Introduction. Mature green vanilla pods accumulate 4-O-(3-methoxy-benzaldehyde)-β-D-glucoside (glucovanillin), which, upon hydrolysis by an endogenous b-glucosidase, liberates vanillin, the major aroma component of vanilla. Little is known on the spatial distribution of aroma-generating phenolics, and the enzymes responsible for their liberation (β-glucosidase) and oxidation (peroxidase). We report here quantitative data with respect to these three components in relation to the anatomy of the pod. Furthermore, the spatial progression of oxidation is shown. Materials and methods. Mature green vanilla pods were analyzed for their contents of phenolics (HPLC), and β-glucosidase and peroxidase activities by spectrophotometric techniques using p-nitrophenyl glucoside and vanillin as substrates, respectively. Lipids were examined under fluorescence microscopy after Nile red staining. Oxidation development was observed on transverse slices of pods. Results and discussion. Phenolics, and β-glucosidase and peroxidase activities showed gradients of increasing-decreasing concentrations from the stem to the blossom end of pods. The β-glucosidase activity is distributed in between the placentae, mesocarp, and trichomes in a [7 / 2 / 1] proportion while that of peroxidase shows a [38 / 1] ratio in the mesocarp and placentae, and was absent from trichomes. Oxidation begins from the blossom end in the placentae, progressively invading the mesocarp and moving towards the stem end. Conclusion. The green mature vanilla pod is spatially heterogeneous for its phenolics, and β-glucosidase and peroxidase activities, its placentae playing an important role in the liberation of vanillin and its subsequent oxidation.

Introduction. Deux espèces de pitaya coexistent à la Réunion : Hylocereus undatus et H. costaricensis. Ces deux espèces, introduites, s'y reproduisent végétativement et, bien qu'elles fleurissent, ne produisent que rarement des fruits. Une étude a donc été menée pour vérifier les causes de l’improductivité de ces espèces et apprécier le rôle d’éventuels agents pollinisateurs. Matériel et méthodes. Deux modes de pollinisation libre (nocturne ou diurne) et deux modes de pollinisation contrôlée (croisement interspécifique manuel et autopollinisation) ont été comparés sur une parcelle plantée avec les deux espèces H. undatus et H. costaricensis intercalées. Les observations ont porté sur la viabilité du pollen, la nature des agents pollinisateurs, les conditions de pollinisation et la fructification. Résultats. Nous avons vérifié que l’absence de productivité des deux clones d’Hylocereus en conditions naturelles était due à leur auto-incompatibilité. En effet, aucune fécondation n’a été observée sur les 200 autopollinisations effectuées en 1999. Cette auto-incompatibilité n’est pas liée à une stérilité du pollen dont la viabilité in vitro s’est révélée satisfaisante. D'autre part, si les abeilles jouent un rôle dans la fécondation des deux clones, les fruits résultant de ces pollinisations libres sont significativement moins lourds que ceux issus d’une pollinisation manuelle croisée. Discussion et recommandations. Seule une pollinisation croisée et manuelle peut donc permettre aux deux clones d’Hylocereus présents sur l’île de la Réunion de produire des fruits de qualité. Un itinéraire technique de fécondation est proposé.

