12 farmers' bulletin 872. 



along each edge of the pole, and the ends to the sides and bottom of 

 the blocks. If unadulterated Paris green is to be used, 8-ounce duck 

 may be used for the bag, but lighter material is necessary for 

 powdered arsenate of lead or Paris green mixed -vvith lime. One of 

 these outfits is shown in figure 7. The poison sifts out over the plants 

 as the pole is jarred by striking it with a stick as it is carried across 

 the back of a mule ridden between the cotton rows. Two rows are 

 thus treated at once and from 15 to 20 acres can be covered by one 

 man during the early morning and evening hours which are suitable 

 for the work. It is best to apply the poison when the plants are moist 

 with dew so that it will adhere to the foliage. It is also necessary 

 to avoid windy periods. 



Care should be taken to protect the animals used in this work from 

 eating the poisoned plants and as far as possible from becoming too 

 much covered with the poison. 



Best results can be secured b}^ making two or three applications of 

 poison at intervals of about a week. In case of rain folloAving the use 

 of Paris green, the crop shovdd be treated again immediately. In 



Fir,. 7. — " Bajr and pole " for use in distritnifins poison in bollworm control. 



rather extensive experiments conducted during 1905-6 an average ex- 

 penditure of $5.21 per acre, over the cost of poison and the expense 

 of application, resulted. Some of the plants were treated once and 

 others received two applications. 



On account of the sporadic occurrence of bollworms in great num- 

 bers in most regions it is rather difficult to foresee just when serious 

 injury is to occur, but it would no doubt be profitable to apply 

 poison each year in the portions of Texas and Oklahoma where boll- 

 worm damage is general and most severe. 



CORN AS A TRAP CROP TO PROTECT COTTON. 



Since the bollworm prefers corn to cotton or most other plants for 

 food it is possible to concentrate the larva> on corn and keep them 

 from becoming so numerous on cotton. To effect such a result it is 

 important that com be planted at such a time as to be in silk and 

 tassel about the 1st of August. If it matures too early it will act 

 only as a breeding place for bollworms, which will niature as the ears 

 harden and a short time later transform to moths which in turn will 

 deposit eggs over adjacent cotton fields. On the other hand, if the 

 plants are in an attractive state, the moths, which fly quite freely, 





