20 BULLETIN 436, U. S. DEPAETMEITT OF AGRICULTURE. 



destroyed and damage to future crops will be greatly lessened. 

 Such cultivation will not only assist in reducing the number of beetles 

 maturing, but it will also aerate the gromid and place it in a thrifty 

 condition, producing strong healthy plants that will be able better 

 to withstand insect attacks. 



This point should not be passed without mention of the fact that 

 stable and barnyard or corral manure, which, in the Salt River VaUey, 

 is ordinarily dumped in waste places, on ditch banks, or absolutely 

 destroyed, as it were, should be utilized in building up the soil and 

 making it still more productive than it is at the present time. Manure 

 is ordinarily not used in the warm southwestern country because it 

 is claimed that it causes burning of the plants and contributes to the 

 dispersion of weed seeds. If manure is thoroughly rotted and 

 properly applied it will not burn the plants, and if rotation of crops 

 is practiced, there will be a minimum of complaint in regard to the 

 dissemination of weed seeds. 



Mr. E. W. Hudson, who has been in charge of the Bureau of Plant 

 Industry Experimental Farm at Sacaton, Ariz., and who is well 

 acquainted with farming conditions in the Southwest, beheves that 

 all manure should be utilized, and if it is to be plowed under it should 

 be applied in the fall, turned under, and given a chance to decay 

 during the cool part of the year. If used at other times of the year, 

 he beheves that it should be applied by the aid of a manure spreader 

 as a light top-dressing. The writer is thoroughly in accord with 

 this latter method, for in addition to putting the nourishment just 

 where it is needed by spreading the manure over the ground where 

 it soon dries, the breeding of fhes is also avoided. If aU manure 

 and refuse were handled m this manner, there would be a consider- 

 able reduction in the fly population of these regions. 



If land weU treated with stable manure is afterwards planted to 

 corn, the plants will be enabled to make a good start and continue in 

 a thrifty condition in spite of flea-beetle attack. 



ERADICATION OF JOHNSON GRASS AND OTHER TROUBLESOME GRASSES. 



Since it has been shown that this flea-beetle lives quite largely 

 upon Johnson grass (SorgTium lialepense) and salt grass (DisticMis 

 spicata), it is obvious that the fewer of these grasses found grow- 

 ing in alfalfa fields or cultivated fields of any kind and also along 

 roadsides and ditch banks, the fewer the number of beetles to attack 

 the cultivated crops. While Johnson grass may be a difficult and 

 troublesome grass to control, yet there is no excuse for allowing it 

 to become an almost inaccessible thicket, 15 to 20 feet wide, along 

 roadsides, fence rows, and ditch banks, as is sometimes found to be 

 the case in Arizona. Each farmer should consider it a part of his 

 duty to the community in which he lives to mow such places two 