Introduction. Films act as semi-permeable gaseous barriers capable of maintaining fruit postharvest quality; thus coatings consisting of non-traditional sources may represent an alternative tool for producers. The objective of our work was to investigate the effect of a galactomannan coating on postharvest quality and physiology of ‘Tommy Atkins’ mangoes. Materials and methods. Physiologically mature mangoes were divided into four lots and stored for 16 d. Control uncoated fruits (lot 1) were stored at ambient temperature (25 °C), the second lot was uncoated and refrigerated (14 °C), the third lot was coated and stored at ambient temperature, and the fourth lot was coated and refrigerated. Fruit were analyzed for physicochemical quality parameters, antioxidant enzymatic activity and lipid peroxidation. Results and discussion. Control fruit (lot 1) lost almost twice the weight of uncoated refrigerated (lot 2) and coated mangoes at both temperatures (lots 3 and 4); the fruit of lot 1 softened faster. Regarding the antioxidant enzymes, the activity of superoxide dismutase decreased throughout storage without statistical differences between treatments and catalasic activity was significantly inhibited under refrigeration. At ambient temperature, coating delayed the catalasic activity peak to day 12, which was coincident with the lowest lipid peroxidation degree, evidencing the association of free radical production and scavenging mechanisms. The galactomannan coating was efficient in reducing weight loss and delaying softening; thus, it maintained quality of ‘Tommy Atkins’ mangoes for a longer period of time than the control treatment during storage at ambient temperature. Refrigeration (14 °C) enhanced the performance of the galactomannan coating; it was effective in slowing down the metabolism and delaying softening to day 12.

Introduction. Le babaco (Carica pentagona Heilb.), plante équatoriale de mon-tagne, est originaire d'Équateur. Ses fruits sont particulièrement appréciés pour leur arôme caractéristique. La plante. Le babaco est un arbuste semi-ligneux de la famille des Caricacées. Cet hybride naturel se cultive en Équateur entre (1500 et 2500) m. Les rendements de production sont compris entre (60 et 80) fruits par plante et par an. Le fruit. Le fruit du babaco est une baie asperme jaune à maturité. Son arôme caractéristique se rapproche à la fois de l'ananas, du citron et de la papaye. Quand le fruit est vert, il exsude un latex qui con-tient une activité protéolytique semblable à celle de la papaye. Transformation. Le fruit est consommé essentiellement à l'état frais. La fabrication de pulpe, conserves et de fruits déshy-dratés est également possible. L'extraction et la purification des enzymes protéolytiques du latex des fruits verts pourrait être une nouvelle voie de valorisation industrielle du babaco. Tendances économiques. Grâce à des rendements de production élevés, ce fruit a éveillé un grand intérêt commercial. L'Équateur et la Nouvelle-Zélande sont les deux seuls pays où le babaco est cultivé à grande échelle. Conclusion. Le babaco présente d'intéressantes perspec-tives économiques, grâce notamment à ses propriétés sensorielles et à ses potentialités comme source d'enzymes protéolytiques.

Introduction. The fruit of `Encore' mandarin (Citrus deliciosa × Citrus nobilis) usually shows chlorotic spots in the epicarp from the first stages of development. Thispeel disorder triggers off, thereafter, the occurrence of a large quantity of dark stains (pre-harvest`peel pitting'). Materials and methods. A biochemical and ultra-structural study of the flavedo,using epicarp with and without stains, was carried out. Quality assays were assessed on the edible portionof the fruit or on juice. Results. The cell structure of pitted and unpitted epicarp analysed byelectron microscopy revealed that dark spots were associated with the degradation of cellular membranes.The peroxidase system that shields the epicarp against photooxidative stress showed an inhibition ofcatalase activity and an increase of superoxide dismutase functioning. Moreover, the activities ofascorbate peroxidase and glutathione reductase remained unaffected in stained tissues. In sunshade trees,it was also found that the number of dark stains per fruit decreased but the internal quality of theendocarp was not significantly affected. The weight and the caliber of the fruit also slightly decreased.Discussion. High light intensities induce an oxidative stress in the epicarp, which is characterized by anincreased peroxidation and degradation of biological membranes. On the other hand, protection againstsolar radiation alleviates the stress, but, although not affecting the internal quality of the fruit,slightly decreases the fruit weight and size.

