A study of fungi responsible for severe leaf spots of common milkweed (Asclepias syriaca L.) in the Hajdúság region (East Hungary), Fusarium sporotrichioides and Alternaria alternata were isolated from infested leaf tissues. F. sporotrichioides was the most virulent fungus in pathogenicity tests conducted on healthy leaves of common milkweed plants. Inoculation of common milkweed (A. syriaca) in different growth stages with F. sporotrichioides yielded similar symptoms as the original ones. Spray mixtures containing 1.0×106 conidia/ml gave effective control when common milkweed plants were sprayed until runoff occurred. Laboratory (wet chamber) and field experiments showed that asexual spores of the fungal pathogen, F. sporotrichioides, exhibited bioherbicidal activity against common milkweed (A. syriaca). More efficient control efficacy was observable on elder plants (at flowering stage) than younger ones. These results initiate that this fungus may be a biocontrol agent for controlling this invasive weed but should clarify its hosts because it could infect cultivated plants as well.

During the 2014 year a fungicide application trial was made as a part of technology development in Debrecen (East-Hungary). Both in this trial and across in Hungary a serious stripe rust epidemic developed and caused great yield losses. The first sympotoms were observed in April on one of trial plots and during some following weeks a serious infection grown up. On the base of 13 fungicide active ingredients and dosages by two spraying applications, their efficacy could be evaluated in stripe rust control. Picoxystrobin 250 g/L acive ingredient applied in 0.6, 0.8 and 1 L/ha dosages (Acanto), picoxystrobin 200 g/L + ciproconazole 80 g/L combined active ingredients in 0.5, 0.75, and 1 L/ha dosages (Acanto Plus), epoxiconazole 83 g/L, moreover protioconazole 125 g/L + tebuconazole 125 g/L combinations gave good efficacy, respectively. The yield of well protected plots were 5 to 8 t/ha, but the losses were 40-70% when fungicides with no sufficient efficacy in stripe rust control were applied. The great infection, which was observed on different grasses late in the Autumn, 2014 might forecast a further stripe rust epidemic for the 2015 year.

Because of the potential importance of peptaibols in the biological control of plant diseases, a transgenic, a T. reesei strain carrying a tex1-promoter: goxA fusion plasmid was constructed for furthur studies. The peptaibol synthetase gene (which is highly similar to T. virens tex1) was identified in the genome sequence of T. reesei. A 900 bp 5’ upstream noncoding fragment, presumed to include the promoter region of tex1, was cloned into the pSJ3 plasmid (which contains the Aspergillus niger goxA gene encoding glucose oxidase). Finally, we transformed T. reesei with the tex1-promoter: goxA fusion containing pSJ3 plasmid.