II.3. BRASSICA CROPS (BRASSICA SPP.) – 185
extensively for 15 years, there is no evidence that volunteer B. napus has increased or is
more prevalent because of the herbicide resistance traits (Hall et al., 2000; Beckie et al.,
2006, 2004).Oilseed certified seed production
The production of oilseed Brassica sowing seed is normally undertaken within the
areas where the Brassica crop is commercially grown. The rules under which pedigreed
seed is produced and identified in the market place are stringent and extensive.
Regulations vary from country to country but the minimum requirements for certified
seed moving in international trade are governed by two international certification
organisations. Both the OECD Seed Schemes and the Association of Official Seed
Certifying Agencies (AOSCA) were developed to facilitate seed trade through mutual
recognition of the official certification labels of member agencies. Member countries
must meet OECD and AOSCA standards, but countries can – and most of them do – have
domestic certification standards that exceed those minimums.Table 3.5. Number of herbicide products available for control of volunteer B. napus with nil,
single or multiple herbicide tolerances in western CanadaHerbicide system Number of products
Susceptible 27
Liberty Link (LL)^1 26
Roundup Ready (RR)^2 25
Clearfield (CF)^3 19
RR × LL 24
RR × CF 17
LL × CF 18
RR × LL × CF 16Notes: 1. LL Glufosinate; 2. RR Glyphosate; 3. CF Imidazolinone.
Source: Downey and Buth (2003). Courtesy AAFC Reseach Station, Saskatoon.
AOSCA has a focus on the United States but its members include also Argentina,
Australia, Canada, Chile, New Zealand and South Africa. AOSCA standards cover not
only varietal certification of seed but also germination, physical purity, disease and other
quality traits. Their varietal certification requirements include a maximum variety
impurity “seed” standard that is used for post-control verification testing.
The OECD Seed Schemes, which largely reflect the requirements of the
European Union seed certification system, are increasingly implemented at the global
level. They comprise 58 member countries including most of the countries discussed
above. China and Pakistan are currently not members of the OECD Seed Schemes
(situation November 2012). However, China is developing standards for Brassica crops
and Pakistan has regulations that are similar to those of India. OECD seed standards do
not deal with germination or physical purity but focus on varietal certification, based
mainly on morphological characteristics during inspections of seed-production crops. In
addition, minimum requirements and standards for verification, using post-control field
testing, are mandatory.
Seed classes allowed are normally designated by the breeder or maintainer of the
variety. For Brassica oilseed, the seed multiplication factor for each generation is
typically large (>1 000:1). Thus, the seed classes designated for its species are normally