A manual of rice seed health testing - IRRI books - International Rice ...
A manual of rice seed health testing - IRRI books - International Rice ...
A manual of rice seed health testing - IRRI books - International Rice ...
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tional levels (Kahn 1988). Quarantine<br />
<strong>of</strong>ficers enforce rules and regulations<br />
and implement safeguard procedures.<br />
Different quarantine procedures<br />
are applicd to <strong>seed</strong>s used for<br />
commnercial purposes and to those<br />
used for scientific ends. Commercial<br />
sced is stringently regulated. Seed<br />
for scientific use is handled more leniently,<br />
in reccognition <strong>of</strong> benefit considerations.<br />
National, local, and state<br />
governments have enacted<br />
quarantine rules and regulations<br />
governing the movement <strong>of</strong> plant<br />
and other materials within their<br />
jurisdictions. The <strong>International</strong> Plant<br />
Protection Convention <strong>of</strong> 1951 binds<br />
almost all <strong>seed</strong>-exporting and<br />
-importing countries to the convention’s<br />
rules, regulations, and policies.<br />
Signatory nations are bound by the<br />
convention’s decisions, which have<br />
the force <strong>of</strong> a legal treaty and are administered<br />
by the Food and Agriculture<br />
Organization <strong>of</strong> the United Nations.<br />
In recent years, regional and global<br />
cooperation in agricultural research<br />
has gained momentum. Consequently,<br />
many organizations (including<br />
the Inter-African<br />
Phytosanitary Commission, 1961; the<br />
European and Mediterranean Plant<br />
Protection Organization, 1965; the<br />
South Pacific Commission; the<br />
Caribbean Plant Protection<br />
Commission; and the Association <strong>of</strong><br />
Southeast Asian Nations [ASEAN]<br />
Plant Quarantine Center and<br />
Training Institute [PLANTI], Kuala<br />
Lumpur, 1981) met and set up<br />
biological standards for national<br />
rules and regulations pertaining to<br />
the safer intercontinental and<br />
interregional movement <strong>of</strong> plant<br />
germplasm and other commodities.<br />
Asian genebanks (for instance, the<br />
Japanese genebank in Tsukuba,<br />
<strong>IRRI</strong>’s genebank, the Chinese<br />
genebank, and the Indian National<br />
Bureau <strong>of</strong> Plant Genetic Resources)<br />
are cooperating commendably with<br />
many nations by exchanging<br />
germplasm. Each bank sets its own<br />
requirements for <strong>seed</strong> <strong>health</strong> during<br />
exchanges.<br />
Quarantine<br />
Pathogens can enter a new<br />
environment, country, or region<br />
through hosts, packings, other inert<br />
materials, insect vectors, birds, and<br />
air currents. Airborne pathogens can<br />
be stopped only by natural barriers<br />
such as oceans and high mountain<br />
ranges. Quarantine <strong>of</strong>ficers can<br />
intercept other pathogens and<br />
exclude or eradicate them.<br />
Exclusion measures include<br />
compulsory quarantine, inspection<br />
(compulsory or voluntary), and<br />
certification <strong>of</strong> planting stock or<br />
germplasm as <strong>seed</strong>.<br />
The importance <strong>of</strong> these measures<br />
became apparent when several<br />
devastating pathogens entered<br />
Europe and America through<br />
exchanged plant material. The<br />
pathogens included those that cause<br />
powdery mildew disease <strong>of</strong> grapes,<br />
citrus canker, potato wart, wheat<br />
flag smut, and Dutch elm disease.<br />
Some pathogens endemic to parts<br />
<strong>of</strong> North America had spread<br />
through nursery stocks to other<br />
regions before the USA established<br />
an internal quarantine system.<br />
Pathogens <strong>of</strong> minor consequence in<br />
their native environments, such as<br />
chestnut blight, may be destructive<br />
in a new environment.<br />
Quarantine systems and regulations<br />
developed after 1870. Individual<br />
American states initiated exclusion<br />
<strong>of</strong> insect pests through quarantine<br />
regulations. Early quarantine<br />
attention focused on propagative<br />
materials such as nursery stocks, but<br />
ignored edible fruits, vegetables, and<br />
<strong>seed</strong>s. The national government did<br />
not restrict plant movement until<br />
1912, when Congress passed the<br />
Federal Plant Quarantine Act. Australia<br />
and the European nations had<br />
imposed restrictions earlier. Some<br />
pests were controlled through exclusion.<br />
Quarantine systems control some<br />
diseases by eradicating the<br />
pathogens. Incoming plant materials<br />
are treated using physical means<br />
(precooling or heat treatment) and/<br />
or chemical methods (biocidal treatment)<br />
to climinate unwanted pathogens.<br />
The importance <strong>of</strong> adequate quarantine<br />
methods to detect and stop<br />
disease cannot be overstated. Seed<br />
being moved internationally and<br />
interregionally should be <strong>health</strong>y<br />
and pathogen-free to avert disease<br />
outbreaks.<br />
Methods used to detect and identify<br />
pathogens and pests <strong>of</strong> <strong>rice</strong> <strong>seed</strong><br />
are described in Part II <strong>of</strong> this<br />
<strong>manual</strong>. The pests and diseases are<br />
described in Part III.<br />
4 <strong>Rice</strong> <strong>seed</strong> <strong>health</strong> <strong>testing</strong> <strong>manual</strong>