Introduction. Since citrus fruits are non-climacteric, commercial harvest for a given variety can occur over a prolonged period in the same orchard. Delayed citrus harvest has previously been reported to influence fruit quality variables during the current season and to reduce the subsequent year’s yield. The aim of our study was to investigate the effect of harvest date on tree yield and fruit quality of two late-maturing Valencia orange varieties during two successive years. Materials and methods. One hundred 9-year-old Campbell and Lue Gim Gong Valencia orange trees budded on Swingle citrumelo rootstock were used. Fruit sampling included fruit harvest at five monthly intervals (April-August) during 2003, and only one harvest date (20 June) during 2004. Results and discussion. Based on seasonal variation of various fruit quality variables during the five harvests conducted in 2003, the most stable fruit quality variables were fruit weight, number of seeds per fruit, rind thickness, juice content and soluble solids content. In general, both varieties produced fruit with similar internal quality characteristics. However, their mean fruit weight differed in 2004 (Lue Gim Gong had larger fruit than Campbell). Furthermore, the annual and cumulative yields of Lue Gim Gong Valencia orange trees over two years were significantly higher than those of Campbell orange trees. Finally, the yield per tree and fruit quality of both varieties in 2003 and 2004 were not affected significantly by the date of harvest during 2003.

Introduction. The mango tree is of prime importance to the rural economy of central and northern Benin since it provides food and crucial nutriments at the end of the dry season. However, mango producers in Benin are confronted with two problems that are closely connected: deterioration of fruit quality by fruit flies and the inadequacy of postharvest methods. In the Sudanian zone of Benin, fruit flies (Diptera Tephritidae) are highly responsible for major production losses. Materials and methods. An inventory of all present cultivars and yields of main mango cvs. (Gouverneur, Eldon, Dabshar, Kent, Smith, Keitt and Brooks) was carried out in Benin on 7 000 fruits near Parakou (Borgou) during the years 2005 and 2006. Sampling of 3 000 young fruits (length range 13–26 mm) was carried out in 2006 in order to detect some very early tephritid attacks. A loss assessment of pre-ripening and ripening fruits was also carried out on 7 750 fruits in 2006. Results and discussion. We identified 29 cultivars in the district of Borgou where 75% of the mango orchards of Benin are situated. Most of these use the ‘gatherer’ production system. The early Gouverneur cultivar had the lowest yield (1.8 t·ha–1), and the late Brooks cultivar had the highest yield (10.4 t·ha–1). Small and immature young fruits allowed development of both C. cosyra and B. invadens in February and March, i.e., before the mango season itself: this result could be a useful result for pest control. For the pre-ripening and ripening stages, average losses due to tephritid varied from 0.34 t·ha–1 to 6.5 t·ha–1 depending on cultivar type, resulting in considerable loss of income for small planters. Taking all cultivars together, losses stood at 17% in early April and exceeded 70% at mid-June. By the middle of the crop year, over 50% losses were recorded. The seasonal cultivar Eldon and late cultivars (Keitt and Brooks) were the most infested. Conclusion. In the Sudanian zone of Benin, the two main species of Tephritidae that have a high economic impact on mango trees are B. invadens and C. cosyra. Our preliminary observations and calculations will be used in a forthcoming article to calculate the economic injury level of these fruit flies.

Introduction. Rambutan is a tropical fruit species with recalcitrant seeds. Despite the expansion of exotic fruit cultivation in Brazil, lots of which fruit species, including rambutan, need basic information, especially in relation to propagation and storage of seeds, which are important for genetic improvement studies, maintenance of genetic sources and seedling production. Materials and methods. A completely randomized design was adopted with treatments distributed in a factorial arrangement, 3 × 4, referring to three seed storage conditions [room temperature conditions; a dry chamber with (18 ± 2) °C and 60% relative humidity; and a cold chamber with (10 ± 2) °C and 70% relative humidity] and four storage times (0, 7, 14 and 21 d). Each treatment of 10 seeds was replicated five times. Data on seedling emergence, emergence rate, plant height, number of leaves and length of main root were submitted to variance analysis and means were separated using Tukey’s test. Correlation analysis between seed moisture and seedling emergence was performed. Results and discussion. Our results indicated that dry chamber conditions promoted the statistically significantly highest seedling emergence after 7 d of storage. Cold chamber conditions promoted an extremely low seedling emergence independently of time. Conclusion. Rambutan seeds can be stored in a dry chamber for 7 d without losing viability; after 14 d of storage the loss of emergence is 60%.

Introduction. In Nigeria, the species M. barteri is under-exploited although the tree is of both medicinal and nutritional importance. It bears succulent black-purple fruits that are edible and stain the tongue. The seeds are often with a conspicuous caruncle, with the endosperm present or absent. We studied the nutritive values of the fruit and seeds. Materials and methods. After sampling the fruits in a forest of Abia State, Nigeria, they were washed and opened. The seeds were removed from the succulent portion (pulp). Both pulp and seeds were dried in an oven at 65 °C for 5 h, before being ground to obtain powdery samples. The crude protein, moisture, crude fat, crude fiber, ash contents, total carbohydrate, vitamin contents (A, C, E, thiamine, riboflavin and niacin) and mineral elements were determined. Results and discussion. The analyses showed that both the fruit and seed of M. barteri are good sources of essential dietary nutrients. The values obtained are comparably higher than those reported for some common tropical African fruits.

