Treatment technologies for soybean seeds: Dose effectiveness, mechanical damage and seed coating

Tecnologias de tratamento de sementes de soja: Assertividade de doses, danos mecânicos e o recobrimento das sementes

ABSTRACT

Seed treatment is an important procedure in soybean cultivation and is currently performed in two ways: industrial seed treatment (IST), performed by the seed companies industry, and OnFarm treatment, performedby the producer. The objective of this research was to compare the influence of industrial and OnFarm soybean seed treatment technologies, including the machines and processes, on the occurrence of mechanical damage and the functional quality of treatment. Soybean seeds were subjected to phytosanitary treatments with different processes and machines: (1) industrial treatment with a batch process; (2) industrial treatment with a continuous flow process, (3) OnFarm continuous flow treatment with dosage distribution via fixed-volume doser and seed mixing via worm screw; and (4) controlrepresented by untreated seeds. The occurrence of mechanical damage was evaluated by the sodium hypochlorite test. The functional quality of the treatments was analyzed by seed coating, determined by means of digital image processing; particle detachment (dust-off); and dose effectiveness of thiamethoxam, determined by high-performance liquid chromatography (HPLC). The treatment of soybean seeds in batch or continuous flow industrial systems ensures better seed coating, greater dose effectiveness, less particle detachment and a lower occurrence of mechanical damage compared to OnFarm application technology. The digital processing of high-resolution images is efficient for quantifying the coating of soybean seeds by phytosanitary products. Seed coating is directly related to dose effectiveness.

Index terms:
IST; OnFarm; digital image processing; HPLC; dust-off.