Introduction. Shea tree (V.paradoxa C.F. Gaertn.), a species endemic to the Sudaniansavanna woodlands, is dominant in the parklands of West Africa whereit is of great socioeconomic importance. However, shea tree hasbeen reported in recent decades to be threatened by plant parasites,Loranthaceae. Our study aimed to assess possible variation of theimpact of these parasites on shea tree fruit yield in two contrastinghabitats. Materials and methods. We selected 41 weaklyand 41 heavily infected shea tree individuals, of similar size,in a protected area as well as in its adjacent parklands. Shea treetraits such as diameter at breast height, canopy diameter, treeheight, canopy height, number of fruit yielded, number of parasite stumpsper tree and an impact index ratio were assessed on each shea treeindividual. Two-way ANOVA was performed to compare parasite impacton shea tree fruit yield in relation to habitat. Hierarchical cluster, canonicaldiscriminant and one-way ANOVA analyses were used to show quantitativetraits that characterize shea tree groups from habitats. Results.Loranthaceae did not reduce fruit yield significantly either inthe parklands or in the protected area. Quantitative traits tendedto discriminate all pooled shea trees in relation to habitats. Sheatree individuals in parklands were characterized mostly by the highestvalue of number of infected stumps per tree and of the impact index ratio,suggesting that many shea tree individuals in parklands were sensitiveto Loranthaceae impact on their fruit yield. Conclusion.These findings were helpful for implementing some shea tree conservationplans.

Introduction. The determination of an adequate container volume that combines rational use of substrate with maximization of vegetative growth is very important to optimize citrus nursery tree production. This experiment aims to evaluate the influence of container volumes on vegetative growth of citrus nursery trees. Materials and Methods. Pera sweet orange nursery trees [Citrus sinensis (L.) Osbeck] budded on Rangpur lime (Citrus limonia Osbeck) were produced in six container volumes [(3.0, 3.8, 4.5, 4.6, 5.0 and 5.8) L], with the respective container dimensions of [(20 × 32, 20 × 35, 22 × 32, 22.5 × 35, 25 × 32 and 25 × 35) cm]. Another 5.0-L container studied had the dimensions of 20 cm x 40 cm. Commercial substrate was composed of Pinus bark and a controlled-release fertilizer was used. Parameter evaluation started after moving the rootstocks from seedling trays, 3.5 months after sowing, to plastic containers and continued until nursery trees reached one year old. The studied parameters were shoot height, diameter and leaf area of rootstocks and nursery trees, bud take percentage and scion and root dry matter of nursery trees. Results and discussion. The development of Rangpur lime plants was not affected by any treatment until budding. The largest container volumes induced faster and more vigorous vegetative development of Pera sweet orange nursery trees budded on Rangpur lime. A 5.0-L container volume could be indicated as a technical and economical option for the production of containerized citrus nursery trees.

Introduction. Tamarindus indica est une espèce fruitièred’intérêt économique. Sa domestication au Sahel impose d’évaluer en préalable lavariabilité de ses caractères phénotypiques sur l’ensemble de son aire de répartition.L’objectif de notre étude a été de caractériser différentes provenances de tamarinier àpartir des caractères phénotypiques de leurs graines et plantules. Matériel etméthodes. L’étude menée en pépinière au Burkina Faso a porté sur l’étude desgraines et germinations issues de neuf provenances dont deux d’Afrique de l’Est, deuxd’Afrique de l’Ouest, deux d’Asie et trois de zones insulaires. Nous avons mesuré lalongueur, la largeur, l’épaisseur et le poids de 100 graines de chaque provenance, et lahauteur, le diamètre au collet et le poids sec de la tige, ainsi que la longueur de laracine principale, le nombre de racines secondaires et le poids sec du système racinairede 50 plantules âgées de 3 mois. Nous avons effectué une analyse de variance, puis uneanalyse en composantes principales sur les données centrées réduites de toutes lesvariables, enfin une classification hiérarchisée ascendante basée sur des indices desimilarité. Résultats et discussion. Les différences entre variables ont étéhautement significatives. Lors de l’étude des graines, nous avons obtenu un groupe lié àla provenance d’Inde et d’Afrique de l’Est, un autre lié aux provenances ouest-africaineset un groupe intermédiaire en provenance de Thaïlande. Lors de l’étude des plantules, ilest apparu un groupe avec croissance aérienne forte et racine principale courte, fortementramifiée et un groupe avec croissance aérienne faible, racine principale très longue, maisfaiblement ramifiée. Le dendrogramme obtenu à partir des ressemblances phénotypiques(variables des graines et plantules) montre une structuration par aire géographique.Conclusion. La variabilité phénotypique inter provenance des plantules etdes graines combinée aux corrélations entre variables pourrait permettre de sélectionnerde façon précoce les provenances en fonction des objectifs définis pour la sélection.

