Crop & Pest Report

Accessibility


| Share

Warmer than Normal Temperatures Hasten Crop Development (06/21/18)

A quick look at the weather data for this season reveals that corn and wheat growing degree days are running well ahead of normal (100 to more than 200 for a May 1st planting date).

Warmer than Normal Temperatures Hasten Crop Development

A quick look at the weather data for this season reveals that corn and wheat growing degree days are running well ahead of normal (100 to more than 200 for a May 1st planting date). This warmer weather is pushing corn and wheat development about 5 to 10 days ahead of normal depending on the location in the state.

Corn is a warm season crop, with optimum growth occurring with cool nights and daytime temperatures near 85 degrees. Recent weather has been nearly ideal for corn growth. In a few fields, yellow flagging has been observed. This occurs when new leaves have difficulty emerging from the whorl because of being slightly crinkled usually during the V5-V7 stages. Buggy whipping is followed by the “yellow flagging” of the restricted leaves once they emerge from the whorl. This phenomenon can occur when there have been cycles of cool and warm temperatures with hybrids differing in their likelihood to show a response. The incidence of buggy whipping/yellow flagging is much less than last year. Generally, the tightly twisted leaves in affected plants will unfurl and the plants will resume normal development after several days.

Small grains are progressing through growth stages quickly. Much of these earlier planted crops are in the boot stage or just beginning to head. I have received a few questions about whether the crop will be shorter than normal due to this accelerated development. It is common for small grain crops that are stressed during vegetative development (in this case average temperatures above optimum is the stress) to be shorter than normal. As I recall, the small grain crop was found to be much shorter than normal last year about this stage of development. However, in the in the areas of the state where there was no serious water stress, small grain crops ended up being about as tall as normal at harvest last season. Small grains have the potential of compensating when conditions turn favorable. So even though it seems likely that the small grain crops will be slightly shorter than normal this year due to their hastened development, the weather during the next week or two can still have an impact on the ultimate height of the crop.

Joel Ransom

Extension Agronomist for Cereal Crops

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

USDA logo

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.