Sunflower Power & Health

October 10, 2016

WITH PERHAPS 25 MILLION ha (62 million acres) of sunflowers grown for seed oil worldwide, sunflower diseases and pests and their remedies have a global impact. “Sunflower oil can be used as an alternative or additive to diesel fuel to create biodiesel, a clean-burning alternative fuel produced from a renewable resource,” wrote G.J. Seiler, one of many worldwide contributing authors to the Compendium of Sunflower Diseases and Pests, a book produced by the American Phytopathological Society (APS), a scientific group whose essence includes plant doctoring, discerning what makes for healthy versus diseased plants. “Use of the product may decrease farmers’ dependence on petroleum fuels by substituting ‘farm-grown’ fuel for use in diesel engines. For use in diesel engines, sunflower oil requires more extensive purification, including removal of waxes and gums. Minor engine modifications, such as improved fuel filters, are also necessary to burn any vegetable oil. Since the energy content of sunflower oil is less than that of diesel fuel, consumption is greater and power output is less.” However, the high-protein residues leftover from sunflower oil extraction have the right amino acid balance to mix with soybean meal to grow healthy chickens and livestock, a virtuous ecological cycling of sunflower plants.

Indeed, in Argentina’s southern Pampas, if you get the planting times right, sunflower and soybean are compatible as intercrops. Working in agriculture, I observed sunflower border rows or perimeters around conventional crop fields attracting pollinators and natural enemies providing biological control of pests. However, sunflowers are so attractive to beneficial insects that they do not want to leave. Thus, sunflower stalks need vigorous shaking to get green lacewings and natural enemies of aphids and other pests to take flight into adjacent crops needing protection. At the moment, fields of GMO canola producing high quality cooking oil are displacing sunflower fields in many areas. But the APS sunflower Compendium awakened my love for sunflowers, as even the diseases afflicting the plants have a certain beauty under the microscope. So, I can see the APS sunflower Compendium serving as an outstanding library reference for biology teachers and students looking for projects in sunflower-growing areas.

R.M. Harveson opens the APS sunflower Compendium with a brilliantly concise narrative chronicling the journey of sunflower seeds from their native North America to Russia, where innovative plant breeders painstakingly created the first modern sunflower seeds high in oils, providing the platform for today’s worldwide sunflower industry. The Mennonites, an anti-violence religious group migrating from Germany (Prussia) and a war-plagued Europe to Russia in the 1780s for free farm land promised by Catharine the Great, pioneered commercial sunflower oilseed farming in a harsh landscape long thought unsuitable for even subsistence farming. Their descendants were lured to Saskatchewan and Manitoba, Canada to create North America’s sunflower industry. During World War II, when “securing the fields of Ukraine was a major objective of Adolf Hitler’s war on Russia,” sunflower oil was a superior antifreeze, lubricating World War II weapons that froze with conventional gun oils. Joe Pappalardo’s excellent and entertaining book, Sunflowers: The Secret History: The Unauthorized Biography of the World’s Most Beloved Weed (Overlook Press) adds color and specifics, and is cited in Harveson’s “Selected References” in the APS Compendium.

Personally, I love the feel on my head and hair of a shampoo blending organic sunflower oil, citrus oils and herbs; and organic sunflower seeds at breakfast supply trace minerals like zinc, which is often deficient in produce grown in local California soils. Sunflower sap, which occasionally has been used medicinally, contains terpenoid compounds that show potential as alternative botanical pesticides. As ingredients in traditional medicines, wild sunflowers have been used for everything from wound healing and rattlesnake bites to combating infection and pain relief. Modern medical uses include topical oil formulations with sunflower oil to improve skin health, fight fungal infections, relieve inflammation and itchy, dry skin, and in dentistry to improve the gums.

Seed hulls of certain sunflower varieties are traditional sources of yellow, ruby red, purple, and black dyes or colorants (e.g. anthocyanins) useful in body painting, cosmetics, foods and textiles. Indeed, some plant breeders are working on a sunflower seed that would be high in oil and have a ruby red husk or hull that could be extracted to replace commercial synthetic red food dyes. Other researchers see the hulls as useful absorbents for wastewater reclamation. But by far, sunflower seed oils (e.g. NuSun for cooking) are the main sunflower item of commerce, and even trade on the commodities futures markets. Sunflowers seeds like Mammoth Russian for eating and snacking or adding to birdseed blends are important crops, but minor compared to the large acreages of sunflower oilseeds grown worldwide.

