To investigate factorial combinations of sowing time, seed rate and herbicides on the management of annual ryegrass in wheat.

General application of Sakura + Avadex over the whole trial site provided good control of ARG. As a result, follow-up application of Boxer Gold @ 1.5 L/ha or 2 L/ha at GS 11 (1-leaf stage) did not significantly reduce ARG plant density.  Post-emergence application of Boxer Gold at 1.5 or 2 L/ha after pre-emergence Sakura + Avadex extended the period of weed control, which reduced spike density of ARG (P=0.02). At both sowing times, increase in wheat plant density from 100 to 200 plants/m² reduced ARG spike density by 44%. Delayed sowing at this site reduced the competitive ability of wheat against ARG. Averaged across the seed rates and herbicide treatments, ARG produced 234 spikes/m² in TOS 2 as compared to 75 spikes/m² in TOS 1 (68% reduction in TOS 1). Additional post-emergence application of Boxer Gold significantly increased wheat grain yield (P=0.008) compared to the baseline treatment of Sakura + Avadex. Wheat yield increased by 9% or 0.4 t/ha with the additional post-emergence treatment of Boxer Gold as compared to Sakura + Avadex treatment alone. Wheat grain yield was also significantly affected by wheat seed rate (P<0.001). Wheat grain yield increased from 4.6 t/ha at the density of 100 plants/m² to the maximum of 5.48 t/ha at the seed rate of 200 plants/m². This yield gain of 0.9 t/ha clearly indicates that early sowing, wheat density of 200 plants/m² and effective use of herbicides can have a large influence on the profitability of wheat in the HRZ.