Introduction. The present study had as objectives to measure the palm leaf divergence angle in the field, to determine the frequency of trees and offshoots showing clockwise and counterclockwise phyllotaxis, to establish the relationship between phyllotaxis of the mother tree and that of its offshoots, and, finally, to determine the effect of the divergence angle value on production. Materials and methods. The vegetal material was composed of four Moroccan cultivars of Phœnix dactylifera L. Observations were conducted in the south of Morocco on 20 trees per cultivar and four offshoots per tree. The divergence angle was measured on adult trees whereas phyllotaxic direction (clockwise or counterclockwise) was noted for both offshoots and adult trees. Results and discussion. This study showed that the phyllotaxic direction of the offshoots presents a clockwise or counterclockwise phyllotaxis independently of the mother plant. The divergence angle varied depending on the cultivar. This character is an interesting criterion, both for the selection of the best adapted cultivars for the marginal date palm growing regions, and for an optimal production.

Introduction. This protocol aims at measuring the mechanical characteristics of bananas, especially peel and fruit hardness, and pulp firmness; it can also allow the mechanical characterisation of green or ripening fruit of different pedo-climatic origins and/or varieties. Materials and methods. This part describes the required laboratory materials and the three steps necessary for the measurement of the mechanical characteristics of bananas. Results. The data allow the drawing of a curve characterising the firmness of the fruit (slope), hardness of the peel (peak) and hardness of the pulp (plateau).

Introduction. For the micropropagation of woody species, contamination of in vitro cultured explants is a constant problem, which can compromise the development of the technique. The aim of our study was to evaluate the effects of an antibiotic and a fungicide on surface and endophytic microorganisms associated with Annona cauliflora, A. bahiensis and A. glabra (Annonaceae) tissue culture. Materials and methods. Our work made it possible to compare a standard disinfection of in vitro cultured explants and the use of either a commercial fungicide, Benlate 500 (50% of benomyl) at (0.0, 1.0, 2.0 and 4.0) ${\rm g} \cdot {\rm L}^{-1}$ , or an antibiotic, ampicillin at (0.0, 1.0, 2.0 and 4.0) ${\rm mg} \cdot {\rm L}^{-1}$ . Results. The study revealed considerable variations in the infection rates within species and according to the concentrations of benomyl and ampicillin used. Benomyl was effective at cleaning leaf segments, and, at a concentration of 1.0 ${\rm g} \cdot {\rm L}^{-1}$ , this fungicide was sufficient to eliminate all fungi. Ampicillin treatments at (0.0 to 4.0) ${\rm mg} \cdot {\rm L}^{-1}$ were ineffective at controlling bacterial contamination. Conclusion. Referring to the difficulty in obtaining an aseptic in vitro culture starting from a woody species, the average number of healthy explants obtained after the disinfection of foliar explants of Annona sp. using the antimicrobial substances tested was significant. Further studies to evaluate the effects of the concentration of chemicals on in vitro plant regeneration for Annona species are needed to clarify the relationship between the concentration and phytotoxic effect of chemicals.

