Friday, June 29, 2012
drought_stress_corn

Indiana: Hot and Dry – Stress on Corn Crop Escalates

AgFax.Com - Your Online Ag News Source


Questions and concerns about the potential of Indiana’s corn crop are increasingly on the minds of growers throughout the state, especially in areas hardest hit by the current drought. Rainfall continues to be hit or miss as isolated storms rumble through the state, dropping decent amounts of rain here and there but missing large areas entirely.

The moderate temperatures enjoyed throughout the state since the end of May delayed the onset of severe drought stress symptoms in many areas, but those temperatures have recently climbed to above-normal levels and, coupled with excessively dry soil conditions, increasingly reveal the severity of the situation in field after field. Areas in the state have already “gone over the brink” to disaster status relative to yield potential.




Eighty seven percent of the state is currently estimated to have subsoil moisture content that is rated short to very short and is higher for this time of the season than any year since 1988. Estimated crop condition continues to worsen; down to 27% good to excellent as of 24 June 2012 and is lower for this time of the season than any year since 1988. For some, the effects of the drought began after planting in fields where seedbed moisture was simply inadequate for germination and emergence of the crop. Large areas in these fields are simply devoid of corn or soybean plants. With no rainfall after planting, many farmers elected not to attempt replanting knowing that the second attempt at establishing a crop would not be successful. The lost yield potential in such fields obviously cannot be recovered.

For other fields where initial stand establishment was satisfactory, the severity of the drought stress on crop development has slowly become worse and/or has escalated in recent weeks as the combination of drought
and heat stress worsens. The severity of the stress is such in some fields that plants are simply dying. Some growers have already worked with their crop insurance adjusters to assess the yield loss potential of their damaged fields and have basically abandoned the crop for this year.

Statewide Effects?

This early in the season, it is difficult to estimate the effects of the drought on the eventual statewide average grain yield because we cannot accurately forecast the weather for the remainder of the season. Trend yield with “normal” weather for corn in Indiana for 2012 would be 163 bushels per acre (bpa).

There is a moderate linear relationship between crop condition ratings (percent good and excellent) throughout June and grain yield at the end of the season that accounts for about 33% of the variability in historical grain yields. Based on that relationship alone, the predicted statewide average grain yield for corn as of the end of June would be 145 bpa or nearly 11% below the trend yield.

However, if the drought continues and crop condition worsens, this estimate would quickly become outdated. For comparison, statewide grain yield for the drought years 1988 and 1991 were 31% and 27% below trend yield, respectively.

Much of the state’s corn crop will enter the critical pollination phase over the next two or three weeks. Continued lack of adequate rainfall during this period will place undue stress on the crop. Forecast excessive heat during the same time period will only amplify the stress; resulting in delayed silk emergence, premature pollen shed, tassels failing to emerge from whorls, potentially inviable silks or pollen, poor synchrony between exposure of silks and availability of pollen, incomplete pollination success, or abortion of newly developing kernels. Yield loss per day during pollination due to severe stress is often estimated to be 5 to 10 percent. Yield loss for any given field could easily approach 100 percent with continued drought/heat stress due to complete failure of the pollination process.

Assessing Drought Effects on Yield

Growers who elect not to abandon drought-stressed fields prior to pollination will be wanting to assess the yield potential of their fields prior to harvest in order to estimate the potential loss of net income and/or to revise their grain marketing strategies for this fall. Assessing yield potential for an individual field cannot be done with any accuracy prior to pollination, but rather depends on assessing kernel set later in the grain filling period. The challenge with assessing yield potential of drought-stressed fields is that of obtaining ear samples that adequately captures the variability of the yield potential throughout a damaged field.

Immediately Following Pollination

Given the severity of the drought stress in some fields, growers may want to assess the success of pollination itself within the first week after pollen shed by sampling ears and conducting the so-called “ear shake” test. This assessment simply gauges the degree to which pollen successfully fertilized the ovules on the ears via the silks, but does not predict the risk of kernel abortion in the few weeks following pollination or estimate grain yield. However, the test will at least give you an idea whether pollination was an absolute failure or was moderately successful. Unfortunately, there will be fields that appear to be only moderately stressed according to windshield surveys that, in fact, are severely stressed to the point that pollination will be a near or total failure. Better to find out the bad news soon rather than be totally shocked later in the season.

Prior to Harvest

Assuming that pollination occurs successfully, then pre-harvest grain yield estimation revolves around kernel abortion and grain filling. Unfortunately, one cannot begin to estimate grain yield for an individual drought-stressed field until the crop is beyond the milk stage of the grain filling period where the risk of kernel abortion tapers off. The risk of kernel abortion is greatest immediately following successful pollination and decreases to nearly zero by about mid-milk stage of grain fill. Once the crop reaches or surpasses the dough stage of grain fill, the “ballpark” grain yield potential can be estimated by documenting effective plant populations and sampling ears throughout the field. Pray for rain or turn on the irrigation.


