Managing for higher yields

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With better seed genetics, more intense input management and a little luck from Mother Nature, the 300-bu. per acre mark is becoming more attainable for more corn farmers. A lot of guys are getting yield jumps with triple stack corn, micro managing planting and spraying, and more liberal use of fungicides.

While a good recipe for high yield corn varies from field to field throughout the Corn Belt, the following guide from Mike Toohill, Midwest Seed Genetics agronomist, can help maximize yields:

1)     Select your high yield fields based on past yield history, drainage, soil fertility, Ph, current residue situation, aerial application accessibility and ease of side dress.

2)     Plant the high yield field as soon as possible after crop insurance date for your county (assuming dry soil conditions and no heavy rain with accompanying "cold shock•bCrLf is in the forecast for the 2 or 3 days immediately after planting).

3)     Utilize a crop safe residual herbicide prior to planting or pre emerge.

4)     Dark soil population recommendations:  Set the planter at 36 to 38,000 seeds per acre in 30-in. rows and 40 to 42,000 seeds per acre in twins, 15-in. or 20-in. rows.

5)      Light soil population recommendations: Set the planter at 32 to 34,000 seeds per acre in 30-in. rows and 36 to 38,000 seeds in twins, 15-in. or 20-in. rows (if these seeding rates scare you on light dirt, just try it on a few rounds).

6)     Make sure the corn roots have access to early season nitrogen (ideally 10 gallons of 28% 2•bCrLf by 2•bCrLf with the planter or if that isn't possible, 30 to 60 lb. of broadcast nitrogen per acre).

7)     Utilize a preventative fungicide 10 to 21 days AFTER VT.   Consider a higher rate if your field pollinates perfectly and moisture has been good.  If ground aphids have been a problem in your area add a long residual insecticide to your fungicide.

Genetics "Today's genetic/trait combination have proven to provide very high yields come fall even after the dry start to the 2007 growing season  and the wet conditions many Illinois growers experienced in 2008,•bCrLf says Toohill (left). "In fact last year (many of our customers) grew the best corn crop of their lives despite later than desired planting dates and record yearly rain fall.•bCrLf

New genetics are coming on the market at super speed so you need a good, trusting relationship with your seed dealer if you want to take advantage of that yield potential. Many two-year-old genetics are already obsolete.

Populations With high-tech seed in most cases you should be pushing populations. "On highly managed soil types - black dirt - almost all of our elite genetics should be planted in the mid 30,000 (seed per acre) if you want a shot at 300 bu. per acre,•bCrLf says Toohill. "I also would not be afraid to plant 30,000 in white soils and 32,000+ in tight clays (on 30-in. rows).

"If you are comfortable dropping 32,000 go to 34,000; if you are comfortable at 34,000 go to 36,000; if you are comfortable dropping 36,000, stay there unless soil fertility is very high, all on 30-in. rows,•bCrLf he recommends. "But if you feel that you are maximizing yields in 30-in. rows with plant populations in the mid to upper 30's, 2009 may be the year to start to experiment with twin rows or 20-in. rows.•bCrLf

Don't let soil type scare you from pushing populations, even on light soil. If it is a total drought on these soils, yields will be disappointing whether you have a final stand of 24,000 or 30,000. Yes, you're out 6,000 seeds in those bad years, but in the 9 out of 10 years you don't have that problem, that extra seed will pay dividends.

Fertility The ideal fertility level for 300-bu. corn is a soil pH of 6.3 to 6.5, a minimum P1 test of 30 to 45 depending on your region, and a minimum K test of 260 to 300 lbs per acre again depending on location. "Ideally we would like to have higher P1 and K test, but with today's fertilizer prices these are minimum levels needed to have a shot at 300,•bCrLf says Toohill.  Growers shooting for very high corn yields should at least consider multiple nitrogen "feedings•bCrLf (especially early, safely near the seed and deeper in the soil profile - maybe some side dress ammonia.) 

What about growth modifiers, foliar applications, micro nutrients or root stimulators? "At least 95% of high yielding farmers I consult with don't use them,•bCrLf says Toohill. "While most of the high yield guys don't play with these, some growers say they contribute at least 5 to 10 bushels to their high yield bottom line.•bCrLf

Fungicides Better use of corn fungicide is one way you can step from 250 to 275-bu. per acre, but you have to get timing right, says Toohill.  "I like spraying later, say, 10 to 14+ days after the start of pollination,•bCrLf he says.  The latter timing tends to help with late season anthranacose control and is a better timing for high yield fungicide •side benefits. (Ethylene reduction and improved respiration efficiency). Later applications also tend to maximize kernel depth, especially if growers receive late season rains and have some late season nitrogen available for uptake.

"Every one of the highest yielding fields I consulted on in 2008 (250 to 280+ bushels/acre) was sprayed with a fungicide,•bCrLf says Toohill.

Share your best tips for high yielding corn below.





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