DOI: 10.5593/sgem2017H/63/S25.014


A. Carabet, R. Stef, M. Iamandei, I. Grozea, A.M. Virteiu
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-29-4 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 63, 111-116 pp; DOI: 10.5593/sgem2017H/63/S25.014


Tomatoes represent the host plant for the pathogen Phytophthora infestans. Together, as plant and pathogen, create a system named by A.R.ROBINSON pathosystem [1]. The plants are known as producers of many metabolites such us therpenes, alkaloids, flavonoides and amino acids. From this point of view naturally occurring substances present in different plants can represent a continuous resource of biological agents. Late blight of potato (Phytophthora infestans Mont. de Bary) is a serious threat to potato production all over the world which not only causes severe crop damages but also contributes to considerable monitory losses due to excessive use of fungicides for its control. The objective of this study is to evaluate the effects of the extracts obtained from Xanthium strumarium on downy mildew in tomatoes. In order to accomplish the study the extracts were prepared using sun dried leaves of Xanthium strumarium. The extract was applied with a sprayer at first symptom occurrence, followed by 7 days treatments intervals. The assessments were conducted 7 dat., 14 dat. and 21 dat. In every assessment, disease incidence in plots treated with plant extracts was lower than control. The lowest attack degree was recorded at 7 dat than followed by 14 dat values and the highest value was recorded at 21 dat 53.93 % related to control (72.93 %). Application of extracts lowered disease severity level which corresponded at 7 and 14 dat. The experimental site provides ideal and conducive environments for downy mildew pathogen (Phytophthora infestans).

Keywords: allelopathy, extract, control, downy mildew, tomato.