This work aimed to evaluate the effect of the cutting height (10 cm and 20 cm) and cutting interval (30 days and 45 days) on the seed production of dallisgrass cultivated under field conditions. Plants were cut between September/2003 and June/2004, nine and six times, for the 30 d and 45 d cutting interval, respectively. Seed harvests were performed on 19/11/2004 (44 g of seeds/row) and 17/12/2004 (15.8 g of seeds/row). There was significant effect of the cutting management in the seed production and germination, with greater seed yield in the 10 cm cutting height (47.9 g of seeds/row) compared to 20 cm cutting height (41 g of seeds/row), and to 45 d cutting interval (50.3 g of seeds/row) compared to 30 d cutting interval (38.7 g of seeds/row). Panicle number was the principal seed production component. For the 1st harvest, the seed germination was superior at the 30 d cutting interval (12.4%) compared to 45 d cutting interval (6.6%); at the 2nd harvest, seed germination was higher in the 10 cm cutting height (5.6%) compared to 20 cm cutting height (3.3%) and to 30 d cutting interval (5.3%) compared to 45 d cutting interval (3.6%). The major limitation for dallisgrass seed production was its continuous flowering and the short interval between the full flowering and the spikelet abscission initiation, which caused different maturation degrees in the lot of harvested seed.
cutting; phenology; reproduction
