Introduction. Pomegranate (Punica granatum L.) is the main and most valuable fruit crop of the northern mountainous region of Oman. Pomegranates are cultivated utilizing traditional farming methods including the determination of harvest dates, harvesting and postharvest handling. Materials and methods. Fruit of four native pomegranate cultivars [‘Hamedh’, ‘Malasi’, ‘Helow’ and ‘Qusum’, literally translated as sour, smooth, sweet and hard-seeded, respectively] were tagged and monitored for 3 months up to commercial harvest. Fruit length (L) and diameter (D) were measured at weekly intervals starting from 66 d after full bloom until harvest (136 d after full bloom). Results and discussion. During the time course of fruit growth and development, significant changes occurred in fruit shape assessed by the [fruit length / fruit diameter] ratio in two cultivars (‘Malasi’ and ‘Hamedh’), but not in the ‘Helow’ and ‘Qusum’ cultivars, which also had larger fruit size at harvest. The lack of obvious changes in fruit shape during growth and development of ‘Qusum’ and ‘Helow’ pomegranate cultivars indicates that the attainment of characteristic fruit shape may not be a good indicator of their maturity for harvest management. Thus, fruit harvesting based solely on size and shape is not sufficient and other physico-chemical fruit attributes should be taken into account when assessing readiness to harvest to ensure optimum income returns to growers.

Introduction. Bananas and plantains (Musa spp.) are staple foods in Cameroon and surrounding countries. Strategies based on the utilization of cultural and locally consumed foods are essential for the identification of solutions for the reduction of micronutrient malnutrition. Materials and methods. To assess the nutritional content of some varieties in order to assist the selection of new Musa hybrids, the carotenoid contents of 19 Musa cultivars and hybrids from the CARBAP (Douala, Cameroon) germplasm were determined at three ripening stages. Frozen pulps were analyzed for their β-carotene, α-carotene and lutein contents using the HPLC method. The retinol activity equivalents (RAE)·100 g–1 fresh weight were calculated for four representative Musa types. Results and discussion. Significant differences were observed between Musa cultivars according to their genotype. Plantain type (Mbouroukou n°1) and Musa hybrid (CRBP 755) exhibited the highest levels of RAE [(148 and 70) RAE·100 g–1] compared with dessert bananas (16 RAE·100 g–1). During ripening, the concentrations of these carotenoids increased or decreased significantly (α = 0.05%) according to the Musa type analyzed. The high β- and α-carotene as well as lutein contents of these Musa sp. could contribute to the nutritional status of people consuming these banana varieties in West and Central Africa and enhance their use in Musa breeding programs.

Introduction. Growing demand in Europe for healthy and nutritious food and beverage products with new flavours creates opportunities for supplying the European market with novel fruit juices including tropical fruits like açaí (Euterpe oleracea Mart.). Materials and methods. One tropical fruit species from Brazil, i.e., açaí, was selected as a case species. Via expert interviews, a review of consumer studies regarding tropical fruit consumption, field visits and literature research, a SWOT analysis was conducted in order to map the opportunities, threats, strengths and weaknesses related to açaí and its potential in the West European fruit juice industry. Results. Opportunities stem from growing consumer interest in natural, healthy and nutritious fruit juices, the need for health-oriented innovations in the food industry and growing interest in variety, novel tastes and ethnic foods. Unfamiliarity, health claim credibility and European market access requirements constitute the main threats. Strengths pertain to the nutritional value of açaí and its tropical origin, and the existence of well-established national açaí markets and processing industries. Weaknesses result from the irregular supply and inconsistent açaí quality, lack of advanced know-how in cultivation and processing issues, and scant insights into the fruit’s nutrient profile. Conclusion. The findings indicate that açaí, which has outstanding nutritional values and health-related benefits, could have substantial potential in the West European fruit juice market. Key attention points pertain to creating awareness among consumers and building familiarity with açaí and its products, and obtaining in-depth knowledge about its nutritional characteristics and concomitant health benefits.

