- Market prices and potential yield penalties in continuous corn can affect your 2015 profits.
- Corn-on-corn rotation can lead to increased crop disease, insect infestations and weed resistance.
- Nutrient and residue management can significantly affect crop volume in continuous corn acreage.
Each season presents itself with a unique set of challenges that can make or break the bottom line, especially for those who plant continuous corn. If continuous corn is on your agenda for 2015, here are some key considerations.
Before purchasing a single bag of seed, growers must analyze their outputs from the previous harvest and determine which crops to plant in the coming year. Moreover, as market conditions remain flat from record corn yields and prices stay low into 2015, growers who plant continuous corn may want to consider alternatives.
Cory Walters, University of Nebraska agricultural marketing specialist, said growers need to check market conditions for alternative crops first. “With some areas seeing as low as $2 corn, growers need to look elsewhere, especially when continuous corn takes additional investment to reach relative yields.”
“With limited volatility in the corn market right now, prices aren’t going to change drastically from 2014 to 2015,” predicted Walters.
Weed, Disease and Pest Management
Maximizing yield in continuous corn takes management and planning, and that means a solid weed management program. Broadleaf weeds like Palmer amaranth and waterhemp continue to develop weed resistance across the Corn Belt and growers need be cognizant about utilizing a variety of chemistries to control weeds.
A zero tolerance approach is best to keep fields clean and to ensure high yields, especially in continuous corn, where every bushel counts. Crop Science recommends utilizing multiple effective modes of action. Use a pre-emergence herbicide containing at least two modes of action, like Corvus®
, tankmixed with an additional weed control agent, such as atrazine, to provide three modes of action.
A second pass during midseason should also use additional modes of action to control weed escapes. Again, Crop Science suggests using a strong post emergence herbicide with two modes of action, like Capreno®
, tankmixed with glyphosate or atrazine. This will also provide three modes of action to control broadleaf weeds and grasses to limit weed competition in your fields for a powerful, end-of-season clean.
For potential disease issues in continuous corn, Fred Below, professor of plant physiology at the University of Illinois, warned growers in the Corn Belt to focus on leaf diseases in particular. “Gray leaf spot, blight and eyespot are key diseases that can limit yield,” he said. “Growers need to be vigilant in their scouting and be ready to make multiple fungicide applications, if necessary.”
Stratego® YLD fungicide
prevents yield loss from both early- and mid-season diseases. It quickly eliminates a wide range of corn fungal diseases and provides curative properties to help plants reach maximum yield potentials.
In the Corn Belt, the most difficult pest to fight in continuous corn is corn rootworm (CRW). CRW can weaken roots, hinder water and nutrient uptake, and force the plant to utilize its photosynthetic resources for root regrowth, rather than for stalk and leaf growth and yield. “Plants with weakened roots are less able to tolerate high winds and are more prone to lodging,” Below said.
For fields with noticeable CRW damage, Below recommends multiple methods to fight the pest that include planting bt-traited rootworm resistant hybrids and using a pre-plant soil insecticide.
Growers who want to prevent CRW or have a field history of noticeable damage can select seeds treated with Poncho®/VOTiVO®
, a seed treatment that protects young plants from pests during critical early development stages, leading to healthier root development and stronger stands. Applied directly to the seed, Poncho/VOTiVO protects the whole plant, above and below ground, preventing damage to early-season seedlings and roots before the pests can strike. To know the signs of CRW, University of Illinois
offers growers vital diagnosis and treatment information.
A strong residue management strategy is going to have the most impact on yield. “You have to find a way to break down and incorporate leftover residue, typically in the fall, to attain decent yields,” Below said. One way to handle residue after harvest is to implement a crusher to downsize residue and leftover stalks. He advised growers to use some type of tillage to incorporate residue and to encourage breakdown over winter.
“Most of the yield penalty in continuous corn is attributed to residue in the fields,” Below explained. Too much residue can tie up nutrients preventing them from being absorbed by roots and limiting yield. Those leftover stalks can also release toxins into the soil (allelochemicals) that actually hurt corn growth. Finally the residue can act as an inoculum for diseases that can decrease crop health, he added.
Since residue can tie-up nutrients, growers need to do a better job of supplying needed plant nutrition, especially nitogen. Growers who apply their nitogen in the spring, rather than the fall, and make multiple applications with a side-dress can help to assure that the nitrogen stays available for plant uptake.
“On average, we suggest you use about 40 to 50 pounds of additional nitrogen in acres with continuous corn, however, even with the additional fertilizer applications, some operations can expect to see about a 25 bu/A yield penalty,” Below said.
“More than anything, continuous corn takes a better crop manager,” he said. “If you scout regularly and have a solid plan in place, you can make a profit with continuous corn, but you are going to have to invest a bit more. Be aware that planting continuous corn should be on your best land to have a chance at high yields year-after-year.”