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 Enquiries SEED News - nov/dec 2005
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This section is coordinated by the professors from the Federal University of Pelotas-Brazil, with the objective of answering the inquiries sent by the readers.
Send your question to e-mail: silmar@seednews.inf.br
I have been reading that the use of lanolin on soybean seeds is beneficial, could you please comment about it?
Soybean seeds, when exposed to a very fast imbibition, present performance problems, as in the event of a strong rain a few hours after sowing - the damage caused by imbibition occurs. In order to avoid such problem, one can cover the seed with a hydrophobic product, as for lanolin. Another product that can be used, which is easily obtained, is mineral oil.
I liked the issue about seed quality and performance. In this sense, I ask: Even an high vigor seed needs protection for improving its performance?
Seeds basically need suitable soil (substrate) moisture and temperature, oxygen, and sometimes light to germinate. In case of such conditions are not favorable, the seed will face difficulties that depending on their magnitude, can bring it to death. So, in order to increase the possibilities, products or processes are applied aiming at increasing seed performance, which will positively respond, even the high vigor ones. Such awareness of the seeds sector as to increasing seeds performance, is one of the great current innovations.
Fortunately, we have been buying seeds to obtain a given population per ha, which in case of the varieties I use is 300,000 plants. To achieve that, I usually note the weight of 1,000 seeds and the germination percentage for assigning the weight I will need per ha. However I would like to know why the seed analysis bulletin does not specify the number of seeds per gram?
I agree that buying seeds per ha instead of weight is a great advance. It is a signal of fine tuning of the agricultural practices. With regards to the weight of 1,000 seeds instead of the number of seeds per gram, it still remains from the old process, when seed is purchased per weight. As such seed quality feature is in the rules for seed testing, it will take a little longer to be changed.
I am using the tetrazolium test for soybeans seeds for fast assigning seed physiological quality. I am able to diagnose the causes of seeds death. I am satisfied with the benefits, but I need to know if this test can be used for other seed species?
As a guideline, the tetrazolium test can be applied to all kinds of seeds as long as adjustments are made concerning seed conditioning, imbibition time period and concentration of the tetrazolium salt. The structure of the seed must be well known.
I know that in seed germination process water availability and suitable temperature are crucial. What is the role of each of these elements?
In summary, it can be said that moisture makes the triggering of the germination process possible, while temperature will speed the process up. There is an optimum temperature for each species to germinate, above which the seed will show abnormalities while, below it, it will take too long to show a normal seedling.
In the process of soybeans seed production, what is the main problem, since I have been reading that the efficiency in seeds production is around 50% in normal years?
As a matter of fact, efficiency in soybeans seeds production is near 50%. However, there are some producers who achieve efficiency over 70%. The main problem is field deterioration, because the seeds have to be harvested as soon as possible and artificially dried, in case moisture is high.
I have been noticing since my grandpa's times, that graphite is used in the sowing process. Inside seeds pack a graphite small pack is inserted to be used on the seed when it is sown.
Graphite is mainly used for giving seeds more fluidity and, thus, a better seed distribution on the sowing process. Currently, with seeds grading (large, medium, and small) and covered with film coating, fluidity is not a problem anymore.
Seeds distribution along the sowing line is important (which is well known) and, for that, several tools are used. However, the best among them is the use of high quality, protected seeds. When low quality seeds are used, even with a suitable sowing, emergence probably will not be good, showing gaps in the growing crop area.
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