Preventing and Managing Dodder in Alfalfa

Tips for preventing and managing dodder in alfalfa. 

A parasitic plant, dodder, has impacted alfalfa production since the 1950s. Its capacity to proliferate very quickly and the long-lived nature of the seeds in the soil make it highly problematic for producers.

What is Dodder?

• Dodder is a non-chlorophyll-producing parasitic weed.
• Dodder’s filaments have suckers which directly tap into alfalfa’s nutrients.
• The filaments of dodder grow quickly to form clusters in the fields that form large circles in plots, which strangle the alfalfa.
• A lot of other plants are sensitive to dodder: clover, beetroot, tomato, carrot, potato, but also some weeds such as knotweed, nettle, Umbelliferae, feverfew...

There are two primary species of dodder that can interfere with alfalfa:

1. Cuscuta Campestris Yunck « big cuscute »Orange filaments
2. Cuscuta Epitymum L. « small cuscute ». Straw yellow filaments

The fight against dodder starts by choosing certified seeds to avoid contamination by seeds. In case of the appearance of a cluster, it is important to rapidly apply chemicals in the zone. Only the destruction of the host plant allows the eradication of dodder. As a precaution, application zones must overlap the cluster by 2 or 3 meters.

The fight against dodder starts by choosing certified seeds to avoid contamination by seeds.
MAS Seeds alfalfa seed is certified to have 0% dodder in the bags.

Biology of Dodder

Germination:

• Seeds germinate at or just below the surface (0-10 mm).
• Big dodder germinate at optimal temperatures of 30°C. Small dodder germinate at optimal temperature of 15-20°C.
• Germination can occur without host plant => Lifetime 10 days.

Rapid Multiplication:

• The filaments grow quickly and it spreads rapidly over a few meters.
• First flowers appear 4 to 6 weeks after germination.
• Thousands of seeds ripen quickly (2000-3000 seeds per stem).

Seed Longevity and Spread:

• Dodder seeds can exist in the soil for a long time.
• Under good conditions seeds can survive in the soil for up to 40 years
• Agricultural machinery and crop production favour the dissemination of seeds across fields
• Farm seeds is the first origin of dodder infestation.
• Stored seeds can be transported by water, animals, tillage or harvest machinery.

How to Fight Dodder?

Preventive way…avoid the introduction in field!

• Use tools cleaned for working the soil, and for the harvesting.
• Sow certified seed, guaranteed without dodder.

Curative way

• In case of early infestation, the only ways to fight dodder is to destroy host plant.
• Burn with straw or use a specific weedkiller (ask advice to your technician) a few meter overflow the rounds.
• If dodder is spread through all the field, it is recommended to destroy the crop.

To get agronomic advice or find seed, contact find your local MAS Seeds representative.