ARID AGRICULTURE. 249 



can be applied to practically any weed problem 

 that may arise. Sweet clover is left out of the 

 list because we consider it one of the desirable 

 weeds. There are places where it is troublesome 

 in dry farming, but as it is a biennial, simply 

 keeping it from going to seed for two seasons will 

 entirely destroy it. There are many weeds like 

 Buffalo burr, rag weed, cow weed, pig weed, 

 lamb's quarters, sunflowers, etc., that must sim- 

 ply be given the hoe or other clean culture. 



Dodder is called "love vine" by many. It is 

 a yellowish or brown, fine stemmed parasitic 

 plant with bunches of whitish flowers. It grows 

 on alfalfa and other small stemmed plants. The 

 small stems twine themselves around the alfalfa 

 and send little roots into the tissues for their food 

 supply. In places where alfalfa does not make 

 the strongest growth the dodder may entirely kill 

 the plants. Alfalfa seed often contains dodder, 

 but there is no excuse for this or for the farmer 

 planting it. Dodder seed is only about half the 

 size of alfalfa seed and may be removed by 

 screening through a screen with twenty meshes 

 to the inch and blowing to remove any un- 

 threshed seed heads of the dodder. 



If dodder appears in the field, it may be de- 

 stroyed by mowing close to the ground, before 

 the dodder blooms, and removing the crop. If 

 the dodder has produced seed, it may be killed 

 by mowing and burning the crop on the ground. 



