DESEMPENHO DE COMBINAÇÕES DE FUNGICIDAS QUÍMICOS E SUA INFLUÊNCIA COM ASPECTOS FITOSSANITÁRIOS DA SOJA (Glycine max)

Abstract

The soybean crop is subject to numerous phytopathogens and the chemical management is the main strategy to prevent the onset of the infective cycle. The objective of this work was to evaluate the performance of chemical combinations of fungicides with other soybean phytosanitary agents (Glycine max). Using NS 7237 IPRO soybean, under no-tillage system, in a randomized block design (four blocks) with seven treatments. The percentage of the severity of the biotic complex (pests and diseases) and abiotic (phytotoxicity) and simultaneous determination of the type of agent at 31, 45, 52, 59 and 73 days after planting (DAP) were evaluated, and the area under disease progression curve (AACPD). Plant height (AP), first node insertion height (AIPN), number of nodes per plant (NNP), number of pods per plant (NVP), number of seeds per plant (NSP), productivity ) and the severity of the disease complex (Sev). Treatment 4 represented by pyraclostrobin + thiophanate methyl in TS, azoxystrobin + benzovindiflupir and oil and propiconazole + diphenoconazole in the first application (V8-R1), azoxystrobin + benzovindiflupir and oil in the second application (V8-R1 + 15 days), trifloxystrobin + prothioconazole and oil in the third application (V8-R1 + 30 days), pyraclostrobin + cyproconazole and oil and copper oxychloride in the fourth application (V8-R1 +15 days) was more efficient in the management of phytosanitary complexes throughout the crop cycle, presenting lower synergisms and averages of phytosanitary severity and AACPD. Only the mean plant height of treatment 4 were statistically higher than the other treatments and the other dependent variables were evaluated. There are few strategies for measuring the effect of biotic and abiotic complexes to recognize synergisms and effective chemical treatments for the control of phytosanitary agents in soybean cultivation.