The influence of sowing method on perennial grass establishment. II. Seedbed microenvironment, germination and emergence

Abstract

'Demeter' tall fescue (Festuca amndinacea Schreb.) and 'Victorian' perennial ryegrass (Lolium perenne L.) were sown separately into a white clover (Trifolium repens L.) dominant pasture. Eight sowing methods were compared to assess the ability of perennial grasses to germinate and emerge from direct drill sowing methods relative to conventional seedbed and aerial sowing methods. Within direct drill treatments, two drill implements were factorially combined with three herbicide treatments. Soil temperature and moisture conditions were cold and moist, but generally adequate for emergence of temperate pasture species. In-groove soil moisture content was always greatest in the disc plus herbicide treatment. Differences in seed level soil temperatures were minor, although diurnal fluctuations were greatest in the aerial plus herbicide treatment. Emergence of ryegrass at 50 days after sowing was similar in all sowing methods (67.9-93.9% viable seed sown) except for the aerial plus herbicide and disc plus band herbicide methods (23.4 and 44.0% of viable seed sown). There was a wide range of emergence percentages for fescue at 50 days after sowing (17.8-69.2% viable seed sown) and again the aerial plus herbicide treatment was lowest. One-pass, band spraying of a paraquat.diquat plus dicamba herbicide mixture at the time of sowing impaired the germination percentage of ryegrass seeds sown with the disc drill. Apart from the aerial plus herbicide treatment, sufficient seedlings passed through the germination/emergence filter in all direct drill and cultivated seedbed treatments to provide for a productive grass-based pasture.