Introduction. Relationships between environmental conditions (climate and soil) and chemical characteristics of banana were studied in Martinique (French West Indies) to contribute to discussions about a quality label based on origin and to help to improve management of banana quality. Materials and methods. Bananas produced at six sites under different conditions and during three periods of the year were harvested at the same stage and ripened under identical conditions. Results. Differences in dry weight and chemical concentrations in the pulp of green fruits were greater between sites than between periods. The pulp dry weight was higher in fruits harvested at the highland site than in fruits harvested at the lowland sites. Differences in Ca and Mg were observed in fruits harvested on vertisol and andosol soils. Fruits produced on brown rust to halloysite soil contained high Mn concentrations. Differences in dry matter, total soluble solids and citric acid concentrations in the pulp of ripe fruits were greater between periods than between sites. Bananas harvested during the hot rainy season had the lowest pulp dry matter and total soluble solids. Bananas harvested during the cool dry season had the highest concentration of citric acid. Carbohydrate (dry matter, total soluble solids, and glucose and fructose) concentrations in fruit pulp decreased with an increase in mean daily temperature from bunch emergence to harvest. Conversely, mineral (P, Mg and Ca) concentrations in fruit pulp increased with an increase in temperature. Conclusion. It is clear that these relationships should be taken into greater consideration when assessing banana quality. The specific environmental conditions in highland areas warrant the creation of a ‘mountain banana’ label.

Introduction. Wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is the most important disease of banana worldwide, causing severe yield losses in commercial and local consumption cultivars. Chemical control is currently the most used method to manage the Fusarium wilt of banana, although it is toxic, expensive and dangerous. Therefore, control through genetic improvement is widely encouraged. Hence, breeding was carried out to develop banana hybrids with putative resistance. Materials and methods. Hybridization of identified resistant diploids with commercial triploids and tetraploids was carried out; it resulted in development of 22 hybrids with improved agronomic characters. In a second step, screening of these hybrids for resistance to Foc race 1 was attempted using the double cup method of challenge inoculation with the pathogen in the roots of the hybrids at optimum level. Host responses of the susceptible and resistant hybrids were examined under greenhouse conditions through biochemical and isozyme analysis. Results. Six hybrids among the 22 hybrids with improved agronomic characters were selected based on their yield and they were evaluated for resistance. Three of them were resistant to Foc and the others were susceptible. The resistance mechanism involving the relation of enzymes such as peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine lyase (PAL), and biochemicals such as phenols, proline and lignin showed relatively higher activity in resistant hybrids and parents than susceptible ones. Isozyme analysis of PO and PPO carried out using selected resistant and susceptible hybrids revealed the induction of specific isoforms in the resistant hybrids upon challenge inoculation. Conclusion. Three hybrids were identified as potential hybrids with good yield and resistance to Foc race 1.

Introduction. RNA isolation is a prerequisite to studying gene expression in banana and to understanding changes occurring in response to the environment. Standard extraction methods do not efficiently extract RNA from plants such as banana, with high levels of phenolics, carbohydrates, or other compounds that bind to and/or coprecipitate with RNA. Materials and methods. Five to seven RNA extraction methods were compared. Four crown-tissue storage methods were also compared. cDNA-AFLP was used to ensure that the obtained RNA was of sufficient quality for molecular applications and that RNA expression was unaltered by in situ storage. Results and discussion. The modified hot-borate method proved to be the best RNA extraction method, allowing high yields of good quality, undegraded RNA from the crown, fruit peel and pulp at all stages of ripening. The RNA obtained by this method was of sufficient quality for molecular applications such as cDNA-AFLP that give highly reproducible results. Freeze-drying of fresh tissues and tissue conservation in hot-borate buffer, two original storage methods, appear appropriate for preserving RNA in situ without ultra-low temperature. The RNA obtained was of high quality, undegraded, and useful for all downstream applications. The genome expression profile obtained by cDNA-AFLP analysis was unaltered by these methods for storing collected tissues. Conclusion. By applying all the suggested procedures in this work, it is possible to store and study gene expression in any banana fruit tissue, whatever the maturity stage, without affecting the RNA expression level.

