s research was developed with the purpose of verifying alterations in the
physiologic and sanitary qualities of cotton seeds, stored during twelve months. Seed lots of the
cv. DeltaPine-AC90, acid-delinted were used in this study, with two vigour levels (high-73% and
low-49%) and treated with fungicides and insecticides: control; Disulfoton + Carboxin + Thiram;
Carbofuran + Carboxin + Thiram; Imidacloprid + Tolylfluanid + Pencycuron. After the treatment,
the seeds were stored under environment without control of temperature and air relative humidity.
Seed samples were taken at the beginning and at every two months to determine seed moisture
content, germination percentage, vigour by electric conductivity, accelerated ageing and cool
germination tests, as well as the seed health test. A completely randomised design was used, with
four replicates, in a factorial outline 7x2x4 (consisting of seven periods of evaluations, two vigour
levels and four chemical treatments). It was verified significant reductions of the physiological
quality for the treated seeds as well as for the untreated ones stored with low vigour. Seed lots
submitted to treatment with Imidacloprid + Tolylfluanid + Pencycuron presented improved
physiological quality, when compared to the other treatments. It was readily perceived that the
vigour seed lots were less tolerant to storage, and their vigour values were drastically decreased
after the eighth month of the storage period. There was an increase in the incidence of Aspergillus
sp. and Penicillium sp., and reduction of Fusarium spp., in both seed lots. Its was concluded that
it is not appropriate to store and chemically treat cotton seeds with low vigour level.