Crop and Pasture Science
Volume 67 Numbers 3 & 4 2016
Pathways to Improved Canola Productivity
Canadian farmer canola yields have increased by 54 kg ha–1 year–1 from 2000 to 2013. The yield improvement was likely due to the use of new hybrid varieties with herbicide tolerance, increased spring precipitation and atmospheric CO2 concentration, and the increase in the use of minimum tillage and better weed control. Future yield goals are discussed.
CP15217Canola integration into semi-arid wheat cropping systems of the inland Pacific Northwestern USA
The inland Pacific Northwestern U.S. has lagged behind similar semi-arid wheat regions in producing oilseeds such as canola. The sustainable integration of canola in this region is challenged with uniquely dry and hot conditions during much of the active growing season, dictating production zone-specific rotation and seeding strategies, as well as nutrient, water, weed and subsoil management.
Blackleg disease caused by the fungus Leptosphaeria maculans is the most important disease of canola worldwide. The impact of this disease on the development of the Australian canola industry, particularly over the last 20 years, is discussed.
Timing of life history events (phenology) is a key driver for the adaptation of grain crops to their environments. Canola breeders face the challenge of developing productive, well-adapted cultivars in the face of global climatic change. We review current knowledge of canola phenology with a focus on flowering time, the genes controlling it and the genomic technologies available to help breeders develop improved cultivars.
CP15283Quantitative genetic analysis of grain yield in an Australian Brassica napus doubled-haploid population
CP15290Assessing progress in breeding to improve grain yield, quality and blackleg (Leptosphaeria maculans) resistance in selected Australian canola cultivars (1978–2012)
Canola is the third largest winter crop in Australia with breeders targeting increased yield, improved quality and resistance to the disease blackleg. Over a 30 year period, grain yield increased by 1.25% per year with 25% of this coming from improved blackleg resistance. Oil and protein content increased by 0.9% and 0.5% per year respectively. Future rates of improvement will need to increase to remain competitive in global markets.
CP15248Relative yield and profit of Australian hybrid compared with open-pollinated canola is largely determined by growing-season rainfall
Profitability of hybrid and open-pollinated (OP) canola can help farmers to decide which canola to grow and has a significant impact on future canola breeding. We compared the yield and gross margins of hybrid and OP canola and investigated the relative advantage of these technologies across a wide range of environments in Australia. Hybrids had yield advantage over OPs in the high yielding environment, but showed little yield or no profit advantage over OPs in the low yielding environment. We conclude the Australian canola industry would be well served by continued availability of OP varieties.
A sophisticated module for the grain crop canola in the Agricultural Production Systems Simulator is described. The module simulates crop development, growth, yield and nitrogen (N) accumulation in response to temperature, photoperiod, radiation, soil water and N supply. A number of areas of attention and improvements required are described.
In order to predict phenological development according to the BBCH coding system for winter oilseed rape within crop growth models we developed a new phenology model from existing approaches. The model was calibrated and validated using data from Germany, Italy and France covering a wide range of years, locations, sowing dates and genotypes. This provides an efficient and widely applicable prediction tool with relevant practical purposes in crop management scheduling.
CP15213Contribution of phase durations to canola (Brassica napus L.) grain yields in the High Rainfall Zone of southern Australia
CP15236Seed yield of canola (Brassica napus L.) is determined primarily by biomass in a high-yielding environment
Biomass and harvest index are two important traits to canola yield. We compared the yield performance of several hybrid and open-pollinated canola over 3 years in southwestern Australia and aimed to identify the key drivers of yield formation. Seed yield of hybrids was attributed primarily to greater biomass in the high yielding environment.
CP15282Re-evaluating sowing time of spring canola (Brassica napus L.) in south-eastern Australia—how early is too early?
A review of sowing date responses in canola for south-eastern Australia suggests that current recommendations for optimal sowing in late April can be moved into early to mid-April with suitable variety choice. Early- to mid-April sowing generated the highest or equal highest yield and oil content in eight out of nine experiments in south-eastern Australia from 2002 to 2012. Declines in seed yield (–6% to –6.5%) oil content (–0.5 to –1.5%) and water-use efficiency (–3.8 to –5.5%) occurred per week delay in sowing after early-mid April.
CP15373Plant density response and optimum crop densities for canola (Brassica napus L.) in Western Australia
We re-evaluated crop density recommendations for canola in Western Australia as increasing adoption of hybrid and glyphosate-tolerant cultivars makes seed more expensive for growers. Economic optimum densities varied widely, but were higher in high yielding environments and for open-pollinated triazine-tolerant cultivars with cheaper seed. There was only a small economic cost for missing the optimum by a small amount, or quite a large amount for open-pollinated triazine-tolerant cultivars, which means growers have some flexibility choosing seed rates.
CP15286Optimising canola establishment and yield in south-eastern Australia with hybrids and large seed
April sowing of canola is considered optimal for grain yield in most canola growing regions of Australia, however surface seedbed moisture is not always available. We found that by increasing the seed size of canola, seed could be safely planted relatively deep into residual moisture from fallow rainfall events. Improving the reliability of establishment in April will help producers capture the profitability and break crop benefits that canola provides.
Efficient and effective nitrogen (N) management depends first on supplying ~80 kg N/t of water-limited yield potential, less indigenous N supply. Fertilizer N can be supplied over two, three or even more applications, as splitting is usually as efficient as at-sowing application. Improving N management will require better tools to assess in-crop N status and evaluating guidelines for the use of enhanced efficiency sources, including opportunities for late application.
CP15214Impacts of high intensity crop rotation and N management on oilseed rape productivity in Germany
The global oilseed rape (OSR) growing area has increased considerably during the last decades and thus caused shorter rotations in many areas of the world. Short rotations, however, cause a yield decrease of OSR and less oil production per acreage. To maintain high yields and quality standards and to grow OSR in a sustainable and environmentally friendly manner short rotations with OSR are not recommended.