Prashant Jha

Prashant Jha is an Associate Professor and Extension Weed Specialist with the Department of Agronomy at ISU. His research program is focused on improved understanding of weed biology and ecology to develop effective, integrated weed management strategies in corn and soybean production systems of Iowa and Midwest, optimization and stewardship of herbicide application technology and herbicide use, and understanding the evolution of herbicide resistance including genetic/molecular and physiological mechanisms, and other factors influencing weed population dynamics and management in agroecosystems. This includes emphasis on late-season weed seed bank management and reducing weed seed inputs at harvest. His research interest also includes UAV and ground-based hyperspectral imaging and machine learning of weed species in-crop for developing weed maps and for early detection of herbicide-resistant weed biotypes in the field. His statewide extension and outreach program is focused on current and emerging weed problems in Iowa and providing research-based information to growers on cost-effective, multi-tactic approaches for prevention and mitigation of herbicide-resistant weeds in agronomic crop production systems. He serves as the herbicide evaluation and demonstration program leader, with the ultimate aim to develop cost-effective and sustainable weed control recommendations for corn and soybean producers in Iowa. His programming supports extension, agribusiness, governmental agency programs, and other educational needs throughout Iowa.

July 22, 2021 12:40 PM

In October 2020, EPA approved five-year registrations (until 2025) for dicamba products including XtendiMax (Bayer), Engenia (BASF) and Tavium (Syngenta) for over-the-top use in Xtend and XtendFlex soybeans. These new dicamba product registrations included national cutoff dates (June 30 in most...

Crop Production, Weeds
June 9, 2021 9:12 PM

Most herbicide labels caution against applications made under environmental stress such as prevailing hot and dry conditions in Iowa this year. This is because of increased risk of crop injury and/or decreased weed control. Weeds growing under hot, dry conditions are often difficult to control...

April 6, 2021 11:06 AM

As it has started to warm up, folks are ready to implement early-spring weed management programs, especially in fields with infestations of winter annuals like field pennycress and marestail (horseweed). Spring burndown (preplant) herbicide programs should target winter annual plants at the...

February 10, 2021 11:46 PM

The following is a brief summary of new products available for weed control in corn and soybean in 2021. None of these are new sites of action herbicides, but are new premixes or revised formulations of existing active ingredients. With growing concerns of weeds developing resistance to...

Weeds, Herbicide Resistance
September 3, 2020 11:57 AM

Downed corn from the August 10 Derecho, which affected millions of acres in Iowa, will contribute to significant volunteer corn populations in crop fields in 2021. Volunteer corn ranging from 800 to 13,000 plants per acre can cause yield losses up to 54% in soybean and up to 13% in corn,...

July 8, 2020 7:00 AM

There is no question that dicamba injury across the Iowa landscape in 2020 is the most extensive it has been since the introduction of dicamba in the 1960s. ISUEO field agronomists and commercial agronomists in several areas of the state report nearly all non-dicamba resistant soybean are...

June 5, 2020 6:47 AM

Numerous herbicides registered for postemergence use on Xtend soybean have excellent activity on important weeds of Iowa’s soybean fields. Unfortunately, herbicide resistance in waterhemp is widespread to the herbicide groups active on this weed: Group 2 (ALS inhibitors), 9 (glyphosate) and 14 (...

Herbicide Resistance
September 30, 2019 1:00 PM

The spread of multiple-resistant weeds threatens Iowa’s production system. In order to slow the expansion of resistance, greater diversity in weed management is necessary.  An October 21 workshop will discuss one potential alternative weed management tool that is used in other parts of the world...

June 14, 2019 12:09 PM

Join the ISU Weed Science Program at the 2019 Herbicide Research and Demonstration Program Field Day on Thursday, June 27!


Weeds, Herbicide Resistance