Biological and chemical control for some fungi associated with potato tuber rot

Abstract

Isolation results from the potato tuber showed appearance of fungi Rhizoctonia solani , Phoma sp (1) and Phoma sp (2) the result also showed great antagonism ability of T.harzianum against isolated fungi under laboratory conditions and Bacillus subtilis showed effective mycelium growth inhibition against isolated fungi bio-pesticides bioassay of Cryptanol and Tobsin _M showed non-significant differences between the fungi in the rates of inhibition percentage .The results of potato disc treated with controlling factors revealed developing dry rot, The biggest inhibition significantly in the development of rot in potatoes disc test was with R. solani and Phoma sp. When they treated with Cryptanol 86.6%, which did not differ significantly from Phoma sp. (2) with Tobsin –M and Phoma sp. (2) and R. solani Phoma sp. (1) When Its treated with T. harzianum 80 % and the lowest percentage of inhibition with R. solani when treated with B. subtilis 53.4% . The results of potato tubers treated with controlling factors reveal that biggest inhibition developing dry rot was with Phoma sp. (2) When Its treated with Cryptanol 95 % which did not differ significantly from the treatment of % sp. (1) with Tobsin-M or Phoma sp. (1) with Cryptanol and Phoma sp. (2) Tobsin –M 92, 90 and 89.1 %, respectively the lowest percentage of inhibition was with Phoma sp. (2) when Its treated with B. subtilis 25 %.