Formulações à base de extratos vegetais combinados ou não com indutores e fertilizantes foliares no manejo de bacterioses do algodoeiro e do feijoeiro

Abstract

In order to obtain formulations based on plant extracts as resistance inducers to Xanthomonas axonopodis pv. malvacearum (Xam) and X. axonopodis pv. phaseoli (Xap), the present work aimed to evaluate the effect of formulations based on plant extracts (exclusevely or mixed with ASM), foliar fertilizers and oils in the management of bacterial blight in cotton and in common bean. The biochemical mechanisms involved in the defense responses against Xam were also assessed. All treatments were sprayed on the shoot, seven days before the pathogen inoculation. The extract of micro-processed rust infected coffee leaf (NEFID) when in mixtures improved the effect of all products, except Fulland® + NEFID, reaching 66.37% of cotton blight control. Coffee husk extract (CFC) reduced the percent of cotton blight severity and the extract of micro-processed coffee husk (NCFC) the bean blight protection one, from 30.21 to 81.87% but did not protect cotton against bacterial blight under greenhouse conditions. The foliar fertilizers Fulland® and Agro-Mos® in vitro inhibited both bacterial growth 0 g c.p./L and 2.5 g c.p./L, respectively for Xam and Xap. NEFID did not inhibit Xam growth. The use of Bion®, Agro-Mos®, NEFID + Agro-Mos® and NEFID increased the activity of peroxidase, chitinase and glucanase; presented variation in the deposition of lignin 8 and 14 days after application of the treatments and did not increase the activity of total soluble phenols.