In this section we try to answer the questions submitted by readers. Doubts about any subject covered by SEEDnews or even other pertinent subjects can be forwarded to firstname.lastname@example.org
Due to the high variety of chemicals being offered for seed treatment, I often end up discussing formulations and different combinations with my team. However, we are concerned about the volume of water to which the seed is exposed in many cases. How can we know if the quality of the seed is at risk?
The benefits of seed treatment are perceived by the farmer, as they can increase the performance of the seeds in adverse conditions, both biotic and abiotic conditions. However, care should be taken to ensure that the seed does not become too moist, as this affects its physiological quality. In soybean seeds, when the seed coat wrinkles is a sign that the water was too much. Thus, as a rule of thumb, the 1% increase in seed moisture after treatments are already indications of possible impacts on the final quality after the operation.
I have a seed processing structure that supports post-harvest soybean activities. However, I would like to use the stationary dryers to reduce the water content of rice from 20% to 13%. What are the possible problems?
Stationary dryers use a lower airflow and a higher relative humidity to dry the seeds in relation to the intermittent dryers. Thus, they have a lower drying rate, and a drying capacity of one to two loads per day is normal. It is emphasized, therefore, in the case of rice, that the drying capacity should be 100% of the estimated production.
I have heard in some conversations that the fact that soybean cotyledons are above ground level after emergence can influence the efficiency of the seed treatment, especially fungicides. Does this really occur?
Seeds in the soaking process need to absorb significant amounts of water (relative to their dry mass) for a relative period below the ground to trigger the germination process, absorbing water and various other elements such as possible chemicals. Thus, after the germination of the seeds, it does not matter if the cotyledons will remain in the place, since all the ingredients present in the soil during the imbibition have already been absorbed.
Recently I learned that many rapid methods for determination of seed moisture content are indirect, through electrical conductivity and need periodic adjustments. In cases where the seed was recently removed from the intermittent dryer, and thus, the internal moisture still appears below the surface, would there be a possibility of inaccuracy in reading?
The rapid methods of determining seed moisture content are quite useful; however, they need precautions such as that mentioned in the drying and periodic gauging process, since they may present imbalances after a certain time and in successive use. Therefore, it is recommended to check it once a year.
During soybean harvest, I often see seeds with ripped tegument without mechanical influence. Could this possibly influence the hypochlorite test for the measurement of such damage?
According to personal experience, if the cultivar presents a significant predominance of the seeds with rupture, about 30% of the seeds numbed in the hypochlorite test (accusing mechanical damage) will be due to the impaired integrity of the tegument. It is worth mentioning that seeds with tegument ripened in soybeans still present subsequent risks of falling quality during all post-harvest operations, such as processing, treatment and storage.