A comparative study of yield components and their trade-off in oilseed crops (Brassica napus L. and Brassica carinata A. Braun)

Canola (Brassica napus L.) and carinata (Brassica carinata A. Braun) are two oilseed crops that have seen a surge in demand in recent years. However, current yields achieved by farmers are inconsistent and significantly lower than those achieved in research experiments. Therefore, a better understanding of the trade-off between yield components is crucial to help breeders develop new high-yielding cultivars and for farmers to manage their crops more effectively. Unfortunately, scientific literature focused on trade-offs between yield components in rapeseed is scarce for canola and lacking for carinata. To address this issue, we conducted field experiments in Uruguay over three consecutive seasons (2016–2018) using the cultivars “Rivette” and “Avanza 641” for canola and carinata, respectively. Our goal was to study yield compensation and determine the comparative performance of canola and carinata across a wide range of sowing dates. Our results showed that carinata yields ranged from 854 kg ha⁻¹ to 7283 kg ha⁻¹, while canola yields ranged from 1152 kg ha⁻¹ to 4489 kg ha⁻¹. Higher biomass production was linked to increased yields in carinata, while an increase in biomass did not necessarily result in higher yields in canola due to a harvest index reduction. Carinata yield was positively correlated with grain number, silique number, and grains per silique. In canola, moderate to large yield changes were primarily influenced by grain number and grain weight, as silique number had a negative trade-off with yield, while grains per silique had a neutral relationship with yield. Our study revealed a distinct yield building process in canola and carinata, despite the general belief that they share physiological similarities and can be managed alike. These findings enhance our understanding of crop knowledge and management, potentially leading to increased crop productivity, and generate more effective breeding programs. Enhancing the yield performance of canola and carinata will position them as economically profitable crops, allowing for greater crop diversification and meeting the growing global demand for biofuels.