284 



Journal of Agricultural Research voi. xvin. no. s 



Table V. — Pressure in grams per square centimeter required to puncture tissue of freshly 

 cut surface of Green Mountain potatoes and results of inoculating these potatoes -with 

 Pythium deharyanum 



Tuber No. 



Diameter 

 of needle 



(in 

 microns). 



Pressure required to 

 puncture cell wall. 



Central 

 part. 



Num- 

 ber of 

 inocu- 

 lations 



Loca- 

 tion of 

 final 

 inocu- 

 lation. 



Results of inoculations. 



37. 

 38. 

 29. 

 30. 



al- 

 66. 

 67- 

 68. 

 69. 

 70. 

 72- 

 73- 

 74- 

 7S- 

 80. 

 61. 

 55- 



Average. 



71 

 71 

 71 

 71 

 71 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 67 

 68.3 



Average for tubers which when inocu- 

 lated in cortex rotted 



Average for tubers which when inocu- 

 lated in cortex did not rot 



Si'SS6-4 

 48, 248. 3 

 37. 747- I 

 39. 390- 7 

 57.571- S 

 42, 812. 7 

 47.566.3 

 31,132.0 

 34, 439- 6 

 33.540-3 

 41,344.0 

 32.372-4 

 42.965- I 

 39,008. I 

 31.276-4 

 60, 103. 9 

 75.525-1 

 47,897.0 



31.938- 2 

 35,648.8 

 32.072. 7 

 28, 500. o 

 47,774-0 

 33,344-0 

 42. 667. o 

 30, 160. 4 

 34. 749- o 

 33,902.0 



25, 736. 6 

 29.457-6 

 39-525-0 



26, 367. I 

 22,843. 6 

 41. 953- 8 

 28.351-7 

 39.152-8 



48, 682. o 



40. 7*1 ■ 3 

 61, 175- 3 



3l;32S-0 



Cortex . 

 ..do.... 

 ..do.... 

 ..do.... 

 ..do.... 

 ..do.... 

 ..do.... 

 ..do.... 



. .do 



..do.... 

 ..do.... 

 ..do.... 

 ..do,... 

 ..do.... 

 ..do.... 

 Deep.. . 

 ..do.... 

 ..do.... 



40 mm. 

 30 nun. 

 27 mm. 

 40 mm. 

 16 mm. 

 30 mm. 

 19 mm. 

 34 mm. 



29 TOTO.. 



49 iDxn. 

 25 mm. 

 25 mm. 



30 mm. 

 33nim. 

 34 mm. 

 12 mm. 

 iSmm. 

 18 mm. 



n 3 days, 

 n 3 days, 

 n 3 days, 

 n 3 days. 

 ,n 3 days, 

 n 4 days. 

 ;n 3 days. 

 in 4 days. 

 in 4 days, 

 in 4 days. 

 in 4 days. 

 in s days. 

 in s days, 

 in 5 days. 

 in 5 days. 

 n 10 days, 

 n 4 days, 

 rot in 2 days. 



Table VI. — Pressure in grams per square centimeter required to puncture tissue of freshly 

 cut surface of Bliss Triumph potatoes and results of inoculating these potatoes with 

 Pythium debaryanum 



Tuber No. 



Diameter 

 of needle 



(in 

 microns). 



Pressure required to 

 puncture cell wall. 



Central 

 part. 



Num- 

 ber of 

 inocu- 

 lations. 



Loca- 

 tion of 



final 

 inocu- 

 lation. 



Results of inoculations. 



Average. . 



71 



71 



71 



71 



71 



67 



67 



67 



67 



68.3 



68.3 



Average for tubers which when inocu- 

 lated in cortex rotted 



Average for tubers which when inocu- 

 lated in cortex did not rot 



• 40: 

 37 



40 



548-1 

 457- 7 

 662.5 

 380. 2 

 028. 7 

 953-9 

 726.4 

 332- I 

 579- I 

 798.6 

 447-3 

 SOi-S 

 282. o 

 282. o 

 705.8 

 000. 3 



36 

 29 

 29.89 



345-4 

 923.0 

 824.6 

 656.5 

 401. o 

 946. o 

 264. o 



610. 2 

 034-0 

 2. O 

 365-0 

 504-4 

 819.4 

 677. 2 

 529.0 



343-4 



41,980. O 



38,998.0 

 42,852.9 



38,209.0 



Cortex . . 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



..do 



Deep 



..do 



32 vnxa. 



31 mm, 

 Do. 



24 mm, 

 19 mm 

 68 mm 

 42 mm 

 28 mm 

 46 mm 



32 raja 

 j8mm 



23 tnm 



24 mm 

 28 TDja 



5 mm 

 Do. 



rot in 3 days, 

 rot in 3 days. 



rot in 3 days, 

 rot in 5 days, 

 rot in 5 days, 

 rot in 5 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 4 days, 

 rot in 2 days. 



