Look Out for Tar Spot on Corn

Sep 27, 2022

By Andrew Kness

Before anyone panics, this disease has not been confirmed in Maryland or Delaware; however, it is close by and could potentially spread to our state. As you’re scouting fields this summer, keep this one in the back of your mind.

Tar spot is a fungal disease of corn caused by Phyllachora maydis. It was first discovered in the United States in 2015. In Latin America where tar spot is more common, another fungal species, Monographella maydis, is known to occur in complex with P. maydis; however, only P. maydis has been found in the United States.

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Figure 1. Map of tar spot in the United States after the 2021 growing season. Map generated from: https://corn.ipmpipe.org/tarspot/.

The initial occurrence of tar spot in 2015 was limited to a couple of counties in Indiana, but by 2018 it had spread across much of the US corn belt and caused serious economic damage. In 2020, tar spot was confirmed in corn fields in Lancaster County Pennsylvania, then the surrounding York, Cumberland, Dauphin, and Lebanon counties in 2021 (Fig 1). We believe this large geographic jump from the corn belt to PA was from variety trial seed that was inadvertently contaminated with infected corn residue.

Symptoms of tar spot are the presence of glossy black, raised lesions on the leaves (Fig 2). These lesions look like someone splattered paint or tar on the leaves, hence the name. These symptoms have been observed to occur from VT to maturity. Lesions are also visible on dried plant parts.

The fungus that causes tar spot overwinters in infected corn residue; however, it is unknown how well, or if, this pathogen will overwinter here in Maryland or if this disease will be of any economic importance in this region.

Currently, there are no management recommendations for this disease for our area, because as stated, it is yet to be confirmed in Maryland and unknown if it will be a problem. For the 2022 corn crop, be on the lookout for this disease in your corn fields, especially if your have any corn hybrid trials or demos planted in your field. If you suspect you found this disease, please contact your local Extension agent and/or submit a sample to the Plant Diagnostic Lab.

Source : umd.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.