For various reasons, sunflowers have not become commercialized as a biotech GMO (Genetically Modified Organism) crop, which makes life easier for organic growers. Though perhaps better known from Van Gogh canvases, sunflowers were experimental subjects on the USA’s Apollo space missions. And “sunflowers have been successfully used as vehicles for the phyto-remediation of soil contaminated with heavy metals and radioactive materials (e.g. following the Chernobyl disaster),” wrote Harveson. In March 2011 after the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident, sunflowers and sunchokes were among the “alternative technology” plantings to concentrate and remove from soils radioactive cesium, which emits gamma rays and has a 30-year half life.

Sunchokes or Jerusalem artichokes, perennial sunflowers grown for edible tubers high in inulins, are sometimes recommended for diabetes and cardiovascular diseases, being associated with lowering blood sugar and cholesterol. Indeed, Jerusalem artichoke chips have been tested as a snack food alternative to potato chips for diabetics, being almost devoid of starch and fats. Several dozen other sunflower species are known, including one that is 92% pure natural rubber. Most likely sunchokes and other sunflower species including backyard ornamentals are subject to pests and diseases similar to those described in the APS Compendium.

To prevent pests and diseases, as a kind of insurance, perhaps 95% of commercial sunflower seeds are coated with neonicotinoid pesticides (e.g. thiamethoxam, clothianidin) at planting time, according to Michael Bredeson of South Dakota State University in Brookings at the 2015 joint meeting in Minneapolis of the Entomological Society of America (ESA), the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America. Bredeson studied 11 commercial sunflower fields, and found that “the seed treatment failed to improve yield or decrease herbivores.” In other words, quite apart from whatever effects on honey bees and beneficial organisms higher in the food chain, the neonicotinoid seed treatments are mostly a waste of resources and money. Though perhaps they do buy peace of mind for commercial sunflower growers, much like any insurance policy.

But the peace of mind bought by unnecessary early-season pesticide seed treatments may bring ecological food chain effects that cost sunflower growers more money and crop loss later in the season. The neonicotinoid pesticides may enter the food chain via plant nectar, plant tissues and predator consumption of tainted prey. Indeed, Pablo Gontijo and colleagues (2015) reported that sunflower seeds treated with thiamethoxam poisoned minute pirate bugs (Orius insidiosus), which are major predators of aphids, caterpillars, spider mites and other pests. Part of the problem is that the beneficial bugs, besides eating pests, also suck moisture directly from plants and thereby become poisoned by systemic pesticides used as sunflower seed treatments.

Likely the poisoned pirate bugs are only the tip of the proverbial iceberg. At the 2015 ESA meeting, Sirilak Lankaew from RYFCRC in Rayong, Thailand reported that cassava cuttings treated preventively with thiamethoxam provided 1-2 months cassava mealybug protection at the cost of food chain effects on beneficial insects via poisoned cassava nectar. Specifically the wasp Anagyrus lopezi, a cassava mealybug natural enemy, feed on the poisoned cassava nectar and “experience acute mortality for up to 21 days after treatment, and have significantly reduced lifespan for at least 42 days after treatment.” With 8 million farming households in Thailand growing cassava and 70% of Thailand’s small-scale farmers using neonicotinoid pesticides, there is a need for alternative technologies “fully compatible with (naturally-occurring and cost-free) biological control.” In sunflower, something like the APS Compendium to identify the potential problems is a good first step towards minimizing unnecessary pesticide treatments and developing alternative technologies.

