196 



Bulletin 252. 



disk of the nozzle. See Cornell Bulletin 254. For use of insecticides in Bor- 

 deaux, see "steely-beetle." 



This is a fungous disease most evident on the leaves making 



Downy large brown spots on upper surface with white downy growth 



mildew. beneath. It also attacks the green fruit, causing what is known 



to growers as "hard white berry." Bordeaux as applied for 



BLACK ROT will coutrol this disease. 



LETTUCE. 

 This is a fungous disease often destructive in greenhouses, dis- 

 Drop or rot. covered by the sudden wilting of the plants. It is completely 

 controlled by steam steriliza- 

 tion of the soil to the depth of two inches or 

 more. If it is not feasible to sterilize the soil, 

 use fresh soil for every- crop of lettuce. See 

 Massachusetts Bulletin 69. 



MUSKMELON. 

 This is commonly called- 

 Downy "blight" and is a very trouble- 



mildew, some disease. The leaves show 



angular, dead brown spots 

 then dry up and die; the fruit often fails to 

 ripen and lacks flavor. It is caused by the same 

 fungus as is the downy mildew of cucumbers ; 

 no effective method of control is known. While 

 Bordeaux has proven effective in controlling 

 the downy mildew on cucumbers it seems to be 

 of little value in fighting the same disease on 

 melons. See Report of Botanist Connecticut 

 Station, 1904. 



Wilt. 



This is same as the wilt of 

 cucumbers ; same treatment is 

 given. 



Fig. 169. Ginseng blight. 



OATS. 



The most common and de- 

 Smut. structive disease of oats is 



smut, carried over from one 

 season to the next by fungus spores on the seed. Entirely prevented by treat- 

 ing the seed oats before planting with a solution of formalin, i pint to 45 or 50 

 gallons of water. Place the oats on a clean floor and sprinkle on the formalin as 

 they are shoveled over. Use one gallon to the bushel. Mix the oats thoroughly, 

 then shovel them into a pile and cover with blankets or canvas. After standing 

 in the pile from two to four hcjurs the oats, if they are to be drilled should be 

 spread out to dry; or they may be sown by hand without drying. Use one peck 

 more seed per acre to allow for swelling* of the grain. Treatment once in three 

 years is usually sufficient to prevent material loss from smut. See U. S. Farmers 

 Bulletin 250 and Wisconsin Bulletin iii. 



