In this 2013 trial:
- The grain yield of canola varieties started to plateau at approximately 20 plants per square metre (plants/m²).
- Hyola 404RR had the flattest yield response meaning that its yields were less affected by lower plant densities.
- Hyola 404RR was the highset yielding variety and also produced highest gross margins.
- Open-pollinated variety treatments were weedier than hybrids especially at lower densities.
The canola industry in Western Australia is expanding in low rainfall areas. Primarily, growers choose open-pollinated Triazine Tolerant (TT) varieties. However breeding companies are favouring the development of hybrids in order to pay for breeding services. Hybrids provide growers with more vigorous seedlings, comparatively better plant establishment and generally higher yields. However growers have to purchase new seed of hybrid varieties every year in order to get these potential yield benefits. Seed for hybrid canola is approximately 25 times more expensive than the seed of open pollinated canola.
To investigate the plant density response to yield and oil content of Triazine Tolerant (TT) and Roundup Ready (RR) hybrid canola in comparison with open-pollinated canola.