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. A study of accessions from the major production areas ofDacryodes edulis (Don) Lam. (Burseraceae) in Cameroon was carried outin order to assess the impact of pedoclimatic parameters and genetic factors on thecharacteristics and the classification of the fruits. The work focused on statisticalanalysis of fruit morphological and chemical parameters to distinguish accessions.Materials and methods. The fruits were collected from five localities ofCameroon (Obala, Boumyebel, Makenene, Njombe and Kekem). Twenty-six characters, amongwhich were eleven quantitative morphological, nine qualitative morphological and sixchemical characters, were the object of a correlation analysis, a principal componentanalysis and hierarchical classification. Results. Among the twenty-sixcharacters studied, eighteen presented interesting morpho-chemical characters todiscriminate the accessions. The fruit quantitative morphological characters were notsignificantly different, while the qualitative morphological and chemical charactersshowed significant differences for the localities concerned. A principal componentanalysis and hierarchical classification distinguished three major groups at a geneticdistance of between 5.70 and 6.92: group I consists of accessions from Makenene and Kekem,discriminated by five characters (lipids, protein, grain colour, texture and colour of themesocarp); group II consists of accessions from Njombe and Obala and was discriminated bysix characters (weight of fruits, amino acids, sugars, phenols, epicarp colour and shapeof grains); group III consists of the accession from Boumyebel and was discriminated byseven characters (fruit length and diameter; [fruit diameter / fruit length] ratio; weightof fruit, mesocarp and grain; and mesocarp thickness). Discussion andconclusion. Like agro-forestry species such as Ricinodendron heudelotiiand Irvingia gabonensis, D. edulis presents intra-specificvariations that are related to pedoclimatic conditions and genetic factors.

Introduction. En Tunisie, les dattes de type Deglet Nour sont réputées pour leur couleur jaune doré et elles présentent une valeur marchande élevée ; elles constituent la majorité des dattes exportées vers l’Europe. L’objectif de nos travaux a été d’étudier l’effet de l’oxygène et de la température sur la dégradation de la couleur de ce type de dattes durant la période d’entreposage. Matériel et méthodes. L’évolution de la couleur de dattes du type Deglet Nour stockées sous humidité relative constante (75 %), à trois températures différentes [(10, 25 et 37) °C] et en présence de trois concentrations d’oxygène [(0, 20 et 40) %] a été suivie chaque semaine durant 35 jours à l’aide de la mesure des paramètres L* et b* de l’échelle Hunter Lab. Résultats. La température a joué un rôle déterminant dans la dégradation de la couleur des dattes durant l’entreposage et l’effet de l’oxygène a été important quoique secondaire. Conclusion. La couleur des dattes au cours de leur stockage se révèle pouvoir être prédite à partir du seul paramètre b* de l’échelle Hunter Lab. Dans le cas des dattes conditionnées sous différentes concentrations en oxygène et à différentes températures, la perte de la couleur initiale du fruit a été davantage expliquée par une augmentation de la température ambiante que par la variation de la concentration en oxygène du milieu de conservation. La dégradation de la couleur serait causée par des brunissements non enzymatiques et enzymatiques oxydatifs.

Introduction. La durée de vie verte (DVV), qui indique l’état physiologique des bananes à la récolte, est un critère de qualité majeur pour l’exportation des fruits. Afin d’évaluer et de comprendre la variabilité de la DVV existant en exploitation, une enquête diagnostic a été menée chez trois producteurs de bananes en Martinique utilisant la méthode des sommes thermiques comme outil de décision de récolte. Matériel et méthodes. Pour chaque producteur, des fruits ont été prélevés en sortie de station d’emballage sur 10 % des régimes récoltés pendant une semaine. Ces bananes ont ensuite été conservées à 14 °C dans des sacs perforés en polyéthylène jusqu’au stade de maturité « tournant vert ». La DVV a été définie par le temps écoulé en jour entre la récolte et ce stade de maturité. Résultats et discussion. La DVV a varié entre (18 et 69) jours avec une moyenne de 42 jours pour l’ensemble des producteurs. Près de 80 % de la production a eu une DVV entre (25 et 50) jours et moins de 4 % en dessous de 25 jours. La variabilité de la DVV a été liée principalement à l’âge des fruits à la récolte, exprimée en somme thermique (R = –0,74). Celle-ci a varié entre (600 et 1150) degrés-jour pour l’ensemble des exploitations. Les fruits contaminés par l’anthracnose de blessure et les pourritures de couronne ont présenté une DVV plus courte que les fruits sains et cela indépendamment du stade de récolte (p < 0,001). L’origine de cette contamination a été discutée. À même somme thermique, des différences significatives de DVV ont été mises en évidence selon le lieu de production (parcelle) (p < 0,001). Des écarts de plus de 7 jours en moyenne ont été observés entre des parcelles provenant du même producteur et situées à même altitude. L’origine de ces différences a également été discutée.