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

    Grain TV: Improved Crop Conditions Likely to Pressure Markets9-2

    DTN Livestock Close: Cattle Complex Makes Significant Price Surge9-2

    Doane Cotton Close: Crop Condition Slips Slightly9-2

    USDA Grain Inspections Neutral for Futures Markets — DTN9-2

    DTN Cotton Close: Lowest Finish Since Aug. 199-2

    Pinnacle Announces the Acquisition of Wellsville’s East Kansas Chemical9-2

    Livestock: Rebuilding U.S. Animal Industries9-2

    DTN Grain Close: Soybeans Rally Despite Strong Greenback9-2

    USDA: Weekly National Peanut Prices9-2

    AgFax Grain Review: Corn to Stay at $4; Corn Thieves Apprehended in Connecticut9-2

    DTN Livestock Midday: Strong Gains Flood into Markets9-2

    National Corn Growers Association Names New CEO — DTN9-2

    DTN Grain Midday: Wheat Trade 7 to 13 Lower9-2

    Brazil Soybean Exports Decline in August — DTN9-2

    DTN Cotton Open: Tumbles to Five-Session Low9-2

    South Carolina: Crop Production Field Day Set Sept. 25 at Blackville9-2

    DTN Livestock Open: Cattle Futures Starting with Firm Undertone9-2

    DTN Grain Open: Higher on Light Buying Interest9-2

    Keith Good: Rail Service Problems Persist; Hog Prices Rebounding9-2

    Texas Cotton Industry Mourns The Death Of Economist Carl Anderson9-1

    Livestock: Market Lessons from 4-H County Fairs – DTN9-1

    China Cotton: Reserves’ Quantity, Quality Cause Problems – DTN9-1

    Welch on Wheat: Spring Wheat Harvest Running 22% Behind9-1

    Welch on Grain: Corn Condition Improves, Well Above Average9-1

    Flint on Crops: Rain Is Better Than Well Water9-1

    Rose on Cotton: Plenty of Gaps and No Rallies Expected8-29

    Peanut Harvest In N. Fla.; Drought Pushes Digging In Lower SE – AgFax8-29

    Rice Crop: Looking for a Normal Crop, Not a Bumper8-29

    Rice Market: Being Short Tricky but Being Long Takes Patience8-29

    Peanut Stocks and Processing: Utilization Up 2%, Stocks at 1.9B lbs8-29

    Cleveland on Cotton: Chinese Demand Pulling Prices Higher8-29

    Doane Cotton Close: Futures Unable to Recover Losses8-29

    AFB Grain-Soybean Close: Modest Losses Across the Board8-29

    AFB Cotton Close: Dec. Moves Fractionally Lower8-29

    AFB Rice Close: Futures Chart New Leg Down8-29

    Farm Bill: Cotton Transition Assistance Enrollment Now Open8-29

    Are USDA Corn Yield Forecasts Getting Better or Worse Over Time?8-29

    USDA: Peanut Price Highlights8-29

    Farmers with Foreign Assets Face New IRS Rules and Serious Penalties8-29

    Mississippi Outdoors: Beaver Management Not a Simple Issue8-29

    Arkansas: Flood Damage to Crops Valued at $35.6M8-29

    Delta Soybean Yields Start Strong; Sugarcane Aphid Marches On – AgFax8-29

    California: Pinnacle Announces Acquisition of Kerman Ag Resources8-29

    Midwest Farm Lenders Expect Solid Output; Lower Farm Income – Federal Reserve8-29

    Farm Payments to Stakeholders Rise as Gov. Payments Decline – USDA8-29

    Young Farmer in Your Future? – Helping Him or Her is Key to Success. – DTN8-29

    Net Farm Income Forecast to Fall,10.6% Decline Crop Value – USDA8-29

    Alabama: Pesticide Clean Days, Sept. 3-48-28

    Oklahoma: Fall Cotton Tour, Hydro, Sept. 118-28

    Rice Harvest Eases Into Gear In Midsouth – AgFax8-28

    Farm Drones Under Scrutiny: Farmers Impatient for FAA Ruling – DTN8-28

    USDA Readies Dairy Program, Producers Able to Sign Up Tuesday – DTN8-28

    U.S. Grain Transportation: Inspections Continue to Increase8-28

    Farm Program Decisions Hinge on Uncertain 2014 Crop Prices8-28

    Raindrops Keep Falling on Heads of Many Midwest Farmers — DTN8-28

    Economist: Big Potential in China for U.S. Corn, Livestock Exports8-28

    John Deere Lays Off 460 from Waterloo, Iowa Factory8-28

    U.S. Energy: Retail Gas Prices Follow Crude Prices Lower8-28

    Gasoline Prices: Decline by 2 Cents8-28

    Propane Stocks: Up to 74.7M Barrels8-28

    Diesel Prices: Average Drops a Penny8-28

    Sugarcane Aphid In Grain Sorghum: Florida, Georgia Find Infestations8-27

    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