WEEDS 111 



will improve the thickness of the turf and retard the growth 

 of weeds, as shown above. Those remaining may be pulled, 

 but some of the newer chemical treatments may be more 

 rapid. A number are in use for spraying, but for scattered 

 weeds in a lawn the spot method is best. A small amount 

 of a chemical is put on the center of the crown or on the cut 

 surface of the tap root of the weed, to destroy the growing 

 point and the conducting system to the older leaves. Am- 

 monium sulphate may be used by dropping a small amount 

 of the powder on the center of the weed. It acts also as a 

 fertilizer to stimulate the grass, making it spotty. Gasoline, 

 carbolic acid, dilute sulphuric acid, or cleaning solution may 

 be used if applied from a small grease can. Only a few drops 

 are needed on each plant, a method surprisingly rapid which 

 does little damage to the grass. The plants will die in one 

 or two days. 



Weeds may be destroyed in paths, tennis courts, and 

 other open areas by spraying with sodium chlorate at the 

 rate of about | pound per gallon of water. This will kill 

 other plants and will prevent plant growth for about a year. 

 Poison ivy may be killed by two or three sprays of this solu- 

 tion at weekly or ten-day intervals. 



Heavy weed infestations may be killed by spraying even 

 on a lawn with iron sulphate or sodium arsenite, but several 

 applications will be necessary and the tops of the grass may 

 be burned with each spraying. For details of these methods 

 Muenscher's book "Weeds," which explains the use of several 

 chemicals, should be consulted. 



REFERENCES 



Monteith, John, and J. W. Bengtson, "Arsenical Compounds for the Control of Turf 

 Weeds, Turf Culture," vol. 1, pp. 10-43, Jan., 1939. Several other articles on weeds 

 will be found in the above number of Turf Culture. 



Muenscher, W. C, Weeds, The Macmillan Co., 1936. 



Sprague, H. B., Better Lawns, McGraw-Hill Book Co., 1940. 



Your State Agricultural Experiment Station Publications on Weeds. 



