The development of the commercial sunflower has been a multi-national effort spanning continents and thousands of years. The sunflower is native to North America and was first grown as a crop by indigenous tribes over 4,500 years ago.
Native Americans cultivated the sunflower from its original bushy, multi-headed type to produce a single-stemmed plant bearing a large flower.
The crop’s multiple uses included milling for flour or meal production to make bread and cakes. Seeds were roasted, cracked and eaten whole, either as a snack or mixed with other grains, nuts and pulses into a type of granola.
The early Americans also discovered that sunflower oil could be extracted and used for cooking.
Aside from the crop’s value as a food, archaeologists have shown sunflower had a variety of non-food uses.
The sunflower’s oils and pigments were used as a sunscreen or the basis for a purple dye for skin, hair or textile decoration, while the plant’s sturdy, fibrous stem was exploited in construction.
The sunflower continued as a staple within North America for about 4,000 years until it was discovered by European explorers in 1510. Spanish sailors were the first to gather up large quantities of sunflower seed and ship it back to Europe.
But for the next 200 years, Europeans overlooked the food and oil-bearing potential of sunflowers. Instead the exotic-looking flowers became widespread across Western Europe as an ornamental or, to a lesser degree, medicinally as an anti-inflammatory.
Sunflower growing developed throughout the 1700s and had spread across Europe into Russia and Ukraine by the turn of the 19th century.
It is in Russia where the crop’s potential for oil production was established. But that development was due in part to a quirk of fate and the Russian Orthodox Church.
During the 18th Century the Church issued a diktat for the period of Lent which banned the consumption of food made from various oils and fats.
To help churchgoers adhere to the rule, the orthodoxy published a list of banned substances. However, it omitted sunflower oil from the list.
Demand for sunflower oil boomed and the crop area expanded to more than 800,000 hectares across Russia and Ukraine in the early 1800s.
As the acreage continued to grow, the market for the crop diverged into two distinct areas – oilseed and seed consumption.
With this divergence, the Russian government established the first research programmes to develop varieties that met the requirements of the twin markets.
An enormous variety known as the Mammoth Russian was developed in the late 1800s. It was packed with many hundreds of large achenes with heads often recorded at more than 50cm in diameter.
At this time a steady trickle of eastern Europeans had begun to emigrate to North America. Among them were Russian settlers who began to import the sunflower, predominantly as a protein-rich animal feed.
The sunflower’s success as an animal feed in the US drove up the planted area and new markets began to emerge with oil processing units founded from the mid 1920s.
The popularity of the sunflower spread across the northern border and the Canadian government began a breeding programme in 1930.
Post war, the growing area continued to rise both north and south of the US border and more farmers began to include sunflower in their rotations. However, the Russian breeding programme, driven by Pustovoit, continued to underpin any performance advancements and the Canadian Government licensed the use of the cultivar Peredovik. This seed produced high yields and high oil contents of about 45% and continued to push up the profitability of the crop.
By the late 1960s breeding programmes had developed beyond yield and oil content alone. Desirable traits like improved disease resistance were being targeted.
However, efforts to create true hybrids were being limited by the sunflower’s ability to self-pollinate with its male and female reproductive parts. This meant attempts to introduce new traits from donor plants were being diluted by the sunflower’s own pollen.
Then, in 1969, a French researcher called Leclercq made a breakthrough that would change sunflower breeding forever.
Working at the French Agricultural Institute (INRA), Leclercq discovered a method of switching off the male part of the flower in a process known as cytoplasmic male sterilisation. This meant pollen from a donor sunflower could be inserted into the still-functioning female reproductive structures of another without dilution from the plant’s own genetic material. One year later in 1970, a US Department of Agriculture scientist called Kinman discovered how to switch the male fertility back on in the resulting hybrid.
Breeding programmes could then, for the first time, create true commercial hybrids that exploited combined traits from different parent plants.
The twin breakthroughs fostered a new age of trait development. Seed companies could market distinct varieties, boasting greater disease resistance and higher yields along with other traits tailored for the confection or oil markets.
These advancements came at a time when the public began to develop a more health conscious approach to their diets. Research in the 1970s showed that sunflower oil was a healthier alternative to the traditionally-used saturated fats. Europeans, in particular, switched to sunflower oil products and demand quickly outstripped supply and the crop boomed.
Over the past 25 years the sunflower market has continued to grow and it now ranks as the fourth most important oil crop in the world, after palm, soybean, and rapeseed.
Market changes have seen the main production area for the crop swing back again to eastern Europe with Russia and the Ukraine dominating global production. In 2017 these two countries combined, accounted for more than 11m tonnes of the world’s 47.9m tonne total sunflower seed production.
According to FAO figures, Russia was marginally ahead with 5.97m tonnes produced against the Ukraine’s 5.81m tonne yield.
Estimates suggest that the crop is worth US$20bn a year, globally.
Notably the increase in seed production has outpaced the area of land devoted to the crop.
Back in 1994, the 18.6m hectares of sunflowers grown yielded a total of 22.0m tonnes of seed.
Twenty-three years’ later the area harvested had risen to 26.5m ha – a 35% increase. But the total yield had more than doubled to 47.9m tonnes.
The performance improvement shows how breeders have continued to hybridise the modern plant over the past three decades. And, how yields have improved despite important new factors emerging that influenced which traits should be targeted.
Rising pressure to reduce overproduction which had been stimulated largely by agricultural support mechanisms in Europe meant yield increases alone were no longer the Holy Grail for breeders. Climate change concerns have also refocused breeding efforts to produce plants that perform better in drought-stressed conditions. For example, altered head shapes to address sunburn, bird damage and diseases have been selected.
“Herbicide resistance has really changed the way farmers consider sunflowers. In years past cultivation was the primary tool for weed control, it was time consuming and wasn’t able to eliminate the weeds that were in the row. Today we select hybrids for they resistance to available herbicide packages. This technology has allowed farmers to be more efficient with their time, and do0 a better job controlling the weeds, resulting in higher yields and cleaner yields.” says Jeremy Klumper, Sunflower Breeder.
‘In more recent years the search for an increasingly diverse number of target traits has been aided by developing technology. At Nuseed, we use genomics to identify gene markers for desirable traits. Although the genetic structure of the sunflower is relatively complex compared with rape and rice, marker assisted selection is beginning to identify candidate genes for improvements.’
Nuseed researchers now have a lengthy list of target traits for the future including:
* Higher seed and oil yield hybrids
* Increased resistance to diseases like downy mildew
* Drought tolerance
* Improved oil properties to maintain appeal to health-conscious consumers
* Confectionary hybrids with lower oil content
* Herbicide-resistant hybrids
* Plant height, ray and disk flower colour
* Flowering period to exploit markets and climate conditions