RESPOSTA ESPECTRAL DE SOJA À NÍVEL DE DOSSEL PÓS-APLICAÇÃO DE FUNGICIDAS FOLIARES

Abstract

Spectral reflectance data obtained using spatial, aerial and terrestrial sensors can increase efficiency and the sampling adoption in agriculture. However, it is not known whether the spectral data used for research and detection of plant stress are also affected by leaf fungicides applied in disease management. This study evaluated the effects of leaf fungicides on the leaf reflectance of soybeans. A field study was carried out in a randomized block design with 17 treatments and 4 repetitions per treatment. The treatments were established by different fungicides applied sequentially in three strategic moments to prevent productive losses associated with end-of-cycle fungal diseases. Canopy level reflectance was measured using a multispectral camera. Assessments were made before and at 2 hours after each spray. Fungicides did not affect leaf reflectance at any wavelength. The third application was essential for higher disease control and productivity. These results contribute to understand the potential morphophysiological effects of fungicides on soybeans, thus demonstrating that drones can be a viable strategy for data acquisition regardless of the fungicides application.