HERBICIDAL CONTROL 9 



in marsh management. Ammate is effective on many marsh and 

 swamp plants, but it is comparatively expensive. The main use- 

 fulness of TCA is on grasses, but in combination with 2,4-D it has 

 proved effective on needlerush. Both Ammate and TCA corrode 

 spraying equipment. The soil sterilants Borascu and Polybor- 

 chlorate have been used successfully for local, small-scale eradica- 

 tion of hard-to-control pests in unflooded sites, but costs are likely 

 to be prohibitive for extensive treatments with these chemicals. 



A number of promising new herbicides have become available 

 recently. Among these is dalapon (2,2-dichloropropionic acid), 

 sold under the names Radapon and Dowpon. It has shown superi- 

 ority to 2,4-D for control of phragmites, maidencane, and certain 

 other narrow-leaf marsh plants. ATA (3-amino-l,2,4-triazole) 

 which is sold as Amino Triazole and Weedazol has important possi- 

 bilities for control of cattails and other plants. It is translocated 

 readily and inhibits chlorophyll production with the result that new 

 growth is often albinistic. Erbon (2-(2,4,5-trichlorophenoxy)- 

 ethyl-2,2-dichloropropionate) has given indication of being valu- 

 able as a temporary soil sterilant in sites that are not flooded for 

 two or three months. It is sold under the names Baron and 

 Novon. Certain formulations of silvex, (2-(2,4,5-trichlorophe- 

 noxy) -propionic acid) have given encouraging results on alligator- 

 weed, specifically Kuron and 2,4,5-T Propionic. Additional prom- 

 ising new herbicides include urea formulations such as monuron, 

 diuron, and neburon, and certain chlorobenzoic derivatives. 



WHEN AND HOW TO SPRAY 



In general, herbicides are likely to be most effective under con- 

 ditions favorable to plant growth — sunny, warm, humid weather. 

 Spraying in early morning or midmorning usually results in good 

 penetration before afternoon or evening showers arrive. Water- 

 soluble herbicides should remain on plants at least 6 hours before 

 a rain. Spraying is easier, safer, and more effective when air 

 movement is limited. 



Volume used depends on the method of spraying (from land, 

 boat, or plane), as well as on the height and density of the vegeta- 

 tion treated. Generally, spraying operations from land or boat 

 use 50 to 500 gallons per acre. Good coverage without wasteful 

 runoff requires careful operation with efficient equipment. In 

 many instances, low-volume spraying with large droplets has 

 proved as effective as thorough wetting with fine high-pressure 

 spray. Most commercial herbicides now include wetting agents 

 that increase adherence of sprays to leaves, but sometimes addition 



