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 Main subject - jan/feb 2006
Seed treatment logistics
Leopoldo Baudet
lmbaudet@ufpel.edu.br
Silmar Teichert Peske
peske@ufpel.edu.br
Treatment is a reality to increase seed performance, mainly for those high value species and varieties or hybrids. Such process involves products, formulations, matching, coatings, and equipments. Its future can be seen in a greater interaction among seed producers, manufacturers, researchers, and the farmer.
In Brazil, almost 100% of the soy bean seeds are treated with fungicide, 30% with insecticides, 50% with micro nutrients and film coating, which assures uniform coverage and adherence to the seeds. The objective is to protect seeds and to increase its performance in the field, either in the early establishment or during its vegetative cycle.
If sowing is not performed under ideal conditions and seeds are not protected, the chances to re-sowing them are great, bringing losses to the farmer. It seems obvious to think, then, that the areas occupied with untreated seeds by farmers who still did not realize how fundamentally important such practice is, are condemned to generate great financial losses.
The reason for the importance of such practice is based on three aspects:
a) value added to seed due to its protection;
b) tool for increasing both production and quality; and
c) more flexible crop management.
Products
Defensive products are indispensable to guarantee a good seed field emergence , protecting them against fungi and insects complex under the soil; to avoid spreading pathogens that can be transmitted by infected seeds and that can cause diseases to plants that are not resistant to certain pathogens; and they also offer an additional guarantee to the plant stand establishment.
Nowadays, a good seed treatment must resemble the following aspects:
a) safety;
b) wide spectrum;
c) efficacy; and
d) cost.
In the future, the most important aspects to be considered are:
a) larger targets (for pathogens that are transmitted by seeds, by soil, and plants);
b) phyto toxicity to seed will be a great concern;
c) reduction of environmental impact;
d) more complex mixtures, such as mixtures with fungicides, insecticides, inoculants, micro nutrients, herbicide and biological protectors, and coatings; and,
e) monitoring of seeds health.
The main benefits are:
a) uniform coverage,
b) improved coloring,
c) better adherence,
d) better visual quality, and
e) faster flow in the sowing machine.
Products to be applied must offer enough protection both to seeds and seedlings in the field, keeping fungi and insects under proper control, as well as they must be compatible to each other to avoid phyto toxicity problems to the plants or a narrowing of their action extent. In a normal application of chemicals via soybeans seeds treatment, 12 to 30g/ha Mo, 2 to 3g/ha Co are applied, something around 200g or 250ml fungicides per 100kg seeds, insecticide, water, and other products such as polymers and dying products; and all these conglomerate can not surpass the final 1 liter per 100kg seeds. It is currently possible due to the kinds of products and equipment highly technical that are available in the market.
Equipments
As to the treatment of seeds, the following aspects deserve to be highlighted:
a) greater availability of equipment for liquid application,
b) lower dosages,
c) new products,
d) more precision and monitoring,
e) better peripherals, and
f) certification of the high value seed treatment.
Currently in Brazil, the treatment of soybean seeds with fungicides, micro nutrients, and inoculation are made in specific machinery or seed treaters, both at the seed conditioning plant (SCP) and the producer's place. The machines available in the market are specifically designed to mix nutrients and micro nutrients, fungicides, insecticides, and inoculants. Such machines must be low costing ones, smaller in size and easy to operate, so that they can make the work in the farm or at the SCP easier.
The current thinking is as follows: "Seed treatment must be done prior to sowing, with a spinning drum or suitable machines; however, it can also be done prior to storing the seeds. Such procedure, however, requests a careful evaluation because treated seeds that are not used for sowing can not be marketed as grain. This, because of the effects they would cause to both human and animal health.
Generally, seed treatment is done by seed producer companies, who sell seed already treated. The big seed companies and cooperatives make their own treatment, usually at the sowing moment.
Hybrid maize and vegetable seeds treated at the SCP must be commented. As they are high value seeds, they are stored in climatic rooms under controlled environment, where carry over is common, that is, high quality, treated and stored seeds are used again in the next crop year. Another crop that we must highlight is hybrid rice seeds, which are 100% fungicide treated, a growth promoter, and a great part also treated with insecticide. This is to improve seed performance and minimize the possible emergence problems.
A question of management: where must the seed be treated?
Soybeans seeds are used as reference in this case due to the magnitude of the business, the difficulties in obtaining a suitable stand, and the risk of treating a seed that, if not treated will be discarded, so that it can not be used even as grain.
Despite treating 100% of the seeds, only about 10% of the soybeans seeds are treated at the SCP. So a question arises: where are they treated? The answer is: often in the field, just before sowing.
Thus, the producer who treats the seeds at the farm exposes himself to the following situations:
a) not having a way to measure the treatment,
b) not having a way to measure the seed, and
c) not having a way to mix seeds and chemical.
In general, in seed treatment with chemicals directly applied to the sowing box a good coverage is not achieved. Seed coverage is critical. An uneven coverage affects the product performance due to its weak adhesion. Currently, with products of low dosages, the process of treating seeds requires more care.
Another aspect to be taken into consideration is that sowing is one of the crucial moments of the crop with regards to precision and timing. So, the focus is to plant well, as fast as possible, in order to make use of the best sowing time and climate conditions. Sowing out the right time affects productivity. Any other task that comes along with will disturb. And the treatment in the field disturbs, because the machines remain stopped longer than necessary (mentioning one item only).
Sowing process greatly affects the success or failure of the crop. At the soybeans seeds conditioning plant another phase was added, the grading phase. It was necessary to grade the seeds to help the sowing process, which must be more and more precise in pursuing to establish a good stand and the suitable numbers of plants per hectare, in order to maximize the crop yield. Thus, we can categorically state that the main concern on sowing is the SOWING itself and not chemicals application.
So it is needed that the seeds are treated at the SCP. There are several advantages: application of better quality products with lower dosage; better control of the application than in the field, allowing a higher precision which must be much higher now than before; today people are much more trained at the SCP; seed treatment equipment to be incorporated at the SCP are better than the ones for treatment at the field level; there is also the operators health and the safety during application which is more controlled at the SCP.
However, it is a management problem, because a decision must be taken to avoid treating seeds that will not be used.
page 2 ->> Seed treatment logistics
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