One approach to developing sunflower soils that are disease-free and avoiding seed treatments is the opposite of crop rotation. Namely growing the crop repeatedly in the same soil so that disease organisms build up and then are destroyed by natural biological agents. It is like the predator and prey cycle, where pests buildup to high levels and even cause some damage before being opportunistically exploited and knocked down by their natural enemies. This approach, known as building a disease suppressive soil, can take a few years; and is perhaps best suited to patient organic growers with the wherewithal to weather those tough early years, and possessed of a confidence, hope or faith that the natural cycles will eventually play out. Likely the Mennonites whose experiences Joe Pappalardo recounts in his book took this route in turning the barren Ukraine, Russian and Canadian lands into productive agricultural fields in the era predating intensive chemical agriculture.

Another interesting alternative technology with ancient roots is interplanting, the idea of mixing different crops in the same fields. In Pakistan, sunflowers are being considered as a healthful alternative for local cooking oil shortages via interplanting sunflowers with the staple mungbean crop. In Florida, sunflower strips have been proven to attract honey bees and a variety of predators and parasitoids supplying natural biological pest control to adjacent organic vegetables. In China, parts of Asia and Africa, and even the Americas, sunflowers are viewed as an alternative technology to reduce herbicide use. Sunflowers provide natural weed control via shading the ground and natural herbicidal compounds (allelochemicals) toxic to some of the world’s worst weeds, such as dodder and barnyard grass. Multiple benefits if you can get rid of a weed patch, produce beneficial insects and pollinators, and harvest some seeds at the same time.

The health benefits of sunflowers will likely be a key driver for this crop in the future, though medicinal sunflower benefits are far from the cutting edge of agriculture and medical research in the genomic era. Broader medical applications may involve anti-inflammatory and cardiovascular benefits, bone health, detoxification, skin protection (e.g. from light & anti-aging) and anti-cancer effects. Applied to the skin, sunflower oil formulations may reduce bacterial and fungal infections, and are touted by some for premature newborns. In Cuba a product called Oleozon, sunflower oil treated with ozone gas, was registered in 1999 to treat fungal skin diseases (tinea pedis); and can stop bacteria and viruses resistant to multiple drugs.

Interestingly, researchers in Iran writing in the Journal of Food Science and Technology like the idea of infusing highly unsaturated oils like sunflower seed oil with raspberry or related Rubus species (e.g. blackberries) as a GRAS (Generally Recognized As Safe) alternative to preservatives like BHA and BHT. Rubus leaves add other medicinal properties to sunflower oil, “including as astringent, hypoglycemic, anti-diarrhea, anti-inflammatory agents for mucous membrane of oral cavity (mouth) and throat.” Many other oils and herbs may have medicinal value when combined with high linoleic acid sunflower oil. Time will tell.

The whole idea of plant medicines may yet return to modern medical practices for a variety of reasons. “Extended life expectancy is accompanied with an increase in age-related pathologies that include cardiovascular and neurological diseases, obesity, and cancer, conditions that are inflicting an immense pressure on health care costs and quality of life,” write researchers Andrea Doseff and Erich Grotewold at The Ohio State University and Arti Parihar in Ujjain, India, in the book, Pigments in Fruits and Vegetables (Springer, 2015). “Thus, there has been an increased interest in recognizing and understanding the mechanisms of action of active nutritional compounds with health benefits, or nutraceuticals, for the prevention and treatment of various diseases.”

The researchers in India and Ohio note that over 8,000 flavonoid chemicals beyond vitamins have been identified, including a range of anthocyanins like those in sunflowers, “which are responsible for providing colors to fruits and vegetables, and have dietary value as color additives with potential health benefits.” Over 10,000 tons per year of anthocyanins from black grapes alone are consumed every year, and this whole general category of plant pigment compounds has “uses in the prevention and treatment of inflammatory diseases including cardiovascular diseases, obesity, and cancers.” Who knows what concentrated research into sunflowers would reveal?

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Compost for Sustainable Soil Fertility & Disease Suppression

July 24, 2010

ABOUT A THIRD of farm energy used for food growing supplies fertility. In Florida alone, the energy used to manufacture the 2 million tons of food crop fertilizer each year equals the energy content of 100 million gallons of diesel fuel. Thus, recycling or composting waste materials into fertilizers and mulches can save energy while reducing pollution and enhancing human and crop health.

