Determinants of yield and quality in winter rapeseed (Brassica napus L.) under Mediterranean conditions

Abstract

SUMMARYWinter rapeseed was introduced into Greece a decade ago to provide oil for biodiesel. To identify agronomic traits affecting yield and quality, three hybrids and an inbred line were tested over two seasons (2005–2006 and 2006–2007) and four locations, in central and northern Greece, varying in pedo-climatic conditions. The large variations in seed yield, quality and agronomic traits were largely ascribed to location; in contrast, cultivar accounted for ⩽0·010 of the variation for many traits. Below 40°N, rapeseed is a risky crop; short season, high temperatures and low rainfall during reproductive growth diminished seed yield and oil content, increased oleic and erucic acid and minimized linolenic acid. A hybrid, Exact, with tall stature and large seeds was adaptive to such conditions. The most productive location had dense stands with tall plants bearing numerous pods on the main raceme. At the site with the coldest winter, plant density (PD) was lowest (ca. 30 plants/m2) but rapeseed compensated by producing large seeds, with high oil content and harvest index (HI). A biplot revealed that the hybrid Excalibur, outperforming the other cultivars for oil content in six out of eight trials, produced the highest and most stable oil yield. Combined data showed that seed yield and oil yield were positively correlated with PD, seed size and HI and negatively to the number of pods on branches and per plant. Large seeds had high seed oil content. Oleic acid was negatively correlated to linolenic acid concentration. High temperatures and low rainfall favoured oleic acid, which was positively associated with seed number per pod.

Quantifying plant biomass and seed production in camelina (Camelina sativa (L.) Crantz) across a large range of plant densities: Modelling approaches

“…However, earlier traits used as essential yield components for seed production per plants such as pod length (Zhang et al, 2010), seed weight per pod (Yang et al, 2012), number of seeds per pod (Chay & Thurling, 1989), and 1000‐seed weight were not significantly correlated with seed yield per plant of B. napus (Bennett et al, 2017). It is noteworthy that the studied traits (i.e., number of seeds, branches, and siliques per plant, and 1000‐seed weight) were not correlated to seed yield (g m −2 ) of camelina (Table S1), similarly to previous results on B. napus (Tsialtas et al, 2017). Contrarily, the results of Berti et al (2011) on camelina indicated that the siliques number per plant and 1000‐seed weight are the leading yield components related positively with seed yield of camelina.…”

“…Contrarily, the results of Berti et al (2011) on camelina indicated that the siliques number per plant and 1000‐seed weight are the leading yield components related positively with seed yield of camelina. The present work showed no correlation between seed yield and plant height as reported by Tsialtas et al (2017). The reason of obtaining this result is not clear but it may have something to do with the plasticity of the yield parameter in the camelina, as previously proposed by Urbaniak et al (2008), McVay and Khan (2011), and Gesch et al (2018), who repeatedly reported that the seed yield (g m −2 ) is little affected over a large range of plant densities because of its yield plasticity.…”

Factors Affecting the Sustainable Adoption of Oilseed Crops in Punjab: A Case Study of District Layyah

“…Breeders and agronomists have a significant challenges in developing new varieties with more reliable yields and quality features. To do this, we must uncover and evaluate data from multi-environment studies that previously had been buried (Tsialtas et al, 2017). Sunflower may become the preferred oilseed crop due to global environmental changes and its capacity to thrive in various agro-ecological situations, including mild drought.…”

The Influence of Herbicide Underdosage on the Composition and Diversity of Weeds in Oilseed Rape (Brassica napus L. var. oleifera D.C.) Mediterranean Fields

“…The oilseed rape crop, which we studied in the present paper, is considered a strong rooting-break species and an improver of soil structure [32,33]. For this last reason, in Mediterranean environments, it is commonly grown in an annual rotation with winter cereals [32,34,35], thus minimizing the risk to cause the selection of herbicide-weed resistance when herbicides are applied at reduced doses.…”