Proteção de plantas de soja com tratamentos fungicidas associados à indução de resistência : efeitos no rendimento da cultura e qualidade de grãos

Abstract

The control of diseases in the soybean crop presents new challenges for each crop, due to the increase of severity, increase of resistance to chemical products, and the emergence of new diseases or pests. Thus, the objective was to determine the productivity and evaluate the quality of soybean grains as a function of the application of fungicides associated or not to the resistance inducer with silica and chelated copper phosphite. The cultivar evaluated was Monsoy 8372 IPRO. The experimental design was randomized blocks with 15 treatments and 4 replicates. The treatments were: T1 (silica and chelated copper phosphite); T2 (silica and chelated copper phosphite + carbendazim, tebuconazole, kresoxim-methyl); T3 (silicon and chelated copper phosphite + picoxystrobin, tebuconazole, mancozeb); T4 (chelated copper silicon and phosphite + epoxiconazole; fluxapiroxade ; pyraclostrobin); T5 (chelated copper silicon and phosphite + picoxystrobin; benzovindiflupir); T6 (carbendazim, tebuconazole, cresoxymethyl); T7 (picoxystrobin, tebuconazole, mancozeb); T8 (epoxiconazole, fluxapiroxade, pyraclostrobin); T9 (picoxystrobin ; benzovindiflupir); T10 (silicon and chelated copper phosphite + carbendazim, tebuconazole, cresoxim- + mancozeb); T11 (silicon and chelated copper phosphite + epoxiconazole; fluxapiroxade; pyraclostrobin + mancozeb); T12 (silica and chelated copper phosp hite + picoxystrobin; benzovindiflupir + mancozeb); T13 (azoxystrobin, benzovindiflupir + trifloxystrobin, proticonazole); T14 (azoxystrobin, benzovindiflupir/silicon and chelated copper phosphite + trifloxystrobin, proticonazole / silicon and chelated copper phosphite); T15 (azoxystrobin, benzovindiflupir / silicon and chelated copper phosphite / mancozeb+trifloxystrobin,proticonazole/silicon, and chelated copper phosphite / mancozeb). There was variation in the number of applications between treatments. The evaluations were in relation to grain yield and quality, being physical quality (mass of a thousand grains, bulk density, real density, and grain size and shape); (germination, accelerated aging, and electrical conductivity of the exudates) and c lassification as per the percentage of stings per bed bug, in order to verify the efficiency of the resistance inductor. The main results indicated that in the treatment T14 (azoxystrobin and benzovindiflupir + silicon and copper phosphite chelated with trifloxystrobin and proticonazole + silica and chelated copper phosphite) resulted in higher productivity and good grain development, presenting the best averages for characteristics of size, grain shape, germination and electrical conductivity of exudates. Four applications were performed in this treatment. The treatments T1 (resistance inducer) and T2 (inductor + carbendazim) had a lower percentage of sti ngs grazed by bed bug. The electrical conductivity of the exudates was positively influenced by the resistance inducer and negatively by the mancozeb.