By Daniela Carrijo
Introduction
During the last few years, there has been an increasing interest in growing sunflowers in Pennsylvania. There are significant markets for sunflower seed and sunflower products, like oil, in the state but traditionally these have been imported from other states or overseas. Recent disruptions in world grain trade and higher transportation costs have caused higher prices for sunflower products like birdseed and sunflower cooking oil. This has created some interest in increasing local production and processing in the state.
Sunflowers are also increasingly used as part of an agritainment enterprise on some farms where sunflower mazes, festivals, photo opportunities, and cut flower sales can generate significant income. Sunflowers can provide a nice link between the farm community and the general public. Sunflowers have also been used as part of cover crop mixes in the state. They have a deep taproot system and can help alleviate compacted soils. Sunflowers also serve to provide some diversity to cover crop mixes and provide pollinator services to honeybees and Monarch butterflies, as well as feed for wildlife and birds.
There were 841 acres of sunflowers grown for grain reported in the 2017 Pennsylvania Census of Agriculture. That acreage reported a yield of over 971,000 lbs of sunflowers. We feel that sunflower acreage has likely doubled since then due to increased farmer interest and profitability. Because of the growing interest in sunflowers, we have reviewed production practices being used by producers in the state and other states to develop some sunflower production recommendations for Pennsylvania.
Crop rotations
Sunflowers can be grown as both a full season crop and as a double crop following barley or wheat. In PA, the most profitable opportunity appears to be as a double crop, in which it would compete with double crop soybeans. Sunflowers are a bit more frost tolerant (typically killed at 28 F compared to 30-31 F for soybeans) and therefore can likely be planted later. In addition, sunflowers are more drought tolerant and have a lower seed cost. These advantages can lead to a more profitable double crop than soybeans in some environments.
Variety types and markets
Sunflowers are generally produced as either black oil seed or striped seed (also known as confectionary) type. Generally, the black oil seed varieties are used for oil and birdseed. The striped varieties are also used for birdseed but are mostly used as snack food. Within the oilseed type, there is variation in the oil content and composition. Generally high oleic (typically >85% oleic acid) varieties are of best use for oil, whereas both mid-oleic and high oleic can be used for bird seed. For the agritainment sector there are a lot of interesting sunflower varieties available in garden seed catalogs that can add diversity to a sunflower planting. These can have different colors, with various shades of yellow or even orange, red or white flowered varieties. All varieties targeted for commercial production are hybrids and all were developed through traditional breeding (there are no GMO varieties to date). Many hybrids have the Clearfield trait which provides resistance to the herbicide imazamox (trade name Beyond) and facilitates weed management.
Planting date
Sunflowers are similar to soybeans in that they can be planted from late April until mid to late July in some areas. For May plantings, sunflowers would compete with high yielding full season crops of corn or soybeans and that may be a challenge economically. Sunflowers are better able to compete with soybeans under double crop conditions, especially under lower yielding double crop soybean conditions.
Variety selection
A big driver of variety selection is the end use. Always check with your market to see if they have special requirements for varieties. As with many crops, sunflower varieties vary in maturity. Planting to maturity can take from 70 to 100 days depending on the variety. Varieties in the 70 to 80-day maturity range seem to be most adapted for double crop production after small grains. We started a research trial in southeast PA looking at two varieties differing in maturity (100-day and 70-day) and planted at two populations (25,000 and 45,000 plants per acre). Stay tuned for research results at the end of the season.
Row width and plant population
Sunflowers can be planted in 30 or 15-inch rows or sown with a grain drill. Most reports from growers in PA have settled on 30-inch row placement with 1-inch deep settings. There are also reports that planting north to south is best with the heads facing either east or west into the rows so birds cannot perch on adjacent heads to feed. This can also assist in the flow of heads into the combine head. Generally, a final stand between 25 to 30,000 plants per acre should be the goal. For best yields, good emergence and uniform stands are critical. While sunflowers will produce bigger heads at lower populations, they do not appear to be as plastic as soybeans in compensating for low stands. As with soybean and corn, plant populations should be adjusted to accommodate varying soil and seed conditions. On droughty soils, seeding rates should be reduced and populations of 20-24000 plants per acre may be justified.
