CULTURAL PRACTICES 



Many of the worst aphid infes- 

 tations on tobacco are started in 

 the plant beds by aphids moving 

 from nearby patches of collard, 

 turnip, mustard, or dock. Beds 

 should be located a safe distance 

 from such sources of aphids, or 

 the winter host plants should be 

 destroyed before the tobacco ger- 

 minates. If this is not done the 

 beds may be reinfested even if 

 they are treated with insecticides. 

 The removal of winter hosts is an 

 effective way to prevent heavy 

 infestations in the field. 



The tobacco field should be free 

 of weeds before the plants are set. 



INSECTICIDE TREATMENT 



Malathion, thiodan and parathi- 

 on are effective insecticides for 

 controlling aphids. Malathion and 

 thiodan are less hazardous to ap- 

 ply. The insecticides can be used 

 as dusts or sprays. 



Select 



ion 



DUSTS 



If you prefer dusts, buy a 

 ready-to-use dust containing 4 

 percent of malathion or thiodan or 

 1 percent of parathion. 



SPRAYS 



For hand equipment, which is 

 used in plant beds, and high- 

 gallonage (50 to 100 gallons per 

 acre) equipment, which is used 

 in the field, buy an emulsifiable 

 concentrate or a wettable powder 

 that contains malathion or para- 

 thion. The amount to mix with 100 

 gallons of water is shown below. 



Malathion — 2 pints of 50- 

 percent emulsifiable concentrate 

 or 4 pounds of 25-percent wet- 

 table powder. 



Parathion — 1 pint of 25-per- 

 cent emulsifiable concentrate or 

 1 pound of 15-percent wettable 

 powder. 



For aircraft sprayers or other 

 low-gallonage (1 to 5 gallons per 

 acre) equipment, buy an emul- 

 sifiable concentrate that contains 

 malathion or parathion. Wettable 

 powders are not suitable; they 

 tend to clog the nozzles. Mix the 

 emulsifiable concentrate with 1 to 

 5 gallons of water. (The amount 

 of water to use depends on the 

 capacity of the equipment.) Use 

 an amount of the concentrate that 

 will give y 5 pound of parathion 

 (actual) or 1 pound of malathion 

 (actual) per acre. 



Application 



The insecticide should be ap- 

 plied to the plants thoroughly but 

 lightly. The dosage depends on 

 the size of the plants. Quantities 

 larger than those recommended 

 increase the cost of treatment and 

 the hazard of excess residues on 

 the tobacco. 



If you use a spray, apply it im- 

 mediately after it has been mixed. 



IN PLANT BEDS 



All cigar-wrapper tobacco plant 

 beds should be treated several 

 times with an insecticide, whether 

 or not aphids are found. Other 

 tobacco plant beds should be in- 

 spected from time to time and 

 treated as needed. It is also a good 

 plan to treat any infested beds a 

 few days before the plants are 

 transplanted to the field. 



The rate of application for dust 

 is 1 pound per 100 square yards ; 

 for spray, 5 gallons per 100 square 

 yards. You can apply dust with- 

 out removing the plant bed cover, 

 provided the cover is dry and is 

 not touching the plants. 



IN THE FIELD 



Cigar-wrapper tobacco plants 

 should be treated in the field once 

 a week for the first 6 weeks. As 

 the tobacco matures, it should be 

 searched often for aphids. Small 



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