Dodder Weed: A Parasitic Plant that Threatens Crops
Dodder Weed: What is it?
Dodder weed is a parasitic plant that attaches itself to other plants, called host plants, to steal their nutrients and water. It has thin, twining stems that can be pale green, yellow, or bright orange in color. Dodder weed is either leafless or has tiny, triangular leaves. It produces cream-colored bell-shaped blooms that contain seeds.
How Does Dodder Weed Spread?
Dodder weed seeds are dispersed through soil, equipment, or infested plant material. When the seeds germinate, they produce rootless seedlings that must quickly attach to a host plant to survive. If they don’t find a host within a few days, they will die.
Once attached, dodder weed uses its suckers, called haustoria, to penetrate the host plant’s stem and suck out its nutrients. This can weaken the host plant, making it more susceptible to disease and insect attacks. Dodder weed can also reduce the host plant’s fruit set and yield, and even kill it.
Common Host Plants of Dodder Weed
Dodder weed can parasitize a wide range of plants, including:
- Alfalfa
- Asparagus
- Melons
- Safflower
- Sugarbeet
- Tomato
How to Control Dodder Weed
Controlling dodder weed requires a systematic approach that includes:
- Removing infested plants: Hand-pull or dig up small infestations of dodder weed. Be sure to remove the entire plant, including the roots.
- Preventing seed production: Mow, prune, or burn dodder-infested plants before they produce seeds.
- Suppressing new seedlings: Use pre-emergent herbicides to prevent dodder weed seeds from germinating.
- Choosing resistant plants: Plant species that are not attractive to dodder weed, such as grasses, lilies, crucifers, legumes, or transplanted trees and shrubs.
Chemical Control of Dodder Weed
Chemical control is not usually necessary for dodder weed management in home gardens. However, in areas with large infestations, herbicides may be used. Be sure to follow the instructions on the herbicide label carefully.
Japanese Dodder: A Special Threat
Japanese dodder is an invasive species that has recently been found in California. It is particularly aggressive and can parasitize a wide range of plants, including citrus trees, ornamental shrubs, and native plants. If you live in California and suspect you have Japanese dodder, contact your county agricultural commissioner or local extension office for assistance.
Tips for Preventing Dodder Weed Spread
- Be careful when moving equipment and clothing from infested areas to uninfested areas, as dodder weed seeds may cling to them.
- Clean your shoes and tires before entering uninfested areas.
- Avoid using infested plant material for mulch or compost.
- Inspect new plants for dodder weed before planting them.
Conclusion
Dodder weed is a serious threat to crops and ornamental plants. By understanding how it spreads and using effective control methods, you can help prevent or manage dodder weed infestations and protect your plants.
