CRANBERRY GROWING 



29 



production. Vines affected by false blossom come to have a witclies'- 

 Iiroom development (Fig. 21 left), and their flowers open facing upward 

 (Fig 21 right) instead of turning down as healthy cranberry blossoms do. 

 It is a virus disease, spread by a leafhopper (Fig. 22), and can be con- 

 trolled by checking the leafhopper with pyrethrum dust or dusts contain- 

 ing rotenone (Fig. 23). Rose bloom is a fungous disease which causes 

 new shoots to be greatly enlarged and rose-colored, the vines sometimes ap- 

 pearing as though they were in full bloom. It affects late varieties most, 

 especially Matthews and Howes. It may be treated by flooding for thirty 

 hours or by spraying wnth Bordeaux mixture, 10 pounds of copper sul- 

 fate and 4 pounds of lime to 100 gallons of water, 250 gallons an acre, 

 or with basic copper arsenate, 6 pounds in 100 gallons of water, 250 gal- 

 lons an acre, about May 25. (H. F. Bergman.) 



Fig. 25. 



A. Webbed Cranberry Branches, work of the Black-headed Fireworm. 



B. Gypsy Mofch Caterpillar Defoliating a Cranberry Branch. 



