This section is coordinated by professors from the Federal University of Pelotas/Brazil, with the aim of answering inquires sent by the readers. Send your questions to

    The continuous breakthroughs in agriculture and the need for high seed performance have led me to treat seeds always with fungicides, insecticides and nutrients. However, I remain dubious about whether the dosage should be the same for large and for small seeds.

    Seed treatment has become a necessity to enhance seed performance and all marketed products bear the recommended dosage printed on the package, usually expressed in g/kg of seed. However, regarding the differences in seed size and applying the recommended dosage based on individual seed weight, smaller seeds will receive less of the commercial product than large seeds. For crops whose seeds are graded by size, e.g. corn and soybean, this inconvenience has been taken into consideration and lots of small-sized seeds are treated to larger doses than large-size seed lots of the same weight.

    I am aware that sowing occurs under extremely variable soil conditions, not always optimal for a fast germination process. Conditions such as low or high temperatures, high or low soil moisture, sowing depth and seed-soil contact can have major influence on germination occurrence and speed. Could you please explain how seeds can overcome these adverse conditions?

    Your approach on the sowing environment is a very realistic one, which clearly exposes the complexity of achieving the target stand. Fortunately science has developed vigor tests that are good in predicting the seeds’ ability to overcome adverse environmental conditions, that are normally encountered at the time of sowing. There are several vigor tests that can be performed upon seeds, being the commonests accelerated aging, cold test and electrical conductivity.

    I manage a seed processing unit (SPU) that manages several soybean lots per day along the harvest season. Through the last years some soybean lots exhibited low quality values, being that they were ultimately discarded during their processing routine. This situation brings about a series of inconveniences that I’d like to avoid in the future, so I will be thankful for your comments on how to identify in anticipation low quality seed lots, so that they’re not allowed into the SPU.

    Allowing entry of low-quality seed lots into the SPU generates a series of inconveniences that could eventually lead to the dismissal of the employee in charge, responsible the unit’s functioning. The solution can be provided by an adequate seed lot sampling and the utilization of simple tests that can rapidly assess seed quality. Among the latter, seed moisture, mechanical injury testing, exudates’ pH and seed percentage with wrinkled teguments. All these tests can be carried out in less than one hour, which greatly improves the SPU’s logistics through the harvest season.

    Seed companies have been increasing the number of hybrid varieties on the market. Could you comment on this?

    Commercial hybrid varieties are now frequent in several species, such the case of corn, a crop that in Brazil has over 80% of its total area (14 million ha) sown with hybrid varieties. The latter are more productive due to heterosis, which delivers a broader genetic constitution. However, not all species have the same easiness for hybridization, as in wheat, which can end up being an extremely costly procedure, economically unfeasible. Hybrid varieties have increased their market shares due to their enhanced productivity as well as for their condition of being more protective against seed piracy.

    I’m an agriculture product retailer and sell seeds from different crops. Many times farmers come to my shop to purchase agrichemicals, however, not seed, since they save their own. How can I talk them into buying commercial seed?

    This is no easy task; however, certain attitudes must be adopted like being totally confident on the seed quality being offered to customers and that they belong to genuine improved varieties. Both traits will make the farmer regard you as a professional player in your business, while at the same time you can advise him on the fact that by purchasing agrichemicals, but no certified seed, he’s applying various products to allegedly improve seed performance when he has no real guarantee that it’ll germinate accordingly. The enhancement products he paid for will give no return if seeds do not originate seedlings. 



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