AgriGold

Study Finds Benefits to Twin Row Corn Planting

July 16, 2010

CHAMPAIGN, Ill. — Twin row planting offers higher yield opportunities, according to a study conducted by Agri- Gold Hybrids. “As far as the agronomics and the actual system itself, I truly believe in twin rows,” said Andy Westhoven, Agri- Gold Hybrids regional agronomist, after unveiling 2009 study results. Westhoven was one of the featured speakers at Agri- Gold’s recent specialty crops conference. Twin row is a relatively new style of planting corn in which the two rows are positioned eight inches apart on 30-inch centers. The twin row concept is gaining interest because 30- inch row cropping equipment still can be utilized, and it provides greater space between plants, thus allowing higher populations and ear counts to reach high yield potential. The added plant spacing can be beneficial in both high yielding environments where population is the limiting factor and in low yielding environments where rooting area is critical for nutrient and water uptake. Corn planting populations depend on four major components, according to Westhoven. “It really starts with yield environment. If a guy has a higher yield environment, he probably tends to plant high populations rather than in marginal soil where he may lower that planting population,” he said. “The next component is looking at different row configurations. For the most part, we’re on 30-inch row centers, but looking at ways to change that to narrower rows or different kinds of configurations to see what we can plant. “The third component is to find the best trait packages that are going to protect those genetics and let them reach their yield potential. The ultimate goal in those traits is to protect that crop. Lastly, it’s the genetics. A lot of the change is attributed to genetics.” Westhoven compared the various plant populations with seed spacing. At 30,000 plants per acre in 30-inch rows, the corn was seven inches apart, and 38,000 plants per acre at 30 inches results in corn about 5.5 inches apart. When increasing to 42,000 plants per acre, the plants were five inches apart. “When you move those to 20-inch rows (at 38,000), we’re about 8½ inches apart,” Westhoven said. “But when you have twin rows, you can gain up to 11 inches apart per seed. “Even if you don’t have that staggered effect, you’re going to be eight inches apart, so you’re still the same distances from seed to seed even when compared to 20-inch rows. I think that’s one of the bigger benefits of planting twin rows.” The root area also decreases when increasing planting populations in 30-inch rows. That is not necessarily the case for twin rows. “For example, at 32,000 plants per acre, when having 30-inch rows, you’re using only 17.1 percent of an acre. With a twin row, you’re using 42.7 percent of an acre,” Westhoven said. “When you go to 42,000 plants per acre on 30-inch rows, you’re only using 13 percent. And with twin rows you’re using 46.7 percent. That’s huge in terms of plant space. “If you’re spacing out those plants a little better, you’re probably going to have a little better utilization of water, nutrients, sunlight, you’re probably getting a row canopy much quicker.” As part of AgriGold’s twin rows testing program last year, the research featured 37 locations across several states. Five hybrids and two genetic families were tested using planting populations from 28,000 up to 43,000 plants per acre. “The obvious goal was to see if there was a yield advantage one way or the other. Before this, we really weren’t favoring one system over another. We just wanted to get some answers to all of the questions we’ve been getting,” Westhoven said. “Secondly, we wanted to determine if there is a genetic response. We also wanted to get those recommendations for plant populations. Before we would give a best estimated guess. “Finally, as an agronomist, we wanted to see what kind of agronomics this has. But the bottom line was to see if we could take those yields to the next level.” Overall, twin rows out yielded 30-inch rows by an average of 4.9 bushels per acre when all hybrids and populations were considered. The trend line for twin rows suggest grain yield continues to increase up to 43,000 plants per acre, while the trend line for 30-inch row systems begins to plateau around 34,00 plants per acre based on 2009 data. “As we increased planting population, our yield increased and also the separation between the twins and the 30s also increased,” Westhoven said. For example, twin rows had a half-bushel advantage over 30s with a plant population of 28,000. The margin increased to a nine-bushel advantage for twin rows at 43,000 plants per acre. Also, in 318 side-by-side comparisons, twin rows demonstrated a positive yield response 69.2 percent of the time. The field-testing also concluded that the twin row system resulted in both significant and slight agronomic differences. A significant agronomic difference was larger stalk diameter that could lead to less stalk and root lodging. Across all populations the twin row system consistently provided greater stalk diameter when compared to 30-inch spacing. Greater stalk diameter is a direct result of reduced competition and larger root systems. Slight ear and plant height differences existed between twins and 30s. Ear heights averaged one inch higher in two rows compared to 30s as populations exceeded 33,000 plants per acre, and plant heights averaged one and one-half inches taller overall populations compared to 30-inch rows.

Categories: General, Agronomic