ANNUAL REPORT. 1940 47 



sensitive ferns; 40 pounds killed the same percentage of feather ferns and 

 about 50 percent of long-leaved asters. Any heavier applications caused 

 serious vine injury. 



A solution of ferrous sulfate (1 lb. FeSOi to a gallon of water), tried 

 on wild bean in June, was successful only when 3000 or more gallons were 

 used to the acre. Some tip injury resulted then, but the treated plots were 

 relatively weedless in August when vine recovery was complete. Wild bean 

 had been cut down 90 percent, asters (long-leaved) 60 percent, manna grass 

 (Glyceria) and reed canary grass 75 percent, haircap moss 90 percent, and 

 feather and sensitive ferns 70 and 90 percent respectively. Treatments in 

 May with this solution might be as effective in killing weeds, possibly 

 without vine injury. 



Iron sulfate solutions of varying concentration and quantity were ap- 

 plied to sensitive and feather ferns. It was concluded that dry applications 

 for these weeds are more feasible. 



Copper Sulfate. Solutions of this chemical caused some injury wlien ap- 

 plied the first week in August. The injury was to vine tips and was like 

 the burning noticed on plots sprayed the last week in July 1939. Grow- 

 ers must not use this spray too early in years with a backward growing 

 season. 



Copper sulfate solutions are still the only effective treatment fur "summer 

 grass" (Panicum verrucosum). They burn the grass tops and prevent seed- 

 ing. It is better to use 20 pounds in 100 gallons of water, at the rate of 400 

 gallons to the acre, than to use a stronger solution more lightly. 



Solutions of copper sulfate were very effective in burning the tops of 

 Joe-Pye weed (Eupatorium purpureum) . This weed is common on only a few 

 Cape Cod bogs but is a serious pest to many Wisconsin growers. 



Copper sulfate, 20 pounds in 100 gallons of water, killed wild bean 

 foliage nearly as well as sodium arsenate spray. 



Paradichlorohenzene. This chemical, applied early in May with a fertilizer 

 spreader, 600 pounds to an acre, and covered with sand, killed white violets 

 very nicely and seems to be the most promising treatment for them so 

 far found. It did not harm cranberry vines. 



Ammonium Sulfamate and Sulfamic Acid. Ammonium sulfamate, scat- 

 tered dry 1200 pounds to an acre, and sulfamic acid, scattered dry 1600 

 pounds to an acre, killed all weeds and cranberry vines, much as sodium 

 arsenite and sodium chlorate do. They failed, however, to show any use- 

 ful selective action. 



Ocean Water. Tests on wild bean in July showed again that ocean water 

 will kill down the weed tops for the rest of the growing season, but it 

 was hard to apply enough to kill the bean without injurying cranberry 

 vines a good deal. About half as many wild bean shoots came up this 

 year on the areas treated with ocean water in July 1939. as were present 

 when the treatments were made. 



