oda ) ▁and ▁veget able ▁or ▁min eral ▁o ils ▁in ▁water ▁are ▁often ▁recommended ▁for ▁cont rolling ▁pow der y ▁mil de w , ▁but ▁such ▁mi xt ures ▁have ▁limited ▁and ▁incons istent ▁effic acy . ▁While ▁sod ium ▁b ic ar bon ate ▁has ▁been ▁shown ▁to ▁reduce ▁to ▁growth ▁of ▁mil de ws ▁in ▁lab ▁tests , ▁sp ray s ▁containing ▁only ▁b aking ▁s oda ▁and ▁water ▁are ▁not ▁effective ▁in ▁cont rolling ▁fung al ▁dise ases ▁on ▁inf ected ▁plants , ▁and ▁high ▁concentr ations ▁of ▁sod ium ▁are ▁harm ful ▁to ▁plants . ▁ ▁Pot ass ium ▁b ic ar bon ate ▁is ▁an ▁effective ▁fung ic ide ▁against ▁pow der y ▁mil de w ▁and ▁apple ▁sc ab , ▁allowed ▁for ▁use ▁in ▁organ ic ▁far ming . ▁ ▁Another ▁non - con vent ional ▁chemical ▁treatment ▁involves ▁tre ating ▁with ▁a ▁solution ▁of ▁calci um ▁sil icate . ▁Sil icon ▁helps ▁the ▁plant ▁cells ▁defend ▁against ▁fung al ▁attack ▁by ▁de grad ing ▁ha ust oria ▁and ▁by ▁producing ▁cal lose ▁and ▁pap illa . ▁With ▁sil icon ▁treatment , ▁e pid erm al ▁cells ▁of ▁whe at ▁are ▁less ▁sus cept ible ▁to ▁pow der y ▁mil de w . ▁ ▁Gen etic ▁resistance ▁The ▁P m 3 ▁alle le ▁is ▁an ▁effective ▁gen etic ▁resistance ▁strategy ▁that ▁protect s ▁host ▁species ▁against ▁pow der y ▁mil de w ▁fung us . ▁ ▁Pow der y ▁mil de ws ▁of ▁various ▁plants ▁