36 PHRAGMITES 



with the stems. In the Southwest the plant has been used for 

 thatching, matting, cordage, and nets. 



On the debit side, phragmites is one of the most common weeds 

 in waterfowl habitat and one of the most difficult to control. 

 Though most stands of this plant occur on comparatively high, dry- 

 parts of marshes, above the important zone for duck foods, it is 

 also a serious competitor with useful plants, particularly in areas 

 where water levels are not constant. Once established on de- 

 watered flats, it is likely to persist indefinitely and has been known 

 to survive in water a foot or more deep for at least 8 years. In 

 the West, phragmites is a pest along irrigation canals, and in vari- 

 ous parts of the country it is a serious fire hazard near industrial 

 installations. 



CONTROL 



Destruction of phragmites is difficult because of its tough, 

 durable rootstocks. Killing the aerial stems by burning, mow- 

 ing, or spraying frequently results in only a temporary setback. 

 The plant is particularly resistant to control measures when it 

 is growing in water. Its most vulnerable stage for treatment 

 is during the time of pollen release, a 3-week period occurring in 

 midsummer to early fall depending on location. In most cases, 

 best results have been obtained by treatment during the vulner- 

 able period, but the effectiveness of dalapon is not limited to this 

 season. 



Dalapon and ATA, either alone or in combinations, have recently 

 shown ability to control phragmites effectively. Ammate and 

 2,4-D have proved unsuitable for this purpose, and TCA, though 

 better, is not satisfactory. On comparatively dry sites, phrag- 

 mites can be eliminated by repeated mechanical operations, such 

 as disking. 



HERBICIDES ON COMPARATIVELY DRY SITES 



Dalapon treatments have given good results on terrestrial 

 stands of phragmites at various times during the growing season 

 from spring when new shoots are about 3 feet high until early 

 fall when the plants are full grown and in their most vulnerable 

 stage. Application of 30 to 35 pounds acid equivalent of dalapon 

 at any time during this 3- to 4-month period has provided good 

 control. ATA at 16 pounds active per acre was also effective if 

 applied during the pluming-flowering stage, a period of 4 to 5 

 weeks. A mixture of dalapon at 15 pounds and ATA at 2 pounds 

 has given good kills at various stages of growth, from early to 