In the book Farmers of Forty Centuries; Or, Permanent Agriculture in China, Korea and Japan, early-1900s agricultural scientist Franklin Hiram King observed amazing levels of soil productivity where rural and urban human wastes were recycled back to the land and farmers planted legume (e.g. soybean; adzuki bean; clover) and other green manure cover crops and crop rotations.

“Japanese society once faced the prospect of collapse due to environmental degradation, and the fact that it did not is what makes it such an instructive example,” writes Azby Brown in his 2010 book, Just Enough: Lessons in Living Green from Traditional Japan. “Japan entered the Edo period in 1603 facing extreme difficulties in obtaining building timber, suffering erosion and watershed damage due to having clear-cut so many of its mountains for lumber, and virtually unable to expand agricultural production…All the more remarkable, then, that 200 years later the same land was supporting 30 million people-2.5 times the population…Deforestation had been halted and reversed, farmland improved and made more productive, conservation implemented…Overall living standards had increased, and the people were better fed, housed, and clothed, and they were healthier. By any objective standard, it was a remarkable feat, arguably unequalled anywhere else, before or since.”

Human waste, euphemistically called night soil, became a valuable soil fertility commodity in old Japan. Perhaps not quite worth its weight in gold, but a valuable commodity bought, sold, traded, and transported long distances from cities to farms. Rather than causing cholera and other diseases by entering the water supply as was common in European cities of the same era, sanitation and composting blessed Japan with multiple dividends. Considerable energy was “expended on toilet design to allow these waste products to be easily collected and processed,” writes Brown. This has culminated in modern dry composting toilets that “by allowing natural composting heat to occur inside a well-ventilated compartment…turn human waste into a dry, nearly odorless compound that looks and feels like peat moss.”

Farmers in old Japan spent their own money to “build toilets and urinals along well-traveled roads for public use, in the hopes of increasing their yields of fertilizer.” Contrast this with the modern difficulty of finding a decent, well-maintained public toilet along roadsides or in cities. China, says Brown, “is poised to become the global leader in composting toilets, partly because relatively few communities are served by the sewer infrastructure and the government is promoting these new designs as an attractive alternative that will help mitigate its freshwater problems as well.”

In the modern Western world, scientists in Germany and the USA have advanced the conversion of animal manures and green plant wastes into composts and tea sprays that boost plant growth and suppress pests. Though long a staple of biodynamics and organic gardening, in the 1980s University of Bonn researchers like Heinrich Weltzien, Andreas Trankner and Ketterer provided experimental proof that watery compost tea sprays high in beneficial microbes reduced powdery mildew on grapes and late blight disease on potatoes. Indeed, in some experiments compost tea sprays formulated from grape marc, earthworm compost, and animal manures equalled synthetic fungicides.

In the USA, in 1969 reports surfaced that some Ohio nursery growers had conquered root rot diseases in rhododendrons, cyclamens, and other ornamentals using pine bark composts and no longer needed methyl bromide soil fumigations. Ohio State University’s Harry Hoitink embarked on scientific studies of this phenomena. To reliably control the plant pathogens causing root rots and other soil diseases, hardwood bark composts were aged like fine wines for 6-12 months or fortified with special biocontrol microbes. In Australia, eucalyptus bark is similarly composted to combat Pythium and Phytophthora root rot pathogens in container or potted plant soils and avocado orchards.

Insect pests can also be controlled with composts. For example, Cornell entomologists like Michael Villani and Roxanne Broadway stopped white grub beetle larvae from attacking turf and lawns using crude proteins extracted from composted leaves and kitchen food wastes. Composted chicken manure and feathers worked best against caterpillars (moth larvae). Cornell University’s Eric Nelson and others have spent years formulating composts to combat root rots on golf greens and maladies like dollar spot and brown patch.

It may take a year or two of aging to brew the right combination of pest-suppressive beneficial microbes in composts. In Japan, composted golf course grass clippings are specially inoculated with a strain of the beneficial bacteria Bacillus subtilis to hasten suppression of the fungus Rhizoctonia solani on golf courses.

However, compost is not always a quick cure. For example, several years of compost applications are needed to control soybean cyst nematodes in agricultural fields or to restore Japanese forest soils. That is because plant ecosystems are complex adapative systems.