Introduction. Prunus amygdalus and P. webbii can be used as rootstocks for almond cultivars due to their adaptability to severe environmental conditions. However, the time required for seedlings to reach a suitable size for transplanting may take 1 to 3 years. Our study tested the effects of foliar application of growth regulators on the vegetative growth and carbohydrate accumulation in shoots and roots of these species. Materials and methods. Six-week-old seedlings were treated with gibberellic acid (GA3) (100 mg·L–1) alone or with GA3 followed by ethephon [(100 and 200) mg·L–1], or chlormequat chloride (CCC) [(500 and 1000) mg·L–1], or paclobutrazol (PBZ) [(500 and 1000) mg·L–1]. Results and discussion. Most levels of plant growth regulators significantly enhanced seedling growth. However, GA3 alone was most effective on stem height, leaf area, and shoot fresh and dry weights of both almond species. The thickest stems of P. amygdalus and P. webbii were obtained from the application of 100 mg GA3·L–1 followed by application of (1000 and 500) mg PBZ·L–1, respectively. In both species, PBZ significantly increased leaf chlorophyll content compared with the controls as well as with the other treatments. Application of GA3 alone on P. webbii and of GA3 followed by 100 mg ethephon·L–1 on P. amygdalus showed the highest root number, and root fresh and dry weights. High levels of soluble sugars and starch in the shoots and roots of both species were observed when GA3 application was followed by PBZ. Conclusion. These results demonstrated that application of plant growth regulators to the seedlings might be a useful way of enhancing growth of P. amygdalus and P. webbii and reducing the time and cost of seedling production.

Introduction. This method is used to forecast the harvest date of banana bunches from as early as the plant shooting stage. It facilitates the harvest of bunches with the same physiological age. The principle, key advantages, time required and expected results are presented. Materials and methods. Details of the four steps of the method (installation of the temperature sensor, tagging bunches at the flowering stage, temperature sum calculation and estimation of bunch harvest date) are described. Possible problems are discussed. Results. The application of the method allows drawing a curve of the temperature sum accumulated by the bunches which have to be harvested at exactly 900 degree-days physiological age.

Introduction. This protocol applies to the characterization of genome structure and evolution of M. acuminata and M. balbisiana genomes; construction of physical maps around markers of interest and QTLs; comparative genomic studies with other monocot species; and study of banana streak virus (BSV) integration patterns in banana nuclear genomes. The principle, key advantages, starting plant material, time required and expected results are presented. Materials and methods. This part describes the required materials, and the protocols for isolation and lysis of banana nuclei; high-molecular-weight (HMW) DNA Hind III digestion and pulsed-field gel electrophoresis (PFGE) analysis; large-scale HMW DNA Hind III digestion and ligation to the pINDIGOBAC–5 vector; and analysis of recombinant BAC clones. It mentions the main problems which can occur. Results. The described protocols will enable the efficient construction of BAC libraries from Musa species. These libraries can be used to construct physical maps and select specific genomic regions to be sequenced.

Introduction. This protocol aims at monitoring the development of Sigatoka disease (Mycosphaerella musicola / Pseudocercospora musae) of banana plants in order to control this disease with a minimum of fungicide applications. A good timing of fungicide application will result in lower cost of control, lower risk of fungicide resistance and lower negative environmental impact. The principle, key advantages, starting plant material and expected results are presented. Materials and methods. Details of the seven steps of the protocol allowing banana plot preparation, data collection, stage of evolution of the disease (SED) calculation, and timing of fungicide applications are described. Possible troubleshooting is mentioned. Results. Weekly observation of selected banana plants allows filling in a data sheet used for the calculation of the SED. A graphic representation of the weekly evolution of this SED can then be used for timing of fungicide spraying decisions.

Introduction. This protocol aims to diagnose under laboratory conditions the main Mycosphaerella spp. pathogens of bananas and plantains. The three pathogens Mycosphaerella fijiensis (anamorph Paracercospora fijiensis), M. musicola (anamorph Pseudocercospora musae) and M. eumusae (anamorph Pseudocercospora eumusae) are, respectively, the causal agents of Black Leaf Streak disease, Sigatoka disease and Eumusae Leaf Spot disease. The principle, key advantages, starting plant material and time required for the method are presented. Materials and methods. The laboratory materials required and details of the thirteen steps of the protocols (tissue clearing and in situ microscopic observations, isolation on artificial medium and cloning of single-spore isolate, in vitro sporulation and microscopic observations of conidia, and long-term storage of isolates) are described. Results. Diagnosis is based on the observations of anamorphs (conidiophores and conidia) which can be observed directly from banana leaves or after sporulation of cultivated isolates if sporulating lesions are not present on banana samples.