The objective of the present study was to analyse mechanical damage and its effect on the germination and vigour of cotton seeds. Samples from five lots of cotton seeds were used, of the ITA-90 variety, 2004/05 crop, soon after processing. The seeds were analyzed for percentage of mechanical damage, moisture content, germination and vigour (accelerated ageing, cool germination, seedling and root length, seedling emergence, first count and speed emergence index tests). The seeds of each sample were separated into classes - whole, creased, cracked and cut seeds, and the percentage of normal and abnormal seedlings was verified, as well as that of deteriorated seeds in the germination tests, emergence of seedlings in the field, the first count and the emergence speed index. A randomized complete design was used, with five treatments (lots) and four replications. It was found that the influence of mechanical damage the quality of seeds depended on the size, depth and location of the damage. Mechanical damage caused more damage to the seeds mainly in the regions of the radicle and plumule. The mechanical damage was characterized by deep cuts and fissures and when they reached the embryo there were reductions in germination and vigor.
Gossypium hirsutum; vigor; germination
