Replanting Corn Fields

May 27, 2016

By Delbert Voight

Some fields with poor corn stands are being evaluated for replanting. The Penn State Agronomy Guide has a discussion about the different factors when considering replanting on pages 68-69.

Population Assessment

Once corn germinates, the population in the field can be determined. First take the width at planting (15” or 30” for corn) and convert the row width from inches to feet by dividing by 12. Divide feet by the square feet per acre (43560). This gives you linear feet. Take the number of plants you find per linear foot in the field and multiply by 1,000 to get the plants per acre (ppa).

Here is an example:

Thirty-inch rows divided by 12 is 2.5 feet. 43,560 square feet in an acre divided by 2.5 gives us 17,424 linear feet. One plant in a foot will yield 17,424 plants per acre. If two plants in a foot, then the plant population will be 34,848 plants per acre.

To simplify this you could now take 17,424 and divide by 1000 to get the number of feet you need to represent 1/1000th of an acre. In this case it would be 17.4 feet. In the field, measure 17.4 feet, count the plants, multiply by 1000 and you will have your plants per acre. Do this in several places and take the average of the field.

Stand Evenness

Often, the greatest challenge to assessing whether to replant is the unevenness of the stand. Penn State research suggests that within row unevenness robs 12% of yield, while between rows unevenness only robs 5% of yield. For each inch of deviation university research suggests a 2.5-5 bu/inch loss. This becomes more critical as populations are increased.

Planting Date and Relation to Yield

Planting corn by April 25th is 100%, the 19th of May is 90% and the 29th of May is 80% of yield potential. In the Agronomy Guide, Tables 1.4-8, 1.4-8A and 1.4-8B on page 69 can offer help in making a determination whether one should keep or replant when comparing the plants per acre at harvest by planting date.

Pest Management

Weeds will invade anywhere light is allowed through to the soil, competing with poor stands, so evaluate potential herbicide costs. Important: Review any pesticides that were previously applied and re-crop restrictions.

And Finally:

Check with your dealer to determine the policy for replant support. There could be on-line tools offered by your seed dealer to help assess a stand.

Source:psu.edu

Video: Will the 2025 USDA December Crop Report Be a Market Mover/Surprise?

Historically, the USDA December crop report is a non-event or another dud report as the USDA reserves any final supply changes to the final report in January of the following year in this case 2026. But after the longest U.S. government shutdown in history at 43 days and no October crop report will they provide more data/surprise and make an exception?
Our China U.S. soybean purchase tracker is now at 26.6% or a total of 3.2 mmt but for traders it’s taking too long to unfold.
The final Stats Canada production report was bearish canola and wheat projection a record crop in both (it adds to the global glut of supplies) and bullish local corn and soybean prices in Ontario/Quebec thanks to a drought. It will not help the fund flow short-term, the USDA may need to offset it?
A U.S. Fed interest rate cut of another 25-basis point next Wednesday (probability 87.1%) could help fund flow and sentiment in stock and ag commodities into year end.
More inflows into Bitcoin this past week saw prices rebound back above 90,000 with support at 82,000 and resistance at 96,000.
A V-shaped bottom in cattle suggest the lows are in after Mexico reported another new world screwworm case. Lower weights, seasonal demand and higher U.S. beef select/choice values with a continued closure of the Mexican border to cattle will result in a resumption of higher cattle futures into yearend.
Australia is expected to produce its 3rd largest wheat crop ever at 36 mmt adding to the global glut of supplies.
Reports of ASF in hogs in Spain the largest pork exporter in Europe could see the U.S. win more pork export business long-term.
If the rains verify into next week of 3-5 inches for Brazil it would go a long way to fixing the dry regions from the last 2-months, but the European weather model has been wrong for the past 2-months!
Natural gas futures are surging to the 3rd price count as frigid hold temps set in.
CDN $ is also surging to end the week on a very resilient economy and better employment numbers suggesting no interest rate cuts next week.
Finally, the CFTC report showed funds were net buyers of soybeans but sellers of corn, canola and wheat. In real time the funds have gone back to selling as they take some profits.