 This is the sugar beet report bringing you the latest information from NDSU throughout the sugar beet growing season. Water hemp can be one of the most challenging weeds sugar beet producers face, but a close and nastier relative is growing in North Dakota, Palmer Amaranth. Quincy Law, NDSU assistant professor specializing in invasive and noxious weeds is here to provide us with the latest information. Quincy, sugar beet producers may already be familiar with water hemp. What is Palmer Amaranth? So Palmer Amaranth is a species that's closely related to water hemp. The main difference here is that Palmer Amaranth is considered noxious whereas water hemp is not and so by law in North Dakota Palmer Amaranth must be controlled. There's some fine details in identifying them and as well as controlling them but largely those two plants pose the same agricultural challenges. How are they identified? We talk about a whole plant family as pigweeds. So there's a number of different pigweeds in North Dakota and so some of the more common ones would be red root pigweed or prostrate pigweed whereas water hemp and Palmer Amaranth while they're also pigweeds are their own species as well and so some of the differences between that are how fast they grow. So Palmer Amaranth and water hemp grow a little bit faster and a little bit taller than then say red root pigweed. When those plants emerge can also differ a little bit. Red root pigweed usually emerges about two weeks sooner than what we see water hemp and Palmer Amaranth emerging in the state. Water hemp and Palmer Amaranth generally emerge around Memorial Day and then continue to emerge all the way into September. As far as identification characteristics, water hemp and Palmer Amaranth are smooth so you won't find any hairs on the leaves or stems whereas red root pigweed the stem is very hairy and so you can distinguish it that way but again these are some pretty fine details and even a trained eye can have difficulty separating them. Is it hard to tell the difference between water hemp and Palmer Amaranth because they're pretty close right? Yeah so it can be very difficult to tell those apart because sometimes water hemp leaves will look a little bit like Palmer Amaranth and that they're a little bit wider and they can get a long petiole or Palmer Amaranth can kind of get the lancy late leaf that you'll run into on water hemp. They can really kind of look like one another. The easiest time to tell them apart is again when they're flowering which is right about now. Why are water hemp and Palmer Amaranth so problematic in sugar beet? So there's a number of reasons that these two species are especially problematic so first they're highly competitive with crops so they can cause significant yield losses. Next they emerge over an extended period of time so many weeds you'll see one major flush whereas Palmer Amaranth and water hemp kind of emerge over an extended period of time. Third both of these species produce an exceptional number of seeds and so that can be troublesome to combat that many seeds and then lastly they're difficult to control and one of those reasons is that they are quick to adapt and evolve herbicide resistance so herbicide resistance is quite prevalent within these species. Should producers be on the lookout for Palmer Amaranth? Absolutely and right now is a great time to be looking for it as these pigweeds all look largely the same and so one distinguishing characteristic is that seed head or the flower and right now Palmer Amaranth is beginning to flower and so it's a little bit easier to tell it apart and so if you see a pigweed that the flower looks a little bit different than what else you've seen then it may be a suspect plant and if so it'd be a good idea to consult with your North Dakota State University County Extension Agent and they can refer any suspect plants to us on campus. Quincy are there any other weed control issues producers should be aware of? Yes so COSA is a problematic weed especially out in western North Dakota but I bring it to light today because North Dakota State University researchers have confirmed group 14 resistant COSA within the state and so we found multiple cases of this and we found it to be resistant to AIM which is carpentra zone as well as Sharpen which is safflufinacil so not specifically a sugar beet issue but more of a widespread North Dakota agricultural issue to be aware of. Thanks Quincy our guest has been Quincy Law NDSU assistant professor specializing in invasive and noxious weeds. This is the sugar beet report bringing you the latest information from NDSU throughout the sugar beet growing season.