If you're looking for a new crop to incorporate on your farm this season, consider sunflowers. Their recently improved genetics and short growing season make them a good double crop.

In March, I attended a workshop on sunflower production and marketing. This workshop, co-sponsored by the Thomas Jefferson Agricultural Institute and the University of Missouri Extension, has helped stimulate a renewed interest in sunflower production east of the traditional Great Plains growing region.

Sunflowers require a shorter growing season and tolerate fall frosts better than soybeans or grain sorghum. This makes them a viable alternative, especially when planted behind winter wheat. Full-season sunflowers can also be grown in our region. In fact, you can expect 33 percent higher yields with full-season compared to double-crop sunflowers. However, unless you need an alternative rotation crop for pest management or have a unique market, conventional crops offer more economic potential in a full-season system.

It is a misnomer to classify sunflowers as an "alternative" crop in our region. They are native to the Midwest and were cultivated here 1,000 years ago. In modern times, there have been several sunflower production cycles, starting with the Southeast Sunflower Growers Association in 1926. Variety (hybrid) improvement and greater demand in the vegetable oil market have stimulated today's interest.

Are sunflowers an economic alternative to your current crops? Sunflower grain prices have ranged from $6.50 to $13.50 per hundredweight during the past 15 years. The 2000 price for sunflower grain was approximately 8 cents per pound with an additional 4 cents per pound Loan Deficiency Payment.

Respectable yields for double-crop sunflowers would be 1,500 pounds per acre. Therefore, growers would net $180 dollars per acre. Assuming equal production costs (big assumption), this would make sunflowers economically equivalent to 36-bushel-per-acre, double-crop soybeans selling for $5 per bushel.

Full-season sunflowers should only be grown in a given field one out of every three to four years. They are successfully rotated with corn, soybeans or grain sorghum.

Sunflowers perform well on most soil types and landscape positions except wet locations. They are deep rooting and can extract moisture and nutrients in a six-foot root zone. They can be produced in droughty environments, provided the soil is deep enough for adequate root proliferation. You may want to avoid sunflower production on shallow soils, wet creek bottoms (except those that are only wet in the early spring) or on soils with severe root-restricting layers.

Oilseed or confection
Most commercial sunflowers are hybrids. And there are two major sunflower types--oilseed and confection. Confection sunflowers are used in the snack-food industry. They should be planted at lower populations than oilseed types. Thinner stands stimulate large seed, which is preferred. Most sunflowers grown in our region will be oilseed hybrids. If growing sunflowers for the birdseed industry, choose oilseed hybrids that produce adequate yields under your growing conditions. NuSun oilseed varieties contain lower saturated fats compared to traditional oilseed hybrids. These seed types produce quality vegetable oils. High oleic acid sunflowers produce specialty oil used in lubricants and food coatings. Before choosing a hybrid, make sure any contracts or "identity preserved" requirements are defined and established.

Because of a relatively short growing season, sunflowers can be planted later or harvested earlier than most row crops. This flexibility spreads out planting and harvest seasons. The short season also allows you to switch to sunflowers if weather conditions cause severe corn, sorghum or soybean planting delays. For most hybrids, a June-planted crop will bloom in August and mature in mid-September.

Do not plant sunflowers into soils that are cooler than 50 degrees. This temperature requirement is rarely an issue for a late-planted crop in our region. Sunflowers should be planted at a soil depth of one to two inches.

When planted one-inch deep into a warm soil, sunflowers should emerge within four to five days. Sunflower production is not sensitive to row spacing. Thirty-inch row spacing is considered standard. Sunflower heads track daily with the sun early in their development, but by maturity all heads remain facing east. Some farmers like to plant their rows north to south so that the heads lean east into the inter-row space, making harvest easier and more efficient.

Sunflower seeding rate should be 15,000 to 25,000 seeds per acre. This is equivalent to three to four pounds of seed per acre. Hybrid sunflower seed has five size ratings ranging from 4,000 to 7,000 seeds per pound.

Weed and pest control
Weeds generally become a problem if they establish during the first two weeks after sunflower emergence. Sunflowers grow fast, especially in warm growing conditions that exist when planted after mid-June. Therefore new weeds are rarely a problem three weeks after emergence.

