The soya stored in field conditions and quality
Roque Craviotto and Miriam Arango, Agricultural Engineers from Seed Technology INTA, EEA Oliveros
It’s a reality that, when our soy seed is ready to be harvest but is not due to continuous and successive rains, for example, the implications are two:
- the actual quality, measured right after the threshing and
- the potential quality, this will be evaluated before the classification and before the sowing.
During the first analysis, there were registered a number of cases where the lots presented an important difference in germinating strength, when the seed has been treated with fungicide for the purpose of this laboratory test. This reveals the presence of dangerous fungi that affect germination severely and can only be eliminated with an adequate "seed treatment".
The magnitude in the difference between seeds that have been treated with fungicide and those that have not, depend on different factors:
- The amount of pathogenic fungi carried,
- The presence of mechanical damage, and
- The physiological condition among others.
Taking into consideration the environment conditions that favor the proliferation of this type of organisms on the seed that is still in the field, we can estimate the future necessity of realizing the cure during quality control in the laboratory. This will avoid the rejection of high germination lots when they, due to not doing the cure, show a low germination muscle during the tests.
The recommended quality control test must show us, not only the level of germination power, but also the power of the seeds lot it self. This last value is a very important agricultural indicative, because it will allow us to determine the possible lot behavior once it is sowed. In this sense, the soy species is very sensitive to sowing environment conditions because seeds lot of similar germination values may vary enormously in the germination and emergency.
The most recommended test to determine the vigor in our seeds are:
- Accelerated aging
- Electrical conductivity and
- Topography for tetrazolio
The last test, although is highly recommended for soy, it is not effective to determine the presence of pathogenic fungi, so the results must be analyzed comparing the other testes.
Much of the fungi that are present today in soy seeds could disappear during the storage, but this depends on the level of humidity in the seed, humidity in the storage environment and the temperature during the storage period.
The seeds, during their stay in the field waiting to be harvested, they suffer -besides pathogenic infections- from the stress that the wrinkling – due to hydration and dehydration during day and night- of the peel causes. This type of environmental damage will not disappear during the storage period, furthermore, it may progress and kill the seeds.
Unfortunately, not harvesting a lot for any reason can cause irreversible damage. This is why we need to analyze our lot immediately after it is harvested, because this will determine its future use as a seeds lot or grain lot.
The quality control for the seed that is destine to be sowed demands that this control be done to prevent, because this will allow us to take adequate decisions from the agricultural and economic point of view.
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Bugs control |
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"Trips" insects in soy fields |
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