In this section we try to answer the questions submitted by readers. Doubts about any subject covered by SEEDnews or even other pertinent to agriculture, can be forwarded to redacao@seednews.inf.br


    I have been searching for articles approaching the soybean seed quality under transportation, but without much success on it. Thus, would you be able to tell if there is any quality loss due to its transportation?

    The species diversity and Its storing capacity under general terms makes It a higher concern on some cases than another, as it is for soybean, which due to its chemical constitution, has less tolerance to several stresses. In Brazil, the tropical and subtropical weather with its high temperatures over critical periods  may cause higher degree of seed respiration, reducing its quality. Under general terms, some studies have shown to be common to decrease until 2% of germination capacity over a transportation exceeding 48 hours, usually when exposed to 30˚C temperature.



    On previous editions, as well as on some didactic books, several tests for seed vigor are mentioned. However, I would like to know which test is the best for determining soybean seed storing capacity.

    Truly, there are several tests available to determine the seed vigor, as: germination index, seedling length,  and/or tissue colorations, as the tetrazolium test. However, although providing a accurate degree of seed vigor, these are not precise on establishing the storing capacity and resistance to several related stresses along time. Nowadays, tests which are able to emulate physiological stresses are known for presenting higher degree of precision when it comes to storing, such as accelerated aging on soybean seeds.



    Under the soybean seed processing at our facilities, we sample seeds at several different stages. However, we are unsure about the minimum legislation requirements in Brazil. Are there demands for sampling and storing unfinished seed lots? 

    Although it is highly important to have an appropriate tracking of the seed processing and its efficiency under internal quality control proceedings, as well as, accurate decisions, the Brazilian government only establishes the need to sample finished seed lots, which have a potential to be eventually marketed/commercialized. Thus, all market remains protected against low quality products.




    I have been reading the main article from the May/June SEEDnews edition about genetic seed. However I would like to know how such seed category is maintained through the years and, can anyone produce it?

   Due to the importance of maintaining a minimum volume of each cultivar with high quality for future use, “live” samples are supplied to the government along with its initial registering and commercialization. However, as only the owner/breeder of each variety has authorization for its production and commercialization, it is of common sense for him to frequently multiply small volumes of it through the years, aiming at high purity levels. The genetic source must always be made from superior categories in Brazil, not being possible to achieve it from others categories as Basic, registered or certified.


    Is it possible to import varieties from other countries to produce and commercialize it in Brazil?
    Due to several environmental particularities, political and social issues of each country, Brazil has established through the RNC (Cultivar National Registration) program, the need to verify the main agronomic characteristics of each variety under VCU tests (cultivation and value use) , which involves 2 years under 3 locations or 3 years under 2 locations on field testing. Besides, to achieve a variety registration, the material needs to attend the DHE standards (Differentiation, Homogeneity and Stability).

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