02155naa a2200193 a 450000100080000000500110000800800410001910000160006024501390007626000090021552014950022465300230171970000210174270000160176370000160177970000170179570000150181277301340182711248572016-02-18       2015    bl uuuu     u00u1 u    #d1 aRIOS, J. A.  aThe integration of fungicide application and host resistance on blast progress on wheat under field conditions.h[electronic resource]  c2015  aWheat blast, caused by Pyricularia oryzae, continues to cause substantial losses in all major wheat-producing regions of Brazil. Fungicide and cultivar resistance are major components of management programs to minimize such losses. Two field experiments (EXP1 and EXP2) were conducted to evaluate the effect of fungicide and host resistance on blast development, as well as selected physiological parameters of the wheat plants. Plots of wheat cultivars BR-18 (partially resistant) and Guamirim (susceptible) were either treated (+F) with epoxiconazol + piraclostrobina or left nontreated (-F), and inoculated with at spore suspension of P. oryzae at anthesis. Blast severity rated on spikes and leaves was used to estimate area under blast progress curve (AUBPC) for each treatment combination. In EXP1, BR-18+F and Guamirim+F resulted in significantly lower AUDPC, 58 and 83% reduction for spikes and 70 and 62% for leaves, respectively, than the untreated checks. The corresponding values for EXP2 were 90 and 92% and 68 and 64% for spike and leaves, respectively. BR-18 had significantly lower AUBPC than Guamirim in both experiments. Maximal photosystem II quantum yield (Fv/Fm), maximal fluorescence (Fm), effective PS II quantum yield (Y(II)), quantum yield of regulated energy dissipation (Y(NPQ)) were superior in treated than nontreated plants. Reduction of blast symptoms in association with better photosynthetic performance occurred in the fungicide-treated resistant cultivar.  aPyricularia oryzae1 aRODRIGUES, F. A.1 aRIOS, V. S.1 aPAUL, P. A.1 aSOUZA, M. A.1 aARAUJO, L.  tIn: 2015 APS ANNUAL MEETING, ., 2015, Pasadena, California, U.S.A. Annals... Pasadena, California: 2015 APS Annual Meeting, 2015.