To determine the response to nutrient input across nine hybrid canola varieties.

• Crop biomass of three hybrids was measured at early flowering (100°C.days after the start of flowering), late flowering (500°C.days after the start of flowering) and again at maturity.
• Differences between varieties and nutrition were observed at the early flowering assessment, with 6.5 t/ha of biomass for the high input nutrition treatment and 5.1 t/ha for the low input treatment. 45Y28 RR and 45Y95 CL both had higher biomass than the TT variety HyTTec Trifecta.
• Growth of these treatments remained consistent across the treatments for the two subsequent assessments, with final biomass rankings similar at crop maturity to the rankings observed at early flowering.
• A 0-10 cm soil test was completed on the high and low input treatments at the early flowering biomass assessment. Despite the large differences in N rate applied, mineral N was the same across the two treatments (~63 kg N/ha in 0-10 cm), but there were large differences in Colwell P between treatments, with high input at 58 mg/kg and low input at 31 mg/kg.
• Grain yield was measured on these three hybrids plus a further six hybrids that did not have biomass assessments. InVigor R4520P was the fastest variety in the trial and had the highest grain yield in a warm and relatively dry spring. Other varieties with relatively high yield included 45Y28 RR, 45Y95 CL and Nuseed Eagle TF.
• The High Input treatment (45 kg P/ha, 225 kg N/ha + 3 t/ha chicken manure) yielded 0.76 t/ha more than the Low Input treatment (15 kg P/ha, 75 kg N/ha).
• Oil concentration was highest in NCH22K902 and 45Y28 RR. The high input treatment reduced oil (down 1.7%) and increased protein (up 2%) across all varieties.
• Detailed yield component assessment including harvest index, seeds/pod and pods/m² was completed on two input levels of 45Y28 RR, 45Y95 CL and HyTTec Trifecta. The High Input treatment increased final biomass of all varieties, but also increased harvest index i.e. more biomass was converted to grain, even at higher biomass levels. The High Input treatment increased seeds/pod, pods/m² and seed size.
• The warm and dry finish to the season combined with good early growth was the conditions where it could be expected to see a crop ‘hay-off’, but these trials show that the opposite, where higher nutrition gave higher biomass, better conversion of biomass to grain and higher yield.

Trial design: Factorial

Rotation position: Wheat 2022, Canola 2021, Pasture 2020
Soil type: Silty loam
Available Nitrogen (kg/ha) 0-100 cm: 119
Colwell P 0-10 cm: 34 mg/kg
pH (CaCl2) 0-10 cm: 5.3
Organic Carbon 0-10 cm: 2.1