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BETTER FRUIT 



Page p 



Black Leaf "40" Spraying to Control Apple Aphis 



[From Bulletin No. 1, Published by The Kentucky Tobacco Product Company, I^ouisville, Ky.] 



PLANT lice are among the most an- 

 noying and expensive pests of agri- 

 cultural crops that the farmer must 

 combat. And yet these small, soft- 

 bodied insects are easily destroyed and 

 elTectively controlled. A few general 

 facts, a few simple directions, and the 

 matter of aphis control loses most of 

 its uncertain and perplexing features 

 and becomes a regular routine part of 

 orchard management. 



Throughout the growing season these 

 plant lice in enormous numbers drain 

 the vitality of the plants attacked, and 

 if not checked often cause large losses 

 to the grower. A single aphis may 

 bring forth from 50 to as many as 150 

 young which, in little more than a 

 week, are themselves ready to produce 

 young. At the approach of cold 

 weather the females (the woolly aphis 

 excepted) lay eggs, in which form the 

 plant lice pass the winter. The woolly 

 aphis passes the winter in form of 

 young lice on twigs, branches and 

 trunk, and as young and old lice on 

 the roots. With the hatching of the 

 eggs in the spring at the time the buds 

 begin to grow, the activity of the plant 

 lice begins, and unless steps are taken 

 in time the number of individuals may 

 become so large as to threaten the life 

 of the plant or destroy a large portion 

 of the season's crop. Plant lice are 

 particularly destructive in the spring, 

 though severe outbreaks may occur at 

 any time during the growing season. 



The aphis generally prefers the 



younger, growing twigs and is found 

 most frequently in the denser parts of 

 the tree. Its sharp, slender beak pene- 

 trates to the interior of the leaf, blos- 

 som, fruit or twig and by this means it 

 sucks the plant juices which constitute 

 its food. As the aphis obtains its food 

 from within the plant, evidently, poi- 

 sons, which must be swallowetl to be 

 effective, such as arsenate of lead, do 

 not bother it in the least. An insecti- 

 cide that will kill merely by touching 

 the insect nnist be used. 



The aphis causes the following types 

 of injury: Reduces the vitality and 

 checks the growth of the tree; causes 

 leaves to curl, turn brown and drop; 

 reduces the yield of fruit; causes fruit 

 to be misshapen ; checks the develop- 

 ment of young fruit; causes the well- 

 known "cluster apples"; checks the de- 

 velopment of the next year's fruit buds; 

 assists in spreading plant diseases, par- 

 ticularly fire blight; weakens or kills 

 young nursery stock. 



A grower with infested trees should 

 spray not only to increase the yield 

 and grade of his own fruit and protect 

 the vitality and growth of his own 

 trees, but also to afford reasonable pro- 

 tection to the trees of his neighbors. 

 Aphids fly or are carried by the wind 

 from one orchard to another. A grower 

 may, then, by neglecting to sprayj 

 cause nearby orchards to be infested 

 even though the neighboring growers 

 have sprayed properly. In fact one 

 neglected orchard may be the center of 

 infestation for a whole communitv. 



Figure 3. Figuhf. 4. Figurk .5. FiGt'RK 6. 



Figure 3 — Ajihids on opening bud; period ff>r spraying. Figure 1 — Apple buds too far 

 advanced foi- aphis spraying. Figi-re .'> — Apllis in cluster of unopened blossoms; a gixul 

 time for spraying. [From tlle New York ((leneva) Experiment Station Circular 23 



The time of spraying is an important 

 item in the control of aphis. Failures 

 to control aphis may often be traced to 

 the fact that the spray was not applied 

 soon enough. The New York (Geneva) 

 Experiment Station gives the following 

 as the times when the green, also rosy 

 or i)uri)Ie aphis are most vulnerable: 

 "When the aphids are appearing on the 

 green tips of the buds and when the 

 leaves have unfolded but have not been 

 curled b\' the lice, which is usually just 

 before or immediately after blossom- 

 ing. 1. Spraying for the newly- 

 hatched lice: Especial pains should be 

 taken to destroy the pest at this stage, 

 as thorough work greatly reduces the 

 subseciuent numbers of the lice and 

 may simplify later spraying operations. 

 Tlie best means of killing the newly- 

 hatched lice is a treatment during a 

 green iind while the buds are still com- 

 pact. (Figure 3.) It is important to 

 spray early, for if the treatment is de- 

 layed the aphids obtain protection in 

 the fuzzy, unfolded leaves of the open- 

 ing buds, where they are protected 

 from applications of spray mixtures. 

 2. Spraying for adults of the first 

 brood and second-brood young: Indi- 

 viduals of these stages are very sus- 

 ceptible to contact sprays. They are 

 usually active upon the trees during the 

 period extending from the appearance 

 of the color in the unopened blossoms 

 (Figure 5) to the dropping of the pet- 

 als (Figure 6)." ' * * 



Make the applications as follows: 

 Spray with "Black Leaf 40" 1 to 1066 

 and soap (% pint of "Black Leaf 40" 

 plus 3 to 4 pounds soap to 100 gallons 

 water) when the buds show green. 

 (See Figure 3.) If lime-sulphur is ap- 

 plied for scale when buds shown green, 

 combine "Black Leaf 40" with it in- 

 stead of making application No. 1. 

 Omit soap. (See Figure 3.) Combine 

 "Black Leaf 40" with scab spray (when 

 blossoms show pink) if treatments 1 

 or 2 were not given or lice are present. 

 Omit soap. (See Figure 5.) Likewise 

 combine "Black Leaf 40" with the first 

 codling-moth spray (when petals fall) 

 if plant lice are present. Omit soap. 

 However, we strongly recommend 

 treatments 1 or 2 or 3 for best results. 

 (See Figure 6.) Thorough work in 

 spraying at these times may make later 

 applications unnecessary. There is no 

 definite rule for spraying in late sum- 

 mer for aphis. The grower should 

 keep watch and spray whenever the 

 plant lice threaten to become numerous 

 and before the leaves curl. 



The forimila: Circular No. 23 of the 

 New York (Geneva) Experiment Sta- 

 tion states: "The most satisfactory 

 IJieiJnration from the standpoint of 

 safety to the buds and effectiveness 

 against the insects is three-fourths of a 

 pint of 'Bhick Leaf 40' to one hundred 

 gallons of water, to which are added 

 from three to five pounds of dissolved 

 soap." This gives a dilution of one 

 part of "Black Leaf 40" to lOOO parts 

 Wilier. The soap is added as a spreader 

 and in iidditiim serves to soften hard 

 water, which occasionall\ renders 

 Continued on page 31 



