12 Farmers' Bulletin 872. 



This gives a very light fluffy powder which forms an excellent 

 dust if blown on the cotton with force. 



The method of application should depend on the acreage to be 

 treated. For poisoning small areas up to about 25 acres hand dust 

 guns which are on the market may be used. About 3 acres a day 

 can be covered with one of these. For larger acreages wheel-traction 

 dusters are obtainable and for very large areas power blowers may 

 be advisable.^ 



Some may prefer the old-fashioned method of applying poison 

 with a bag and pole. This method lacks thoroughness and while 

 satisfactory for controlling the leaf worm it does not give best results 

 against the boUworm. This equipment may be carried across the 

 back of a mule, the poison being jarred out through the bags by 

 movements of the animal and by tapping the pole. The construction 

 of one of these outfits is very simple. Rectangular bags of 8-ounce 

 duck are nailed to either end of a 4-inch board of a length equal to 

 the distance between two cotton rows, as is shown in figure 7. 



a ^ S 



1 ', ■ "1 



Fig. 7. — "Bag and pole" for ut<e in dis'jributing poison in bollworni control. 



To get best results the dusting should be done when the plants are 

 covered with dew. This necessitates making the application during 

 the night or in the early morning hours. Windy periods should be 

 avoided. 



It should be remembered that all of these arsenicals are poisonous 

 to man and animals although they are not dangerous if properly 

 handled. Calcium arsenate is less injurious to man than Paris green. 

 Men employed in distributing the poison should change their clothes 

 and bathe immediately after ceasing Avork. No case of poisoning of 

 animals used in drawing the machines has been observed, but if they 

 are inclined to eat the cotton plants it is best to safeguard them by 

 using muzzles. 



The number of applications should depend largely on the abun- 

 dance of eggs deposited during the few weeks following the first 

 application. Some years the boUworms appear in great numbers at 

 one time while in other seasons they are more or less distributed 

 through the late summer. On the average it is believed that two 

 applications of poison 7 to 10 days apart will give best results. If 

 a heavy rain should follow within 24: hours after an application 

 another treatment should be given. After the poison is well dried on 

 with the dew it will withstand considerable rain. 



1 For discussion of du.sting machinery for boll-weevil control sec Farmers' Bulletin 1098. 



