Submitted to: International Grasslands Congress
Publication Type: Proceedings
Publication Acceptance Date: April 1, 2005
Publication Date: July 1, 2005
Citation: Bartholomew, P.W., Williams, R.D. 2005. The effect of harvest management on forage production and self-reseeding potential of Italian ryegrass (Lolium multiflorum L.)[abstract]. In: Milne, J.A., editor. Pastural Systems in Marginal Environments. Wageningen Academic Publishers, The Netherlands. p. 116. Interpretive Summary: ABSTRACT ONLY
Technical Abstract: If Italian ryegrass (Lolium multiflorum L.) (IRG) can be managed to produce a seed output sufficient for effective re-establishment, without compromising forage yield, it may provide an alternative to perennial cool-season grasses in the Southern Great Plains. Italian ryegrass was no-till overseeded into dormant unimproved warm-season pasture in fall of 2002. In spring of 2003 ('year 1'), initial harvest date treatments, 17-April, 1-May and 15-May, were combined with forage offtake treatments of 100, 76 and 53% of available forage at each harvest. Following initial harvest, IRG was allowed to regrow, set seed and to re-establish from seed deposited, without further management input. Early harvest and reduced offtake decreased year 1 forage yield at first harvest, but increased the amount of seed deposited and number of seedlings re-established in year 1. In 2004 ('year 2') there was a residual effect of year 1 harvest date and offtake treatments on forage production of the self-seeded crop that was manifested in a lower mean yield with late harvest and increased offtake. However, in year 2 there was no significant difference (P>0.05) in seed deposition, in mean seed weight, or in emerged seedling numbers among year 1 harvesting treatments. The seedling population achieved by self-seeding in year 2 was on average 22% of the lowest population achieved in year 1, and only 15% of that produced by drilling IRG at 30kg/ha in the fall. The poor re-seeding performance in year 2 may have resulted from a combination of high seedling populations, and associated low seed weight, and from premature germination arising from greater than average rainfall in June and July in year 2. The results demonstrate the uncertainty of self-seeding as a means of pasture renewal.