Taiwan
September, 2008
Source:
The
World Vegetable Center Newsletter
Almost half of the world’s 28.41
million tonnes* of chilies are produced in China, India,
Indonesia and Thailand. Chili is a good source of cash for
subsistence farmers, generating up to four times the income of
cereal crops
under optimal conditions and providing a major source of
employment for women. However, average chili yields in the Asian
tropics are generally low (about 5-10 t/ha) and unstable due to
preand post-harvest diseases.
Severe yield losses are caused by insect-transmitted Cucumber
mosaic virus (CMV), Chili veinal mottle virus (ChiVMV) and Chili
leafcurl virus (CLCV) as well as fungal diseases such as
anthracnose and Phytophthora blight and also bacterial wilt.
Smallholder farmers often try to minimize yield losses by
applying pesticide cocktails every 3-7 days. Improving the
resistance of the crop to diseases is a more sustainable option.
If supplemented
by improved crop management practices this can improve yields,
reduce risks to farmers and produce a crop that is also safer
for consumers.
“Understanding the diversity of the pathogens and their
virulence is a prerequisite to developing stable multi-disease
resistant lines,” says Dr. Sylvia Green, the virologist at AVRDC
-
The
World Vegetable Center. In a German-funded project, pathogen
isolates were collected in all participating countries, and
tested against a
broad array of lines with different resistance genes. Efficient
specific diagnostic methods for all six pathogens, including
molecular markers were developed and shared with the national
partners.
The results evoke optimism. Multiple distinct strains of virus
and pathogen species causing the diseases have been identified,
and several sources of resistance have been detected. These
resistant lines have been crossed by participating national
agricultural research and extension systems with their preferred
local chili cultivars. Advanced selections displaying resistance
to as many as four of the target pathogens have been identified,
and are currently being multiplied and tested in farmers’
fields, using improved management practices such as drip
irrigation and starter solutions to further increase yields.
“Sources of resistance and multiple-disease resistant chili
lines will be freely distributed as international public goods,”
says Sylvia Green. “We hope that more than 30% of farmers will
adopt the improved chili cultivars and
management practices.” Chili yields are expected to increase by
20% and the area under production by 10%. Most importantly,
pesticide inputs will be lowered significantly, improving the
safety of chili farmers and their communities, reducing the
environmental impact, and providing safer, lower cost chilies
for all consumers.
* Source: FAO Statistics Division 2008, 26 September 2008 |
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