OBSERVATION CONCERNING ZEA MAYS – FUSARIUM ROSEUM AND ZEA MAYS – USTILAGO MAYDIS PATHOGENIC SYSTEM AT MAIZE HYBRIDS CREATED BY PIONEER DUPONT COMPANY PUBLISHEDFloarea Adam, Gheorghe Popescu, Dorin Jurca
Corn hybrids PR 39D81 (extra-early), PR 38R92 (early), PR 38A24 (half-early), PR 37D25 (half-early), PR 37M34 (half-early), PR 37W05 (half-early), PR 35P12 (half-late), PR 36K67 (half-late) are tested in Arad County area (Şagu – SC. Agrogil) for natural infection with Fusarium roseum and Ustilago maydis parasite fungi. The company specifies tolerance for Ustilago maydis in case of PR 38R92 and PR 37W05 hybrids, but they have any reference for Fusarium roseum, this situation influencing our decision concerning the realisation of this study. Fusarium roseum fungus aggressiveness oscillates between 4.79% and 45.0% registered in case of PR 35P12 and PR 38R92. In comparison with PR 37D25 tester variant are registered infection increases statistically provided by PR 38R92 (early), PR 37W05 (half-early) and PR 36K67 (half-late). In case of PR 35P12 is registered a decrease of infection from statistical point of view, this hybrid maintaining also the signification trend in comparison with the experience average (-25.77%). Ustilago maydis attack is extremely damaging in hybridising plots, but in our case is low except control variant – PR 37D25 where the aggressiveness is 8.54% and PR 37W05 half-early hybrid (14.5%). In the case of these two variants, the results are statistically provided as very distinctively significant in comparison with the experience average that is 7.58%. There are not registered an attack in case of PR 38A24, PR 37M34 and PR 36K67, which will be studied during the next years. There is recommended special protection measures for kernels affected by Fusarium roseum during storage and Ustilago maydis in hybridising plots and especially in case of ice drops falling down.
Fusarium roseum; Ustilago maydis; Zea mays; pathosystem; aggressiveness