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We examined the effects of two water quantities (6600 m3/ha, which is regular commercial practice, and 5000 m3/ha) in combination with two irrigation intervals (every 3 days, which is commercial practice, and five pulses daily) on the distribution of water, nitrates and roots in the soil, and on the nutrition, growth, flowering and yield of the Dwarf Cavendish banana. With the pulsed irrigation method, the water tension in the upper soil layer is lower than that in the 3-day interval treatment and so the period of water stress for the banana plant is reduced. The pulsed system reduced soil temperature, encouraged shallower rooting, and reduced leaching of nitrates. Most of the vegetative parameters showed that suckers irrigated by pulses and with the reduced water amount were almost equal to suckers irrigated as in commercial practice. A more efficient use of water by shortening the irrigation interval was found to be a good way of saving water in banana plantations.

Fungal Volatile Organic Compounds (VOCs) repel banana black weevil (BW), Cosmopolites sordidus (Germar, 1824), the key-pest of banana [Musa sp. (Linnaeus, 1753)]. The entomopathogens Beauveria bassiana (Bb1TS11) and Metarhizium robertsii (Mr4TS04) were isolated from banana plantation soils using an insect bait. Bb1TS11 and Mr4TS04 were pathogenic to BW adults. Bb1TS11, Bb203 (from infected palm weevils), Mr4TS04 and the nematophagous fungus Pochonia clamydosporia (Pc123), were tested for VOCs production. VOCs were identified by Gas Chromatography/Mass Spectrometry&ndash, Solid-Phase Micro Extraction (GC/MS-SPME). GC/MS-SPME identified a total of 97 VOCs in all strains tested. Seven VOCs (styrene, benzothiazole, camphor, borneol, 1,3-dimethoxy-benzene, 1-octen-3-ol and 3-cyclohepten-1-one) were selected for their abundance or previous record as insect repellents. BW-starved adults in the dark showed the highest mobility to banana corm in olfactometry bioassays. 3-cyclohepten-1-one (C7), produced by all fungal strains, is the best BW repellent (p &lt, 0.05), followed by 1,3-dimethoxy-benzene (C5). The rest of the VOCs have a milder repellency to BW. Styrene (C1) and benzothiazole (C2) (known to repel palm weevil) block the attraction of banana corm and BW pheromone to BW adults in bioassays. Therefore, VOCs from biocontrol fungi can be used in future studies for the biomanagement of BW in the field.