Pacific Pests, Pathogens, Weeds & Pesticides - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Sik we i mekem kakae blong taro i roten – afta long havest (Taro corm rots - post-harvest) (179)

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Photo 1. The dry white crumbly rot at the bottom of the corm is caused by Pythium splendens. The pinkish tissues above and slightly to the right are a reaction to infection by the corm tissues. The white semi-circle on the left is the cottony growth of Athelia rofsii.

Photo 2. Light brown firm rot caused by Phytophthora colocasiae. The rot on the lower left side is caused by Athelia rolfsii. The corm has been incubated at high humidity overnight to stimulate the growth of the fungus.

Photo 3. Light brown firm rot in a taro corm caused by Phytophthora colocasiae, after about 8 days.

Samari

  • Oli faenem olbaot long ol tropikol rijen, long plante kakae. Hemi wan rabis sik.
  • Hemi wan ringworm o fangi, wota mold (oomycetes) mo bakteria we i mekem kakae blong taro i roten. Oli go insaed long kakae blong taro long taem blong havest taem se ol smosmol tiub we oli gro long saed saed blong kakae blong taro (suckers), oli brok. Olgeta we yumi save gud long olgeta hemi: (i) Athelia – pink wetem waet boda long saed; (ii) Pythium – hemia we i roten i waet; (iii) Phytophthora lif blong taro i drae – hemia we i roten i braon; (iv) Lasiodiplodia – hemia we i roten i blak, sopsop, smel nogud; mo (v) Erwinia – hemia we i roten i sopsop.
  • Kontrolem wetem fasin blong faming: havest, karemaot ol gru mo graon mo putum long (i) insaed long graon we i gat ol lif, o (ii) plastik bag o (iii) plastik katen, sipos hemi blong maket.
  • Kontrolem wetem kemikol: impruvum storej long ol plastik bag long wei blong draonem ol kakae blong taro long blij wota (1% blong 1 kasem 2 minits).

Komon nem: Taro corm rots (post-harvest)

Saentifik nem: Olgeta ia hemi wanem we i roten insaed long ol kakae blong taro afta long havest:

Athelia rolfsii (luk Fact sheet no. 11)
Lasiodiplodia (Botryodiplodia) theobromae
Pythium splendensPhytophthora colocasiae (luk Fact sheet no. 14)
Erwinia spisis: Erwinia carotovora subsp. carotovora (luk Fact sheet no. 101, 214, 289, 296); we naoia nem blong olgeta hemi Pectobacterium carotovorum subsp. carotovorum, mo
Erwinia crysanthemi.

Photo 4. Black spongy rot caused by Lasiodiplodia theobromae. These rots usually follow those of Pythium and Phytophthora, or they come in later after the corms have started to lose moisture.

Photo 5. These two corms have been in a plastic bag for 4 weeks; the one on the left is still healthy whereas the one on the right has been destroyed by the soft rot bacterium, Erwinia chrysanthemi.

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