172 



Journal of Agricultural Research 



Vol. IV, No. 2 



Table I. — Results of inoculating sugar-beet leaves of different ages « with Phoma betae 



and Phyllosticta betae 



Phoma betae. 



Phyllosticta betae. 



Age Average 

 of number 

 leaves of 



and 



series 



No. 



stomata 

 per sq. 

 mm. of 

 upper leaf 

 surface. 



Num- 

 ber of 

 inocu- 

 lations 

 per 

 leaf. 



Condition of leaf four 

 days after inocula- 

 tion. 



leaf.* upper leaf 

 surface. 



Num- 

 ber of 

 inocu- 

 lations 

 per 

 leaf. 



Condition of leaf four 

 days after inocula- 

 tion. 



Num- 

 ber of 

 infec- 

 tions 

 per 

 leaf. 6 



5 " 



al 



62.8 



73-8 

 60. I 

 68.3 

 79.2 



76. S 



61.5 

 73-8 

 60. I 

 100. o 

 90. 2 

 65.6 

 82.0 

 68.3 

 85.2 



87.4 

 84.0 

 82.0 

 82.0 

 65.6 

 84.7 

 82.0 

 86.9 

 82.0 

 73-8 

 84.0 

 95-6 



Total . 



65.6 

 60. 1 



76. 5 

 65-6 



73-8 

 57-4 

 62.8 

 87-4 



87.4 



Total . . 



106. 6 

 103.8 

 117- 5 

 103.8 

 no. 7 

 103.8 

 109.3 

 no. 7 

 103.8 

 106. 6 

 112. 7 

 106. 6 

 117.5 



Total . 



Yellowing 



Old mature 



Yellowing 



Beginning to yellow . 

 SHghtly yellowed . . 



Yellowing 



Old yellowing 



Yellowing 



....do 



Old mature 



...do 



Beginning to yellow . 



Old mature 



...do 



Mature 



....do 



do 



do 



Old mature 



do 



do 



do 



Mature 



Old mature 



do 



Mature 



Old mature 



do 



do 



do 



Slightly yellow . . . 

 Beginning to yel- 

 low and dying. 



Yellow 



do 



Yellow and dead . . 

 Beginning to yellow 

 Quite yellow 



Yellowing 



...do 



...do 



Still somewhat 



green. 

 Still green 



71.0 

 60. 1 

 61.5 

 71.0 

 87.4 

 82.0 

 90. 2 

 71.0 

 90. 2 

 76.5 

 98.4 

 76. 5 

 90. 2 

 87.4 

 71. o 

 60. o 



82.0 



71. o 



84.7 



95-6 

 82.0 

 82.0 

 68.3 

 73-8 

 92.9 

 86. I 

 84. 7 

 84.7 

 9S.4 

 92. 9 

 98.4 

 87.4 

 79.2 



82.0 

 71. o 

 79.2 



76. S 



84.7 

 73-8 

 73-8 



73-8 



lOI. I 



106. 6 

 109.3 

 no. 7 



48 



Yellow 



Old mature 



Old yellow 



...do 



Mature 



Yellowing 



Old mature 



Beginning to yellow 



Mature 



Old yellow 



Mature 



Yellowing 



Old mature 



do 



Mature 



Mature 



Old mature 



Mature 



...do 



Beginning to yellow 



Mature 



....do : 



do 



do 



do 



do 



do 



do 



do 



do 



Beginning to yellow 

 Mature 



Yellow. . . . 

 Still green. 



Slightly yellow 



Still green 



do 



do 



Rather more green 

 than yellow. 



Yellowing : 



Yellow and dying . . . 



Still rather green 



Yellow 



.do. 



o Inoculations made on plants in the greenhouse of Bureau of Plant Industry, at Washington, D. C, on 

 January 15 and 24, 1914- 



i> Phoma betae was reisolated from all infected spots that are indicated in series i and 2. 



c The leaves in this series occupied the outermost position on the beet plants. 



<i The leaves designated as " young mature" were those occupying a medium position in the plant growth. 



