Farm Table says:
What is the problem?
Decreasing crop plant population and increasing row spacing decreases crop competitive ability against weeds, and generally wider row spacing will reduce crop competition for homogeneously distributed production factors.
What did the research involve?
In 2012, rotation trials of three years’ duration were initiated
– Rotation 1. Wheat – lupin– canola
– Rotation 2. Lupin – wheat – canola
– Rotation 1. Wheat – chickpea
– Rotation 2. Chickpea – whea
At the Cunderdin site in 2014, annual ryegrass density was quite high and control of this weed was poor in wheat crop in 2012.
What were the key findings?
Rainfall was extremely low at both sites in the 2012 season leading to very poor crop growth. Dimethenamid herbicide was more effective on annual ryegrass than simazine in lupin and chickpea crops resulting in greater lupin grain yield at Cunderdin.
At Cunderdin wide rows (44 cm) reduced crop establishment by 20-25% in all crops compared to 22 cm row spacing. Wide rows also reduced grain yield of wheat but grain yield of lupin and canola remained unaffected by row spacing.