312 



REPORT OF THE COMMISSIONER OF AGRICULTURE. 



places the leaves were scorched seriously. The arsenic used on section 12 did not. 

 scorch the cotton, nor did it kill many worms at first, but later it destroyed a good 

 number. By far the best results were obtained on section 13, where the worms were 

 quickly and thoroughly killed, and only at long intervals conld a scorched leaf be 

 found. Though the Tesas worm-destroyer used on section 14 was applied according 

 to directions, it being stated that more than one measure, about 4^ ounces to the 

 barrel of water, would injui-e the cotton, it killed remarkablj' few catpr])illers. 



A light but steady rain fell all of the night following August 13, continuing through 

 the next day and night and a part of the 15th. An examination of the cotton after 

 this rain showed that little poison was then adhering to the leaves. In all of my ex- 

 periments 1 found that full-grown caterpillars never ate the poison, but webbed up 

 immediately after it was apjdied. These excepted, there were few living worms on 

 any of these sections excepting 14 where I could not see that the poison had done any 

 good. On the 21st of August most of the foliage had been eaten from this section, 

 while little was removed from the adjoining section 13. When I compared section 12 

 with th.e uupoisoned cotton on a neighboring plantation — from Avhich it was separated 

 only by a ditch — at this latter date I could see that the arsenic had done good, for 

 the cotton was not nearly so badly eaten where the poison was used as just across the 

 ditch, and at the time of poisoning it was infested worse than the oilier. 



Much of this cotton wa« as high as the top of the wagon-box, and there was none 

 tliat was not bent as the axle passed over it; yet I found tbat very little damage was 

 done by driving down the rows, though occasionallj^ bolls were jolted off and now 

 and then the driver ran the wheels on a row so as to injure it, but this was the result 

 of carelessness. Unless cotton is very higli and closely interlocked between the row« 

 I should not hesitate to drive a large-wheel wagon over it if necessary in poisoning. 



August 29 five sections were poisoned, as shown in the following table. But one 

 pump was used, the nozzle of which had been reamed so as to discharge a larger 

 quantity of water for a given expenditure of labor. With this we were able to dis- 

 tribute 40 gallons of water yier acre. As before, one man drove and another hauled 

 water to the side of the field. 



I)at.\ 



Name of poison. 



C 



Aug. 29, 1879 



Arsenic ' 16 oiuices 



FoTrler's solntion* 3 quarts 



London purple 



Texas worm destroyer. . 

 London purple 



4 gallons . . 

 4 gallons.. 







16 ounces 



1 measure. I 



8 ounces . . | 2 gallons . . I j 



48 hours 



fi Few. 



■ I Scarce any. 



I Few. 



I Scarce any. 



; Very few. 



* A.2 Os., 384 grains. Ka COs, 384 grains. H» 0., 3 quarts. 



In preparing Fowler's solution on a large scale tSe potassium carbonate may be replaced by the mncli 

 cheaper sal-soda. As recommended by Gapt. JT. D. Cross, of Selraa, sal-soda and gr.ay arsenic are taken 

 in equal proportions by weight ; the soda is dissolTed in a little boiling water, the arsenic is then added, 

 and, when dissolved, water is added in such quantity as to make one gallon of the solution for each 

 ounce of arsenic used. He recommends the use of i-lj gallons of this normal solution for each barrel 

 of water. 



With our single pump we were able to cover only five rows of cotton for each trip 

 across the field and do it well. Including the time spent in tilling the barrel, it took 

 45 minutes for each barrel of poison put out ; or, in ten hours, three hands and fotu: 

 males would poison about 13 acres. 



On the 1st of September a light rain in the early afternoon became heavier about 

 4 p. m. and lasted till some time in the night, a few drizzling showers having fallen 

 the day before. 



When these poisons were applied there were scarcely any worms on the cotton poi- 

 soned, but many eggs. On the 4th of September I noted that these had hatched, but 

 few larvae had yet eaten, through the leaves so as to reach such poison as the rains 

 had left. Of the few worms on the cotton before the rain I had noticed a small num- 

 ber of dead ones, the most being found on section 17, the next on 15, the next on 16, 

 but neither 18 nor 19 did much good. Coming as they did, the rains removed the 

 greater part of the poison before the young worms could eat it, so that little goo<l was 

 done by this poisoning. 



