Accessing Corn Pollination and Fertilization

This year has been incredibly challenging in Ohio. Parts experienced a wet spring with delayed planting, and others experienced dry conditions followed by heavy rains. Corn emergence has been all over the board and stands have been erratic due to the early season growing conditions. These weather issues could have an impact on corn pollination across Ohio and other Midwestern states.

Two major factors that impact corn pollination are heat and drought. Drought stress or extreme heat can prevent the corn plant from functioning properly during pollination. Drought stress can slow silk elongation and can cause pollen shed to be accelerated. With this out of sync, pollen shed may occur before silks are fully exposed and can cause poor fertilization. High temperatures can cause the pollen to have reduced viability and can dry out and damage exposed silks. Other factors can also impact pollination.

Compared to past years, the spring weather in Ohio was warmer and there was more rain. The Ohio State University CFAES Weather system collects data from locations all over the state and is a great resource for growers to utilize. From April 1 to May 25 of 2023, Ohio received 4.1 inches of rain and 470.1 GDUs (growing degree units). In 2024, using the same dates, there was 7.79 inches of rain and 720.5 GDUs.¹ The increase in GDUs helped speed seedling emergence but could lead to a warmer summer. The large amount of rain has caused corn stands to be uneven, which could have an impact on pollination. With these stressful conditions, yield potential may be reduced. Under stress, some corn products fare better than others (Figure 1). The ears show how erratic emergence can impact ovule (potential kernel) fertilization.

Another factor that can impact pollination in corn is insects. Insects, such as corn rootworm beetles feed on silks, pollen, and ovules. With the early elevated heat, there may be more corn rootworm beetles earlier than normal. Japanese beetles also feed on the silks and can affect ovule fertilization. Scouting for these insects should be included while assessing corn for diseases to determine if an insecticide should be included with a timely fungicide application.

It is important to look at your fields to access corn fertilization. Throughout the field, pull back the husks on multiple ears to determine if fertilization was successful. If possible, look at the same product across different fields and soil types. This can help determine if there is an issue and if it was related to a single field or soil type. Some corn products handle stress better and may help you make product selections for the future. Growers also need to look at GDU’s to determine if the product hit pollen shed at a time that could impact fertilization. For example, 100-day and 112-day corn products would shed pollen at different GDU’s; therefore, if the 100-day corn was not in extreme heat, its fertilization could be better than the 112-day product. Be sure to consider these and other factors to help determine the success of corn fertilization.

If you have any questions about the products you planted, please contact your Channel^® Brand SeedPro, FSR, or Technical Agronomist for assistance. Thank you for your continued support of the Channel^® Brand and we look forward to a great harvest.

Channel Agronomist
Corey Prosser

Sources

¹CFAES weather system. The Ohio State University. https://weather.cfaes.osu.edu/

Thelen, M. 2013. Successful corn pollination is dependent upon many factors. MSU Extension. Michigan State University. http://msue.anr.msu.edu/news/successful_corn_pollination_is_dependent_upon_many_factors

Thomison, P. and Minyo, R. Assessing the success or failure of pollination in corn. Agronomic Crops Network. Ohio State University Extension. The Ohio State University. https://agcrops.osu.edu/newsletter/corn-newsletter/2017-23/assessing-success-or-failure-pollination-corn

Web sources verified 5/28/24. 1110_430801