Pacific Pests, Pathogens, Weeds & Pesticides - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Fa'amai o le lausului uliuli Sigatoka (Banana black Sigatoka) (002)

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Photo 1. Reddish-brown and black streaks of black Sigatoka, Mycosphaerella fijiensis, on the upper surface of a leaf, with some developing white or tan centres where the spores are produced. Note that the spots have bright yellow haloes, or margins.

Photo 2. Long streaks with bright yellow margins typical of infection by black Sigatoka, Mycosphaerella fijiensis. Note the blighted areas at the leaf tip and margins where the spots have joined together to cause the blight.

Photo 3. Typical decay of a leaf infected with black Sigatoka, Mycosphaerella fijiensis, showing the brown streaks, some with white centres, and the edges of the leaf decaying before other parts where the streaks have joined together.

Aotelega

  • Molimau i le lalolagi atoa. O le lega e mafua ai le vave pe o lau, e amata mai i pito o le lau. O lau pito I lalo e mafua ai le 35-50% le sosolo o le faamai. E sosolo le siama i taimi timuga ae feaveai e le matagi.
  • O togafitiga fa'aleaganu'u: toto i 'ele'ele e lelei alavai, fa'asaga lau ile la ma fa'asaga foi ile ala savili ina ia vave ona mago lau; 2.5 mita le va; faamama le vao; aveese lau pe a >50% ua afaina; tamaifai, tu'u 3-4 laau, ia aoina ma aveese lau ua afaina i le taimi o le seleselega; mo ituaiga e tetee I faamai e pei o (FHIA), fa'afeso'ota'i le SPC CePaCT mo nisi fai pea manaomia.
  • I le faaogaina o vailaʻau ma puipuiga – ia faaoga le (copper, mancozeb, chlorothalonil), faaopopo ai ma le suauu misting oil ina ia aoga le vailaau I lenei faamai. Ia feauauai ma le (triazoles, strobilurins), ina ia fesuiaʻi ai auala o puipuiga.

Igoa masani: lausului lanu uliuli.

Igoa Faasaienisi: Mycosphaerella fijiensis. O le igoa lea e mafua mai i le tulaga tau feusuaiga o siama, o le igoa fa'afeusuaiga o siama o le Paracercospora fijiensis (sa faaigoa muamua o le Pseudocercospora fijiensis).

Diagram. Life cycle of black Sigatoka, Mycosphaerella fijiensis. Note that there are two types of spores, but it is the sexual stage that produces the ascospores that are considered the most important in disease development. The spores are discharged from the top surface of the leaves and spread by wind.

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