Do you know your crop growth stages?

Jun 20, 2019

By Meaghan Anderson

Staging crops is an underappreciated but incredibly important skill. One very important reason to know how to stage your crops is because herbicide products may have limits on what growth stages of the crop they can be applied. This ICM Blog will discuss staging corn and soybean as well as share resources that can be used to double check herbicide labels prior to spraying your crops.

Note: When a field of corn or soybeans has 50% or more of the plants at a given stage, the field is at that growth stage.

Staging Corn

Corn growth stages are classified as vegetative or reproductive. The leaf collar method is one method used to stage corn while it is in the vegetative stages. With this method, the vegetative stages are based upon the number of visible leaf collars. Staging begins at emergence (VE), and each new leaf with a fully developed leaf collar is called stage V(number). Figure 1 below shows a corn plant at V2 because it has two leaves with a fully developed leaf collar. The third leaf does not have a collar yet. Vegetative leaf staging for corn plants ends when the corn develops a tassel (VT); once the plant has silks visible outside of the husks it has reached the first reproductive stage (R1). Read more about corn growth staging here.

Figure 1. Corn at growth stage V2. Photo by Meaghan Anderson.

Many herbicide labels have restrictions that eliminate the option of spraying once corn reaches stage V6 or earlier. Check the herbicide label on the product or on a website like www.cdms.net to determine the stage at which herbicide applications should cease.

Staging Soybean

Just like staging corn, soybean growth stages divides plant development into vegetative (V) and reproductive (R) stages. The vegetative stages are numbered according to how many fully-developed trifoliate leaves are present. Soybean plants will continue to produce new leaves throughout most of the growing season, but the reproductive (R) stages begin when the first flowers develop on plants and include pod development, seed development, and plant maturation.

Soybean growth staging is especially important this time of year as soybeans will soon begin flowering due to their photoperiod sensitivity. Flowers have already been observed in some of the early planted soybean fields in Iowa. When soybeans are planted early or we have warm weather in the early growing season, plants may begin flowering before the summer solstice. When soybeans begin to flower, they have reached the reproductive stage. We stop counting the number of trifoliate leaves. Soybean flowering begins with stage R1, which is defined as when 50% of the plants in a field have at least one flower anywhere on the plant (Figure 2). Stage R2 is when 50% of the plants in the field have a flower at one of the two uppermost nodes on the plant. Read more about soybean growth stages here. Many soybean herbicide labels have restrictions once soybean fields reach flowering. It is important to know the limitations of postemergence herbicides for soybean fields, know the crop stage of the soybean field you plan to treat, and be aware of the rotational restrictions to corn next year before application.

Figure 2. Soybean plant at stage R1 (flower on any node of the plant). Photo taken June 19, 2019 by Rebecca Vittetoe.

Source:iastate.edu

Video: Why Rob Saik is Trying to Build the World’s Most Connected Agriculture Network

In a recent interview at the SeedLink Conference in Brandon, Man., Rob Saik, author, speaker, and CEO of AGvisorPRO, took a trip down memory lane, reminiscing about the beginnings of his career and what the future holds.

Graduating from the University of Alberta in 1983, Saik embarked on a journey that started in Brandon, Man. “I got a job with Elanko, got a U-Haul truck, threw everything I had into it, drove to the Victoria Inn, and lived there for three months while they tried to find an apartment for me to move into. So I started my career in Brandon,” Saik shared.

Fast forward to the present, Saik has evolved into an accomplished author and speaker, traversing the globe to engage in high-level discussions about the future of agriculture and the critical role it plays in feeding the world. Yet, despite his global presence, he finds himself back in Brandon, addressing a group of seed growers. But why? Saik emphasizes the fundamental importance of seeds, stating, “It all begins with a seed, doesn’t it?”

Reflecting on his own experiences as a farmer, Saik expresses his excitement when a planted seed germinates and evolves into a thriving crop. He underscores the significance of technology and breeding in seed development, recognizing the crucial role they play in ensuring farmers can propagate seeds, grow profitable crops, and contribute to global food security.

Saik delves into the challenges faced by the agricultural community, particularly the rapid pace of technological advancements. He believes that the key lies in connecting farmers to experts swiftly, boosting farmers’ confidence in adopting new technologies, and ensuring the timely implementation of these advancements. According to Saik, this approach is crucial for steering agriculture towards sustainability and profitability.

As Saik works on his upcoming book, tentatively titled prAGmatic, he sheds light on its central theme. “The thesis would be that I want to write a book that takes what the consumer wants, challenges what the consumer believes, and positions that against what the farmers can actually do pragmatically,” he explains. The book aims to bridge the gap between consumer expectations and the realistic capabilities of farmers, promoting sustainable intensification as the necessary path to feed the planet.

Looking ahead to 2024, Saik emphasizes the need for enhanced connectivity within the seed industry. He discusses his platform, AgvisorPro, which is designed to facilitate connections between farmers, experts, and companies in a way that transcends conventional social media platforms. Saik envisions a credible, connected agricultural network that goes beyond the noise of platforms like LinkedIn or Twitter.

In a passionate vision for the future, Saik imagines a tool for teachers that allows them to pose questions from students, answered by verified farmers and ranchers. This, he believes, would provide an authentic and valuable educational resource, connecting classrooms with individuals who truly understand the intricacies of agriculture.