498 



A. G. KAIS AND G. A. SNOW 



moderately susceptible to the North Carolina isolates but extremely resis- 

 tant to the Mississippi and Wisconsin isolates. 



An analysis of variance for proportion of plants with galls at 

 12 months showed a significant interaction between the five species of 

 pine and the three geographic sources of C. quercuum. 



The shape of galls on the pines inoculated with the C. quercuum 

 isolates can be compared by examining the ratio of gall diameter to gall 

 length (D/L ratio) in Table 1. The larger this ratio, the more globose 

 the gall. Almost always, the ratio increased markedly between 6 months 

 and 12 months. 



Table 1. Mean ratio of gall diameter/gall length 6 and 12 months 

 after inoculation with C. quercuum isolates 



Pine host 

 and month 



Wisconsin 

 1 2 



Geographi 



c sources 



North Carolina 

 1 2 



Mississippi 

 1 2 



Sand 



0.16 (1) 



0.30 (9) 0.27 (13) 0.20 (2) 0.22 (1) 

 .86 (9) .66 (11) 



Jack 



.26 (15) 

 .65 (6) 



.75 (1) 



48 (7) 

 91 (2) 



41 (7) 

 86 (4) 



Shortleaf 



6 



12 



.22 (2) 



18 (2) .20 (5) 



.42 (12) .40 (12) 

 ,72 (11) .95 (7) 



Loblolly 



12 



12 (10) .18 (14) 

 33 (3) .39 (12) 



.51 (15) .38 (12) 

 .88 (13) .95 (11) 



Slash 



.13 (14) .15 (15) .18 (13) .12 (12) 

 .29 (11) .40 (10) .58 (2) --- 



.25 (13) .20 (15) 

 .51 (7) .46 (6) 



, Numbers of plants with galls shown in parentheses 

 Dashed lines indicate that no plants had galls. 

 No test. 



At 12 months there were no obvious differences in the reactions of 

 the pines to the four isolates of C. fusiforme (Fig. 2) . Slash and 

 loblolly pine were extremely susceptible, while shortleaf, jack, and san 

 pine were resistant to all four isolates. The susceptible pines inocula 

 with the C. fusiforme isolates usually formed only fusiform galls (Table 



ted 

 2) 



