Evaluation of pre-seeding herbicides in wheat crop

Effective wild oat control with pre-emergent herbicides is necessary in minimum tillage systems. Pre-seeding herbicides do not work as well in minimum tillage systems compared to systems using full cut cultivation where stubble biomass is lower. If stubble biomass is very high, pre-seeding herbicides are more effective if used with a high water spray volume (i.e. up to 100 L/ha) and a course spray droplet size. Stubble biomass can be reduced (i.e. stubble placed into windrows and burnt). Burning windrows will kill the weed seeds within the windrow; reducing the weed seed bank for the following year. Pre-seeding herbicides will be more effective where stubble biomass is reduced. For most fields, 50% ground cover is enough to prevent erosion. Both sites have more than enough stubble to avoid erosion over summer. The next year, knockdown herbicides were used to control initial wild oat emergence, and then both sites were sprayed with Triflur Xcel® 1.5 L/ha (with 100 L/ha of water) pre-seeding. Wild oat density was very high. As a result, placing chaff (and wild oat seeds) in windrows or spreading chaff did not affect average number of wild oat plants per metre.