. Bulletin of the Department of Agriculture. Agriculture; Agriculture. DAMPING-OPF TN POREST NURSERIES. 59 figure 18. This suggests, further, that part of the lack of activity was due to the failure of the fungus to maintain itself vigorously in the soil till the pines reached a stage of sprouting in which they could be readily attacked. Direct inoculations after the seed starts to sprout are therefore desirable to supplement the experiments reported. The survivals in the controls did not show any such asymmetrical distribution. While the Eheosporangium has given rather definite evidence
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. DAMPING-OPF TN POREST NURSERIES. 59 figure 18. This suggests, further, that part of the lack of activity was due to the failure of the fungus to maintain itself vigorously in the soil till the pines reached a stage of sprouting in which they could be readily attacked. Direct inoculations after the seed starts to sprout are therefore desirable to supplement the experiments reported. The survivals in the controls did not show any such asymmetrical distribution. While the Eheosporangium has given rather definite evidence of parasitism on Pinus banksiana under favorable conditions, the activity of the strains available has been much less than that of the Pythium debaryanum strains. In view of the fact that the fungus has not so far been isolated from pine it can be concluded to have no general importance in pine seed beds. Its very rapid growth on prune agar makes it very easy to isolate when present. PHYTOPHTHORA SPP. Phytophthora fagi E. Hartig has been commonly reported as the cause of death of seedlings of va- rious plants in Eu- rope, including con- ifers and herbaceous plants as well as beech (5, 8, 15, 55, 56, 57, 59, 73, 104.) It has been grouped with the rather indefinite Phytophthora omnivora and with P. cactorum, the enemy of cactus, ginseng, and other plants. Wil- son (147, p. 54) considered it distinct, but Eosenbaum (114), in his biometric comparison of Phytophthora cactorum and a single strain of P. fagi, failed to find significant morphological differences. If P. fagi is even physiologically different from the American strains of P. cactorum, its introduction into the United States is to be guarded against. There is certainly no fungus in the United States causing the damage to coniferous seedlings which European reports have attributed to P. fagi there. As P. fagi attacks roots, it presumably can be carried in soil as well as on plant IO 13 IS IB SZ ZS 28 SEEDUA/GS SURVI
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