Introduction. The fruit of Averrhoa carambola L., or carambola, is an attractive tropical fruit of the Oxalidaceae family. As most of the carambola crop is consumed fresh, very few carambolas are processed. However, the high variability in fruit quality produced by Caribbean countries is a major limitation to market penetration. Processing of carambolas could allow the utilization of low quality fruits, which cannot be marketed, to reduce waste, improve on the economic returns of farmers and increase the value of the crop. Our work thus aimed at studying carambola wine quality in relation to certain treatments applied before the fermentation of the must. Materials and methods. Pectolase was added to the pasteurized carambola pulp to the concentrations of (0, 0.1, 0.2 and 0.3)%. Another treatment used pectolase to 0.3% with addition of 1% of citric acid and 0.25% of ascorbic acid and associated with the use of various yeast strains of Saccharomyces cerevisiae from various wines (Super, Chablis and Sweet Mead). The must was adjusted to 25 °Brix and pH 3.0–3.5. The carambola wine quality obtained at the end of each treatment was assessed using physicochemical characteristics and sensory evaluations. Results and discussion. Addition of pectolase improved the carambola wine’s light transmittance, sensory color, sensory clarity and overall acceptability. Addition of 1% citric acid and 0.25% ascorbic acid to the must resulted in less dark and yellow wines with a more acceptable color. Wines fermented with the Chablis yeast strain had the highest clarity (88.55% of light transmittance). The wines were microbiologically stable. Conclusion. Carambola wine treated with 0.3% pectolase with the inclusion of 1% citric acid and 0.25% ascorbic acid with different yeast strains had (7.35 to 7.65) °Brix, (10.25 to 11.50)% alcohol, pH 3.01 to 3.02, (79.20 to 88.55)% of light transmittance and (17.50 to 17.76) mg ascorbic acid·100 mL–1. These wines had overall acceptability rating from slightly to moderately liked and they were judged as superior.

Introduction. The traditional curing of vanilla pods includes “killing” andsweating steps when pods are exposed to heat (35–65 ℃) for various lengths of time.Although it is known that liberation of vanillin and other phenolics from theirnon-aromatic glucosides is due to the action of an endogenous β-glucosidase, itsin vivo kinetics remained unknown. Materials and methods.Mature green vanilla pods were pretreated for 2 h at 50 ℃, 55 ℃ and 60 ℃, then stored for118 days at 27 ℃. Phenolic glucosides and their aglycons were extracted at regularintervals during the storage period and analyzed by HPLC. Results anddiscussion. All phenolic β-glucosides were slowly hydrolyzed during the storageperiod with production of vanillin, p-hydroxybenzaldehyde, vanillic acid,and other unknown aglycons. Most of the β-glucosidase was heat-denatured by thepretreatment, and analysis of its kinetic parameters showed that it adopts, invivo, an allosteric mode of functioning with a lower affinity for glucovanillinthan in vitro, where it behaves as a Michaelian enzyme.Conclusion. Extensive research is needed to confirm the allostericmechanism of the vanilla β-glucosidase in vivo.

