2G 



trap rows ma}- be made more effective bj' planting- rows of peas alter- 

 nately with rows of corn. The peas should come into full bloom at the 

 time the corn is silking. This will necessitate planting the peas about 

 the time the corn appears above the ground. The advantage gained 

 by the use of trap crops can not be expressed in pounds of seed cotton, 

 as it is impossible to arrange a test so that the area left for comparison 

 will be subjected to the same conditions without haying it adjacent 

 and consequently^ equally' subject to protection b}^ the corn. Boll- 

 worm moths fl}' freel}^ and are therefore attracted to fresh corn from 

 a considerable distance, and the influence of the "trap rows is thus quite 

 general. 



During 1903 tests of corn trap crops for protecting cotton against 

 the more destructive August generation of boUworms were made at 

 Calvert and Wills Point, Tex. Early in August the number of 

 eggs upon 8 tvpical plants in the trap rows at Wills Point was 

 found to be, on an average, 49.5 per plant, 804 eggs being the maximum 

 number found on a single plant. No account was taken of eggs 

 deposited on plants previous to or succeeding this time. From these 

 figures some idea may be gained of the vast number of eggs which 

 are thus diverted from cotton. In 190-i tests of corn as a trap crop 

 were made at Sulphur Springs, Quinlan, and Hetty, Tex., and at 

 Shreveport, La. The same general plan was carried out in all of 

 the above localities, protection from the August brood onl}' being 

 sought. Belts from 10 to -10 feet wide extending across the field were 

 left implanted at the time of planting cotton, and these were seeded to 

 Mexican June corn by June 1 in rows from 5 to 6 feet apart. Ten 

 days later cowpeas were planted between the rows of corn, thus leav- 

 ing ample room for cultivation. The corn was planted in about the 

 j)roportion of 10 rows to -10 rows of cotton, and the individual fields 

 varied from 20 to -10 acres. 



The following table, computed from counts made of the number of 

 eggs on 20 typical plants in trap rows on the farm of Mr. J. T. Har- 

 grove, Sulphur Springs, Tex., will give an idea of the number of eggs 

 kept from the cotton b}- a few acres of trap corn. The figures show 

 the average number of eggs for each plant and the a^-erage number 

 on the various portions of the plants: 



Table VII. — Distribution and average number of holhvorm eggs on coim. 



