ensuring well-being. Cross-cultural epidemiological studies reveal a preventive effect of this consumption on certain human pathologies, whence the emergence of preventive nutrition. Changes in biodiversity dietary intake. Industrially-processed products, undergoing a greater or lesser degree of refinement, were developed during the last century; they focused on a few productive species and varieties. The concept of high-calorie foods, an energy source, which has been prevalent in dietetics over the past few decades, had minimised the role of fruit and vegetables in the diet, due to their low calorie content. Plant biodiversity in foodstuffs originating from the American tropics. There are few cultivated major species and varieties in terms of biodiversity. 40% of the edible plant species in the world today originate from the American tropics. Of the planet's 250 000 estimated plant species, 100 000 are believed to be from the Americas. Preserving the beneficial properties of processed products. To improve recovery of the properties of the fresh resource for the consumer, innovation in the processing methods is required, with unit operations ensuring the best possible preservation of the healthy compounds. Conclusion and prospects. Communication on fruit and vegetables has not enjoyed the same research and publicity resources as many processed products. Knowledge of and information on food resources, diet and health have become a major challenge. The relative wealth of the plant biodiversity from the American tropics represents a heritage we need to reharness.

Introduction. The technology for citrus rootstock production through improved sowing methods and fertilizer inputs offers greater opportunity in the certified citrus plant production system. Our work evaluated the influence of seed coat removal and different controlled-release fertilizer concentrations on plant emergence and plant growth of two citrus rootstock cultivars. Materials and methods. Decoated and not decoated seeds of Rangpur lime (Citrus limonia Osbeck) and Swingle citrumelo [Citrus paradisi × Poncirus trifoliata (L.) Raf] were sown in 50-cm3 tubes. Fertilizer concentrations were (0, 1, 2, 3, 4 and 5) kg·m–3 of controlled-release fertilizer (NPK 19-06-10) incorporated into the substrate. The experimental layout followed a randomized block design with 2 × 6 factorial (seed coat removal × fertilizer concentration) for each rootstock. Results and discussion. Seed coat removal resulted in faster plant emergence and higher dry weight for both rootstocks. Vegetative growth increased with controlled-release fertilizer concentrations.

Introduction. Açaí is a common palm in the Amazon River basin, from which a much-appreciated drink is prepared in the North of Brazil. Despite the strong increase in the drink market, some basic questions about the fruit postharvest physiology have not been properly studied. Our paper presents results about the fruit water absorption at different temperatures and times of storage, which may help the development of more efficient procedures for fruit transport and processing. Materials and methods. The experiments began approximately 3 h after harvest of fruits collected early in the morning. In a first experiment, to evaluate the effect of temperature on water absorption, fruits were submitted to five treatments: 0 °C, 6 °C, 12 °C, 26 °C and 39 °C. Each treatment was applied to 50 fruits, with four repetitions. Fruits from each lot were put into a beaker with water at the temperature of the selected treatment. Lots were weighed before immersion and every 10 min up to 60 min. The fruit relative increase in mass (dMasserel) was calculated according to experiment time. In a second experiment, to evaluate the effect of storage, fruits collected at the same spot were immediately stored in the lab at 10 °C under relative air humidity of 81% to 87%. After (5, 6 and 7) days of storage, the dMasserel curves were determined. Results and discussion. Between 0 °C and 26 °C, the absorption reaches an asymptote after 30 min, and at 39 °C, the absorption continues to increase for a longer period. The maximum (dMasserel) regarding the temperature was fitted by a parabole, with a minimum at 13 °C. Fruits stored at 10 °C presented an increase in the absorption rate after the fifth day. Conclusion. Our data suggest that: (i) water absorption is minimum at 13 °C; (ii) the imbibition rate is temperature-related, and (iii) fruit stored at 10 °C, and relative humidity 81% to 87%, increases its water absorption rate at the end of the shelf-life time (5th day).

Introduction. Scars and blemishes on citrus fruits render them unacceptable to prospective local buyers as well as the export market. To ameliorate this situation, the populations of the phytophagous mite Polyphagotarsonemus latus Banks (one of the agents at the origin of the damage observed) and its predatory mites were assessed in an orchard in the National Horticultural Research Institute (NIHORT), Ibadan, Nigeria, during the 2000 and 2001 fruiting seasons. The damage inflicted upon the fruits of 12 varieties of orange trees was studied jointly. The aim of the study was to identify appropriate periods to initiate control and to assess varietal effects on mite attack. Materials and methods. Twelve varieties of sweet oranges arranged in a randomized complete block design with four replications were used for the study. A stand of each variety was sampled per replicate to assess mite population and damage. Results and discussion. Mite populations and their damage on sweet orange varieties increased to fruit maturity. Washington Navel, Valencia Late, Agege and Lue Gin Gong varieties were most susceptible to mite attack and recorded higher fruit damage than the other varieties. The populations of the predominant predatory mites (the Bdellidae family) that attacked P. latus were significantly (P < 0.05) correlated with their prey at high population periods. The detrimental effects of pesticide overuse on natural enemies were highlighted. Conclusion. The progressive increase in mite population suggests the need for initiating control of phytophagous mites in July before the peak population period of September for Nigeria.