Conventional wisdom says lowering your corn plant populations will help boost yields if dry weather conditions prevail in 2013.
That may or may not be a good strategy, depending on your soil type, management practices and hybrids selected.
Here’s what the experts say to consider before you head to the field next spring.
Higher plant populations are a trend farmers have followed in recent years to boost corn yields. Last season, though, that practice appeared to backfire in some drought-hit areas. There, producers with lower plant populations often harvested better yields because fewer plants meant less competition for available moisture. The obvious question now: should farmers in dry areas lower their plant populations in 2013?
"Plant populations need to stay about where they are," says Steve Gauck, team sales agronomist in southern Indiana and central Kentucky for Becks Hybrids.
"If you want to make some minor changes that’s fine, but don’t make a huge adjustment just because Mother Nature threw us a curve ball last season," he adds.
Darren Hefty agrees. "If it’s shaping up to be a dry season, you might back off populations a tick, say 500 plants, but be cautious—you don’t want to go overboard," says Hefty who co-owns Hefty Seed Company, Baltic, S.D., with his brother, Brian.
The most important considerations in any year are to have a good understanding of the hybrids you selected, the type of ground they can perform in best and what agronomic practices will coax the most yield out of each one, adds Ken Ferrie, Farm Journal field agronomist, based in Heyworth, Ill.
"It’s important to evaluate the strengths and weaknesses of each hybrid and then manage for both," he notes.
Mike Kavanaugh, AgriGold agronomy manager, notes that corn growers have different soil types, row configurations, fertility programs and overall yield environments, and that this criteria should be matched to the hybrids they select each year.
"It is a fact that some genetics prefer higher populations and some don’t and that perfect growing conditions can maximize yield, but when extreme hot, dry conditions occur, all genetics are susceptible to plant cannibalization which ultimately creates another set of issues," Kavanaugh says. "Get with your seedsman and make sure you understand the limits of your hybrids."
University of Illinois agronomist Fred Below doesn’t disagree with Kavanaugh but says higher corn populations can be a benefit in a dry year if farmers manage their crop intensively.
The reason is that more corn plants in the field can absorb more sunlight, even if plant leaves are rolled. That sunlight translates to more yield.
"In our 2012 test plots we still wound up with higher yields in dry conditions this past year—35 to 40 bushels more per acre—with the higher plant populations," Below says. "The key was intensive management of the crop."
Below’s definition of intense management includes banding fertilizer to get more efficient uptake, crop rotation, using high tech hybrids and using fungicides to keep leaves green longer.
In 2012, the extreme heat at pollination time affected corn yields in a similar manner due to the lack of moisture, according to Kavanaugh. "In each corn growing geography, planting date coupled with hybrid maturity made a huge difference in yield outcome," he explains.
In some cases, Kavanaugh recalls, "You could see a 100-bushel difference between maturities in any given latitude depending on whether the hybrid was shooting or pollinating before, during or after those 105-degree temperatures we had."
Gauck saw similar scenarios in southern Indiana and Kentucky and advises:
"You’ve got to plant a variety of maturities and spread your planting dates out so those hybrids don’t all try to pollinate at once. Planting all your corn acres in a short window will put you at a pretty high risk."
Gauck advises farmers in a corn-soybean rotation to plant some of their corn acres, then switch to soybeans and then come back to corn to finish up the planting process.
This past fall, Hefty says he got questions from corn growers about whether to plant more flex-style hybrids on their farm to hedge against drought next season.
"Flex-style hybrids are not an automatic solution to dry weather conditions," Hefty says.
Peter Thomison, Ohio State University Extension agronomist agrees.
"Ear type must be considered in conjunction with overall hybrid performance," Thomison says. "You want to select a hybrid for its performance not because it possesses a particular trait or characteristic like flex or fixed ear size."
Editor's Note: As we prepare to put 2012 to bed, it is always a good idea to reflect on the past year. For the remaining days of 2012, the editors at AgWeb.com will bring you stories that were important this year and will continue to be top of mind in 2013.