Leverage our extensive testing data in many environments to find the best planting rate for your product with our Planting Rate Estimator.
Use ToolDelayed Corn Planting in the Southern U.S.
Something went wrong. Please try again later...
Key Points
- Corn yield potential in the Southern U.S. generally declines when planting is delayed beyond April; however, good yields are still achievable through mid-May in many areas.
- Late-planted corn generally develops at a faster rate due to greater heat unit accumulation, which can affect the timing window for herbicide and nitrogen applications.
- Additional management of late-planted corn may be required to minimize yield-limiting factors such as heat stress, insect pressure, and disease pressure.
Planting Date Impact on Corn Yield
- Recommended planting dates for corn in the Southern U.S. can range from late-February to April depending on location.
- Corn yield potential generally declines when weather conditions cause planting to be delayed beyond April; however, relatively good yields are still achievable through the first half of May in many areas.
- In an 8-year University of Arkansas study, corn yield was maximized with April planting, but yield potential remained above 90% through the first half of May (Table 1).
- In a 3-year Mississippi State University study, 90% yield potential was achievable with irrigated corn planted through May 5, and 84% through May 15 (Table 2).
- Yield potential in both studies declined below 80% when planting was delayed until late May.
- Irrigated corn is generally able to sustain yield potential with delayed planting longer than dryland corn. Irrigation can also help mitigate the added risk of yield loss from heat stress during pollination and grain fill that comes with later planting.
Table 1. Delayed corn planting effects on corn yield in an 8-year study at Marianna, Arkansas (Kelley, 2021).
Planter image courtesy of Deere and Co.
Table 2. Delayed corn planting effects on irrigated corn yield in a 3-year study conducted at Starkville and Stoneville, Mississippi (Larson, 2016).
Growth and Development of Late Planted Corn
- Late-planted corn generally develops at a faster rate due to greater heat unit accumulation.
- Timing of corn development stages in a University of Arkansas planting date study is shown in Table 3.
- More rapid development of late-planted corn means that applications of sidedress nitrogen and herbicides will generally need to be made sooner after planting compared to earlier-planted corn.
- Late-planted corn often grows taller due to longer day lengths during vegetative growth, which can make it more susceptible to lodging.
Table 3. Planting date effect on timing of corn development stages in a 2011 University of Arkansas planting date study using a 114-day hybrid (Kelley, 2021).
- In addition to accumulating GDUs more rapidly, late-planted corn can also adjust its development, requiring fewer GDUs to reach maturity.
- A three-year study conducted by researchers at Purdue and Ohio State Universities found an average of 244 less GDUs were required when planting was delayed from late-April or early May to early or mid-June (approximately 40 days) (Table 4).
- This is an average reduction in hybrid GDU requirement of about six GDUs per day of planting delay.
Table 4. Reduction in GDUs required to reach 50% black layer with delayed planting in a three-year study (Nielsen, 2003).
Management of Late-Planted Corn
- Planting corn later than normal does pose some challenges and additional management may be required to prevent or minimize yield-limiting factors such as heat stress, insect pressure, and disease pressure.
Foliar Diseases
- Late-planted corn is generally at greater risk for yield loss from foliar diseases because the corn is not as far along in its development when foliar diseases begin to infect the crop.
- Southern rust is of particular concern because of its ability to rapidly infest a field under favorable conditions. Re-infection can occur in as little as seven days, so fields may be damaged very quickly (Figure 1).
- Choose hybrids with solid disease resistance. Scout and apply foliar fungicides as needed. Economic yield responses to foliar fungicides are generally more likely with late-planted corn.
Figure 1. Corn treated with 6.8 fl oz/acre of Aproach Prima fungicide on July 16, 2015, in a Pioneer Agronomy study near Winchester, AR. Southern rust pressure was low at the time of application but increased in severity and ultimately caused premature death in the non-treated check before the end of the season (Malone and Poston, 2015).
Corn Earworm
- Late-planted corn can be at greater risk for damage from corn earworm.
- Light traps or pheromone traps can indicate when adults are flying. Scouting can be done in the field by looking for eggs on the green silks and turning back the silks at the tip of the ear to look for larvae.
- Pioneer® brand corn with Optimum® Leptra® insect protection provides strong above-ground insect control with a superior level of efficacy against ear-feeding pests for cleaner ears and improved grain quality.
Heat Stress and Irrigation Timing
- If available, irrigate in a timely fashion especially during pollination. This will help ensure that the corn plant cools adequately during periods of intense heat that later-planted corn has to endure.
- Higher temperatures during pollination and grain fill increase the vapor pressure deficit, which increases the amount of water needed by the crop to sustain photosynthesis.
- Corn planted after April may require 1 or 2 more furrow irrigations or 2 or 3 more pivot irrigations compared to corn planted in March or April (Kelley, 2021).
References
- Kelley. J. 2021. Arkansas Corn: What are the Yield Expectations of May Planted Crops?
- Larson, E. 2016. When does Corn Yield Potential begin to Suffer from Late Planting? Mississippi Univ. State Extension
- Malone, D., and D. Poston. 2015. Corn Yield Response to DuPont™ Aproach® Prima Fungicide in the Southern U.S. Pioneer Agronomy Research Update. Vol. 5 No. 17.
- Nielsen, R.L. 2003. Estimating Yield and Dollar Returns From Corn Replanting. AY-264-W. Purdue Univ. Coop. Ext. Service.
AVBL,YGCB,HX1,LL,RR2 (Optimum® Leptra®) - Contains the Agrisure Viptera® trait, the Bt trait, the Herculex® I gene, the LibertyLink® gene, and the Roundup Ready® Corn 2 trait. HX1 - Contains the Herculex® I Insect Protection gene which provides protection against European corn borer, southwestern corn borer, black cutworm, fall armyworm, western bean cutworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer; and suppresses corn earworm. YGCB - The Bt trait gene offers a high level of resistance to European corn borer, southwestern corn borer and southern cornstalk borer; moderate resistance to corn earworm and common stalk borer; and above average resistance to fall armyworm. LL - Contains the LibertyLink® gene for resistance to Liberty® herbicide. RR2 - Contains the Roundup Ready® Corn 2 trait that provides crop safety for over-the-top applications of labeled glyphosate herbicides when applied according to label directions. Roundup Ready® is a registered trademark used under license from Monsanto Company. Agrisure Viptera® is a registered trademark of, and used under license from, a Syngenta Group Company. Agrisure® technology incorporated into these seeds is commercialized under a license from Syngenta Crop Protection AG. Liberty®, LibertyLink® and the Water Droplet Design are trademarks of BASF.
The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.