Introduction. Dacryodes edulis and Canarium schweinfurthii are two tropical multi-purpose trees in Cameroon which produce fruits (African pear and Black olive, respectively) for human consumption, which are marketed more and more on the national and international markets. This study aimed at characterising these two fruits starting from their physical and chemical properties. Materials and methods. Fruits were collected during the harvest peak in three agro-ecological zones of Cameroon. The physical properties measured were the weight, the length, the fruit circumference and the pulp thickness, while the chemical analyses included the moisture and protein, lipid and ash contents. Results. The fruits from the humid forest were largest (96 g), whereas the smallest came from the grassland (54 g). The highest pulp per fruit content (69% for the African pear and 57% for Black olive) was observed in fruits harvested in the humid forest zone. The strongest correlation (r = 0.25) between the fruit weight and that of pulp was observed for Black olive produced in the humid forest zone. The crude protein rate was highest (8%) in fruits from the humid forest, whereas that of the lipids (42%) prevailed in the semi-forest zone. Conclusion. The humid forest zone offers the best agro-ecological conditions for commercial production of the fruits of D. edulis and C schweinfurthii. These two fruits contain proteins and lipids in significant quantities and can, consequently, be used as alternative sources for these nutritive elements.

Introduction. Pitaya (Hylocereus undatus) is an exotic fruit species little known in Brazil and which needs basic studies about plant nutrition, propagation and physiology. Emphasizing the co-existence of juvenile and adult stages in the pitaya canopy, the plant is generally propagated by cuttings. Materials and methods. A completely randomized design with four treatments and five replications was adopted. Each treatment was represented by the part of the canopy from which the cutting was taken (upper, middle and lower cutting and cuttings from young plants). The following variables were registered: % cuttings with roots, % of live cuttings, root density, root diameter, root area, root length and root dry mass. Results were submitted to variance analyses, Tukey’s test at 0.01 probability error and simple correlation analysis. Results and discussion. The results indicated that the position from which the cutting is taken had a quantitative effect on rooting formation of pitaya cuttings. Juvenile cuttings presented 35% more cuttings with roots than adult cuttings. Root density, root area, root length and root dry mass depended on juvenility, the highest results being registered for juvenile cuttings, independently of the variable. Conclusion. Juvenile and adult stages co-exist in the pitaya canopy. Juvenility is an important rooting factor for red pitaya cuttings.

Introduction. High–density orchards of ‘Amrapali’ mango trees become overcrowded and show progressive decline in yield after 14–15 years of planting; hence, trees require pruning for sustainable production. Reduction in yield in such orchards is due to poor light interception and a low photosynthetic rate, which influence vegetative growth, flower initiation, fruit set and, thereby, the fruit yield. Hence, to help design a tree canopy for optimum plant growth and yield, we studied the effect of pruning on light interception and on different leaf physiological parameters of ‘Amrapali’ mango trees under high density. Materials and methods. Sixteen-year-old trees of an ‘Amrapali’ mango high-density orchard were subjected to tipping and light, moderate and heavy pruning; un-pruned trees were used as control. The available photosynthetic photon flux (PPF) and leaf physiological parameters such as rate of photosynthesis, specific leaf weight (SLW) and leaf chlorophyll (Chl) content were measured in pruned and un-pruned tree canopies, following standard procedures. Results and discussion. The percent available PPF was greater in all pruned tree canopies than in un-pruned tree canopies; this could be due to tree openness caused by pruning. The light interception was lower at the lowest height of the tree canopy, probably because the center of the tree canopy was partially blocked by new growth or criss-cross branches. The rate of photosynthesis was greater in leaves that developed in pruned tree canopies than in those developed in un-pruned tree canopies, although there was no difference in SLW; this could be due to better light interception in pruned trees. In contrast, total leaf chlorophyll content was the highest in leaves that developed in un-pruned and tipped tree canopies; this may be due to increased shade owing to overlapping or crowding of tree canopies in these trees, indicating that mango leaves that developed in shade appeared to be more physiologically efficient at synthesizing chlorophyll than leaves that grew in the sun or on the sunny side. Conclusions. The studies indicated that pruning ‘Amrapali’ mango trees by removing about 10–15 cm of the top from old branches improves light penetration, which influences the leaf physiology considerably. Hence, it would be useful for designing high-density ‘Amrapali’ mango orchards to maximize productivity, although it requires additional studies to recommend a particular pruning intensity.