Mother nature has ‘designed’ plants in such a way that they can survive, thrive and complete their life cycle to produce offspring for future generations. With respect to canola, the question is: can we improve on this to better match this plant to evolving farming systems and changing regional climates?
Plant architecture is an important agronomic trait for matching plant type not only to growing environments but also to farming systems.
The term ‘plant architecture’ refers to the three-dimensional arrangement of the plant’s organs and structures such as shoots, leaves and pods. It could be considered its ‘functional design’.
Improved knowledge of plant architecture aids our understanding of the genetic, physiological and agronomic drivers that contribute to local adaptation and crop yield.
It can be a useful tool in the toolkit to manipulate canola growth and development to reduce the impact of risks – in particular frost, heat and drought – and boost canola yield.
With co-investment from the New South Wales Department of Primary Industries (DPI) and GRDC through the Grains Agronomy and Pathology Partnership (GAPP), a team of researchers has been assembled to investigates these aspects, includes Brett McVittie (technical officer, canola genetics), Mathew Dunn (research and development agronomist) and Dr Rajneet Uppal (crop physiologist), all based at the Wagga Wagga Agricultural Institute.
Learning from history
Researchers are growing historical and contemporary canola varieties of Australian origin in order to quantify the variation in canopy architectural traits.
In 2021, NSW DPI planted 34 open-pollinated canola varieties and 10 hybrids (released since 1978) plus four ‘check’ accessions (from GRDC National Brassica Germplasm Improvement projects), representing conventional and different herbicide resistance groups (Triazine, Roundup Ready® and Clearfield®, comprising spring and semi-winter varieties).
Evaluating historical and contemporary varieties in the same experiment allows you to estimate yield improvement associated with changes in plant architectural traits over 50 years. It also defines the yield architecture traits that drive yield potential by ensuring a balance between vegetative growth and seed yield.
In the 2021 season, NSW DPI measured several traits at the vegetative stages (seedling emergence, fractional ground cover, above-ground shoot biomass, leaf area index, leaf number, thickness and orientation, leaf angle), and reproductive stages (days to flowering, flowering duration, maturity, branch number, plant height, plant density, branch and pod orientation angle, length of the primary branch, number of pods on a primary branch, pod canopy depth, pod strength and yield and its components).
From these measurements the plant trait or attributes overall contribution to yield will be estimated and genetic correlations between all pairs of trait measurements will be calculated.
In addition to investigating canola varietal variation for the architectural traits, the team is conducting two experiments to investigate the effect of plant density and nitrogen status on the plant architecture in an open-pollinated canola cultivar, ATR Bonito (PBR).
This research is being carried out in collaboration with Colin McMaster (Orange Agricultural Institute, NSW DPI) and Danielle Malcolm (NSW DPI, Wagga Wagga). Both trials were conducted at two sites – Canowindra and Wagga Wagga.
Commensurate with growers experiences the team are recording higher branch numbers when plants are spaced 45 centimetres apart, compared to when sown at densities of 15 or 30 plants per square metre. Once the trial is harvested, the relationship between different plant architectural trait components and canola yield will be investigated.
More information: Dr Harsh Raman, 0477 359 146, firstname.lastname@example.org