RHODE-ISLAND-GREENING EXPERIMENTS, 1906-7. 



23 



ing variety, used in this instance, is noteworthy, in view of the invari- 

 able injury noted with this sort from western New York. 



The following day, December 1, additional fruit of all of the 

 varieties above listed in the table was fumigated, using gas, however, 

 at the strength of 0.50 gram of potassium cyanid per cubic foot — an 

 excessive amount. A final examination of this fruit, January 5, 

 showed that no injury had resulted in the use of gas at this strength, 

 including the Rhode Island Greening. 



RHODE-ISLAND-GREENING-INJURY SERIES. 



The injury resulting from fumigation to the Rhode Island Greening 

 variety from western New York required further tests to determine, 

 if possible, a strength of gas or period of exposure which, while 

 effective against the scale, would not cause injury to the fruit. The 

 experiments bearing on this subject are brought together in Table 

 VII. 



Nos. 44, 44a, and 44b, while made to determine the relative effec- 

 tiveness of the gas on scales on dry, moist, and wet fruits, are here 

 inserted as bearing on the subject in hand. All the fruit was from 

 the same orchard and kept under the same conditions. It arrived 

 in Washington from the orchardist on October 18, and was at once 

 placed in cold storage until fumigated. 



Nos. 44, 44a, and 44b were fumigated December 1, 1906, and Nos. 

 53 to 59, January 22, 1907. Subsequent to fumigation fruit was 

 kept in the storage house on the Agricultural Department grounds, 

 as described. The further details are given in the table below. 



Table VII. — Effect on the Rhode Island Greening apple of different strengths of hydro- 

 cyanic-acid gas, with different periods of exposure. Fruit loose in one-third bushel 

 baskets. 



Experi- 

 ment 

 No.- 



Condition of fruit. 



44 



Drv 



44a.. . 





44b 



Wet 



52 



53 



Slightly moist 



do 



54 



do 



55 



do 



56 



do 



57 



do 



58 



do 



59 



.. .do.. 



Check.. 





Rate at ! 

 which po- Length 



tassium | ofex- 



cyanid was posure 



used. 



Gr.per cu.ft. Hours 



Date of 

 examination. 



0.30 

 0.30 

 0.30 



! 



1 



0.15 



1 



0.15 



2 



0.15 



4 



0.20 



1 



0.20 



2 



0.20 



4 



0.25 



1 



0.30 



h 



Not treated 





Jan. 3. 



do. 



do. 



/Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 \Feb. 4. 

 /Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 \Feb. 4. 

 /Jan. 28 

 /Feb. 4. 

 /Jan. 28 

 /Feb. 4. 



Effect on fruit. 



Number 



badly 



injured. 



Number 

 slightly 

 injured. 



Number 

 showing 

 no injury, 



24 

 19 

 17 

 28 

 26 

 15 

 7 

 11 

 4 

 25 

 19 

 7 

 5 

 5 



.S 



5 



Total 

 num- 

 ber of 

 apples. 



Many fruits showing scald. 



50 



52 



49 



52 



48 



48 



46 



