Lesson 1.1 Negative Effect of Pest to Crop Flashcards
They are the primary cause
of crop losses among the biotic factors of the environment.
(insects, fungi, bacteria, viruses,
nematodes, vertebrate pests, and weeds)
a fungal-like
organism. It caused a famine that led to the deaths and migration
of Europeans (mostly Irish) to the US, Canada and Australia.
Potato late blight (Phytophthora infestans)
that caused the great Bengal famine in India
during World War II;
Rice brown leaf (Helminthosporium oryzae)
epidemic caused by Puccinia
graminis tritici;
Wheat rust
(Diabrotica virgifera
virgifera) common name
Western corn rootworm
caused by
Microcyclus ulei; Colorado potato beetle and
mountain pine beetle
South American rubber blight
Crop that has higher Estimates of actual losses of major crops (%) due to pests
worldwide from 2001-2003 (Modified from Oerke, 2006)
Rice 10.2 (15.1 animal pest)12.2 37.5
Potatoes 8.3 10.9 (21.1diseases) 40.3
Type of Damage that Pests do to Crops
Direct injury and
Indirect injury
(includes direct physical damage to the crop, which
eats leaves or burrows in stems, fruits, or roots);
A. direct injury
includes introduction or transmission of a bacterial,
viral, or fungal infection into a crop.
Indirect damage
feeding on roots that cause rotting of the
roots by plant fungi and bacteria;
Nematodes
Rotting of seeds is cause by
Fungal and bacterial pathogens
Rotting of seeds is cause by
Fungal and bacterial pathogens
Postharvest losses causing dry rots and soft rot
insects such as weevils and
borers and plant pathogens
Molds that produce mycotoxins such as aflatoxin fumonisin, These toxins are reported to
be carcinogenic to man, and
• Many other different kinds of damage.
aflatoxin of Aspergillus flavus
and fumonisin of Fusarium sp.
