Abstract – Introduction. The susceptibility of banana fruit to crown rot andanthracnose, the two main banana post-harvest diseases, is influenced by many pre-harvestabiotic factors. Mycosphaerella leaf spot diseases (MLSD) of bananas arebiotic pre-harvest factors, which have an influence on fruit physiology. The fruit’ssusceptibility to post-harvest diseases may also be influenced by foliar diseases causedby M. fijiensis, responsible for black leaf streak disease (BLSD), andM. musicola, which causes sigatoka disease (SD). The aim of our studywas to determine the influence of these biotic pre-harvest factors on banana fruit’ssusceptibility to crown rot and anthracnose. Materials and methods. A diseaseseverity gradient was established in two experimental fields (Cameroon for BLSD andGuadeloupe for SD) where, at the flowering stage, six different levels of MLSD severitywere selected. Fruit susceptibility was determined through necrotic surface assessmentsafter artificial inoculation by Colletotrichum musae on the 3rd hand ofharvested bunches. Results and discussion. BLSD significantly influencedbanana sensitivity to crown rot (P < 0.001) but only had a slighteffect on the development of anthracnose ( P = 0.041). SD had no effect(P > 0.05) on banana susceptibility to either post-harvest disease.These results are discussed with emphasis on the influence of variations in thesource-sink ratio on fruit physiology. The influence of BLSD on crown rot disease suggeststhe need to take into account the management of these foliar diseases for an alternativecontrol method of post-harvest diseases through integrated pest management programs.

Introduction. Bananas are harvestedat the green preclimacteric stage prior to sale. The time betweenharvest and the initiation of the natural ripening process is calledgreen life. Black Leaf Streak Disease and Sigatoka Disease are themain foliar diseases affecting banana production. Sigatoka Disease (SD)is due to Mycosphaerella musicola, which frequently causesearly ripening in commercial banana plantations, considered as animportant source of damage. Our work aimed at determining the effectivenessof the removal of necrotic leaves, one month before harvest, onrecovering banana quality arising from SD-infested plants. Materialsand methods. Banana plants (totaling 80) at the floweringstage were selected in an experimental plot. These plants were dividedinto two groups of SD infestation levels: level 1 (Severity Indexat flowering < 10%) and level 2 (Severity Index at flowering > 25%).We divided each group into two treatments: a treatment with no necroticleaf removal and a treatment with necrotic leaf removal. Fruitswere harvested at the same physiological age, at 900 degree-days. Fruitquality was characterized by weight, diameter, % of ripe fruit inthe field and fruit green life. Results. Our resultsshowed that the removal of necrotic leaves causes a reduction insize parameters but leads to a strong reduction in SD effects onthe fruit maturity, thereby preventing premature ripening. Bananaplants whose necrotic leaves were removed produced fruit with a verylong green life. Discussion. Removal of necrotic leaves allowsthwarting the negative effect of SD on fruit physiology. This showsthat the presence of necrosis during the last month of fruit growth isresponsible for this fruit physiological modification characterizedby early ripening. Conclusion. Removal of necroticleaves one month before the date of harvest may be a technique thatcan limit production losses when the infestation level by SD ishigh.

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.

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 at (i) analysing the nature of host-parasite interactions (resistance or susceptibility), and (ii) studying the variability of the pathogenicity of different pathogen populations (intra/inter-specific) with regard to both virulence and aggressiveness using artificial inoculation with Mycosphaerella fijiensis or Mycosphaerella musicola on plants and banana leaf pieces. The principle, key advantages, starting plant material and time required for the method are presented. Materials and methods. Laboratory materials required and details of the sixteen steps of the protocol (conidial inoculum preparation, artificial inoculation on banana plants and artificial inoculation on banana leaf pieces) are described. Possible troubleshooting is discussed. Results. Typical symptoms of the different diseases are obtained after artificial inoculation.

Introduction. Banana plants (Musa sp.) face problems caused by diseases such as Yellow Sigatoka (Mycosphaerella musicola), which is responsible for significant economic losses. Through micropropagation techniques, a somaclone variety called CIEN BTA-03 resistant to this disease was obtained. The purpose of this study was to compare fruits of somaclone CIEN BTA-03 and its parental clone Williams. Materials and methods. Fruits from both clones were studied, determining shape, weight, dimensions, proportions, pulp viscosity and consistency, total solids, soluble solids, pH, titratable acidity, sugars, ash, total phenolic content and crude fiber, and analyzing their color, odor and taste. Results and discussion. Clones differed in shape, weight and [pulp/peel] ratio. Pulps also differed in viscosity, pH, and soluble solids, sugars and phenolic compound contents. Differences between the two clones favored clone CIEN BTA-03, since it was better ranked for the color, odor and taste characteristics. Conclusion. Despite being resistant to Yellow Sigatoka, somaclone CIEN BTA-03 shows better sensory characteristics than its parental clone Williams.