Fertility
Fertilizer requirements for sunflowers are modest. Penn State recommendations call for 70 pounds of N per acre for a 2000 lb yield goal and a crop removal of 40 pounds of P2O5 and 30 pounds of K2O. On many of our soils with a history of manure, P and K can be eliminated and N recommendations can be reduced. Locally growers are achieving 2200lb double crop yields with 40 lb of applied N. Excessive N applications could result in more lodging and disease severity and should be avoided.
Weed control
There are numerous products labeled for control of weeds in sunflowers commonly available at local dealers. Double-crop sunflowers have few weeds to manage. A few examples of potential sunflower herbicides include but are not limited to residual products containing metolachlor (Dual), sulfentrazone (Authority) and pendimethalin (Prowl) as well as post products containing quizafop (Assure), sethoxydim (Poast) or clethodim (Select). The key is to control broadleaves with residuals as in crop solutions for broadleaves are limited for this crop.
Insects and disease
There have been few insect problems reported in Pennsylvania production fields so generally there is not a need to spray insecticides. There are also some diseases that may impact the crop. Seedling disease could be an issue in some environments since sunflowers lack the vigor of soybeans. Benefits to seed treatments with fungicides have been reported in some areas to improve stands and rooting at seedling stages. Other potential sunflower diseases that might be a problem in our area include Sclerotinia (white mold), and leaf diseases like Alternaria leaf blight, Septoria leaf blight, and leaf rust. These might be a particular problem under the high humidity in late season double crop production in Pennsylvania. Growers have done some trials with an early heading application of a fungicide with positive results. However, more research in this area is required and response can vary from farm to farm.
Wildlife
Birds, deer and groundhogs can all be pests of sunflowers. For deer and groundhogs, management tactics would be similar to those used for soybeans. For birds, as mentioned previously, planting in north south rows helps to avoid feeding damage. It may be necessary to avoid planting near wetlands or other areas with high densities of birds. Larger fields also help to limit damage compared to small, isolated fields. Applications of fungicides at heading may be warranted if diseases are present on leaves below the seed head. Scouting is important. In our plots near Lebanon PA last season we saw a 400lb per acre increase on fields with visible disease and no response where diseases did not exist.
Harvesting
Sunflowers are generally ready for combine harvest when the back of the flowers turn brown. Sunflowers may be harvested with numerous types of combine heads. However, the harvest loss may be extreme with many heads. Local farmers have modified heads to reduce harvest loss. One example is this row crop head modified with a simple pan that funnels shattered seed back on the platform. Be sure to carefully investigate combine headers before harvesting on a large scale.
Yield performance:
There is not a lot of yield performance data available in Pennsylvania and most of what is available is double crop. Farmers report yields of 1500 to 2200 pounds per acre following wheat in South Central PA. The good double crop yield potential here could be due to late August and September rainfall we often get in our region, which would coincide with flowering, which is when sunflowers have the highest water requirements. These yields are comparable or even higher than that from states with similar growing seasons like Kansas or Missouri. The potential yield of full season sunflowers has not been documented well, but we would estimate it in the 2500 to 3000 lb/ac range under good conditions. In many areas, such as the Dakotas, full season yields are comparable to our double-crop yield potential.
When harvesting sunflowers, be aware that they can produce a lot of dust. Sunflowers can require one or two cleanings to get the chaff out of the grain. Sunflowers also have a test weight of 30 lb/bu, so this requires more trucking for a given weight of sunflowers.
Sunflower prices fluctuate as other commodity prices do. Prices in sunflower producing areas in the Dakotas have ranged from 10 to nearly 30 cents/lb over the last 20 years. There is an additional cost to transport sunflowers to our markets for processing. Assuming a local price of 30 cents/lb, a 2000 lb/ac sunflower crop would generate more revenue than a 35 bu/ac soybean crop at $13.50/bu with less drought and frost risk.
Potential of sunflowers as a crop in Pennsylvania
Sunflowers have some potential to increase in acreage in our state. We have a large demand for sunflowers as birdseed, our snack food industry uses a substantial amount of sunflower oil, we have markets for the sunflower meal as a livestock feed, and we have shown there is a good potential for agritainment of sunflower fields. In addition, our producers have shown that good yields are possible under double crop conditions, and they seem to be profitable under current prices. Sunflowers are more drought and frost tolerant than soybeans, thus could be a good alternative in drought-prone areas or when planting is delayed. Sunflowers would also add some diversity to our grain crop rotations and provide benefits to pollinators and wildlife. That said, every new crop comes with challenges. If growing sunflowers for the first time, we recommend trying it out in a small acreage first.
Source : psu.edu