Crop & Pest Report

Accessibility


| Share

Soybean Transitioning to Reproductive Phase (07/05/18)

Soybean plants in our area are transitioning from the vegetative growth stages to the reproductive phase of their crop development cycle.

Soybean Transitioning to Reproductive Phase

Soybean plants in our area are transitioning from the vegetative growth stages to the reproductive phase of their crop development cycle. Thus far, the 2018 growing seasons has provided timely precipitation and warm growing conditions. The additional Growing Degree Day units have accelerated the crop development and the production of the first soybean flowers. Flowering was observed in some of my research plots during the last week in June. The soybean plant usually begins the reproductive period (Table 1) after the 4-6 trifoliolate leave stage has been reached. The first flower can be found lower on the stem and this stage is called reproductive one (R1) and is depicted in photos 1 and 2. Full flowering or bloom (R2 growth stage) is reached when many nodes on the stem have flowers and a flower is open at the one of the two uppermost nodes on the main stem. Soybean is mostly self-pollinating with natural crossing occurring at a rate of less than 0.5 percent, and the pollination may occur the day before the full opening of the flower.

kandel.1

The soybean plants will continue to develop new leaves during the flowering period. As weeds are still emerging, it is important to recognize that herbicides can only be applied before a designated growth stage is reached. It is important to always follow labeled herbicide use instructions to prevent any damage or yield loss.

 kandel.2 3

 

 Hans Kandel

Extension Agronomist Broadleaf 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.