KETAHANAN Peronosclerospora maydis TERHADAP FUNGISIDA

• Main Authors: , Dwi Astuti Yuniasih, , Prof. Dr. Ir. Christanti Sumardiyono, SU
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2014
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/130710/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=71137
• Institution: Universitas Gadjah Mada

Intensive using of metalaxyl to control corn downy mildew caused emergence of resistant strains of P. maydis to metalaxyl. These resistant strains have caused major damage due to downy mildew. Therefore, it is necessary to manage P. maydis resistance againts fungicide. One of the strategies resistance management is using different active ingredients fungicide, but have same ability to control corn downy mildew.The aims of this study is to determine the effectiveness of fenamidone fungicides and mix formulation fenamidone and propamocarb hydrochloride as subtitute of metalaxyl to inhibit the development of downy mildew, and to find out the possibility of the emergence of resistant strains to the fungicides tested in this study. The experiment was conducted in vitro to determine inhibition ability of fungicides againts conidial germination of P. maydis, and to know the ability of fungicides in suppressing the development of downy mildew conducted in planta and field efficacy trials in Kediri. Source of inoculum is P. maydis Klaten isolate and Kediri isolate. The results showed that the application fenamidone at highest dose (32 ml/kg) and the mixture of fenamidone and propamocarb hydrochloride at highest dose (80 ml/kg) failed to inhibit the development of downy mildew. It meaned that P. maydis Kediri isolate as apparently resistant to both of fungicides. It is presumably because of the similar mode of action between fenamidone and metalaxyl which is inhibiting respiration of pathogen. Therefore the mixture of fenamidone and propamocarb hydrochloride was unsuitable to control downy mildew. To avoid the emergence of resistant strains, resistance management of P. maydis riquired wisely to replace fungicide that has a different mode of action.