Nitrogênio em cobertura e qualidade fisiológica e sanitária de sementes de pain？o (Panicum miliaceum L.)

nitrogen can influence the seed quality of several crops and its effects vary with the environmental conditions and the plant stage when the nitrogen is applied. however, little is known of the influence of nitrogen fertilization on seed quality in proso millet (panicum miliaceum l.). the objective of this study was to evaluate the effect of dosages and times of nitrogen top-dressing applications on the physiological and sanitary quality of proso millet, cv. al tibagi, seeds grown under field conditions. seeds were produced between december, 2005 and february, 2006 and laboratory evaluations between march and august, 2006. a completely randomized block design in a 4x2 factorial was used, with a combination of four dosages (0, 30, 60, and 120 kg ha-1 of n) and two application times (14 and 28 days after emergence) of nitrogen fertilizer (urea) in top-dressing with four replications. nitrogen application increased seed vigor, expressed by the tests of accelerated ageing and field emergence. nitrogen application of proso millet at 28 dae results in higher ive and percentage of field emergence. the sanitary quality of proso millet seed was not influenced by the dosages and times of application of the nitrogen fertilization.