Friday, June 14, 2013

Illinois Corn: Reports of Uneven Plant Sizes, Colors

AgFax.Com - Your Online Ag News Source


The corn crop that was planted in May is up and growing in most fields, but there have been numerous reports of fields with uneven plant sizes and colors, including purple and yellow plants. Many are wondering if this will decrease potential yields.

Based on past experience many people expect to see purple corn when soils are cool and dry during early plant growth stages, or in that rare field with low soil test phosphorus levels. The purple color is from a pigment that forms when there is more sugar in the leaves than the plant can utilize. Low phosphorus inhibits sugar movement out of leaves, and cool, dry soils reduce root growth and sugar movement to the roots. Both of these increase sugars in the plant and can make the tissue turn purple.




Soils are not cool and dry in Illinois now, but surface soils are drying out in many fields, and it’s likely that roots growth up to now has been restricted some by having soils too wet and in some cases also compacted by tillage and planting operations. In fields where the plants have taken up enough nitrogen and water to grow well but roots remain constricted, purpling might be common now, especially in those hybrids that have a tendency to form the purple pigment.

We expect the problem of purple corn to correct itself as root growth continues. It will help if wet soils continue to dry out, but in fields with dry surface soils, root growth might benefit from some rainfall. The high sugar content that leads to purpling means that the plant is producing sugars through photosynthesis, which is a good sign. There is no evidence that temporary purpling affects yield of the crop, though factors such as soil compaction that can lead to purpling might also reduce yields if the weather is dry later in the season.

Other fields are showing the yellow color that characterized nitrogen deficiency. In some cases this diagnosis is strengthened by our being able to see patterns such as N applicator knife tracks where the plants are greener. As is the case with purpling, we tend to see more yellow plants in the lower areas of the field. This is both where soils were wetter at planting time, so are more compacted, and where we would expect more N loss and poor root growth due to wet soils.

Some have already responded to yellow corn by applying a higher rate of sidedress N than had been planned, or by, or applying sidedress N on top of a full rate of N already there. Some may even have applied foliar N or broadcast urea by air to try to get N into plants quickly. If soils are still wet in such fields, plants are continuing to struggle with poor root growth and poor root function, so adding N might not have much immediate effect.

It is likely that the problem of yellow corn is, like that of purple corn, more related to poor root growth than to low level of soil nutrients. Student interns working at the Orr Center in Perry sampled soils the first week of June in a study where different N rates were applied as UAN in the first week of April. That site received some 17 inches of rain in April and May, and we expected that some of the N would have been moved to below the top two feet.

In fact, we found as much or more total N (nitrate plus ammonium) in the top two feet the first week of June than we applied as UAN the first week of April. We recovered about 90 lb. of N where we had applied 60 lb., and just over 240 lb. of N where we had applied 240 lb. So it’s likely that some of the N there now was produced by mineralization, and that some fertilizer N was moved down below two feet deep, but the net amount available to the crop after high-loss conditions certainly has not been drastically reduced.

As soils dry out in most areas of Illinois and temperatures stay warm, it’s likely that many fields with yellow corn plants will improve, in some cases rapidly. Late planting and warm temperatures do tend to favor top growth over root growth, but we expect that as leaves grow and start improve in color and as soil oxygen levels increase as soils dry, sugars will become more available to the roots as well as the tops, and this will further improve root uptake of nutrients.

If crop color remains poor even after a week of drying soils and good growing conditions, then it is possible that N movement to below the rooting depth is affecting the ability of the crop to grow out of this problem. Our soil measurements suggest that in most cases N is likely still present, but a small “booster” shot of N might help the crop revive and reach the N more quickly. The crop has roots extending to the middle of the rows by the time it have 4 or 5 leaves, so injecting N between the rows should work to get it into the plant.  Broadcast urea will need some rainfall to reach the roots.


Tags: , , , , , , ,


Leave a Reply

Name and Email Address are required fields. Your email will not be published or shared with third parties.

Sunbelt Ag News

    Georgia: 2 Counties Declared Natural Disaster Areas10-22

    Arkansas: 2 Counties Designated Natural Disaster Areas10-22

    DTN Cotton Close: Mixed on Light Volume10-22

    DTN Grain Close: Wheat Higher, Corn, Soybeans Pull Back10-22

    AgFax Grain Review: More Lawsuits Against Syngenta; Harvest Well Behind Pace10-22

