Product Specifications for Vegetable Seeds

Pubblicato il 19 luglio 2002 in: qualità delle sementiESAproduzione e commercio sementi


Product Specifications for Vegetable Seeds

Enclosed please find the latest update of ESA Product Specifications for Precision seeds.
In addition to the Specifications for Germination, this new version also contains the Product Specifications for varietal purity

These specifications are meant to facilitate communication between seed suppliers and professional users of vegetable seeds. They provide a guideline about what can be expected as minimum quality test-result, when buying Precision seeds from ESA members.
Seed suppliers are therefore requested to publish those specifications (as far as agreed for publication) in their catalogues/leaflets.

These Specifications are not meant to be absolute minimum standards for delivery.
In case the quality tests of seed suppliers indicate a lower quality-level than given in these published Specifications, seed suppliers have the obligation to arrange a clear communication with prospective seed users. This communication is aimed at informing professional seed users about the quality they can expect, so they can make their own risk assessment and decide if these seeds still meet their requirements.
Product Specifications and related communication are important tools to manage customer relations and to support handling of customer questions about product quality.

We trust that all seed companies associated with ESA, will apply and publish these Product Specifications.


Vegetable growing has become a highly specialized and intensive activity. As a result of the ever increasing demand for better quality vegetable growers and plant raisers require an improved quality of the basic material.
The demand for specific seed forms and more information about seed quality has strongly increased to better influence emergence and required number of plants.

Seed is a natural product. The often varying environmental conditions thus influence final results. It is therefore often not possible to give detailed information about emergence and other physical seed characteristics. To meet the wishes of clients as much as possible (company name) has made up quality standards for the various seed categories.

The germination percentages mentioned are (company name) minimum required figures and made up according to ISTA methods and tolerances. In cases where the seed does not apply with these product specifications (company name) will inform the client.



Normal Seed
In general, normal seed has not been subjected to special processes. It is sold by weight and/or by count, depending on the product. Normal seed complies with national standards.

Precision Seed
Precision seed has been subjected to additional processes. It has a uniform size and high germination. Precision seed is sold by count.

Priming is defined as an activation of the germination process with the purpose to obtain faster or more uniform emergence after sowing. Primed seed is sold by count.

Pelleting is defined as the process of changing the seed form by covering it with a material, the main purpose being to improve uniformity of size and shape resulting in improved sowing ability. Also additional ingredients may be added. Pelleted seed is sold by count.

Filmcoating is a full covering, usually pigmented layer, around the seed. The original seed form remains intact. Additional ingredients may be added. Filmcoating treatments that contain insecticides are normally identifiable by color coding. Filmcoated seed is sold by count.

Gluecoating is a process which fixes the applied crop protection products in an almost dustfree manner to the seed. A pigment may be added.

Germination figures relate to ISTA procedures and are valid at the time of despatch.

ESA Product Specifications for varietal purity of precision seeds


Vegetable seeds are seldom 100% pure. Sibs and off-types occur as a result of technical limitations and variable seed production conditions. Additionally the expression of sibs and off-types may vary depending on growing conditions.
Customers have their requirements and expectations for varietal purity of vegetable seeds. These are based upon their experiences in the different crops, the ‘average’ performances obtained by the seed-industry and the technical developments in vegetable production.
It is therefore advisable to develop specifications for varietal purity, in order to have a clear tool to support communication between suppliers and customers on this subject.

Definition of varietal purity:

Varietal purity rate is defined as: the percentage of plants from a seed-lot that meets the variety description.
The UPOV-guidelines allow a certain variation in expression, within the variety description. This variation is crop-dependent and is related to the multiplication techniques used for that crop.
It is the responsibility of each seed supplier to decide if a specific plant observed can be classified as ‘pure’, within the variation allowed, or is to be classified as ‘not pure’. Internally each seed supplier will have its own specifications for off-types. The ESA varietal purity specifications do not differentiate between levels.
Each seed producer decides its own communication policy towards customers, within the general guideline given by the ESA specifications for precision seeds. It is evident that in case of serious harmful off-types, this communication will have been already made in case of low percentages of off-types. This will also depend on the specific market situation.
Above definition for varietal purity requires a clear coherence between the official variety description and qualifications in catalogues/leaflets of seed producers.


Precision seed


Asparagus germ. 85%  
Brassica’s (Cabbage, Brussel Sprouts,
Broccoli, Kohlrabi, Curly Kale, Chine Cabbages). Cauliflower
germ 90%
var. pur 93% germ. 90%
var. pur. 90%
seed size 0,20/0,25 mm
Dwarf beans
Climb. Beans
Broad Beans
germ. 85%
1 unit 100.000 seeds germ. 95%

germ. 85%
1 unit 25.000 seeds
Beetroot (monogerm)
Beetroot (multigerm)
germ. 80%

germ. 90%
seed size 0,50 mm<
Carrots germ. 85%
seed size 0,20/0,25 mm
Celery/Celeriac germ. 90% 90%
Chicory Witloof germ. 85%
seed size 0,20/0,25 mm
Corn Salad germ. 85%
seed size 0,20/0,25 mm
Cucumber germ. 92%
indoor var. pur. 99%
outdoor var. pur. 98%
pickling var. pur. 98%
Eggplant var.pur. 98%
germ. 90%
Endive germ. 90% 92%
Fennel germ. 90%
seed size 0,20/0,50 mm
Gherkin germ. 88%  
Leek OP           F1 germ. 90% germ. 85%
seed size 0,20/0,25 mm
90 %

85 %
Lettuce – (Butter head, Bata-
via, Iceberg, Cos)

- other types

germ. 93%
var. pur. 98% germ. 93%
var. pur. 95%
Charentais type

- other types

germ. 95%
var. pur. 98% germ. 90%
var. pur. 98%


germ. 90%
seed size 2,0/2,75 mm



germ. 87%
seed size 0,20/0,25 mm



germ. 85% - 88%
1 unit 100.000 seeds



germ. 88%



germ. 92%
seed size 0,20/0,25 mm



germ. 80%



germ. 85%
seed size 0,75 mm


Sweet corn

normal germ. 90%
supersweet germ. 85%


Sweet/Hot pepper

germ. 90%
var. pur. 97%



germ. 92%
var. pur. 97%



germ. 92%
fresh market – var. pur. 98%
processing – var. pur. 95%



normal germ. 90%
seedless germ. 85%
var. pur. 98%


Definition of the terms describing the reaction of plants to pests and pathogens

1. Preamble

- There exist differing degrees of specificity in the host/parasite relations. The identification of that specificity generally requires the use of highly elaborate analytical means.

- Recognizing whether a plant is subject or not to parasites may depend on the analytical method.

- It is important, in general, to stress that the specificity of pests or pathogens may vary over time and space and that new pathogen races or new pest biotypes capable of overcoming a resistance may emerge.

2. Definitions

Immunity: Not subject to attack by a specified pest or pathogen.Resistance:

Ability: of a cultivar to limit the development of a given pest or pathogen throughout the whole or a part of a growing cycle. Several resistance levels may generally be defined.

Tolerance: Ability of a cultivar to tolerate the development of a pest or pathogen whilst displaying disorders that are without serious consequences for its growth, appearance and yield.

Susceptibility: Corresponds to a zero resistance level of a cultivar with respect to a given pest or pathogen.

Articoli correlati

Ultimi articoli pubblicati