QUALITY ASSURANCE FOR Pea SEED

Analysis of seed in germination laboratory


We analyse constantly the following parameter:

  • Moisture content - (Method Pfeuffer, after harvest for each field lot) 
When moisture>14%: Take immediate action.
  • TSW = 1000 seed weight
  • germ = germination in sand, untreated, (2 x 100 seeds) and also treated with common treatment (when repeated: in soil).
If need be controlled, test by ''Landwirtschaftskammer''.
  • Electrical conductivity (not required for round peas, as results are not relevant)
  • Technical purity (accord. ISTA)
  • Judgement of seed (visual by experienced experts)
  • PSbMV-test (Pea Seed born Mosaic Virus)
Visual and serological test by PGRO, UK.
  • Ascochyta - Microbiological test by LWK or PGRO
  • Pseudomonas syringae pv. pisi - Test by PGRO, when questionable by field inspection.


Importance of electrical conductivity for peas

Basis:
Soaking of pea seed in water and the
diffusion of salts and carbonhydrates from seeds.
Measuring unit means
24 µs or less: earlier sowing time under unfavourable weather conditions is possible.
25-29 µS: peas can be planted early. Risk of poor emergence under unfavourable conditions.
30-43 µS: peas are not suited for an early planting (under unfavourable conditions).
44 µS and more: peas are not suitable for planting.


Reason for high conductivity:

small cracks in seed skin, fungus infection, "Hollow heart" (physiological disorder, occurs during germination in the adaxial surfaces of the cotyledons as a result of the collapse of dead cells) or "Marsh-spot" (Manganese deficiency at pH above 6,8; necrotic spots on the adaxial surfaces of the cotyledons.

Consequence:
penetration of disease pathogens, for ex. Pythium spp.

Please note:
small seeded pea varieties often correlate with higher E. C.-factors. According to PGRO, Waverex with E. C. factors < 35 µS is suitable for most planting times!


Special Features of PSbMV Tests


PGRO uses the "indirect ELISA" procedure when testing for PSbMV. The whole kernel – inclusive of seed and skin – is used.

When infection is > 5% according to this method, PGRO recommends not to use this particular lot as seed.

According to PGRO however only 10% of the seedlings, which grow from infected seed (after indirect ELISA test), are virus infected.

The "MINK" test is more effective but also more labour intensive and expensive. Here the virus is tested in the seedling (also by ELISA method). If the infection is 1% or more, PGRO recommends this seed not be used for planting. PGRO carries out this test on demand. This test is recommended when the infection of seed is +-5%.

The sample must be a representative sample of the seed lot, as only 100 seeds are used for the test



What is „HOLLOW HEART“?

 

Symptoms of Disorder

Hollow Heart, or cavitation, is a physiological disorder which results in the appearance of hollows and, in severe cases, deep fissures in the adaxial surfaces of the cotyledons of germinated pea seeds. Affected seedlings are often weak and stunted compared to normally developed seedlings. Poor seedling establishment in early sowings of peas has been associated with the presence of high levels of hollow heart affected seedlings. (See seed vigour.)

Economic Importance

Reduced seedling establishment can occur when high levels of hollow heart are present in the seed.

Prevention and Control

Hollow heart appears to be mainly associated with wrinkled seeded vining pea varieties. The disorder has been associated with those seed crops which have been subjected to high daytime temperatures during the late maturation stages of the seed.
While an examination of germinated seedlings can be made during the routine germination test, most severely affected seed lots can be detected by the electrical conductivity test routinely used to assess seed vigour.

 

 

Quality assurance for bean seed

Laboratory analyses of bean seed


Beans
We constantly analyse the following parameter:

Moisture content
(Method Pfeuffer, after harvest for each field lot)
when moisture is >14%: Take immediate action.

TSW = 1000 seed weight

germ = germination in sand, untreated, (2 x 100 seeds) and also treated with common treatment (when repeated: in soil). If desired control analysis by Chamber of Agriculture

Technical purity
(accord. ISTA)

Seed inspection
by experienced personnel