The wheat crop also provides some initial weed control to double-crop sunflowers. But volunteer wheat often becomes a problem weed. In full-season sunflowers, delayed planting is a good weed management strategy because it allows weeds to germinate before the burndown treatment.

Burndown, preplant, pre-emergent and postemergent herbicide weed control programs are available for sunflowers. A nonselective burndown herbicide should be adequate for late-planted or double-cropped sunflowers, provided a quick crop canopy is established.

Preplant incorporated products like Prowl, Treflan and Eptam provide good residual grass control. Spartan received a Section 18 this spring for preplant incorporated or pre-emergent residual broadleaf control in sunflowers. Postemergent grasses in sunflowers can be managed with Poast Plus or Select (new label in 2001) herbicides. Please review all labels and crop rotations before selecting sunflower herbicides.

Sunflower agronomists claim commercial hybrids do not become a volunteer weed problem. The reasons for this are: most seed left on the ground is eaten, sunflower hybrids rarely cross with weedy types, second-generation hybrid vigor is poor and sunflower hybrid seed purity is excellent.

Major sunflower insect pests include head moths, cutworms, midges, stalk borers, weevils and grasshoppers. Most foliar insect feeding is cosmetic and does not influence yield. In our environment, oil-type hybrids rarely require an insecticide application. But get to know the pests involved and be prepared to act when occasional outbreaks occur. Plan on at least one insecticide application with confection hybrids, as the snack-food industry does not like bugs, regardless of their protein value.

Birds are the most common animal pests to sunflowers. In large fields, this activity is relatively small and limited to field margins. However, in small fields, especially those surrounded by roosting sites, birds can become a problem. Avoid planting sunflowers in these areas. If full-season sunflowers are an option, early planting (May) will time harvest to occur before fall flocking.

Traditionally, root and stem fungal diseases caused severe sunflower production problems in our region. However, today's hybrids offer much greater disease resistance compared to a few years ago. White mold can be a problem. If you have seen this disease in soybeans, don't rotate to sunflowers. Most sunflower seed comes with a pretreated fungicide to defend against seedling diseases.

Several native sunflower species serve as hosts for sunflower-loving insects and diseases. These native sunflowers have variable growing seasons that spread host/infection dynamics over a wide time period. Avoid planting sunflowers in fields with a history of sunflower weed problems.

Nutrient requirements
Full-season sunflowers require 50 to 100 pounds of nitrogen per acre depending on the previous crop and yield goal. Double-crop no-till sunflowers require 80 pounds of nitrogen per acre. Some Great Plains growers prefer to sidedress nitrogen after emergence. But the appropriate nitrogen application timing in our region is immediately prior to planting.

Aglime, phosphorus and potassium nutrition for sunflowers should be based on soil tests and yield goals. If soil-test levels are optimum, crop removal quantities of potassium and phosphorus can be added anytime before planting for full-season or in addition to and applied with the wheat fertilizer application the previous fall for double-crop sunflowers.

Secondary and micronutrient fertilizers containing sulfur, calcium, magnesium, zinc and boron are rarely needed for sunflowers. They have a deep rooting system and can extract nutrients throughout the soil profile.

Sunflowers reach physiological maturity when the back of the head is yellow. Most producers harvest sunflowers when the back of the head is brown. If bird damage is severe or widespread lodging is occurring, harvesting between these growth stages followed by grain drying should be considered. Harvest is done with a combine, using row-crop headers, corn heads or a small-grain platform. A corn head will require the addition of a stationary knife. Pans added to a small-grain platform head will help control harvest loss. You will need to work on combine settings to address light-seed-weight issues. Cutting should be set as high as possible, only harvesting the sunflower heads.

Sunflower test weight is 28 to 32 pounds per bushel. This makes harvest, storage and transportation volumes high. Because of the high oil content, sunflowers store poorly when grain moisture exceeds 10 percent at cool temperatures and 8 percent at warm temperatures.

For more information read these references:

• High Plains Sunflower Production Handbook: www.oznet.ksu.edu
• Alternative Crop Guide: SUNFLOWER A Native Oilseed with Growing Markets: The Jefferson Institute: www.jeffersoninstitute.org
• National Sunflower Association: www.sunflowernsa.com n