21 



Description. Dodder differs from ordinary weeds in possessing- no 

 leaves. The yellow thread-like stems of the plant twine around the clover 

 plants and send into their tissues small short rootlets, which are called 

 suckers or haustoria. By means of these suckers the Dodder draws from 

 the clover the food necessary for its growth and reproduction. It thus 

 kills the clover by robbing the plant of its food and causing it to starve. 



Fig. 20. Seed of Dodder. 

 Enlarged about 12 times. 



The yellow thread-like stems of the Dodder first appear quite early in the 

 season. They soon spread from plant to plant until a tangled mass of 

 yellow threads covers a whole patch of clover. Badly infested fields may 

 become entirely covered with this pest in a short time. On these yellow 

 threads are produced dense clusters of small white flowers, which are 

 succeeded by rounded, brown seed pods. Each plant produces a large 

 number of seeds. The seeds vary in size from 1-24 to 1-15 of an inch; 

 are grey or yellowish brown in color, vary greatly in shape, but are gen- 

 erally somewhat oval in outline, and the surface is dull and roughened. 



Eradication. Great care should be taken to secure clover seed free 

 from Dodder seed. Clover seed containing this impurity is dear at any 

 price. Small patches should be mowed, raked and burnt early enough to 

 prevent seeding. If, by any chance, some of the seeds are scattered 

 before the patches are mowed, several thorough hoeings should be given 

 in order to prevent any young plants from getting established. Badly 

 infested fields should be plowed ar.d put under a hoed crop for a season. 

 Clover should not again be sown in the field for two or three years. 



