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. 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. 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.

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. 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. Although almond (Prunus dulcis L.) is one of the most important cultivated fruit trees in Lebanon, cultivated accessions have not yet been inventoried, and the identity of the varieties is unknown. Our study therefore aimed at assessing the genetic diversity of cultivated almonds in Lebanon using morphological characters. Materials and methods. Field surveys were performed in 2002-2003 with the aim of collecting different accessions of cultivated almond trees throughout the country. Thirty-six accessions were characterized in their cultivated habitats by using 20 qualitative and quantitative traits related mainly to the fruit, according to descriptors previously established by the International Plant Genetic Resources Institute (IPGRI). Results. A large diversity was revealed among accessions, probably due to genetic differences. Based on the qualitative studied traits, the dendogram indicated that most of the accessions were clearly distinguishable and only two cases of synonymy were observed. They have been clustered into three main groups at 0.37 of Jaccard similarity distance. Conclusion. This study needs to be completed by a DNA analysis, in order to highlight the influence of environmental conditions on the variability in the P. dulcis germplasm and to confirm the genetic distances among accessions.

Introduction. Cropping systems of the mango trees in West Africa are very varied. Each one of them developed in a specific context where the agronomical practices and the varietal composition of the orchards contribute to the diversity observed. The study undertaken should make it possible to better understand the influence of the potential outlets on the evolution of the regional mango production. Principal cropping systems. In the studied area, the main part of the mango orchards has less than 10 ha; their production is extensive and uses few inputs. They belong in majority to growers whose principal activity is centred on agriculture. Certain plantations close to 100 ha, found in Senegal or in Côte.d'ivoire, belong to exporters and profit from a technical assistance. Agronomical practices. The study of the agronomical practices used in mango orchards of West Africa made it possible to analyze the aspects of seedling production, choice of the site, installation of the orchard before plantation, plantation and maintenance of the trees, fire protection, water management, as well as the effect of the export market on the varietal choice and the varietal offer during a harvest campaign. Diseases and enemies. An inventory of the pathological problems and physiological diseases likely to devalue the production were carried out. Marketing. This part made it possible to distinguish intercontinental exports, requiring a specific harvest and conditioning organization, and the local, national and regional markets. Processing. Today, the share of transformed mangos into West Africa uses only one negligible proportion of the total production. Conclusion and prospects. Beside a traditional production which presents signs of brittleness appear modern orchards. More than a necessary intensification of the orchards, a rationalization of the agronomical practices, plant health protection, fruit harvest or handling are impossible to circumvent. Downstream, the export path is confronted with a fast evolution of the exogenous regulations, based on qualitative and sanitary standards increasingly strict.