Worst Weeds, Ranked
It’s no secret that weeds are a farmer’s enemy—but which weeds pose the biggest threat? The Weed Science Society of America (WSSA) recently deployed a survey to nearly 200 weed scientist across North America to find out more about weeds in farmers’ fields.
WSSA asked weed scientist to identify the most troublesome weeds as well as the most common weeds in their state. They considered herbicide resistance, frequency and crop affected by the weeds while making their rankings.
While palmer is only listed as the most troublesome weed in cotton, it’s ranked first overall because most respondents listed it as problematic.
Most Troublesome
1. Palmer Amaranth
2. Common Lambsquarters
3. Horseweed (Marestail)
4. Morning Glory (ivyleaf, pitted, tall)
5. Waterhemp (tall, common)
6. Nutsedge (yellow, purple)
7. Kochia
8. Common Ragweed
9. Giant Ragweed
10. Nightshade (eastern black, hairy)
Most Common
1. Common Lambsquarters
2. Foxtail (giant, green, yellow)
3. Morning Glory (ivyleaf, pitted, tall)
4. Palmer Amaranth
5. Redroot Pigweed
6. Waterhemp (tall, common)
7. Horseweed (Marestail)
8. Common Ragweed
9. Barnyardgrass
10. Velvetleaf
| Broadleaf Crop | Most Troublesome Weed | Most Common Weed |
| Alfalfa | Canada Thistle | Dandelion |
| Canola | Kochia | Wild Oat |
| Cotton | Palmer Amaranth | Morning Glory |
| Fruit and nuts | Field Bindweed | Horseweed (Marestail) |
| Peanuts | Nutsedge | Palmer Amaranth |
| Pulses | Common Lambsquarters | Common Lambsquarters |
| Soybeans | Horseweed, Waterhemp | Waterhemp |
| Sugar Beets | Common Lambsquarters | Common Lambsquarters |
| Vegetables | Nutsedge | Common Lambsquarters |
Does this match what you consider the worst weeds in your fields? Let us know!