    DTN Livestock Midday: Hog Futures Lead Complex Higher10-22

    2 Families, 2 Approaches to Building Ranch Tourism — DTN10-22

    DTN Grain Midday: Trade Firm but Off Highs10-22

    Don’t Just Piggy-Back on Others’ Prices in Ag Commodity Markets10-22

    DTN Cotton Open: Higher in Subdued Dealings10-22

    DTN Livestock Open: Trade Off to Sluggish Start10-22

    DTN Grain Open: All 3 Commodities Begin Higher10-22

    National Cotton Council Commends Timely APH Announcement10-22

    Keith Good: APH Yield Exclusion Implementation Draws Praise — Mostly10-22

    Grain TV: Positive News for Soybeans10-21

    DTN Livestock Close: Cattle Futures Move Lower10-21

    Wheat Growers to Seek Inclusion in APH Yield Exclusion for 2015 – DTN10-21

    Doane Cotton Close: Positive Chinese Economy Boosts Prices10-21

    Farm Shop Dream Requires Thoughtful Planning – DTN10-21

    USDA: Weekly National Peanut Prices10-21

    USDA to Implement APH Yield Exclusion for 2015 Spring Crops10-21

    Arkansas: USA Rice Outlook Conference Set Dec. 7-9 in Little Rock10-21

    AgFax Cotton Review: Lower Acres May Close Mill; Australia Acres Up10-21

    DTN Fertilizer Trends: High Costs May Alter Growers’ Tactics for 201510-21

    AFB Grain-Soybean Close: Wheat, Soybeans Down, Slight Gains in Corn10-20

    AFB Cotton Close: Selling Accelerates10-20

    AFB Rice Close: Reverses Off Positive Early Trade10-20

    Herbicide Resistant Weed Summit’s Slides, Webcast Available Online10-20

    Rice and Sugar: Thailand’s Quest for World Domination10-20

    AgFax Peanut Review: NM Down 6M Pounds as State Celebrates 100 Year Crop10-20

    Livestock: WTO Rules Against U.S. in COOL Dispute — DTN10-20

    Wheat Scientists, Breeders Advocate Biotech Crop — DTN10-20

    Good on Grain: Storage Issues May be Less Severe Than Anticipated10-20

    Brazil Soybeans: Planting Falls Further Behind — DTN10-20

    Flint on Crops: Cover Crops Provide Many Benefits10-20

    New Holland Combine Sets Guinness Harvest Record10-18

    Rice Market: Sideways Movement Continues10-17

    Rice Crop: Delta Region Saw Harvest Delays with Storms10-17

    Rose on Cotton: Dec Contract Still Under Pressure10-17

    Cleveland on Cotton: Exports Lowest in ‘My Memory’10-17

    Brazil: Beef Production Steps Up Over Next 10 Years10-17

    Soybeans: Neonic Seed Treatment Little or No Benefit, says EPA – DTN10-17

    Informa Forecast: Soybean Acres Up 4.3M in 2015 – DTN10-17

    DTN Grain Close: Prices Down for the Day, Positive for the Week10-17

    Crop Margins Tighten, Living Expenses Not Far Behind10-17

    USDA: Peanut Price Highlights10-17

    Georgia: 6 Counties Declared Natural Disaster Areas10-17

    Livestock: WTO Ruling on Country of Origin Labeling Expected Soon — DTN10-17

    U.S. Energy: Narrowing Brent-WTI Spread Impacts Global Crude Markets10-17

    Gasoline Prices: Show 9-Cent Decline10-17

    Propane Stocks: Rise by 0.7M Barrels10-17

    Diesel Prices: Average Decreases 4 Cents10-17

    Georgia Blueberries: State Leads Nation in Production — 96M Pounds10-17

    Farm Bill Contingency Plans: How Optimistic are You? – DTN10-16

    Arkansas Agriculture Secretary Calhoun Retiring10-16

    Georgia: Waste Pesticide Disposal, Quitman, Oct. 3010-16

    Global Ag: Ebola Hits West Africa Hard – DTN10-16

    Grain Markets: Crop Prices Up After Bearish USDA Report10-16

    Brazil Soybeans: Dry Conditions Put Planting on Hold10-16

    U.S. Grain Transportation: Rail Backlog Grows, Secondary Bids Spike10-16

    U.S. Drought Outlook: Improvements for Southwest, Southern CA10-16

    Sunbelt Ag Events

     

    About Us

    AgFax.Com covers agricultural trends and production topics, with an emphasis on news about cotton, rice, peanuts, corn, soybeans, wheat and tree crops, including almonds, pecans, walnuts and pistachios.

      

    This site also serves as the on-line presence of electronic crop and pest reports published by AgFax Media LLC (formerly Looking South Communications).

        

    Click here to subscribe to our free reports.

      

    We provide early warnings and confirmations about pests, diseases and other factors that influence yield. Our goal is to quickly provide farmers and crop advisors with information needed to make better and more profitable decisions.

         

    Our free weekly crop and pest advisories include:

    • AgFax Midsouth Cotton, covering cotton production and news in Alabama, Arkansas, Louisiana, Mississippi, Tennessee and Missouri.

    • AgFax Southeast Cotton, covering cotton production and news in Alabama, Florida, Georgia, North Carolina, South Carolina and Virginia.

    • AgFax Southwest Cotton (new for 2013!), covering cotton production and news in Texas, Oklahoma, Kansas and New Mexico.

    • AgFax West (formerly MiteFax: SJV Cotton), covering California cotton, alfalfa, tomatoes and other non-permanent crops in California's Central Valley.

    • AgFax Rice covering rice production and news in Arkansas, Louisiana, Mississippi, Missouri and Texas.

    • AgFax Peanuts, covering peanut production in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Texas and Virginia.

    • AgFax Southern Grain: covering soybeans, corn, milo and small grains in Southern states.

    • AgFax Almonds, covering almonds, pistachios, walnuts and other tree crops in California's Central Valley.

    • AgCom 101, providing guidance to ag professionals involved in social media.

    Our newsletters are sponsored by the following companies: FMC Corporation Chemtura Dow AgroSciences.

          

    Mission statement:

    Make it as easy as possible for our community of readers to find and/or receive needed information.

              

    Contact Information:

    AgFax Media. LLC

    142 Westlake Drive Brandon, MS 39047

    601-992-9488 Office 601-992-3503 Fax

    Owen Taylor Debra L. Ferguson Laurie Courtney

          

    Circulation Questions?

    Contact Laurie Courtney