Introduction. Penicillium digitatum is a commercially important postharvest pathogen of citrus that is responsible for significant annual global losses. Strains of the fungus, which exhibit strong resistance to widely used synthetic fungicides, are of major concern to the industry. The aim of the study was to investigate the antifungal activities of polar extracts and compounds from Lippia species, indigenous to South Africa, against a Guazatine®-resistant strain of P. digitatum.Materials and methods. In vitro tests were done by incorporating the compounds and plant extracts into Malt Extract Agar at concentrations ranging from (0.2 to 1.0) mg·mL–1. An in vivo (curative) assay was conducted using the checkerboard technique on ‘Valencia’ oranges. Results and discussion. A strong correlation between the in vitro and in vivo results was observed. All the compounds and extracts were able to inhibit fungal growth at concentrations above 0.6 mg·mL–1. Verbascoside was the most active compound, while extracts of Lippia javanica and Lippia rehmannii caused significant inhibition of mycelial growth. The observed activity was largely ascribed to the presence of verbascoside in the plant extracts. Conclusion. Polar extracts of Lippia species have potential as environmentally friendly alternatives for the control of P. digitatum on citrus.

Introduction. Fruit ripening is the process resulting in changes in color, taste and texture, which make the fruit acceptable for consumption. Since a wide spectrum of physiological, biochemical and organoleptic changes are involved in the development of a soft, edible, ripe fruit, we studied theses changes in an underutilized fruit, khirni [Manilkara hexandra (Roxb.) Dubard]. Materials and methods. The changes in biochemical composition, which includes chlorophylls, carotenoids, anthocyanins, sugars, starch, free amino acids, phenols and proteins, and the specific activity of enzymes such as amylase, invertase, catalase, peroxidase, pectinmethylesterase, polygalacturanase and cellulase were analyzed in the fruit of Manilkara hexandra at five sequential developmental stages (young, premature, mature, preripened and ripened fruit stages). Results and discussion. The pulp of khirni fruit tastes sour during its growth period, but turns sweet when it ripens. A decreasing trend in chlorophylls occurs simultaneously with an increase in the quantity of total carotenoids and anthocyanins. Further, an increase in the quantity of sugars, proteins and phenols occurs towards the ripened stage, but starch and total free amino acids show a decrease in their quantities. Also, khirni fruit exhibits climacteric behavior with its increased rate of respiration and ethylene production. The moderate to significant changes in the activity of enzymes such as amylase, invertase, catalase and peroxidase involved in a number of catabolic and anabolic reactions indicate that these enzymes also have an active role in the process of khirni fruit growth and ripening.

Introduction. Green mould, Penicillium digitatum (Pers.: Fr.) Sacc., causes economically important postharvest disease in citrus. Materials and methods. Ethiopian plant extracts of Acacia seyal (Del. Var. Seyal) and Withania somnifera (L.) Dual were used to test the control of green mould in wound-inoculated fruit, stored for 21 d at 7 °C and at > 85% RH. The chemical compositions of the two extracts were determined using high-performance chromatography. Thereafter, freshly harvested (naturally infected) fruit were subjected to different postharvest treatments and stored for 50 d to investigate the effects of the two plant extracts on fruit quality parameters. Treatments included (pre-wax + leaf extracts), (wax + leaf extracts incorporated into wax, Citrosol A®), (leaf extract alone), (fruit washed in chlorinated water at 5.25%), (untreated fruit) and (commercially treated fruit). Results. Extracts of A. seyal and W. somnifera reduced the incidence of green mould by 56.1% and 50%, respectively, in wound-inoculated fruit. A. seyal extract contained a high concentration of gallic acid (60.3 mg·mL–1) whilst W. somnifera contained low concentrations of caffeic acid (8.7 mg·mL–1), salicylic acid (6.3 mg·mL–1) and 3,4 dihydroxy benzoic acid (3.8 mg·mL–1). Green mould was absent in naturally infected fruit subjected to (pre-wax + leaf extracts), (wax mixed with leaf extracts) and (leaf extracts) treatments. (Pre-wax + leaf extracts) and (wax mixed with leaf extract) treatments significantly reduced weight loss; retained firmness and colour; and they maintained eating qualities and a maturity index (SSC/TA) similar to commercial treatment. Conclusion. Both extracts of A. seyal and W. somnifera showed potential to be used as an alternative in combined applications with wax application under low temperature storage to replace synthetic fungicides, to ultimately control green mould and retain overall fruit quality.

