Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
Ascochyta pisi on peas, Colletotrichum lindemuthanium on beans; and Botrytis, Colletotrichum
linicola, and Aureobasidum lini on flax. The demand for better seed quality, greater sensitivity and
shorter turnaround times for seed testing is forcing seed health testing laboratories to incorporate
new technologies which will provide the user with a significant level of reliability, sensitivity, and
reproducibility of the test . In last 35 years, several seed health testing procedures, published by
International Seed testing Association (ISTA) are now obsolete and need to be revised or
revalidated by newer technology due to fast pace of technological development.
Seed Testing Methodologies
• Many conventional seed health testing methods have been developed such as:
• agar plating
• blotter test
• seedling bioassay
• microscopic observation
• Direct isolation of pathogens
• growing on test
• However, they are multi-stage, and are often slow, cumbersome time consuming,
labour-intensive and subjective.
Seed Health Test Organization
During the past decade, several organizations have begun to address this situation by
promoting research, development, implementation, and standardization of seed health testing
methods.
These organizations include:
• The International Seed Testing Association (ISTA),
• International Seed Federation (ISF),
• International Seed Health Initiative (ISHI), and
• The National Seed Health System (NSHS) In the United States
Earliest amongst these was ISTA, which formed a Seed Health Committee (SHC) as early
as 1928. The committee was alternatively referred to as the SHC or Plant Disease Committee
(PDC) until 2002, when the PDC was finally designated to SHC. In first several decades SHC of
ISTA focused on cataloguing seed-borne microorganisms rather than the practical aspects of
detecting pathogens in a phytosanitary context. The current Seed Health Committee’s objective is
to “develop and publish validated procedures for seed health testing, and to promote uniform
application of these procedures for evaluation of seeds moving in international trade”
The International Seed Health Initiative-Vegetables (ISHI-Veg) started in 1993 as an
initiative of the vegetable seed industry. International Seed trade Federation (ISF) started two
more ISHI’s (ISHI for herbage crops in 1997 and ISHI for field crops in 1999). These ISHI’s put
more emphasis on quarantine pathogens and their impact on the international seed trade. In 2002
- 119 -