Know the insights of “Seed Vigour – the Concept, Significance, Manifestation and Measurement”

July 28, 2021 Gubba Seed In E News

Gubba seed cold storage, in collaboration with National Seed Association of India organised a webinar on “Seed Vigour – the Concept, Significance, Manifestation and Measurement” on 19/7/21 from 3pm to 5pm. We had close to 200 attendees. Our keynote speaker, Dr.Malavika Dadlani is the former Joint Director (Research) and Head, Division of Seed Science and Technology, Indian Agricultural Research Institute, New Delhi. She has nearly 40 years of research, teaching, extension and management experience and is well known nationally and internationally in the field of Seed Science and Technology. She was a member of the ISTA Vigour Committee from 2001 for 10 years and currently a member of Seed Science Advisory group (SSAG) of ISTA. Her areas of special interest include Seed Viability, Vigour and Invigoration; Variety purity and Seed Production and Quality Assurance systems. She has served various high level committees in India dealing with technical, policy and regulatory issues. She received several awards and recognitions for her contributions in the area of seed research and teaching.
Dr.Malavika Dadlanienlightened the participants with an exclusive presentation from her rich experience for 1:30 mins.

Here is the Q/A of the session –
Is there any effect of dormancy on seed vigour? if yes how can we overcome effect of dormancy on seed vigour.
A: Dormancy results in the inability of the seed to germinate. Though there are no studies (in my knowledge) that has shown a relationship between dormancy and vigour, since evaluation of vigour is relevant only if the seed lot exhibits an acceptable level of germination, vigour can be assessed after the release of dormancy. The treatments for the release of dormancy vary from species to species.

  1. Vigour Rating continues to be ‘broad/ general’ as High- Medium- Low based on the Benchmark kept by the Analyst / User of the Result. So, what is High for one may be Medium for the other. It’s time now to get away from ‘General Rating’; and instead quantify in numbers with the Unit of measurement depending on the Type of Vigour Test followed. Also, as with the Standard for Germination [ Minimum] , for Vigour also Minimum standards will have to be fixed for various crops , Test Method wise . Then only , it can reflect on the Label ; and help the seed user.
    A: Yes, that would be the ideal situation. However, as we saw during the presentation, it is difficult to fix universal ‘Vigour Standards’. However, for in-house quality control, seed companies have set some internal standards (eg. EC, AAT, CD etc.) and maintain (in cold storage) necessary Reference samples for the purpose of comparison.
  2. Q: What type of vigour test we can try for cucurbits or Gourds…
    Ans: Since there are no tests recommended for these crops, you may review the literature. However, to begin, you may go for Vigour Indices based on G% and seedling growth or tests like AAT.
  3. How we can improve seed vigor
    A: There are many ways to enhance seed vigour by physical, chemical, physiological / biochemical and biological treatments. However, this is a topic of deliberation at length. May be we can discuss it sometime later.
  4. How to estimate seed vigour for vegetative propagated planting material like potato,cassava, sweet poato etc.
    A: Sorry, today’s lecture deals only with true seeds not all plant propagules.
  5. At what situation we go for seed testing of vigour
    A: We discussed at length today, that the purpose of vigour testing may be many, from assessing the probable relative storability to the planting value of the seed lots.
  6. Is there any application of chemicals before harvesting the seeds for maintaining more and long time vigor in the seed lots?
    A: No. However, the favourable growing conditions of the seed crop and care in harvesting have significant effect on the seed vigour.
  7. What is the validated vigour test for cabbage and cauliflower
    A: There is no vigour test that has been validated for cabbage and cauliflower. However, Chlorophyll fluorescence is a good indicator of seed vigour in many Brassica spp. Similarly, RE test as given for B. napus can be tried. Salt saturated test is also recommended for small seeded spp.
  8. How to reduce paddy Seed dormancy
    A: Some paddy varieties (specially the scented ones) do exhibit short dormancy and need a period of ‘after-ripening’ Pre-heat and KNO3 treatments work well in paddy.
  9. Thank you madam for your wonderful explanation regarding seed vigour, my question is for cold test which substrate we can use soil and sand in the ratio of 2:1 or only soil?
    A: Thanks. For Cold test normally a Sand/Soil mix is used as substratum keeping the Water Holding Capacity (WHC) at 70%.
  10. As there is no vigour standards, then results may compare with germination % or any other?
    A: As mentioned, vigour estimation is meaningful only when germination is up to an acceptable standard.
  11. Can we enhance the seed vigour by seed treatment?
    A: Yes. Certainly. As mentioned before, we can discuss this topic separately.
  12. I studied concept of vigour for the first time 38 years ago. But the procedure and measurement parameters are not validated yet. The procedures are still too ambiguous, tedious and lengthy. Even after that it does not find a place as a label claim! So vigour is still an academic exercise and discussion.
    A: No comment.
  13. For paddy dormancy breaking can be used GA-3 or any other chemical?
    GA3 is not very effective in paddy. HNO3 is recommended.
  14. How would you correlate seed vigour and hybrid vigour? Could seed vigour be used as a criteria for hybrid evaluation at least at initial screening stage?
    A: Hybrid vigour may be manifested in different criteria at different growth stages. Hence, it is not necessary that seed vigour be representative of hybrid vigour.
  15. Good afternoon madam, is there any chemical or any growth promoter treatment to enhance Vigour of Validated seed lots?
    A: I do see a lot of interest to know about seed vigour enhancement treatments. We can discuss this on another occasion.
  16. In India most commonly which method of vigour test is followed?
    A: There is no common recommendation for all crops. However, first count of germination and Vigour Indices based on G% and seedling growth are most commonly used. AAT and EC test are also commonly used.
  17. Thank you mam for the valuable information my question is which method is easy and rapid for estimating seed vigour? According to you mam
    A: Thanks. Please see the comment above.
  18. Will Seed treatment increase any kind of germination factor
    A: yes, seed treatments can improve germination.
  19. Can we consider that all Good vigour lots perform well in the field level
    A: It can not be said with 100% certainty, but probability of a HV seed lot performing better than LV lot, is better.
    A: Yes, as presented in the seminar, research on automation is in advance stages.
  21. Thanks for a very informative session Mam. What may be the probable reasons for variation in vigour percentage of different lots which are from the same production year and stored in the same storage condition?
    A: Thanks. Each seed lot from the same location may differ significantly due to several factors.
  22. we are dealing with majorly in soybean crop. So many times soybean seed vigour and germination shows huge difference ranging while testing and also differ shows in soil emergence why?
    A: Yes, soybean is a sensitive crop. It is both sensitive to mechanical injuries and a poor storer. That is the reason why so many tests are validated for soybean.
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