verely you cannot cut away all blighted parts 

 without killing the trees. In these cases, it is 

 often effective to paint the cankered or dis- 

 eased areas with a formulation of zinc sulfate. 

 However, because this chemical can injure the 

 healthy tissues next to treated areas, you should 

 apply it carefully. 



To prevent secondary infection by other or- 

 ganisms in tree parts that you have pruned, 

 treat wounds and cuts larger than 1 inch in 

 diameter with a tree-wound dressing. 



After making each cut, dip the pruning tools 

 in diluted household bleach (sodium hypochlo- 

 rite). Mix 1 cup of 5.25-percent commercial 

 bleach with 9 cups of water. Because this solu- 

 tion will corrode metals, wash tools in water 

 each day at the end of pruning. Tools then 

 should be dried and oiled to prevent them from 

 rusting. 



Spraying and dusting 



The antibiotic, streptomycin, is one of the 

 most effective materials known for control of 

 fire blight. Begin antibiotic sprays as soon as 

 color is detected in the flower buds and every 

 3 to 5 days until the petals fall. Continue appli- 

 cations at 7- to 14-day intervals following the 

 bloom period. Stop spraying apples 50 days be- 

 fore harvest and pears 30 days before harvest. 

 Early evening and nighttime applications of 

 antibiotics provide better fire blight control 

 than daytime applications. 



Antibiotic sprays are partially absorbed by 

 plg.nt foliage which may cause some yellow- 

 green mottling of the leaves (chlorosis). This 

 mottling disappears only after you stop using 

 the antibiotic. 



You can supplement pruning and the appli- 

 cation of zinc sulfate paints with a spray of 

 weak bordeaux mixture. This is prepared by 

 mixing 2 pounds of copper sulfate and 6 pounds 

 of hydrated lime in 100 gallons of water, or 

 two-thirds tablespoon of copper sulfate and 6 

 tablespoons of lime in 1 gallon of water. 



A commercial tribasic copper sulfate spray 

 mixture may also be used. Mix 1 pound of active 

 ingredients in 100 gallons of water, or 1 table- 

 spoon in 2 gallons of water. Also, a copper- 



lime dust mixture may be used; mix 20 parts 

 finely ground copper sulfate with 80 parts hy- 

 drated lime. 



Copper-base sprays or dusts applied to fruit 

 trees during or after spring blossoming may 

 cause the fruit to russet (develop rough, tough 

 skin). To minimize this when sprays are used, 

 apply sprays only when they will dry quickly. 



PRECAUTIONS 



Pesticides used improperly can be injurious to man, 

 animals, and plants. Follow the directions and heed all 

 precautions on the labels. 



Store pesticides in original containers under lock and 

 key — out of the reach of children and animals — and 

 away from food and feed. 



Apply pesticides so that they do not endanger hu- 

 mans, livestock, crops, beneficial insects, fish, and wild- 

 life. Do not apply pesticides when there is danger of 

 drift, when honey bees or other pollinating insects are 

 visiting plants, or in ways that may contaminate water 

 or leave illegal residues. 



Avoid prolonged inhalation of pesticide sprays or 

 dusts; wear protective clothing and equipment if speci- 

 fied on the container. 



If your hands become contaminated with a pesticide, 

 do not eat or drink until you have washed. In case a 

 pesticide is swallowed or gets in the eyes, follow the 

 first aid treatment given on the label, and get prompt 

 medical attention. If a pesticide is spilled on your skin 

 or clothing, remove immediately and wash skin thor- 

 oughly. 



Do not clean spray equipment or dump excess spray 

 material near ponds, streams, or wells. Because it is 

 difficult to remove all traces of herbicides from equip- 

 ment, do not use the same equipment for insecticides or 

 fungicides that you use for herbicides. 



Dispose of empty pesticide containers promptly. 

 Have them buried at a sanitary land-fill dump, or 

 crush and bury them in a level, isolated place. 



note: Some States have restrictions on the use of 

 certain pesticides. Check your State and local regula- 

 tions. 



PROTECTl 



v4J 



(/j4p«&!U&g^ 



Washington, D.C. 



Prepared by 



Plant Science Research Division 



Agricultural Research Service 



Revised February 1972 



For sale bv the Superintendent of Documents, U.S. Government 



Printing Office, Washington, D.C. 20402— Price 10 cents 



Stock Number 0100-1605 



ft U.S. GOVERNMENT PRINTING OFFICE: 1971 0—444-306 



