Marestail
The first glyphosate-resistant weed identified in U.S. row crops in 2000, marestail is a dangerous weed. It produces up to 200,000 seeds/plant and grows up to 5-6 feet tall. The seeds are highly mobile, which results in rapid spread.
Marestail usually germinates in fall and spring, but can germinate year-round.
Waterhemp
Waterhemp produces up to 1 million seeds/plant and can grow as much as 1 inch/day. The average height is 4-5 feet tall, with some weeds reaching up to 12-feet tall.
The pollen from these weeds can travel ½ a mile or more and because of the cross pollination that occurs, resistance can spread quickly.
Palmer Amaranth
Palmer amaranth thrives in reduced-, minimum- or no-tillage systems because it germinates close to the soil surface. It can produce 10,000 to 100,000 seeds/plant and has the potential to overtake the crop due to its rapid growth and aggressive competition.
Palmer amaranth has prolific seed production and germination throughout the season. It has a faster growth rate and is more competitive than other pigweed species, with growth rates approaching 3 inches/day.
When allowed to compete throughout the growing season, Palmer amaranth can create yield losses up to 91% in corn. It can reach 8 feet in height.
Pre-emergence control of Palmer amaranth
49-57 days after emergence (DAE)
Morningglory
Once established, morningglory is very difficult to control with post-emergence applications of herbicides. It competes with corn crops for nutrients and has the potential to reduce yield.
Morningglory can produce up to 500 seeds/plant, and, due to an extremely hard seed coat, some seeds can remain viable in the soil for more than 50 years.
Pre-emergence control of ivyleaf morningglory
62 days after treatment (DAT)
Giant Ragweed
Field research demonstrates that season-long competition from just 2 giant ragweed plants per 110 square feet can reduce corn yield by 13%.
Giant ragweed often grows taller than the crop, sometimes up to 5 feet taller. It can produce up to 5,100 seeds per plant.
Pre-emergence control of giant ragweed
49-58 days after emergence (DAE)
Resistance Fighter®When it comes to the future of your operation, actions speak louder than words. For decades, Syngenta has been collaborating with university experts and conducting research to solve problems associated with resistant weeds. See how our
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