Introduction. In the southern Sudanian zone of Benin, fruit flies are major pests and responsible for considerable yield losses in mango production. The two main species of economic importance affecting mango trees in Benin are Ceratitis cosyra and Bactrocera invadens. During the 2006 crop year and across seven main cultivars, losses stood at 17% in early April and exceeded 70% in mid-June. By the middle of the crop year, over 50% of losses occurred in mango orchards. Materials and methods. The Stone and Pedigo method was used to compute the economic injury level, using variables such as pest control costs, level of losses and mango prices. Results and discussion. The Economic Injury Level (EIL) was highly variable. For the cultivar Kent, for example, it varies from (30 to 75) fruit flies captured per ha and per week, whereas for Keitt the level ranges from (24 to 57) fruit flies·ha–1·week–1. EIL variability depends among other things on market price fluctuation. This method is based on the early introduction of detection traps in mango orchards. A weekly monitoring of trapped fruit flies is used to compute the EIL and make a decision about pest control. Pest control (GF-120 in this case) is recommended if the gross returns exceed production costs. If the number of trapped fruit flies is below the EIL, a treatment is not recommended because pest control will not be profitable. Conclusion. The EIL is an accurate tool to set the optimal (economic) timing of pest control treatment in mango orchards. These preliminary results should lead to the introduction of integrated pest management (IPM) activities to deal with the fruit fly species that are threatening the profitability of mango production in central and northern Benin.

Introduction. Probably because pomegranate trees are established in orchards as own-rooted plants, there are no studies regarding scion-rootstock combination effects on growth, tree size, yield and fruit quality of this fruit tree. Thus, the main aims of our experiment were to study the effects of some pomegranate rootstocks on growth and yield characteristics of Iranian commercial cultivars used as scions. Materials and methods. Our research was carried out between the 1999 and 2007 growing seasons at a collection of 760 pomegranate cultivars in the Yazd Province of Iran. Rootstocks were provided via clonal propagation using stem cuttings similar in height, diameter and age (2 years old) from ‘Golnar Farsi’, ‘Torsh Ma’ moly Zabol’, ‘Yek Killoy Hoshak Saravan’, ‘Poost Syah’, ‘Khafri Poost Sefid Jahrom’, ‘Zagh’, ‘Shavar’ and ‘Malas Esfahani’. Budding materials were provided from fruit-bearing trees in good vigor, using buds on current season growth of the ‘Zagh’, ‘Shavar’ and ‘Malas Esfahani’ pomegranate cultivars. Effects of the scion-rootstock combinations were investigated on tree size, vigor and yield of pomegranate. Results. The data indicated that grafting led to higher yield than the own-rooted plants, but grafted trees showed lower vigor and tree size compared with ungrafted trees. Application of ‘Torsh Ma’ moly Zabol’ as a rootstock led to the lowest tree size and height, and the lowest rate of sunburn scald disorder. The highest yield and the lowest sucker production were obtained in plants grafted on ‘Golnar Farsi’ rootstock. Conclusion. Our results suggest that application of ‘Torsh Ma’ moly Zabol’ as a rootstock can be useful to establish a high-density plantation.

