Farm Table says:
What is the problem?
An average yield of canola in the high-rainfall zone (HRZ) of southern Australia is about half the predicted potential yield based on seasonal water supply.
The Study of this canola production is to sow cultivars as early as possible to maximise vegetative growth and enable seed maturity to be completed before severe drought stress and high temperatures occur, which are detrimental to seed filling and oil accumulation.
What did the research involve?
This study used data from HRZ field experiments, detailed in Rifkin to test the ability of APSIM-Canola and CAT-Canola crop models to simulate phenology, biomass, and yield for the three defined canola cultivars.
Field experiments were conducted across four sites in southeastern Australia that assessed phenological development, aboveground biomass and grain yield of a range of short- and long-season canola cultivars.
The APSIM-Canola model version 7.3 was parameterized against the field data of three cultivars (Hyola50, Taurus, and CBI8802) measured at Hamilton, Lake Bolac, Inverleigh, and Naracoorte.
The CAT-Canola model was applied to consider the productive benefit of long-season canola (winter and spring types) across the south-eastern Australian HRZ over a 50-year period.
Over the 50-year simulation period, the decision to sow at each site for a given TOS was based on whether the site had sufficient water available to support germination of the crop.
What were the key findings?
Both models (CAT-Canola and APSIM-Canola) were tested against aboveground biomass at harvest and harvested grain yield.
The purpose of this modeling exercise was to establish where in the study area long-season spring- and winter-type canolas have a competitive yield advantage over short-season canola.
Both the late-maturing spring-long (CBI8802) and winter (Taurus) outperformed the current standard cultivar spring short (Hyola50) across much of the study area supporting the hypothesis that long-season cultivars have the potential to increase canola production (area and yields) in the HRZ of southeastern Australia.
This study has provided breeders, growers, and advisors with information on where in the HRZ a longer-season canola cultivar can be grown to improve overall crop productivity. It has also provided evidence that new canola types may be required to maximise grain yields not only for the HRZ but potentially also in lower rainfall regions.