Systemic Acquired Resistance of Cotton, Soybean and Common Bean to <i>Rhizoctonia solani</i> and <i>Sclerotium rolfsii</i> Induced by Shale Water Seed Treatment

Abstract

Root rots of cotton, soybean and common bean caused by <i> Rhizoctonia solani </i> and <i> Sclerotium rolfsii </i> are basically soil-borne diseases and are difficult to control through the use of fungicides. One of the alternatives to control these diseases could be through the induction of Systemic Acquired Resistance (SAR). It is believed that shale water as a by-product obtained during the process of extraction of petroleum from fossil rock may act as an inducer of SAR to some pathogens of some crop plants. The objective of the present investigation was to verify the effect of seed treatment with shale water in inducing SAR to <i> R. solani </i> and <i> S. rofsii </i> root rots of cotton, soybean and common bean. Seed treatment experiments were conducted in the greenhouse on seedlings of these three crops using naturally or artificially infested soil with <i> R. solani </i> or with <i> S. rolfsii </i> . Treatments with seeds treated with shale water significantly reduced the average number of plants infected with the two pathogens. Consistent results were obtained in repeated experiments. SAR in cotton and common bean to R. solani varied between 86.16% and 91.13%, while for <i> S. rolfsii </i> in soybean and common bean varied between 84.0% and 57.54% and was long lasting. This is the first report giving strong indication of SAR of the three crops to <i> R. solani </i> and to <i> S. rolfsii </i> . Patent regarding this investigation is obtained with Petrobras, Brazil, under the number IVP 12/039.