Introduction. The subjectivity of the external criteria used for the determination of mango maturity at its harvest led to the search for additional more reliable parameters to determine the optimal harvest maturity and able to replace the external and internal morphological indices. Materials and methods. Some physicochemical characteristics, such as colour of pulp, soluble dry extract, titratable acidity and weight loss, were evaluated on fruits of the cv. Kent (Mangifera indica L.) collected in North Cote d’Ivoire. The days necessary for ripening after harvest were estimated. Measurements were correlated to five maturity stages corresponding to the fruit harvest carried out at (76, 82, 88, 94 and 100) days after flowering. On each date of harvest, batches of 52 fruits were gathered. On half of them, maturation was observed as of harvest, the other half being kept at room temperature and the ripening evaluation then being done at the end of storage. Results. According to the harvest date, the soluble dry extract values varied from 8.3 °Brix to 10 °Brix at fruit harvest, and from 14.2 °Brix to 20 °Brix after ripening of the fruits stored at ambient temperature. Titratable acidity was correlated positively with maturity stage. Time to ripen and weight loss continuously decreased with the fruit maturity. For mangos of the cv. Kent, the date of the most suitable harvest seemed to be at 94 days after flowering. Mangos collected at 100 days after flowering developed better organoleptic characteristics such as sugar content, peel aspect and pulp colour than those of the fruit harvested earlier. Conclusion. Starting from the 94th day after flowering, the mango of the cv. Kent collected under the conditions of the North Cote d’Ivoire develops its best organoleptic characteristics during ripening.

Introduction. Mature green vanilla pods accumulate 4-O-(3-methoxy-benzaldehyde)-β-D-glucoside (glucovanillin), which, upon hydrolysis by an endogenous β-glucosidase, liberates vanillin, the major aroma component of vanilla. Sites of storage of glucovanillin in the pod have been controversially reported for decades; we aim, using precise and widely accepted technical terminology, to clarify this controversy by providing an anatomical, histochemical and biochemical evidence-based picture of glucovanillin accumulation sites. The pod also synthesizes an oleoresin and a mucilage of unknown constitutions; we report here their localization and structures. Materials and methods. The pod anatomy was examined by light and epifluorescence microscopy. A protocol was established allowing fine hand-dissection of diverse anatomical parts of the pod (mesocarp, placentae, trichomes, intralocular interstitial cell-free region and seeds). Glucovanillin and γ-pyranones were extracted and analyzed by HPLC, while the structures of the mucilaginous polysaccharides were determined after permethylation. Results and discussion. Glucovanillin is essentially stored in the placentae (92%) and marginally in trichomes (7%); traces were measured in the mesocarp and intralocular interstitial cell-free medium. Trichomes store massive amounts of a fluorescing oleoresin (44%) rich in alkenylmethyldihydro-γ-pyranones and synthesize a mucilage made of a glucomannan and a pectic polysaccharide carrying monomeric arabinose and galactose side-chains. Conclusion. To date, the physiological roles of glucovanillin, long-chain pyranones, and mucilage remain unknown.

Introduction. Root-knot nematodes (Meloidogyne sp.) cause significant economic damage to Prunus species in China. One of the most economical and environmentally sustainable methods to reduce the impact of root-knot nematodes is the use of resistant rootstock cultivars. Our aim was to examine resistance to M. incognita and its mechanisms. Materials and methods. Four rootstocks were assessed: Tsukuba-4 (P. persica), Tsukuba-5 (P. persica), Nanking cherry (P. tomentosa) and wild peach (P. persica). The susceptible tomato (Lycopersicon esculentum Mill.) cultivar ‘Baiguoqiangfeng’ was used as a positive control. Results. Nematodes did not penetrate roots of Tsukuba-4 and Tsukuba-5, which were considered to be immune varieties. Nanking cherry was highly resistant to M. incognita, whereas wild peach was susceptible. Conclusion. The differences in resistance among the rootstocks were not attributed to differences in effects of root diffusates, but were related to the different structural organizations of the root tips. The epidermal structure of Tsukuba-4 and Tsukuba-5 completely prevented the penetration of second-stage juveniles of M. incognita (J2). In Nanking cherry, penetration of J2 juveniles was reduced, and the development of nematodes from the J2 to female stage was delayed.