Thinking About Solid Seeding?
Monday, January 1, 1996
filed under: Planting Systems
If Kent McKay’s phone log is any indicator, the level of interest in solid-seeded sunflower just continues to grow — and grow. McKay, who is area extension agronomist for North Dakota State University’s North Central Research & Extension Center at Minot, estimates that at least 15 percent of sunflower acres in his region were planted in solid-seeded (i.e., “narrow-row”) spacings in 1995.
Reflecting that trend, this past year also saw the Minot center hosting its initial field tour and program focusing exclusively on solid-seeded sunflower. In 1995, station researchers conducted the first year of a study to gather data on how various sunflower hybrids perform in narrow row widths. Under contract with a private seed company, they are comparing such traits as yield, oil content, plant height and lodging in row spacings of from six to 30 inches with plant popula-tions ranging from 18,000 to 40,000. Such data will help university and seed company personnel determine manage-ment recommendations for specific hybrids when planted under narrow-row patterns.
For those producers who are thinking about growing solid-seeded sunflower for the first time, McKay and NDSU Fargo-based extension agronomist Duane Berglund offer several preliminary suggestions based on research and grower experience to-date:
• If you are a first-year sunflower grower, consider holding off on solid seeding until you have some experience with this crop under your belt. At the very least, discuss the dos and don’ts of solid seeding with university or seed company personnel — and with veteran growers who have developed successful solid-seeding systems.
• If you haven’t solid seeded sunflower previously, don’t do so with your entire sunflower acreage the first time around. Ease into it, discovering and comparing what works on your farm — or what doesn’t — with solid-seeded versus conventional sunflower.
• Plant a shorter or reduced-height hybrid — especially if your seeding rate is being increased from previous levels. Tall types will grow even taller under higher-end populations — and may possess weaker necks, which then tend to entangle with adjacent plants.
• Use row spacings in the neighbor-hood of 10 to 14 inches. That should result in roughly equidistant spacings among plants both within the row and between adjacent rows.
• Be sure you’re seeding into moisture and that you have adequate seedbed packing. As with any planting system, good seed-to-soil contact is essential.
• Per-acre seeding rates will vary, but optimum stands at harvest appear to be somewhere in the range of 21,-24,000. Higher populations could jeopardize the crop if there’s a lack of growing season moisture. Along with possible moisture stress, excessively high populations also mean more plants competing for nutrients and sunlight.
• Do not solid seed confection sunflower. Higher plant populations result in smaller heads and thus smaller individual seeds. That translates into discounts in the marketplace.
• Avoid solid seeding on sandy soils.
• Solid seeding can be additionally risky if you are a no-till producer or if perennial weeds are a serious problem in your fields. (If a no-tiller does wish to try solid seeding, however, an early preplant treatment of Prowl at the maximum label rate is an option. If a half inch or more of precipitation arrives prior to planting, the standard seven-day activity window of the Prowl could expand up to 20 days.)
• Producers applying a preplant incorporated soil herbicide should use the maximum rate since in-season cultivation will not be an option. (Sunflower seedlings can be harrowed or rotary hoed while in the two-, four- or six-leaf stages. However, each such operation can be expected to reduce the sunflower stand by about five to seven percent.)
Bruce Due, sales agronomist with Mycogen Plant Sciences, offers these additional observations regarding solid-seeded sunflower:
• Going to narrow rows does not automatically mean seeding rates should be increased over what the producer has been using with conventional rows. Plants will, however, be spaced in a more equidistant pattern within and between rows — an advantage in terms of ground cover and the efficient use of soil moisture and nutrients. Due says he is more comfortable with a seeding rate in the 23,-24,000 range than with one in the upper 20s because plants stalks with higher populations are typically smaller. Also, higher-end populations (27,-28,000 or more) can increase the risk of certain diseases — especially in a wetter year — due to the moist micro-environment under the plant canopy.
• Proper calibration of one’s air drill is essential. Calibrate early in the process, not after a significant portion of the field has been seeded. Be sure to check with your drill manufacturer if you are uncertain as to the proper settings for your seed size and population objective.
• Seed size will affect one’s seeding rate per acre, so always recalibrate if changing sizes. Generally speaking, size four seed has done the best job across a variety of air drill brands and models.
• Weed control is a major challenge for most solid-seed producers. Be particularly “in tune” with weed history and current conditions on solid-seeded fields.
• Using a harvest attachment with nine- or 12-inch pans allows one to combine in any direction, which is entirely feasible under a solid-seeded situation.
• Solid-seeded sunflower fields can look “ugly” early in the season. But take heart. As long as there’s an adequate plant stand and decent weed control, the yield will be there at the end of the season as well as or better than in a conventional row-crop field.